CN118251183A - Apparatus and method for controlling removal of obstructive material - Google Patents
Apparatus and method for controlling removal of obstructive material Download PDFInfo
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Abstract
Methods and apparatus (devices and/or systems, including aspiration catheters and systems for controlling one or more aspiration catheters) for removing clot material are described herein. The described methods and devices may use one or more sensors inside and outside of the aspiration catheter to control the operation of the aspiration catheter to prevent excessive blood loss and improve the operation of the device.
Description
Priority claim
This patent application claims priority from the following U.S. provisional patent applications: U.S. provisional patent application No. 63/202,880 entitled "DEVICES, SYSTEMS, AND METHODS FOR SENSING CLOT MATERIAL" filed on 28, 6, 2021; U.S. provisional patent application No. 63/203,672, entitled "APPARATUSES AND METHODS FOR CONTROLLING REMOVAL OF OBSTRUCTIVE MATERIAL", filed on 7.27, 2021; U.S. provisional patent application No. 63/287,049, entitled "APPARATUSES AND METHODS FOR CONTROLLING REMOVAL OF OBSTRUCTIVE MATERIAL", filed on 7, 12, 2021; U.S. provisional patent application No. 63/310,989, entitled "APPARATUSES AND METHODS FOR CONTROLLING REMOVAL OF OBSTRUCTIVE MATERIAL", filed on 2.16 of 2022; and U.S. provisional patent application No. 63/345,028 entitled "APPARATUSES AND METHODS FOR CONTROLLING REMOVAL OF OBSTRUCTIVE MATERIAL" filed on 5/23 of 2022. Each of these applications is incorporated by reference herein in its entirety.
Incorporated by reference
All publications and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
Background
Occlusion of blood vessels, including veins and arteries, can lead to serious medical and health problems. For example, thromboembolism is a feature of many common life-threatening conditions. Examples of potentially fatal diseases caused by thrombotic occlusion include pulmonary embolism, deep vein thrombosis, and acute limb ischemia. Acute pulmonary embolism is an important cause of death in the united states. Pulmonary embolism can be a complication of deep vein thrombosis with an annual incidence of 1% in patients aged 60 and older. All of the above diseases are examples of conditions in which treatment may include aspiration or evacuation of clots and/or blood.
However, vacuum assisted thrombectomy systems sometimes have to be terminated due to the risk of excessive patient blood loss, especially when large aspiration catheters are used. During aspiration thrombectomy, the tip is exposed to healthy blood and may remove blood at full flow prior to contact with clot material and/or when the catheter tip is out of contact with clot material (e.g., thrombus or other occlusive material). In such cases, the blood loss rate may be too high and, in some cases, may lead to premature termination of the procedure. With a catheter of size 8French, the blood loss rate may be in the range of 20-25cc per second. Because the maximum allowable blood loss is 300-1000ml, the catheter cannot be operated in unrestricted mode for more than about 20-50 seconds. When the physician manually operates the system, the total blood loss may reach unacceptable levels before enough clot is removed. Furthermore, reliably identifying whether the tip of the catheter is in contact with a clot or undesirably aspirating healthy, clot-free blood is a significant problem, and such manual control is not optimal.
This problem may be exacerbated when the clot is hard and difficult to remove, which may delay the time to apply the suction and extend the overall process. Although a chopper (macerator) may be used for clot removal, control of the chopping may make guiding and control of the catheter (e.g., suction catheter) difficult.
It can also be difficult to determine when a clot is sucked into the lumen of the aspiration device, including when the aspiration device is occluded. In addition, it would be very helpful to accurately and/or quantitatively determine how much clot has been removed.
Accordingly, it is desirable to provide methods and apparatus (e.g., systems, devices, etc.) for controlling aspiration of thrombi and clots using aspiration catheters that limit or minimize blood loss. It would be particularly useful to provide devices and methods that include shredding control in which blood loss during aspiration procedures is limited or minimized. The methods and apparatus described herein may address these issues.
Summary of the disclosure
Described herein are methods and apparatus (e.g., devices and/or systems, including aspiration/thrombectomy devices, aspiration/thrombectomy catheters, and systems for controlling the same) for removing obstructive material (e.g., clot material) in a body lumen. Although the following discussion is primarily directed to clot material, the present technology is configured to remove other types of obstructive material, such as clot (e.g., thrombogenic) material (e.g., plaque) and/or other obstructive material (including gift presented to a senior at one's first visit as a mark of esteem organisms (e.g., bacterial material surrounded by a platelet/fibrin layer)). Generally, the methods and apparatus described herein are configured to control the operation of a suction catheter and/or a shredder incorporating a suction catheter. In some embodiments, the present technology includes one or more sensors coupled to and/or integrated with one or more components of the treatment system (such as an aspiration catheter, which may also be referred to herein as an aspiration catheter). The one or more sensors may provide sensor data that may be analyzed by a system including a controller having one or more processors to verify the presence of clot material such that the controller may coordinate the operation of the aspiration catheter and/or the chopper. These devices (e.g., devices, systems, etc.) can provide accurate and rapid confirmation that clot material is near, adjacent to (including in contact with) and/or within the lumen of the aspiration device. In some examples, these devices may provide a quick and accurate estimate of the amount of clot that is removed. These devices may also provide an indication of the clot removal rate (e.g., travel of clot material within the lumen of the aspiration device).
One or more sensors described herein may be positioned at specific locations on or in the aspiration catheter and/or (in some alternative examples) the chopper assembly. The location of the sensor may be important in providing control information for controlling and/or coordinating the activity of the aspiration catheter and/or the chopper assembly. As will be described herein, any suitable type of sensor may be used, including combinations of different types of sensors. The sensor types may include sensors for detecting electrical characteristics, such as impedance (e.g., bioimpedance, including bioimpedance spectroscopy (bioimpedance spectroscopy)), sensors for detecting pressure, and/or sensors for detecting optical characteristics (e.g., spectroscopy). The sensor types may include ultrasonic sensors. The sensor type may include an optical sensor (including a sensor for detecting color). Any combination of these sensors may be used.
The sensor may be present on a distal and/or laterally outer region of the catheter, and/or within the catheter lumen (e.g., at a distal region, a proximal region, and one or more medial end regions). For example, pairs of sensing electrodes may be used outside and/or inside the aspiration catheter.
The methods and apparatus described herein may generally use these sensors to provide output (visual, audio, data, etc.) to a user and/or to store for subsequent analysis. For example, the methods and apparatus may be used to provide output to a user (e.g., doctor, nurse, surgeon, technician, etc.) of the proximity of clot material to, adjacent to, and/or within an aspiration catheter. In some examples, these devices may provide an indication that clot material has entered and passed through (or stuck to) the lumen of the aspiration catheter. The methods and devices may optionally be used to automatically and/or semi-automatically control the operation of one or more aspects of the device, such as applying suction, shredding, etc. For example, the device may automatically or semi-automatically control the on/off pumping and/or adjust (increase, decrease, etc.) the pumping level.
For example, methods are described herein, including methods of controlling an aspiration catheter. These methods may include: detecting clot material at the distal end of the aspiration catheter using a first sensor or a first set of sensors on the distal end of the aspiration catheter; once clot material is detected, suction through the suction catheter is turned on or increased; detecting clot material within the distal end of the aspiration catheter using a second sensor or a second set of sensors within the distal end of the aspiration catheter to confirm that the clot material has been aspirated into the aspiration catheter; and stopping or reducing the application of suction through the suction catheter after the first sensor or first set of sensors and the second sensor or second set of sensors no longer detect clot material.
A method may include: inserting an aspiration catheter into a lumen of a blood vessel; detecting a clot material at the distal end of the aspiration catheter using a first sensor and/or a first set of sensors on the distal end of the aspiration catheter, wherein detecting the clot material comprises processing signals from the first sensor or the first set of sensors to confirm the presence of the clot material; once clot material is detected, suction through the suction catheter is turned on or increased; monitoring that clot material has been drawn into the aspiration catheter using a second sensor or a second set of sensors within the distal end of the aspiration catheter; and stopping or reducing the application of suction through the suction catheter after the first sensor or first set of sensors and the second sensor or second set of sensors no longer detect clot material.
In general, the methods described herein can be used to confirm the presence and/or proximity of a clot material relative to a sensor. As mentioned, detecting the clot material using the first sensor or the first set of sensors may include detecting the clot material by one or more of: electrical characteristics (e.g., impedance), ultrasound, and/or optical detection. In particular, detecting the clot material by the first sensor or the first set of sensors may comprise detecting the clot material by impedance.
Any of these methods and devices may be configured to turn on or increase the suction when the controller determines that the clot material is near or on and/or within the distal end of the catheter, and in particular within the distal end of the catheter. The controller may process signals from the sensor or sensors to confirm the identity of the clot material rather than blood, vessel walls, or other non-clot material. In some examples, multiple sensor types or modalities (modalities) may be used to confirm the identity of the clot material, for example using bioimpedance (or bioimpedance spectroscopy) and/or ultrasound and/or one or more optical characteristics (e.g., color). When the controller determines that the clot is in proximity to one or more of the sensors, the controller may turn on the suction. In some examples, the aspiration catheter may include a low level of aspiration (e.g., between 0.5-50 mmHg); thus, when a clot is identified or confirmed, the controller can increase the suction to a higher (or high) level of suction (e.g., greater than about 300mmHg, greater than 350mmHg, greater than 400mmHg, etc.).
Similarly, the second sensor and/or the second set of sensors may be configured to sense the same modality or a different modality than the first sensor or the first set of sensors. Any of the sensors of the first or second set of sensors may be configured to sense different modalities (e.g., impedance, ultrasound, optics, etc.). Thus, any of these methods can confirm (using the controller) that clot material has been aspirated into the aspiration catheter by detecting clot material within the lumen of the aspiration catheter using the second sensor or the second set of sensors based on one or more of impedance, ultrasound, and/or optical detection.
Generally, the methods and devices described herein can process signals from a first sensor or a first set of sensors to confirm the presence of a clot material and/or process signals from a second sensor or a second set of sensors to confirm the presence of a clot material. The processing of the sensor signals may include averaging (time averaging), windowing, etc. The signal processing of the sensing signal may be analog or digital signal processing, as the signal from the sensor may be continuous and/or analog, or may be sampled and digitized at a sampling frequency. The signals can be transmitted to the controller for processing in real time. The controller may process the signal in real time or allow processing in a slightly delayed manner. During a medical procedure, signals may be processed and/or stored and/or transmitted for display and/or storage.
For example, signals from one or more sensors (particularly including adjacent sensors of the same type or different types) may be processed using one or more analog signal processing techniques, such as by convolving the signals. The analog signal may be transformed from the time domain to the frequency domain (e.g., by fourier transform, laplace transform (LAPLACIAN TRANSFORM), etc.) or represented as a Bode Plot (Bode Plot), which includes the spectral impedance measurements. Digital signal processing may also be performed, for example, including a function analysis (functional analysis) and/or numerical analysis techniques, such as decomposition into eigen-mode functions (INTRINSIC MODE FUNCTION) and/or wavelets (wavelets). Any of these methods and devices can determine noise in the sensor to help distinguish and verify contact or proximity to the clot material.
The controller may identify the clot material based on the characteristics of the sensed values. For example, signals from the first sensor or first set of sensors and/or the second sensor or second set of sensors may be processed to reduce noise and/or amplify the signals, and may then be compared to known or expected values corresponding to the clot material within a predetermined or calculated confidence range to allow the controller to distinguish between the clot material, blood, and vessel wall. For example, in any of these examples, the treatment may include a treatment for distinguishing between contact with the lumen wall of the vessel in which the aspiration catheter is located.
The methods and devices described herein may provide a number of advantages for systems that measure pressure or flow to control aspiration operations but are unable to confirm the identity and/or characteristics of the clot material. In some cases, the methods and devices described herein may further include a sensor for detecting pressure and/or flow within the lumen of the aspiration catheter.
In general, the methods and apparatus may be configured to turn on or increase attraction after a turn-on delay. In some examples, the turn-on delay may allow for further sensing and processing to determine and/or confirm the presence of clot material, and/or allow a user or device to be configured to attract and/or chop clot material. For example, the turn-on delay may be a predetermined delay (e.g., between 0.1 seconds and 10 seconds, between 0.1 seconds and 8 seconds, between 0.1 seconds and 7.5 seconds, between 0.1 seconds and 6 seconds, between 0.1 seconds and 5 seconds, between 0.1 seconds and 4 seconds, between 0.1 seconds and 3 seconds, between 0.1 seconds and 2 seconds, between 0.1 seconds and 1 second, etc.); in some examples, the turn-on delay may be defined based on user input. For example, in some (semi-automatic) configurations, once clot material is confirmed at or near the distal end of the device, the device may alert the user that suction may or should begin and may enable the user to manually initiate suction thereafter. This may be useful for a number of reasons, including allowing a user to position the shredder within the lumen of the aspiration catheter.
As described above, the methods and devices may be configured to allow for automatic stopping or reducing aspiration (and/or, in some examples, if included, a shredder), including automatic stopping after no clot material is detected within the aspiration catheter and distal to the end of the aspiration catheter. In general, the methods and apparatus may be configured to stop or reduce the application of suction by: once the first sensor or first set of sensors and the second sensor or second set of sensors no longer detect clot material, the application of suction through the suction catheter is stopped or reduced after a predetermined delay period. For example, the stopping delay may be between 0.1 and 10 seconds, between 0.1 and 8 seconds, between 0.1 and 7.5 seconds, between 0.1 and 6 seconds, between 0.1 and 5 seconds, between 0.1 and 4 seconds, between 0.1 and 3 seconds, between 0.1 and 2 seconds, between 0.1 and 1 seconds, etc. In some examples, the system may issue a stop alert, which may indicate a stop of the aspiration catheter (and/or shredder), or may alert the user to manually stop aspiration and/or shredder operation. As used herein, the alert may be an audible alert (tone, bell, etc.) and/or a visual alert (light, indicator, etc.), a tactile alert (e.g., buzzer (buzzer), vibration, etc.).
Any of the methods described herein can be used to remove clot material from a lumen of a body, such as a blood vessel (e.g., artery, vein, etc.). In some examples, the methods may include methods of performing thrombectomy using suction. The suction may be used alone or in combination with another device or subsystem, such as a mechanical device (e.g., stent-retrieving device (stent-RETRIEVER DEVICE)). The methods and devices described herein may be used in any suitable region of the body, including, but not limited to, the lungs (e.g., within the pulmonary arteries), peripheral vasculature, neurovasculature, and the like.
Also described herein are means for performing any of these methods, including means for controlling aspiration within an aspiration catheter. For example, an apparatus may comprise: a suction catheter; a first sensor or a first set of sensors on the distal face of the aspiration catheter; a second sensor or a second set of sensors within the lumen of the aspiration catheter; and a controller comprising one or more processors, wherein the controller is configured to activate or increase aspiration through the aspiration catheter when signals from the first sensor and/or the first set of sensors indicate that clot material is in front of the distal end of the aspiration catheter and/or aligned with a particular portion of the aspiration catheter (e.g., an opening in the catheter wall).
Any of these devices may include a shredder within (and/or configured to fit within) the lumen of the aspiration catheter. Other examples of shredders are described below. The shredder may be a separate element slidably disposed within the lumen of the aspiration catheter, e.g., it may be inserted into or removed from the lumen, or it may be integrated into the aspiration catheter. As will be described in more detail below, the shredder may also be controlled by the same controller (or a separate controller) as used for suction through the suction catheter. The sensors (e.g., first sensor or first set of sensors and second sensor or second set of sensors) may provide input to the controller (or controllers) for processing to identify the presence and/or proximity of clot material at or near the distal end of the aspiration catheter and within the lumen of the aspiration catheter.
The sensor or set of sensors within the lumen of the catheter may be positioned along all or part of the length of the lumen of the catheter. In some examples, the device may include one or more sensors within a distal region of a lumen of the aspiration catheter. The distal region may include a length of the aspiration catheter lumen extending proximally from the distal end of the aspiration catheter to a chopper (which may be positioned more proximally within the catheter lumen). Any of the examples described herein may include a shredder; however, as described herein, these methods and apparatus may also be used without a shredder or adapted for use without a shredder. In some examples, the distal region may be referred to as a monitored distal region. In some examples, the distal region may have an inner diameter that is greater than an inner diameter of a more proximal region of the aspiration catheter; the sensor may be included in this larger area. Alternatively, the distal region may have the same outer diameter (or alternatively a smaller outer diameter) as the more proximal region of the catheter (including the region immediately adjacent the end). One or more sensors (e.g., in some examples, a second sensor or a second set of sensors) may be contained within a larger diameter distal region, or they may extend proximally beyond the larger diameter region. As will be described in some examples, the larger diameter region may be expandable (e.g., may be biased to expand). In any of these devices, one or more sensors within the lumen may be coupled (via wires or wirelessly) to the controller. Similarly, one or more sensors (first sensor or set of sensors) on the distal end of the aspiration catheter may be wired or wirelessly connected to the controller. For example, in any of these devices, one or more electrical connections (wires, lines, traces, etc.) may be made directly or indirectly between the sensor and the controller. In some examples, each sensor is coupled to ultimately connect to the controller via one or more wires extending proximally along the aspiration catheter (along an outside of the aspiration catheter or within a sidewall of the aspiration catheter). Separate power and data lines may be used, or the same (power and data lines) may be used on the same device.
In some examples, the apparatus may include a pump coupled to the controller. Any suitable pump that provides suction may be used. For example, the pump may be a positive displacement pump (positive displacement pump) (e.g., diaphragm pump, gear pump, peristaltic pump, piston pump, etc.) or a powered pump (centrifugal pump, etc.). The pump may be controlled by a controller. For example, the controller may output control signals to turn the pump on, turn the pump off, or adjust the rate or suction applied by the pump. Thus, the apparatus may include a pump coupled to the controller. Alternatively, the suction may be provided by a manually driven pump (vacuum source).
In some examples, the pump is not directly included in the device, but (or in addition) the device may include one or more valves and/or manifolds to adjust the suction source, such as the suction source received from a "wall" suction or the suction source provided by a separate pump. Thus, the system may include a suction interface that may control suction into the suction catheter to allow suction (open), not allow suction (closed), or adjust suction levels (higher/lower, including within a predetermined range of negative pressure). The attraction interface may be part of the controller or may be coupled to the controller. For example, the controller may include one or more valves for regulating suction through the suction catheter. In some examples, the device may include a pump, and the controller may regulate the applied suction by controlling the suction interface rather than directly controlling the pump.
As described above, the first sensor or first set of sensors and/or the second sensor or second set of sensors may be one or more of the following: acoustic sensors, electrical sensors (e.g., bio-impedance sensors), and optical sensors. The sensors of the first set of sensors may be the same or different. Similarly, the sensors in the second set of sensors may be the same or different. The first sensor may be identical to the second sensor. The first set of sensors may be the same as or different from the second set of sensors. In some examples, groups of sensors (pairs of sensors, three or more sensors, etc.) may be combined in similar locations to provide multiple sensing modalities at substantially the same (or the same) location. In general, the sensor may be one or more of the following: acoustic sensors, electrical sensors (e.g., bio-impedance sensors), and optical sensors.
In any of these devices, the first sensor or first set of sensors may be disposed on a deformable covering (cover) that extends at least partially over the distal end of the aspiration catheter. The deformable cover can be deformed to open or close to allow clot material to enter the lumen of the aspiration catheter while restricting the flow of blood into the aspiration catheter. The deformable covering may be a sheet of material, such as a polymeric material (e.g., without limitation, silicone), that can expand/contract. The deformable cover may include one or more openings, and/or slits, cuts, etc. for allowing the cover to deform (yield) to allow clot material into the cover. In some examples, the first sensor or the first set of sensors may be disposed on the periphery of the distal-side opening of the aspiration catheter. The first sensor or first set of sensors may generally be forward looking, e.g., distally looking within the lumen.
As used herein, the term distal or proximal may refer to a direction away from or toward the body of a user operating the device. For example, the distal end of the aspiration catheter is typically the end that is inserted into a subject (e.g., a patient) by a user and moved away from the user into the subject.
As noted above, generally these devices may include a set of sensors (e.g., optionally, a second sensor or a second set of sensors) within the lumen of the aspiration catheter, which may be referred to as an internal sensor. The internal sensor or set of sensors may be disposed on a sidewall of the lumen of the aspiration catheter. In some examples, the internal sensor or set of sensors may be on a shredder component within the lumen of the aspiration catheter. In some examples, the internal sensor set may be on the wall (sidewall) of the lumen and the exterior of the shredder ("shredder component"). Thus, in some examples, the positioning of the internal sensor or the set of sensors may be adjustable within the lumen of the aspiration catheter. When used with an external sensor or group of sensors, the internal sensor may alternatively be referred to as a second sensor or group of sensors. The internal sensor or sensors may be used without an external sensor or set of external sensors ("first sensor or set of sensors").
One or more processors within the controller can control the application of suction through the suction catheter by directly and/or indirectly controlling the pump (e.g., using one or more valves, etc.).
In some examples, the processor may be configured to deactivate or reduce aspiration through the aspiration catheter for a predetermined delay time (stopping delay) after the signal from the first sensor or the first set of sensors indicates that the clot material is not in front of the distal end of the aspiration catheter and the signal from the second sensor or the second set of sensors indicates that the clot material is not within the lumen of the aspiration catheter. The stopping delay may be based on a predefined time period (e.g., between 0.1 seconds and 10 seconds, between 0.1 seconds and 8 seconds, between 0.1 seconds and 7.5 seconds, between 0.1 seconds and 6 seconds, between 0.1 seconds and 5 seconds, between 0.1 seconds and 4 seconds, between 0.1 seconds and 3 seconds, between 0.1 seconds and 2 seconds, between 0.1 seconds and 1 second, etc.). In any of these methods and apparatuses, the stopping delay may be based on one or more of the following: the length of the aspiration catheter, the flow rate (flow rate) of the substance within the aspiration catheter, and the strength of the applied aspiration.
For example, an apparatus described herein includes: a suction catheter; a first sensor or a first set of sensors on the distal face of the aspiration catheter; a second sensor or a second set of sensors within the lumen of the aspiration catheter; and a controller that receives input from the first sensor or the first set of sensors and the second sensor or the second set of sensors, and that includes one or more processors, wherein the one or more processors are configured to analyze the signals from the first sensor or the first set of sensors to confirm that the clot material is in contact with or adjacent to the first sensor or the first set of sensors, and to confirm that the clot material is within the lumen of the aspiration catheter based on data from the second sensor or the second set of sensors; further, wherein the controller is configured to activate or increase aspiration through the aspiration catheter when the one or more processors indicate that the clot material is forward of the distal end of the aspiration catheter, and wherein the controller is configured to deactivate or reduce aspiration through the aspiration catheter after a predetermined period of time from when the processor indicates that the clot material is not forward of the distal end of the aspiration catheter and the processor confirms that the clot material is not within the lumen of the aspiration catheter.
Methods and apparatus for controlling a shredder within an aspiration catheter are also described herein. In any of these devices, the shredder may be controlled separately from (or separately from) the control of the suction through the suction catheter as described above. For example, the methods and apparatus (systems and devices) described herein may include only methods and apparatus for controlling a shredder within an aspiration catheter.
For example, the methods described herein include: applying suction to draw the clot into the suction catheter; detecting clot material within the aspiration catheter using a sensor or set of sensors within the distal end of the aspiration catheter; once clot material is detected within the aspiration catheter, driving a chopper within the aspiration catheter; and stopping driving the chopper after the sensor or set of sensors within the aspiration catheter no longer detects clot material.
A method may include, for example: applying suction to draw the clot into the suction catheter; detecting clot material within the aspiration catheter using a sensor or set of sensors positioned on a chopper within the distal end of the aspiration catheter; upon detection of the clot material, the chopper is driven; and stopping driving the shredder after the sensor or set of sensors no longer detects the clot material.
The sensor or set of sensors may be on the shredder. For example, the sensor or set of sensors may be on the exterior of the shredder. In some examples, one or more sensors may be on a distal region of the shredder, proximate to a cutting member (e.g., cutting element) of the shredder. In some examples, the one or more sensors may be on a distal region of the elongate body of the shredder. Typically, a chopper can be used to break open the aspiration catheter.
The shredder is typically configured to destroy obstructive material. The shredder may comprise a wire, blade, etc., or a plurality of wires, blades, plates, threads, etc. The cutting member (e.g., wire, blade, threads, etc.) may be moved, and in some examples, rotated, to cut the clot material. For example, in some examples, a shredder may include a plurality of shredded wires having a linear configuration. Alternatively or in combination, the shredded wires may be partially or wholly straight, round, curved, spiral around an axis, or have a random profile, or any combination thereof. The shredder may have a distal hub (hub) at its distal end that is coupled to an internal shredder shaft (e.g., rotating shaft), and may include a proximal hub at its proximal end. The plurality of cutter wires may be attached to the cutter drive shaft, the distal hub, or the proximal hub, or any combination thereof. The inner shaft may be concentrically surrounded by the outer shaft. The inner and outer chopper shafts may be flexible. The inner (rotatable shaft) may be a drive shaft.
In some examples, the shredder includes a threaded distal blade within a shredder distal housing having one or more openings for receiving and destroying clot material such that the clot material can be removed relatively easily along the aspiration catheter.
Thus, any of the methods described herein may include rotating or otherwise actuating the cutting members of the shredder by driving rotation of the shredder (e.g., drive shaft), thereby driving the shredder. In some examples, the shredder may be driven or actuated by extending the cutting member out of a protective housing (e.g., distal housing). The shredder can be positioned within the lumen of the aspiration catheter, for example, by being advanced distally within the lumen of the aspiration catheter. Any of these methods may include extending the chopper within the lumen of the aspiration catheter prior to applying the aspiration to aspirate the clot into the aspiration catheter.
Any of these methods may also include applying suction by applying intermittent suction. The suction may be applied in one mode (e.g., a repeating pattern of high/low negative pressure) or in an oscillating pattern. The attraction may be applied at a constant level.
In any of the methods and devices described herein, the clot material may be detected by a sensor or a set of sensors sensing one or more of the following: impedance (including impedance spectroscopy), ultrasound, and/or optical detection. For example, detecting the clot by a sensor or a set of sensors may include detecting a clot substance based on the impedance.
Using a sensor or set of sensors within the distal end of the aspiration catheter to detect clot material within the aspiration catheter may include detecting clot material on or adjacent a window of a cutter exposing the chopper.
Also described herein are devices configured to control the action of the shredder based on the presence and/or proximity of clot material. For example, an apparatus described herein includes: a suction catheter having a suction lumen; a shredder comprising an elongate body, wherein the shredder is configured to extend distally through the suction catheter to a distal region of the suction catheter; a sensor or set of sensors within the lumen of the aspiration catheter; and a controller comprising one or more processors, wherein the controller is configured to activate the chopper when a signal from the sensor or set of sensors indicates that clot material is within the lumen of the aspiration catheter.
As described above, a sensor or set of sensors (in some examples, a second sensor or set of sensors) may be positioned on the shredder. The sensor or set of sensors may be on the lumen of the aspiration catheter. As described above, the sensor or set of sensors may include one or more of the following: acoustic sensors, electrical sensors (e.g., bio-impedance sensors), and optical sensors. In any of these examples, the sensor within the lumen of the aspiration catheter may be positioned on the sidewall of the lumen and/or on the shredder.
In any of these methods and devices, the controller may be configured to deactivate the chopper when a signal from the sensor or set of sensors indicates that the clot material is no longer in the lumen of the aspiration catheter. For example, the controller may be connected to a motor that drives rotation of a drive shaft of the shredder. The controller may be connected to the shredder motor (shredder driver) directly or indirectly. The controller may send digital and/or analog signals to the chopper for opening (activation) when the clot material is within the lumen of the aspiration catheter, including when the clot material is near (in proximity to) the cutting member of the chopper (and in some cases only when the clot material is near the cutting member). The controller may also send digital and/or analog signals to the chopper for shut-down (deactivation) when the clot material is not within the lumen of the aspiration catheter and/or when the clot material is not near the chopper cutting member. The controller may generally be configured to activate the shredder by driving rotation of a drive shaft extending through the elongate body.
In some examples, the shredder includes one or more side windows configured to expose the cutting member (e.g., rotating the cutting member).
For example, described herein are apparatuses comprising: a suction catheter having a suction lumen; a shredder comprising an elongate body enclosing a drive shaft, wherein the shredder is configured to extend distally through the aspiration catheter to a distal region of the aspiration catheter; a sensor or set of sensors on the distal region of the shredder; and a controller comprising one or more processors, wherein the controller is configured to activate the shredder when a signal from the sensor or set of sensors detects a clot material, and deactivate the shredder when a signal from the sensor or set of sensors does not detect a clot material.
Any of the methods described herein may include controlling the aspiration and chopper of the aspiration catheter device by sensing the clot, and may include any of the constituent steps for any of the methods described above. For example, the methods described herein include: detecting clot material at the distal end of the aspiration catheter using a first sensor or a first set of sensors on the distal end of the aspiration catheter; once clot material is detected, suction through the suction catheter is turned on or increased; detecting clot material within the distal end of the aspiration catheter using a second sensor or a second set of sensors within the distal end of the aspiration catheter to confirm that the clot material has been aspirated into the aspiration catheter; once clot material is detected within the aspiration catheter, driving a chopper within the aspiration catheter; stopping driving the chopper after the second sensor or the second set of sensors within the aspiration catheter no longer detects clot material; and stopping or reducing the application of suction through the suction catheter after the first sensor or first set of sensors and the second sensor or second set of sensors no longer detect clot material.
For example, a method may include: inserting an aspiration catheter into a lumen of a blood vessel; detecting a clot material at the distal end of the aspiration catheter using a first sensor or a first set of sensors on the distal end of the aspiration catheter, wherein detecting the clot material comprises processing signals from the first sensor or the first set of sensors to confirm the presence of the clot material; once clot material is detected, suction through the suction catheter is turned on or increased; monitoring that clot material has been drawn into the aspiration catheter using a second sensor or a second set of sensors within the distal end of the aspiration catheter; upon detecting clot material within the aspiration catheter from the second sensor or the second set of sensors, driving a shredder within the aspiration catheter; stopping driving the shredder after the second sensor or the second set of sensors no longer detects the clot material; and stopping or reducing the application of suction through the suction catheter after the first sensor or first set of sensors and the second sensor or second set of sensors no longer detect clot material.
Any of the devices described herein may also or additionally be devices for controlling the aspiration and morcellation of clot material (e.g., controlling the aspiration through an aspiration catheter and the operation of a morcellator within an aspiration catheter). For example, an apparatus may comprise: a suction catheter having a suction lumen; a shredder comprising an elongate body, wherein the shredder is configured to extend distally through the aspiration catheter to a distal region of the aspiration catheter; a first sensor or a first set of sensors on the distal face of the aspiration catheter; a second sensor or a second set of sensors within the lumen of the aspiration catheter; and a controller comprising one or more processors, wherein the controller is configured to activate or increase aspiration through the aspiration catheter when a signal from the first sensor or the first set of sensors indicates that clot material is forward of the distal end of the aspiration catheter, and further wherein the controller is configured to activate the chopper when a signal from the second sensor or the second set of sensors indicates that clot material is within the lumen of the aspiration catheter.
In some examples, the apparatus includes: a suction catheter having a suction lumen; a shredder comprising an elongate body enclosing a drive shaft, wherein the shredder is configured to extend distally through a lumen of the aspiration catheter to a distal region of the aspiration catheter; a first sensor or a first set of sensors on the distal face of the aspiration catheter; a second sensor or a second set of sensors within the lumen of the aspiration catheter; and a controller that receives input from the first sensor or the first set of sensors and the second sensor or the second set of sensors and that includes one or more processors, wherein the one or more processors are configured to analyze signals from the first sensor or the first set of sensors to verify that the clot material is in contact with or adjacent to the first sensor or the first set of sensors and to verify that the clot material is within the lumen of the aspiration catheter based on data from the second sensor or the second set of sensors; further, wherein the controller is configured to activate or increase aspiration through the aspiration catheter when the one or more processors indicate that the clot material is forward of the distal end of the aspiration catheter, further wherein the controller is configured to activate the shredder when a signal from the second sensor or the second set of sensors detects the clot material and deactivate the shredder when a signal from the second sensor or the second set of sensors does not detect the clot material, and wherein the controller is configured to deactivate or reduce aspiration through the aspiration catheter after a predetermined period of time from when the processor indicates that the clot material is not forward of the distal end of the aspiration catheter and the processor confirms that the clot material is not within the lumen of the aspiration catheter.
Generally, described herein are methods of detecting an occlusion (e.g., a clot) using a thrombectomy device (including but not limited to an aspiration catheter) to control aspiration for removing and/or sensing the occlusion and/or for controlling a chopper within the thrombectomy device.
For example, any of the methods described herein can include a method comprising: moving the thrombectomy device within the vessel; detecting an occlusion in an extraction zone distal to an extraction inlet of a thrombectomy device using a sensor configured to sense an occlusion in the extraction zone of the thrombectomy device; determining whether the occlusion is a vessel wall or a clot material; if the obstruction is a clot material, a clot extraction response is triggered, wherein the clot extraction response includes one or more of the following: signaling to the user that the thrombectomy device is in contact with the clot material, activating the extractor to remove the clot material from the extraction inlet, and/or activating the shredder within the extraction chamber region of the thrombectomy device; and stopping the extractor when the clot material is no longer within the extraction chamber region based at least in part on one or more of a sensor configured to sense clot material within the extraction chamber region and a change in chopper response.
Any suitable thrombectomy device may be used in the methods described herein, including, but not limited to, thrombectomy devices that apply suction. The thrombectomy device may be a mechanical thrombectomy device that removes a clot by grasping and/or otherwise pulling the clot. For example, the thrombectomy device may include one or more stent-based thrombectomy devices that pull a mesh or other substance to engage (engage) and capture a clot with or without aspiration.
In general, the methods and devices may be configured to determine a distance between a clot material and a wall of a blood vessel. The clot material may be thrombus, atherosclerosis, embolism, plaque, or the like. In some examples, the clot material may be within a blood vessel and/or a pulmonary blood vessel. For example, the clot material may be a pulmonary embolism.
Generally, the apparatus described herein may include an extraction region distal to an extraction inlet of a thrombectomy device. For example, the extraction zone may be a zone within a few millimeters (e.g., within 10mm, within 9mm, within 8mm, within 7mm, within 6mm, within 5mm, within 4mm, within 3mm, within 1mm, etc.) from the inlet opening into the portion of the thrombectomy device from which clot material is removed. The extraction inlet may be an inlet into the chamber of the device, for example in a variant where clot removal is by application of suction, may be an inlet into the suction catheter. In some examples, the extraction inlet may be at least partially covered; for example, the extraction inlet may be covered with a material, such as a membrane, having holes ("extraction holes" or simply "holes") formed therethrough. The extraction inlet may be covered with a fluid impermeable material; the cover material may be an elastic film.
Detecting an occlusion within the extraction area may include sensing the occlusion by one or more techniques, such as by bioimpedance. For example, detecting an obstruction within the extraction zone may include detecting a change in pressure. Detecting an occlusion within the extraction region may include optically detecting a clot material. Detecting an obstruction within the extraction zone may include detecting contact with the obstruction using a contact sensor.
In some examples, the sensor may include a contact sensor, and wherein detecting an obstruction within the extraction zone includes detecting contact with the contact sensor.
Determining whether the occlusion is a vessel wall or clot material may include applying suction and determining whether the occlusion is drawn into an extraction chamber region of the thrombectomy device through the extraction inlet. In some examples, determining whether the occlusion is a vessel wall or clot material includes applying suction and determining whether the occlusion is drawn into an extraction chamber region of the thrombectomy device beyond an extraction inlet a predetermined distance. For example, determining whether an occlusion is a vessel wall or clot material may include applying suction, waiting 100-1000 milliseconds, and determining a change in chopper response of a chopper within the extraction chamber. Determining whether the occlusion is a vessel wall or clot material may include applying suction and monitoring pressure within the extraction chamber.
In any of these methods, triggering a clot extraction response may include transmitting a signal that the thrombectomy device is in contact with the clot material. The signal may be audible (e.g., tone, hum, beep, recorded message, etc.) and/or visual (e.g., light/LED, display, etc.), tactile (e.g., vibration, resistance, etc.), and so forth. In any of these methods, triggering the clot extraction response may include automatically activating an extractor by applying or increasing suction through the thrombectomy device to remove clot material from the extraction inlet, wherein the extractor includes a suction source. For example, triggering the clot extraction response may include automatically activating an extractor to remove clot material from the extraction inlet, wherein the extractor comprises a mechanical extractor. In some examples, triggering the clot extraction response includes automatically activating or increasing a chopper within an extraction chamber region of the thrombectomy device. Alternatively or additionally, the methods and devices may include emitting a signal of clot material in (or once in) the aspiration catheter, including providing a reminder of where in the lumen of the aspiration catheter is occluded and/or where there is occlusion (e.g., distal region, proximal region, or one or more intermediate regions) in the catheter.
In any of these methods and apparatuses, detecting an occlusion within the extraction region may include detecting an occlusion on an outside of a cover covering an extraction inlet of the thrombectomy device, wherein the cover includes an expandable aperture through which clot material may be extracted.
Thrombectomy devices that may perform any of these methods are also described herein. For example, an apparatus may comprise: an elongate body having an aspiration lumen extending therethrough; an extraction chamber region in fluid communication with the aspiration lumen at a distal region of the elongate body; an extraction inlet at a distal end of the extraction chamber region into the extraction chamber region; an occlusion sensor configured to sense an occlusion in the extraction region distal to the extraction inlet; and a controller configured to detect an occlusion within the extraction area using the occlusion sensor to determine whether the occlusion is a vessel wall or a clot material and trigger a reminder indicating a property of the occlusion, wherein the controller is further configured to manually or automatically activate the aspiration within the extraction chamber area when the controller determines that the occlusion is a clot material.
Any of the devices described herein can include a shredder within the extraction chamber region configured to shred the clot material within the extraction chamber region.
As mentioned, any of these means may comprise a cover overlying the extraction inlet. The covering may include an expandable aperture therethrough. The holes may be slits, cuts, gates (flaps), etc. The extraction chamber region may be expandable.
In any of these devices, the occlusion sensor may comprise a contact sensor. The occlusion sensor includes a pressure sensor. The occlusion sensor may comprise an optical sensor. The occlusion sensor may comprise a bio-impedance sensor having two or more electrodes.
Any of these devices may include a suction regulator (regulator) coupled to the controller, wherein the controller may be configured to apply suction using the suction regulator to determine whether the occlusion is a vessel wall or a clot material.
Generally, any of these devices may include an extraction chamber. The extraction chamber may refer to a distal region of the aspiration catheter lumen, which may be similar or identical to a proximal region or more intermediate regions of the catheter lumen; alternatively, in some examples, the extraction chamber may be a structurally different region of the catheter. As mentioned above, the extraction chamber may be partially or fully covered by a cover. The extraction chamber may be an expandable region. As described herein, the extraction chamber may be partially or completely closed to prevent lost blood from entering the device (e.g., when drawing suction), or may minimize the amount of blood lost through the device. Thus, in general, the extraction chamber may refer to a distal region of a catheter (e.g., a suction catheter) as described herein.
Any of these devices may include an extraction chamber sensor configured to detect obstructions within the extraction chamber; in some examples, the controller is configured to determine whether the occlusion is a vessel wall or a clot substance based on an output of the extraction chamber sensor when the suction is applied. The extraction chamber sensor may be one or more of the following: a contact sensor, a pressure sensor, an optical sensor, or an electrical sensor (e.g., a bio-impedance sensor). In some examples, the controller is configured to determine whether the occlusion is a vessel wall or a clot material based on a change in chopper response.
Generally, any of these devices may include a shredder and a shredder driver that drives operation of the shredder. The shredder may be operable to reciprocate and/or rotate one or more members under the drive of the shredder driver. The controller may be configured to detect a change in energy applied to drive the shredder to determine whether the occlusion is a vessel wall or clot material. In some examples, the controller may be configured to detect a change in vibration of the shredder to determine whether the occlusion is a vessel wall or clot material. In any of these devices, the controller may be configured to determine the load on the shredder or a change in the load of the shredder based on sound emitted by the shredder and/or the driver (e.g., drive shaft, etc.). Thus, any of these devices may include a microphone input for detecting sound from the device (e.g., from a shredder).
For example, an apparatus described herein may comprise: an elongate body having an aspiration lumen extending therethrough; an extraction chamber region at a distal region of the elongate body in fluid communication with the aspiration lumen; a shredder within the extraction chamber region, the shredder configured to shred the clot material within the extraction chamber region; an extraction inlet at a distal end of the extraction chamber region into the extraction chamber region; an occlusion sensor configured to sense an occlusion within the extraction region distal to the extraction inlet; and a controller configured to detect an occlusion within the extraction area using the occlusion sensor to determine whether the occlusion is a vessel wall or a clot material and trigger a reminder indicating a property of the occlusion, wherein the controller is further configured to manually or automatically activate the attraction within the extraction chamber area when the controller determines that the occlusion is a clot material; wherein the controller is further configured to stop the drawing through the extraction chamber region when the controller determines that there is no more clot material in the extraction chamber region.
Also described herein are methods of optically detecting a clot and differentiating between a wall and a clot by spectroscopy. For example, a method may include: moving the thrombectomy device within the vessel; detecting an occlusion in the extraction region distal to the extraction inlet of the thrombectomy device using an optical sensor on the thrombectomy device; determining whether the occlusion is a vessel wall or a clot material based on the reflectance spectral values of the occlusion; if the obstruction is a clot material, a clot extraction response is triggered, wherein the clot extraction response includes one or more of: signaling to the user that the thrombectomy device is adjacent to the clot material, applying suction from the extraction inlet, and/or activating a shredder within an extraction chamber region of the thrombectomy device; and stopping the aspiration when clot material is no longer detected within the extraction chamber region.
Any of these methods may include detecting clot material within the extraction chamber region based at least in part on one or more of: a sensor configured to sense clot material within the extraction chamber region and a change in chopper response. As mentioned, the method may comprise detecting obstructions within the extraction zone by detecting obstructions on an outside of a cover covering an extraction inlet of the thrombectomy device, wherein the cover comprises expandable holes through which clot material may be extracted. Detecting an obstruction within the extraction zone using an optical sensor may include detecting contact between the optical sensor and the obstruction. In some examples, detecting an occlusion within the extraction region using an optical sensor may include detecting an oxygenation level of the occlusion (oxygenation level).
In general, triggering a clot extraction response may include transmitting a signal that the thrombectomy device is in contact with the clot material. In some examples, triggering the clot extraction response includes automatically activating or increasing the suction by applying or increasing the suction through the thrombectomy device to remove clot material from the extraction inlet. Triggering a clot extraction response may include automatically activating or increasing chopper activity within an extraction chamber region of a thrombectomy device.
In any of these methods and devices, stopping aspiration may include stopping aspiration after a predetermined period of time after clot material is no longer detected within the extraction chamber region.
Methods of mechanically removing a clot (without or in addition to suction) are also described herein. For example, a method may include: detecting an occlusion in an extraction area within the vessel adjacent to an extraction inlet of the thrombectomy device using an optical sensor on the thrombectomy device; determining whether the occlusion is a vessel wall or a clot material based on the reflectance spectral values of the occlusion; triggering a clot extraction response if the occlusion is a clot substance, wherein the clot extraction response comprises one or more of: signaling to the user that the thrombectomy device is in contact with the clot material, activating the extractor to capture the clot material, and/or activating the shredder within the extraction chamber region of the thrombectomy device; and stopping the extractor when clot material is no longer detected within the extraction chamber region.
In some examples, activating the extractor to capture the clot material includes applying suction from the extraction inlet.
Thrombectomy devices including one or more optical sensors are also described herein. For example, an apparatus may comprise: an elongate body having an aspiration lumen extending therethrough; an extraction chamber region at a distal region of the elongate body in fluid communication with the aspiration lumen; an extraction inlet at a distal end of the extraction chamber region into the extraction chamber region; an optical sensor configured to sense obstructions within the extraction region distal to the extraction inlet; a light source coupled to the optical sensor; an optical detector coupled to the optical sensor; and a controller coupled to the optical detector and configured to detect an occlusion within the extraction area and determine whether the occlusion is a vessel wall or a clot material based on a reflectance spectrum value of the occlusion, wherein the controller is further configured to trigger a reminder indicating a property of the occlusion and provide manual or automatic activation of the attraction within the extraction chamber area when the controller determines that the occlusion is a clot material.
The optical sensor may include a sensing fiber and an emitting fiber. In some examples, the distal ends of the sensing fiber and the transmitting fiber may be embedded within a spherical material having a first refractive index, wherein the sphere is at least partially coated or covered with a material having a second refractive index. For example, any of these devices may include a shredder within the extraction chamber region configured to shred the clot material within the extraction chamber region; the device may include a cover over the extraction inlet, the cover including an expandable aperture therethrough. The extraction chamber region may be expandable.
Any of these devices may include an aspiration modulator coupled to the controller, wherein the controller is configured to apply aspiration using the aspiration modulator to determine whether the occlusion is a vessel wall or clot material.
As mentioned, the controller may be further configured to determine whether the occlusion is a vessel wall or a clot material based on a change in chopper response. Any of these devices may include a chopper driver, wherein the controller is configured to detect a change in energy applied to drive the chopper to determine whether the occlusion is a vessel wall or clot material. The controller may be configured to detect a change in vibration of the shredder to determine whether the occlusion is a vessel wall or clot material.
For example, an apparatus may comprise: an elongate body having an aspiration lumen extending therethrough; an extraction chamber region at a distal region of the elongate body in fluid communication with the aspiration lumen; a shredder within the extraction chamber region, the shredder configured to shred the clot material within the extraction chamber region; an extraction inlet at a distal end of the extraction chamber region into the extraction chamber region; an optical sensor configured to sense obstructions within the extraction region distal to the extraction inlet; a light source coupled to the optical sensor; an optical detector coupled to the optical sensor; and a controller coupled to the optical detector and configured to detect an occlusion within the extraction area and determine whether the occlusion is a vessel wall or a clot material based on a reflectance spectrum value of the occlusion, wherein the controller is further configured to trigger a reminder indicating a property of the occlusion and provide manual or automatic activation of the attraction within the extraction chamber area when the controller determines that the occlusion is a clot material; wherein the controller is further configured to stop the drawing when clot material within the extraction chamber region is no longer detected based at least in part on one or more of the sensor configured to sense clot material within the extraction chamber region and the change in chopper response.
Methods of detecting a clot (and/or distinguishing clot material, vessel walls, or other materials) based on contact pressure are also described herein. For example, a method may include: moving the thrombectomy device within the vessel; detecting contact between an occlusion adjacent an extraction inlet of a thrombectomy device within an extraction zone using a sensor on a distal end of the thrombectomy device within or adjacent the extraction zone; determining whether the occlusion is a vessel wall or a clot material by applying suction from an extraction inlet and detecting the occlusion in an extraction chamber region of the thrombectomy device; if the obstruction is a clot material, a clot extraction response is triggered, wherein the clot extraction response includes one or more of: signaling to the user that the thrombectomy device is in contact with the clot material, applying or increasing suction, and/or activating a shredder within the extraction chamber region of the thrombectomy device; and stopping the aspiration when clot material is no longer detected within the extraction chamber region.
Detecting an obstruction within the extraction chamber region may be based at least in part on one or more of: a sensor configured to sense clot material within the extraction chamber region and a change in chopper response. For example, detecting the contact may include optically detecting the contact. Detecting contact may include detecting contact using a pressure sensor. In some examples, detecting contact includes detecting contact using a contact sensing balloon.
In any of these methods, determining whether the occlusion is a vessel wall or clot material by applying suction may include applying a suction pulse (e.g., a pulse between 5 seconds and 1 millisecond, such as between 2 seconds and 1 millisecond, between 1 second and 1 millisecond, less than 5 seconds, less than 4 seconds, less than 3 seconds, less than 2 seconds, less than 1 second, 900 milliseconds or less than 900 milliseconds, 800 milliseconds or less than 800 milliseconds, 700 milliseconds or less than 700 milliseconds, 600 milliseconds or less than 600 milliseconds, 500 milliseconds or less than 500 milliseconds, 400 milliseconds or less than 400 milliseconds, 300 milliseconds or less than 300 milliseconds, 200 milliseconds or less than 200 milliseconds, 100 milliseconds or less than 100 milliseconds, 75 milliseconds or less than 75 milliseconds, 50 milliseconds or less than 50 milliseconds, etc.). In any of these methods and devices, the method or device may apply a low level of constant or variable attraction, and the pulses may be pulses of higher attraction (e.g., 2-fold higher, 3-fold higher, 4-fold higher, 5-fold higher, 10-fold higher, 15-fold higher, 20-fold higher, 50-fold higher, 100-fold higher, etc.).
Any of these methods may include detecting the clot material by using a sensor configured to detect an occlusion within the extraction chamber, thereby determining whether the occlusion is a vessel wall or a clot material. For example, the sensor may comprise one of the following: bioimpedance sensors, optical sensors, pressure sensors, and contact sensors. As described above, determining whether the occlusion is a vessel wall or a clot material may include detecting the clot material based on a change in response of the shredder. For example, the change in response of the shredder may include a change in the electrical load of the shredder. The change in response of the shredder may include a change in vibration of the shredder. The change in response of the shredder may include an acoustic change in the shredder.
In any of these methods and apparatuses, triggering a clot extraction response may include transmitting a signal that the thrombectomy device is in contact with the clot material. Triggering the clot extraction response may include automatically activating an extractor by applying or increasing suction through the thrombectomy device to remove clot material from the extraction inlet, wherein the extractor includes a suction source. Triggering the clot extraction response may include automatically activating an extractor to remove clot material from the extraction inlet, wherein the extractor comprises a mechanical extractor. In some examples, triggering the clot extraction response includes automatically activating or increasing a chopper within an extraction chamber region of the thrombectomy device.
Detecting an occlusion within the extraction region may include detecting an occlusion on an outside of a cover covering an extraction inlet of the thrombectomy device, wherein the cover includes an expandable aperture through which clot material may be extracted.
Methods of mechanically removing a clot (without or in addition to suction) are also described herein. In some of these examples, attraction may be used to distinguish between walls and clots. For example, a method may include: moving the thrombectomy device within the vessel; detecting contact between obstructions within the extraction region distal to the extraction inlet of the thrombectomy device using a sensor on the distal end of the thrombectomy device within or adjacent the extraction region; determining whether the occlusion is a vessel wall or a clot material by applying suction from an extraction inlet and detecting the occlusion in an extraction chamber region of the thrombectomy device; if the obstruction is a clot material, a clot extraction response is triggered, wherein the clot extraction response includes one or more of: signaling to the user that the thrombectomy device is in contact with the clot material, activating the extractor to capture the clot material, and/or activating the shredder within the extraction chamber region of the thrombectomy device; and stopping the extraction when the clot material is no longer detected within the extraction chamber region. In any of these methods, activating the extractor to capture the clot material may include applying suction from the extraction inlet.
Also described herein are thrombectomy devices that include one or more pressure sensors configured to detect a clot near or within an extraction chamber. For example, an apparatus includes: an elongate body having an aspiration lumen extending therethrough; an extraction chamber region at a distal region of the elongate body in fluid communication with the aspiration lumen; an extraction inlet into the distal end of the extraction chamber region; a contact sensor within the extraction zone adjacent the extraction inlet, wherein the contact sensor is configured to detect a contact pressure; a sensing subsystem configured to detect clot material within the extraction chamber region; and a controller coupled to the contact detector and the sensing subsystem and configured to detect contact with an occlusion in the extraction area based on the contact sensor and to determine whether the occlusion is a vessel wall or a clot material based on the sensing subsystem, wherein the controller is further configured to trigger a reminder indicating a property of the occlusion when the controller determines that the occlusion is a clot material and to provide manual or automatic activation of the attraction in the extraction chamber area; wherein the controller is further configured to stop the aspiration when clot material is no longer detected within the extraction chamber region.
The sensing subsystem may include one or more of the following: bioimpedance sensors, pressure sensors, and optical sensors. The apparatus may include a shredder within the extraction chamber region configured to shred the clot material within the extraction chamber region. In any of these devices, the sensing subsystem may be configured to detect a change in chopper response. As mentioned, any of these devices may include a cover over the extraction inlet, the cover including an expandable aperture therethrough. The extraction chamber region may be expandable.
Methods of detecting a clot are also described herein, such as by applying an attracting pulse (e.g., on demand or periodically) to see if the clot is pulled partially or completely into the extraction chamber and/or the cover, and devices configured to perform the methods are also described herein. The presence of clot material can be confirmed by detecting a change in chopper activity and/or by sensing in the chamber by an internal sensor. For example, a method may include: detecting clot material in an extraction region distal to an extraction inlet of an intravascular thrombectomy device by applying an attractive pulse through the extraction inlet; during or immediately after the aspiration pulse, confirming that clot material is within the extraction zone by detecting clot material within the extraction chamber region of the thrombectomy device; if it is confirmed that the clot material is within the extraction zone, triggering a clot extraction response, wherein the clot extraction response comprises one or more of: signaling to the user that the thrombectomy device is in contact with the clot material, activating the extractor to capture the clot material, and/or activating the shredder within the extraction chamber region of the thrombectomy device; and stopping the extraction when the clot material is no longer detected within the extraction chamber region.
Detecting clot material within the extraction chamber region may be based at least in part on one or more of: a sensor configured to sense clot material within the extraction chamber region and a change in chopper response. Applying the attraction pulse may include applying the attraction pulse having a predetermined duration between about 0.1 seconds and 10 seconds. Detecting the clot material within the extraction chamber region of the thrombectomy device during or immediately after the aspiration pulse may include detecting the clot material using a sensor configured to detect an obstruction within the extraction chamber.
The sensor may include one or more of the following: bioimpedance sensors, optical sensors, pressure sensors, and contact sensors. Alternatively or additionally, detecting clot material within the extraction chamber region of the thrombectomy device during or immediately after the aspiration pulse may include detecting clot material based on a change in response of the chopper. The change in response of the shredder may include a change in the electrical load of the shredder and/or a change in the vibration of the shredder and/or a change in the sound of the shredder, such as an acoustic change of the shredder.
In any of these examples, triggering the clot extraction response includes transmitting a signal that the thrombectomy device is in contact with the clot material. Triggering the clot extraction response may include automatically activating an extractor to remove clot material from the extraction inlet by applying or increasing suction through the thrombectomy device, wherein the extractor includes a suction source. Triggering the clot extraction response may include automatically activating an extractor to remove clot material from the extraction inlet, wherein the extractor comprises a mechanical extractor. Triggering a clot extraction response may include automatically activating or increasing a chopper within an extraction chamber region of a thrombectomy device.
Detecting clot material within the extraction region can include applying an aspiration pulse through an expandable aperture in a cover covering an extraction inlet of a thrombectomy device.
For example, a method may include: moving the thrombectomy device within the vessel; detecting clot material within an extraction zone adjacent to an extraction inlet of a thrombectomy device by applying an aspiration pulse through the extraction inlet during or immediately after the aspiration pulse while operating the chopper within an aspiration chamber region of the thrombectomy device and confirming clot material within the extraction zone based on a change in chopper response; if it is confirmed that the clot material is within the extraction zone, triggering a clot extraction response, wherein the clot extraction response comprises one or more of: signaling to the user that the thrombectomy device is in contact with the clot material, activating the mechanical extractor to capture the clot material, and/or activating the shredder within the extraction chamber region of the thrombectomy device; and stopping extraction after clot material is no longer detected within the extraction chamber region based on the change in chopper response.
Also described herein is an apparatus comprising: an elongate body having an aspiration lumen extending therethrough; an extraction chamber region at a distal region of the elongate body in fluid communication with the aspiration lumen; an extraction inlet into the distal end of the extraction chamber region; a shredder within the extraction chamber region; and a controller configured to be coupled to the suction regulator and to control application of a suction pulse from the suction regulator through the extraction inlet when the shredder is operating, and to confirm the presence of clot material within the extraction chamber region by detecting a change in the shredder response during the suction pulse, further wherein the controller is configured to perform one or more of: signaling the presence of a clot material, activating suction to capture the clot material, activating a chopper, and/or stopping suction after clot material is no longer detected within the extraction chamber region based on a chopper response during capture of the clot material.
Also described herein are methods of detecting clots using a sensor that detects an opening to a well in an extraction chamber (e.g., separation of sides of a partially or fully closed well). For example, a method may include: moving the thrombectomy device within the vessel; detecting clot material within the extraction zone adjacent to the extraction inlet of the thrombectomy device by applying an attractive pulse through the extraction inlet and detecting separation between two or more sides of the aperture through the cover overlying the extraction inlet of the thrombectomy device; if the separation between the two or more sides exceeds a threshold, triggering a clot extraction response, wherein the clot extraction response comprises one or more of: signaling to the user that the thrombectomy device is in contact with the clot material, activating the suction to capture the clot material, and/or activating the chopper in the extraction chamber region.
Any of these methods may include stopping the clot extraction response immediately or after a delay (allowing clot material already within the device to be cleared) when a clot is no longer detected outside the extraction area and/or within the extraction chamber. For example, any of the methods and apparatus may be configured to stop the clot extraction process after the separation between the two or more sides no longer exceeds a threshold when suction is applied.
Detecting separation between two or more blades (leaflets) may include detecting separation between two or more electrodes on the blades based on impedance measurements. Detecting separation between two or more blades may include optically detecting separation between two or more blades.
Also described herein are apparatuses comprising: an extraction chamber region in fluid communication with the aspiration lumen at a distal region of the elongate body; an extraction inlet into the extraction chamber region; a cover covering the extraction inlet; a hole through the cover, the hole having two or more sides; a sensor configured to detect separation between two or more sides of the aperture; and a controller configured to be coupled to the suction regulator and to control application of a suction pulse from the suction regulator through the extraction inlet and trigger a clot extraction response if separation between two or more sides exceeds a threshold, wherein the clot extraction response comprises one or more of: signaling contact with the clot material, activating attraction to capture the clot material, and/or activating a chopper in the extraction chamber region. The apparatus may include a shredder within the extraction chamber region. The controller may be further configured to stop the suction after the separation between the two or more sides is less than a threshold.
Generally, described herein are devices for detecting clot material within an aspiration catheter (with an aspiration lumen) using a sensor within (or at least partially within) the aspiration lumen. In some examples, the sensor is a deflection sensor that includes a deflectable member. The device (e.g., controller and/or sensing circuitry) can detect deflection of the deflectable member to confirm that clot material is present within the aspiration lumen and/or to distinguish clot material from the vessel wall at the distal end or distal region of the apparatus.
For example, described herein are apparatuses comprising: an elongate body having an aspiration lumen extending therethrough; a deflection sensor extending at least partially into the aspiration lumen, the deflection sensor comprising a deflectable member having a first region coupled to a wall location within the aspiration lumen and a second region spaced apart from the first region by a length of the deflectable member, wherein the deflectable member has an undeflected configuration and a deflected configuration, wherein in the deflected configuration the second region has an axial offset relative to the wall location that is different from the axial offset between the second region and the wall location in the undeflected configuration; and a controller configured to detect an occlusion within the aspiration lumen based on a signal from the deflection sensor indicative of deflection of the deflectable member.
The deflectable member may be configured as an elongated member that protrudes into and/or through the aspiration lumen (e.g., through a distal region of the aspiration lumen (also referred to herein as a clot extraction chamber region)). In a first configuration, the deflectable member may be disposed transverse to the long axis of the suction lumen. In some examples, the deflectable member may be arranged along the longitudinal axis and/or helically wound (as a spring or the like) about the longitudinal axis. In some examples, the deflectable member may be referred to as a tentacle (whisker); for example, the deflectable member may comprise deflectable tentacles.
The deflectable sensor may include a first electrode at the first region and a second electrode on a wall of the suction lumen opposite the deflectable member, wherein when the deflectable member is in the undeflected configuration, the deflectable member extends through the suction lumen such that the first electrode is proximate the second electrode, and when the deflectable member is in the deflected configuration, the first electrode and the second electrode are axially spaced farther apart than in the undeflected configuration. In some examples, the device may include a third electrode axially spaced apart relative to the wall location within the aspiration lumen such that in the deflected configuration, the first electrode is closer to the third electrode than in the undeflected configuration.
In some examples, the deflectable member comprises a shape sensing optical fiber. Alternatively or additionally, in some examples, the deflectable member comprises a piezoelectric material. For example, the controller may be configured to detect a transition of the deflectable member between the undeflected configuration and the deflected configuration based on the piezoelectric signal. In some examples, the deflectable member comprises a variable resistance material that changes resistivity when bent; the controller may be configured to detect a change in resistance when the deflectable member is bent.
In any of these examples, the controller may be configured to determine whether the occlusion is a vessel wall or a clot material. For example, the controller may be configured to determine whether clot material is stuck within the aspiration lumen, including in particular at the distal end of the aspiration lumen (commonly referred to as a "lollipop (lollypopping)", with a portion of the large clot stuck in the distal region of the aspiration lumen), using one or more of a signal from the deflection sensor indicative of deflection of the deflectable member and/or pressure within the aspiration lumen and/or flow within the aspiration lumen.
In some examples, the deflectable member is in a distal region of the aspiration lumen configured as an extraction chamber region. In the first configuration, the deflectable member may extend protruding from the wall of the suction lumen and may be configured to deflect such that the second region of the deflectable member is axially and radially displaced relative to the undeflected configuration. In some examples, the extraction chamber region is expandable; alternatively, in some examples, the extraction chamber region is not distinct from the rest of the aspiration lumen, but rather refers to the distal region of the aspiration lumen at the distal end of the device. In any of these devices, the wall location within the suction lumen is about 5mm from the distal end of the suction lumen of the elongate body.
The deflectable member may generally be configured to couple to a wall of the aspiration lumen at a first region (e.g., a first end) and deflect or deform such that a second region (e.g., a second end region) of the deflectable member moves relative to the first region when a force is applied by a substance (e.g., blood or clot substance) within the aspiration lumen. Typically, the deflectable member is configured to resiliently deflect such that it returns to the first (undeflected) configuration when the force interacting with the substance in the aspiration lumen is removed. In some cases, the deflectable member is formed from a superelastic material, such as a nitinol material (e.g., nitinol) and/or a polymeric material. The deflectable member may include a polymeric inner liner, a reinforcement layer, and a polymeric outer jacket. In some examples, in the first configuration, the first electrode is spaced apart from the second electrode by a distance of between about 0.01mm to about 2mm.
In any of these devices, the aspiration lumen may be covered or partially covered. For example, the device may include a cover over the distal end of the aspiration lumen, the cover having an expandable hole therethrough. In any of these devices, the suction lumen may be surrounded by a deformable lip (deformable lip).
Any of these devices may include a shredder within the suction lumen and the shredder is configured to shred the clot material within the suction lumen. Any of these devices may include a shredder driver. The controller may manually or automatically control the application of energy to drive the shredder (e.g., the drive shaft/drive line of a rotary shredder). In some examples, the controller is configured to apply pulsed attraction.
As mentioned, the device may include a pressure sensor configured to determine the pressure within the aspiration lumen. Any of these devices may include a flow sensor configured to determine flow through the aspiration lumen.
The controller may be configured to trigger a reminder indicating a property of the obstruction. When the controller determines that the occlusion is a clot material, the controller may be configured to manually or automatically activate the suction.
Any of these devices may include one or more stops (stop) within the aspiration lumen to prevent the chopper from being advanced distally over the deflectable member.
The devices described herein may include a plurality of deflection sensors within the aspiration lumen. For example, the device may include a second deflectable member extending from a wall of the aspiration lumen, wherein the second deflectable member is located at a more proximal region of the aspiration lumen.
For example, described herein are devices (e.g., thrombectomy devices) configured for identifying and/or detecting the presence of a clot material and/or distinguishing between the clot material and a vessel wall to remove the material from the vessel using one or more deflectable tentacles. Any of these means may include: an elongate body having an aspiration lumen extending therethrough; deflectable tentacles extending from the wall of the suction lumen; a first electrode at a distal region of the deflectable whisker; a second electrode on a wall of the suction lumen opposite the deflectable whisker, wherein the deflectable whisker has a first configuration in which the deflectable whisker extends across the suction lumen such that the first electrode is proximate the second electrode and a second configuration in which the deflectable whisker is deflected such that the first electrode is spaced further from the second electrode than the first configuration; and a controller configured to detect an occlusion within the aspiration lumen based on an electrical signal between the first electrode and the second electrode indicative of deflection of the deflectable whisker.
In some examples, the apparatus may include: an elongate body having an aspiration lumen extending therethrough, wherein a distal region of the aspiration lumen is configured as an extraction chamber region; deflectable tentacles extending from the walls of the extraction chamber region; a first electrode at a distal region of the deflectable whisker; a second electrode on a wall of the aspiration lumen opposite the deflectable whisker, wherein the deflectable whisker has a first configuration in which the deflectable whisker extends to protrude across the extraction chamber region such that the first electrode is proximate the second electrode, and a second configuration in which the deflectable whisker is deflected such that the first electrode is spaced apart from the second electrode compared to the first configuration; and a controller configured to detect an occlusion in the extraction chamber region based on the electrical signal between the first electrode and the second electrode and determine whether the occlusion is a vessel wall or a clot material.
In any of these devices, the controller may be configured to determine whether the occlusion is a vessel wall or a clot material. For example, the controller may include one or more processors that may analyze the electrical signal (e.g., impedance, conductance, etc.) between the first electrode and the second electrode and determine whether the tentacles deflect due to aspiration of clot material within the lumen (e.g., within the extraction chamber region) based on time-varying electrical characteristics (e.g., comparison of the impedance before, during, and/or after the application of the aspiration (e.g., aspiration pulse)).
In any of these devices and methods, the deflectable whisker may be in a distal region of the aspiration lumen configured as an extraction chamber region. In a first configuration, the deflectable whisker may extend protruding from a wall of the suction lumen, and in a second configuration may deflect such that a distal region of the deflectable whisker is axially and radially displaced relative to the second electrode. As described above, the extraction chamber region may be expandable.
In some examples, the deflectable whisker may be within about 5mm from the distal end of the suction lumen of the elongate body. The deflectable whisker may comprise a superelastic material. In some examples, the deflectable whisker includes a polymer liner, a reinforcement layer, and a polymer outer jacket.
In any of these examples, the device may include a cover over the distal end of the suction lumen, and the cover may have an expandable hole therethrough.
As described above, any of these devices may include a shredder within the suction lumen and configured to shred the clot material within the suction lumen. The deflectable tentacles may be prevented from damaging by limiting the travel of the chopper within the suction lumen (e.g., preventing the chopper from traveling over the tentacles) and/or including one or more features on the chopper, such as a distally extending sleeve or strap (cuff) that deflects the deflectable tentacles distally and away from the chopper opening.
Any of these devices may include a pressure sensor configured to determine the pressure within the aspiration lumen and/or a flow sensor (e.g., a thermal anemometer (thermal anemometer), such as a hot wire anemometer) for determining the flow within the aspiration lumen.
Any of these devices may include a shredder driver. The controller may control the drive (e.g., drive line) that rotates the cutting elements within the shredder.
In any of these devices, the controller may be configured to apply pulsed attraction. The use of pulsed attraction may allow the device to determine the presence of clot material.
In any of these devices, the controller may be configured to trigger a reminder indicating the nature of the obstruction. The controller may also be configured to manually or automatically activate the suction when the controller determines that the obstruction is a clot material.
The devices described herein may include a plurality of deflectable tentacles. For example, the device may include a second deflectable whisker extending from a wall of the aspiration lumen, wherein the second deflectable whisker is located at a more proximal region of the aspiration lumen.
In some examples, the first electrode may remain separate (e.g., not in contact) from the second electrode. This may increase the sensitivity of the device. For example, the first electrode may be separated from the second electrode by between about 0.01mm and about 2 mm.
Also described herein are methods of controlling the devices described herein, and/or methods of removing clot material, and/or methods of distinguishing clot material from a vessel wall. These methods may be particularly suitable for removing clot material without removing excess blood.
For example, a method may include: applying suction through a suction lumen of an intravascular device; detecting deflection of a deflectable member extending at least partially within an extraction chamber region at a distal end region of the aspiration lumen; determining whether deflection is caused by clot material trapped in the extraction chamber region; triggering a clot extraction response if clot material is captured in the extraction chamber region, wherein the clot extraction response comprises one or more of: signaling the user that the device is adjacent to the clot material, applying continuous suction through the suction lumen, and/or activating a shredder within the extraction chamber region of the device.
Applying the suction may include applying a suction pulse. The aspiration pulse may allow the device to detect and/or remove clot material without removing excess blood from the subject. The attraction pulse may be, for example, 2 seconds or more (e.g., 1.5 seconds or more, 1 second or more, 0.9 seconds or more, 0.7 seconds or more, 0.6 seconds or more, 0.5 seconds or more, 0.4 seconds or more, 0.3 seconds or more, 0.2 seconds or more, 0.1 seconds or more, 50 milliseconds or more, 10 milliseconds or more, 5 milliseconds or more, 1 millisecond or more, etc.).
Any of these methods may include stopping aspiration when the deflectable members (e.g., using one or more deflectable members) indicate that clot material is no longer within the extraction chamber region and/or no longer within the aspiration lumen. Stopping aspiration may include stopping aspiration after a predetermined period of time after clot material is no longer detected within the aspiration lumen (e.g., after 1 second, after 2 seconds, after 3 seconds, after 4 seconds, after 5 seconds, after 6 seconds, after 7 seconds, after 8 seconds, after 9 seconds, after 10 seconds, after 12 seconds, after 15 seconds, etc.). The attraction may be stopped manually or automatically.
Any of these methods may include sensing one or more of the following: suction lumen pressure and/or flow rate through the suction lumen. The method may further include determining that clot material is within (e.g., trapped within) the aspiration lumen using one or more of a pressure within the aspiration lumen and/or a flow rate through the aspiration lumen. Any of these methods may further include distinguishing between blood vessel wall and clot material using one or more of pressure within the aspiration lumen and/or flow rate through the aspiration lumen.
Triggering the clot extraction response may include a signal that the transmitting device is in contact with the clot material. In some examples, triggering the clot extraction response includes automatically activating or increasing the suction by applying or increasing the suction through the suction lumen to remove clot material from the extraction chamber region. Alternatively or additionally, triggering a clot extraction response may include automatically activating or increasing chopper activity within the extraction chamber region.
The deflectable member may be part of a deflection sensor that identifies deflection of the deflectable member by sensing one or more parameters (e.g., electrical or mechanical parameters). The deflectable member may be part of a sensing circuit configured to detect a change in shape or deflection of the deflectable member within the aspiration lumen (or region of the aspiration lumen, such as an extraction chamber region). Note that in any of the devices described herein, a different extraction chamber region may be included as part of or in fluid communication with the aspiration lumen. Alternatively, in some examples, the extraction chamber region may be an undivided (undivided) section of the aspiration lumen (e.g., at or near the distal end).
For example, detecting deflection of the deflectable member includes detecting a change in resistance, conductance, or inductance of the deflectable member. In some examples, detecting deflection of the deflectable member includes detecting a change in shape of the deflectable member using a fiber optic bend sensor. In some examples, detecting deflection of the deflectable member includes detecting a change in voltage or current in a sensing circuit to which the deflectable member is electrically coupled.
For example, a method may include: moving the device within the blood vessel; applying suction through a suction lumen of the device; detecting an occlusion in the extraction chamber region at a distal region of the aspiration lumen through the device using deflectable tentacles extending at least partially across the extraction chamber region; determining whether the occlusion is a vessel wall or clot material based on an electrical signal between a first electrode at the distal end of the deflectable whisker and a second electrode in communication with the wall of the extraction chamber region; if the obstruction is a clot material, a clot extraction response is triggered, wherein the clot extraction response includes one or more of: signaling the user that the device is adjacent to the clot material, applying continuous suction through the suction lumen, and/or activating a shredder within the extraction chamber region of the device.
In any of these methods, applying suction may include applying one (or more) suction pulse.
Any of these methods may include stopping the aspiration when clot material is no longer detected within the extraction chamber region. For example, ceasing aspiration may include ceasing aspiration after a predetermined period of time after clot material is no longer detected within the aspiration lumen.
The methods may further include sensing one or more of the following: suction lumen pressure and/or flow rate through the suction lumen.
As described above, triggering the clot extraction response may include a signal that the transmitting device is in contact with the clot material. For example, triggering a clot extraction response can include automatically activating or increasing suction by applying or increasing suction through the suction lumen to remove clot material from the extraction chamber region. In some examples, triggering the clot extraction response includes automatically activating or increasing chopper activity within the extraction chamber region.
Methods of performing pulmonary embolism resection are also described herein. For example, a method of performing a pulmonary embolism resection may include: advancing the aspiration catheter into the pulmonary artery (e.g., into the left pulmonary artery in some examples); applying suction through a suction catheter; when flow through the aspiration catheter is occluded, determining whether the identity of the occlusion is a clot material or a vascular anatomy; and outputting an indicator of the identity of the clot material. Advancing the aspiration catheter may include advancing the aspiration catheter through the pulmonary valve and into the pulmonary artery around the bend.
Generally, determining whether the identity of the occlusion is a clot material or a vascular anatomy may include detecting the clot material using an intra-luminal sensor. For example, determining whether the identity of the occlusion is a clot material or a vascular anatomy may include deflecting a deflectable member within a lumen of the aspiration catheter. Determining whether the identity of the occlusion is a clot material or a vascular anatomy may include optically confirming that the occlusion is a clot material.
In any of these examples, outputting the indicator may include triggering a reminder to the user. Outputting the indicator may include ceasing application of suction when the identity of the occlusion is a vascular anatomy.
Methods and devices for determining characteristics of clot material within an aspiration lumen are also described herein. For example, described herein are apparatuses comprising: an elongate body having an aspiration lumen extending therethrough; a first internal impedance sensor at a distal region of the aspiration lumen; a second internal impedance sensor at a proximal region of the aspiration lumen; and a controller configured to track clot material within the aspiration lumen based on signals from the first and second internal impedance sensors.
For example, an apparatus may comprise: an elongate body having an aspiration lumen extending therethrough; a first internal impedance sensor at a distal region of the aspiration lumen, the first internal impedance sensor comprising a first pair of ring electrodes extending proximally (extending adjacently) at least partially around the aspiration lumen; a second internal impedance sensor at a proximal region of the aspiration lumen, the second internal impedance sensor comprising a second pair of ring electrodes extending proximally at least partially around the aspiration lumen; and a controller configured to track clot material within the aspiration lumen based on the time-varying impedance signal from the first internal impedance sensor and the time-varying impedance signal from the second internal impedance sensor, and to determine a size estimate of the clot material.
The first internal impedance sensor may include a pair of ring electrodes extending radially around the aspiration lumen. In some examples, the ring electrode comprises a ring electrode that extends radially (fully or partially) around the aspiration lumen. In some examples, the ring electrode comprises a spiral electrode. The pair of ring electrodes may be spaced apart from each other by a distance of between 1mm and 20mm (e.g., between 5mm and 20mm, between 5mm and 10mm, etc.). The pair of ring electrodes may each extend radially more than 40 degrees around the suction lumen. One or both of the first impedance sensor or the second impedance sensor may include an ac power source configured to establish and control a variable voltage between the ring electrodes of the first internal impedance sensor. The controller may be further configured to determine a size of the clot material based on the signals from the first internal impedance sensor and the second internal impedance sensor. In some examples, the controller is configured to determine a flow rate of clot material within the aspiration lumen. The controller may be configured to distinguish between clot material and a vessel wall based on signals from the first and second internal impedance sensors. In some examples, the controller is further configured to adjust the suction through the suction catheter based at least on the signal from the first internal impedance sensor.
Also described herein are methods of tracking clot material within an aspiration catheter by detecting a time-varying impedance signal from a first impedance sensor (e.g., a first pair of ring electrodes) in a distal region of the aspiration lumen and by detecting a time-varying impedance signal from a second impedance sensor at a proximal region of the aspiration lumen. The method may include identifying a matching pattern indicative of the clot material from both the first impedance sensor and the second impedance sensor and determining a time delay between the matching patterns to estimate a rate of travel of the clot material within the aspiration lumen. The method may further include estimating the time it takes for the clot material to pass through the second impedance sensor at the proximal end of the aspiration lumen to estimate the length of the clot material, and/or estimating the amount (e.g., volume, size, etc.) of clot material removed using the known cross-sectional area of the aspiration lumen.
Any of these methods may include applying an alternating current power (e.g., an AC voltage) to establish and control a variable voltage between sensing electrodes forming the first impedance sensor and/or the second impedance sensor. Separate AC voltages may be applied from different or the same AC voltage sources. Any of these methods may include using signals from the first impedance sensor and the second impedance sensor to distinguish between blood vessel walls and clot material.
Any of these methods can include outputting tracking data, e.g., outputting a removal rate of clot material and/or outputting a size (e.g., length, volume, etc.) of clot material removed through the aspiration lumen and/or outputting a presence and/or location of a clot within the aspiration lumen.
For example, generally, methods of using impedance sensing to detect and/or track clot material within a suction catheter lumen are described herein. The methods and devices may be particularly useful for determining whether clot material is still in the lumen of a catheter. In general, knowing whether a clot substance is within a lumen can be very helpful because if it is stuck within the lumen, suction/pressure alone may not be sufficient to detect the substance. When the clot material is stuck within the lumen, the physician may need to know this, including when contrast needs to be applied through the lumen. If the clot material is still present in the catheter, the clot material may be driven back into the patient, which may cause additional problems for the patient. For example, described herein are apparatuses comprising: a flexible elongate catheter having an aspiration lumen extending therethrough; an internal electrical impedance sensor comprising two or more electrodes within the aspiration lumen; and a controller coupled to the internal electrical impedance sensor and configured to apply an alternating current between the two or more electrodes and detect obstructive material within the aspiration lumen based on an electrical impedance signal from the internal electrical impedance sensor.
In any of these devices, the internal electrical impedance sensor may be configured to operate at 50kHz or higher (e.g., 100kHz or higher, etc.). The internal electrical impedance sensor may be within about 20mm of the aspiration opening (which opens into the aspiration lumen at the distal end region of the flexible elongate catheter). The controller may also be configured to output a signal indicative of the obstructive material within the aspiration lumen.
The controller may be configured to apply the alternating current after beginning aspiration through the aspiration lumen.
Any of these devices may include a second internal electrical impedance sensor comprising two or more electrodes at the proximal region of the aspiration lumen.
The apparatus may include a current generator configured to apply an alternating current.
In general, the two or more electrodes may be any suitable electrode. In some examples, the two or more electrodes include an annular electrode extending radially at least partially around the aspiration lumen. For example, the ring electrode may comprise a spiral electrode. The ring electrodes may be spaced apart from each other by a distance of between 0.1mm and 20 mm. The ring electrodes may each extend radially 30 degrees or more around the suction lumen.
For example, described herein are apparatuses comprising: a flexible elongate catheter having an aspiration lumen extending therethrough; an internal electrical impedance sensor comprising two or more electrodes within the aspiration lumen between the proximal and distal ends of the flexible elongate catheter; and a controller coupled to the internal electrical impedance sensor and configured to apply an alternating current between the two or more electrodes to detect obstructive material within the aspiration lumen based on electrical impedance signals from the internal electrical impedance sensor and to output a signal indicative of the obstructive material within the aspiration lumen.
In general, these devices may include only catheters (for use with the controllers and other system components), or may include only controllers and other system components for use with the catheters described herein. For example, the apparatus may include: a flexible elongate catheter having an aspiration lumen extending therethrough; a suction opening at a distal region of the flexible elongate catheter; a first internal electrical impedance sensor comprising two or more electrodes extending at least partially around the aspiration lumen at a distal region of the aspiration lumen; a second internal electrical impedance sensor comprising two or more electrodes extending at least partially around the aspiration lumen at a proximal region of the aspiration lumen; and one or more connectors at the proximal region of the flexible elongate catheter, wherein the one or more connectors are in electrical communication with the first internal electrical impedance sensor and the second internal electrical impedance sensor, further wherein the one or more connectors are configured to be coupled to the controller to provide electrical impedance input to detect obstructive material within the aspiration lumen based on electrical impedance signals from the first internal electrical impedance sensor and the second internal electrical impedance sensor.
The first internal electrical impedance sensor may be within about 20mm of the suction opening into the suction lumen. Any of these devices may include a proximal suction port in communication with the suction lumen. The suction opening may be on a tapered side of the distal region of the flexible elongate catheter. The two or more electrodes of the first internal electrical impedance sensor may comprise annular electrodes. The ring electrode of the first internal electrical impedance sensor may comprise a spiral electrode. The ring electrodes of the first internal electrical impedance sensor may be spaced apart from each other by a distance of between 0.1mm and 20 mm. The ring electrodes of the first internal electrical impedance sensor may each extend radially 30 degrees or more around the aspiration lumen.
Also described herein is a method of detecting an obstructive material within a lumen of an aspiration catheter, the method comprising: applying suction through the lumen of the aspiration catheter; applying a variable current between two or more electrodes of a first internal electrical impedance sensor within a lumen of the aspiration catheter between a proximal end and a distal end of the aspiration catheter to generate an impedance signal; and detecting obstructive material within the lumen of the aspiration catheter based on the impedance signal. Detecting the obstructive material may include distinguishing the obstructive material from blood within a lumen of the aspiration catheter based on the impedance signal. Any of these methods may include outputting a signal indicative of the obstructive material within the lumen of the aspiration catheter.
Any of these methods may include analyzing the impedance signal to detect a change in impedance that is indicative of the proximity of the obstructive material to the first internal electrical impedance sensor. Applying the variable current may include applying a variable current having a frequency of 50kHz or greater. Any of these methods may include determining whether the obstructive material is occluded within the lumen based on the impedance signal.
In any of these methods, applying a variable current between two or more electrodes may include applying a plurality of frequencies to obtain an impedance spectrum, wherein detecting an obstructive material within the lumen includes detecting the obstructive material using the impedance spectrum. Any of these methods may include determining a rate of movement of the obstructive material within the lumen. The method may include applying the same or different variable current between two or more electrodes of a second internal electrical impedance sensor within the lumen of the aspiration catheter, and detecting obstructive material in the vicinity of the second internal electrical impedance sensor within the lumen of the aspiration catheter.
Also described herein are devices configured to use electrical impedance to determine an identity of a substance at a suction opening. For example, the methods and devices described herein may include one or more sensors (suction opening sensors) at the suction opening for distinguishing between a clot and a blood vessel wall. In these devices and methods, a force (e.g., suction) may be applied between the substance and the suction opening at the distal (tip) region. In general, it may be difficult to distinguish between a clot and a vessel wall, especially when suction is initially applied, during which time the substance may block the suction opening into the suction lumen and because the device is against the vessel wall or against a large clot, it may be unclear whether this is a blockage. In general, this may result in a long delay while the physician waits to see if the substance is to be removed by aspiration (or increasing aspiration). Thus, it would be beneficial to more accurately and quickly distinguish between the agglomerated material and the wall material. Furthermore, it may be particularly beneficial to provide an analytical technique that separates substances (clots or walls) from blood and/or separates substances (clots or walls) from situations where both walls and vessels contact the aspiration opening (which may give ambiguous results). As described herein, the use of an impedance sensing electrode at the distal aspiration opening (or recessed only relative to the distal aspiration opening) may allow for rapid identification of wall or clot material.
For example, an apparatus described herein includes: a flexible elongate body having a suction lumen extending therethrough; a suction opening into the suction lumen at a distal region of the flexible elongate body; a suction opening sensor comprising two or more electrodes positioned at an edge of the suction opening; and a controller coupled to the suction opening sensor and configured to distinguish between a clot and a vessel wall based on the impedance signal between the two or more electrodes when a force is applied to the flexible elongate body or through the suction lumen. The controller may be configured to distinguish between a clot and a vessel wall when the negative pressure within the aspiration lumen exceeds a threshold. The controller may be configured to distinguish between a clot and a vessel wall when the mechanical force exerted on the aspiration opening exceeds a threshold.
In some examples, the suction opening is on a tapered side of the distal region of the flexible elongate body. The two or more electrodes of the suction opening sensor may be recessed with respect to the edge. Two or more electrodes of the suction opening sensor may be recessed into the suction lumen at the edges. The two or more electrodes of the suction opening sensor may be equally spaced from each other on the edge of the suction opening. The two or more electrodes of the suction opening sensor may be positioned opposite each other across the suction opening. In some examples, two or more electrodes of the suction opening sensor are positioned opposite each other across the suction opening at the region of minimum diameter.
Any of these devices may include a plurality of smaller flow regulating openings into the aspiration lumen positioned adjacent the aspiration opening and a second impedance sensor including two or more electrodes positioned adjacent the plurality of smaller flow regulating openings.
An apparatus may include: a flexible elongate body having a suction lumen extending therethrough; a suction opening into the suction lumen at a distal region of the flexible elongate body; a suction opening sensor comprising two or more electrodes positioned at an edge of the suction opening; and a controller coupled to the suction opening sensor and configured to distinguish between a clot and a vessel wall based on the impedance signal between the two or more electrodes when the negative pressure applied through the suction lumen exceeds a threshold.
Also described herein are apparatuses comprising: a flexible elongate body having a suction lumen extending therethrough; a suction opening into the suction lumen at a distal region of the flexible elongate body; a suction opening sensor comprising two or more electrodes positioned at an edge of the suction opening; a proximal suction port in communication with the suction lumen; and one or more connectors at a proximal region of the flexible elongate body, wherein the one or more connectors are in electrical communication with two or more electrodes of the suction opening sensor, further wherein the one or more connectors are configured to be coupled to a controller to provide electrical impedance input to distinguish between a clot and a vessel wall when a force is applied to the flexible elongate body or through the suction lumen.
The device may include a second set of two or more electrodes in proximity to the suction opening sensor within the suction lumen, and further, one or more connectors may be in electrical communication with the second set of two or more electrodes to provide differential electrical impedance input from the two or more electrodes of the suction opening sensor when a force is applied to the flexible elongate body or through the suction lumen to distinguish between a clot and a vessel wall.
The suction opening is angled. Two or more electrodes of the suction opening sensor may be recessed from the edge. Two or more electrodes of the suction opening sensor may be recessed into the suction lumen at the edges. The two or more electrodes of the suction opening sensor may be equally spaced from each other on the edge of the suction opening. The two or more electrodes of the suction opening sensor may be positioned opposite each other across the suction opening. The two or more electrodes of the suction opening sensor may be positioned opposite each other across the suction opening at the region of minimum diameter.
Any of these devices may include a plurality of smaller flow regulating openings into the aspiration lumen positioned adjacent the aspiration opening and/or a second impedance sensor including two or more electrodes positioned adjacent the plurality of smaller flow regulating openings.
Also described herein is a method of distinguishing between a blood clot and a blood vessel wall, the method comprising: applying suction through a lumen of a flexible elongate catheter, wherein the flexible elongate catheter comprises a suction opening at a distal region and two or more electrodes at or adjacent the suction opening; and determining whether the suction opening engages a blood clot or a blood vessel wall based on impedance measured from two or more electrodes at or adjacent the suction opening when the force at the suction opening exceeds a threshold.
The force at the aspiration opening may include a negative pressure within the lumen. Any of these methods may include transmitting a reminder indicating whether the suction opening is engaged with one or both of a blood clot and a blood vessel wall.
The methods described herein may include applying an alternating current having a frequency between about 1kHz and 1 MHz. For example, the alternating current may have a frequency between about 10kHz and 100 kHz.
The methods described herein may include delaying the step of determining whether the suction opening is engaged with the blood clot or the blood vessel wall for a delay period after the force exceeds the threshold. In any of these methods, determining whether the suction opening is engaged with the blood clot or the blood vessel wall may be based on the following differences: the impedance measurement of the two or more electrodes at or adjacent to the suction opening differs from the impedance measurement of a second set of two or more electrodes positioned proximally of the two or more electrodes at or adjacent to the suction opening. Any of these methods may include adjusting suction through the lumen based on impedance measured from two or more electrodes at or adjacent to the suction opening.
Also described herein is a method of removing obstructive material from a blood vessel, the method comprising: applying negative pressure to a suction lumen of a flexible elongate catheter having a suction opening and two or more electrodes at or adjacent the suction opening; while applying the negative pressure, making impedance measurements from two or more electrodes at or adjacent to the suction opening; and adjusting the negative pressure based on the impedance measurement made.
In general, the methods and devices described herein may use impedance sensing to track clot material within the lumen of a catheter. Tracking the substance may include confirming that the clot substance is within (or has left) the aspiration lumen, determining the flow rate of the substance through the aspiration lumen, estimating the volume or amount of clot substance removed through the aspiration lumen, and the like.
For example, an apparatus may comprise: a flexible elongate body having a suction lumen extending therethrough; a first pair of electrodes within the aspiration lumen; a second pair of electrodes proximal to the first pair of electrodes; and a controller coupled to the first and second pairs of electrodes and configured to track clot material within the aspiration lumen based on electrical impedance signals from the first and second pairs of electrodes.
The first pair of electrodes may include a pair of ring electrodes extending radially at least partially around the aspiration lumen. The pair of ring electrodes may include a ring electrode extending radially around the aspiration lumen. The pair of ring electrodes may include a spiral electrode. The pair of ring electrodes may be spaced apart from each other by a distance of between 0.1mm and 20 mm. The pair of ring electrodes may each extend radially 30 degrees or more around the aspiration lumen. The first and second pairs of electrodes may constitute a quad detector. For example, the first pair of electrodes may be spaced between 0.1mm and 20mm from the second pair of electrodes along the distal-to-proximal length of the aspiration lumen.
Any of these devices may include an ac power source coupled to the first pair of electrodes and configured to apply a variable voltage. The controller may be further configured to determine a size of the clot material based on the electrical impedance signals from the first pair of electrodes and the second pair of electrodes. The controller may be configured to determine a flow rate of the clot material within the aspiration lumen based on the electrical impedance signals from the first and second pairs of electrodes.
The controller may be configured to distinguish between clot material and a vessel wall based on electrical impedance signals from the first and second pairs of electrodes. For example, the controller may be further configured to adjust the suction through the suction lumen based at least in part on the electrical impedance signal from the first pair of electrodes.
An apparatus may include: a flexible elongate body having a suction lumen extending therethrough; a suction opening at a distal region of the flexible elongate body leading to a suction lumen; a first pair of electrodes within and extending at least partially around the aspiration lumen; a second pair of electrodes extending proximally of and at least partially around the first pair of electrodes within the aspiration lumen; a proximal suction port in communication with the suction lumen; and one or more connectors at the proximal region of the flexible elongate body, wherein the one or more connectors are in electrical communication with the first and second pairs of electrodes, further wherein the one or more connectors are configured to be coupled to a controller to provide electrical impedance input to track clot material within the aspiration lumen based on electrical impedance signals from the first and second pairs of electrodes. The first and second pairs of electrodes may constitute a quad detector comprising two pairs of electrodes. The first and second pairs of electrodes may be spaced apart from each other along the distal-to-proximal length of the aspiration lumen by a distance of between 0.1mm and 20 mm.
A method of tracking clot material within an aspiration lumen of a catheter may include: receiving a first impedance signal from a first pair of electrodes within the aspiration lumen; receiving a second impedance signal from a second pair of electrodes within the aspiration lumen; and estimating one or more of a flow rate of the clot material and a volume of the clot material from the first impedance signal and the second impedance signal. Any of these methods may include outputting one or more of a flow rate of the clot material and a volume of the clot material. The method may include detecting occlusion of the catheter based on the first impedance signal and the second impedance signal. Any of these methods may include adjusting the suction through the suction lumen based on the first impedance signal and the second impedance signal.
Estimating one or more of the flow rate of the clot material and the volume of the clot material may include correlating the first impedance signal and the second impedance signal. Estimating one or more of the flow rate of the clot material and the volume of the clot material may include determining a time difference between correlations of the first impedance signal and the second impedance signal.
All methods and apparatus described herein (in any combination) are contemplated herein and may be used to achieve the benefits described herein.
Brief Description of Drawings
A better understanding of the features and advantages of the methods and apparatus described herein will be obtained by reference to the following detailed description that sets forth illustrative embodiments, and the accompanying drawings, in which:
fig. 1A schematically illustrates one example of a device for controlling an aspiration catheter.
Fig. 1B is an end view of one example of an aspiration catheter forming part of the device of fig. 1A.
Fig. 1C schematically illustrates another example of an apparatus for controlling an aspiration catheter.
Fig. 1D shows an end view of the suction catheter portion of the device of fig. 1C.
Fig. 2 is an end view of one example of an elongate shaft of an aspiration catheter described herein.
Fig. 3 is an end view of an example of an elongate shaft of an aspiration catheter including a monopolar impedance sensor on a distal end of the catheter (showing a single electrode on a distal side of the aspiration catheter).
Fig. 4 is an end view of an example of an elongate shaft of an aspiration catheter including a bipolar impedance sensor on a distal end of the aspiration catheter (including two proximal electrodes on a distal portion of the catheter).
Fig. 5 is an end view of an example of an elongate shaft of an aspiration catheter including several electrodes positioned circumferentially around an opening of a distal portion of the aspiration catheter (radially away from the center and outer limits of the distal portion of the catheter).
Fig. 6 is an end view of an example of an elongate shaft of an aspiration catheter including bipolar impedance sensors on the aspiration catheter (showing the same circumferential distribution as in fig. 4, with each monopolar electrode replaced by a proximal bipolar electrode pair).
Fig. 7 is an end view of an example of an elongate shaft of an aspiration catheter including bipolar impedance sensors on a distal portion of the aspiration catheter (including a single electrode pair, wherein each electrode is located on opposite half-circles of the distal portion of the catheter and radially away from the center and outer edges of the distal portion).
Fig. 8 is an end view of an example of an elongate shaft of an aspiration catheter including a bipolar impedance sensor on a distal portion of the aspiration catheter (including two electrode pairs, wherein each electrode of each pair is located on opposite half-circles of the distal portion of the aspiration catheter and each pair of electrodes is rotated 90 ° relative to each other about the center of the distal portion).
Fig. 9 is an end view of an example of an elongate shaft of an aspiration catheter including a monopolar impedance sensor on an impermeable wall portion of the aspiration catheter (including a single monopolar electrode externally fitted to an impermeable wall of a closed interior region).
Fig. 10 is an end view of an example of an elongate shaft of an aspiration catheter including a bipolar impedance sensor on a wall portion of the aspiration catheter (showing a single pair of proximal electrodes externally mounted to a wall enclosing an interior region).
Fig. 11 is an end view of an example of an elongate shaft of an aspiration catheter including a monopolar impedance sensor on a wall portion of the aspiration catheter (including several monopolar electrodes mounted circumferentially and externally on a wall enclosing an interior region).
Fig. 12 is an end view of an example of an elongate shaft of an aspiration catheter including bipolar impedance sensors on a wall portion of the aspiration catheter (showing several pairs of proximal bipolar electrodes circumferentially and externally mounted on a wall enclosing an interior region).
Fig. 13 is an end view of an example of an elongate shaft of an aspiration catheter including bipolar impedance sensors on wall portions of the aspiration catheter (showing a single pair of distal bipolar electrodes positioned opposite each other, circumferentially, and externally on a wall enclosing an interior region).
Fig. 14 schematically illustrates an example of a device that includes an aspiration catheter, where aspiration is controlled at least in part by a controller that receives input from one or more sensors on a distally facing portion of the catheter and one or more sensors within a lumen of the aspiration catheter for sensing clot material at or near these regions.
Fig. 15 schematically illustrates an example of a device including a suction catheter and a shredder, both controlled by a controller that receives input from a plurality of sensors.
FIG. 16 schematically illustrates an example of an apparatus including a suction catheter and a shredder, both controlled by a controller that receives input from a plurality of sensors; the example shown in fig. 16 also includes positive and negative pressures.
Figures 17A-17E illustrate the operation of a device similar to that shown in figure 16 for removing clot material from a blood vessel with minimal blood loss.
Fig. 18A-18E illustrate the operation of a device for removing clot material from a blood vessel similar to that shown in fig. 16, the device including an aspiration catheter.
Fig. 19 is an example of a state diagram for an apparatus described herein.
Fig. 20 illustrates one example of a shredder that may be used as part of any of the devices described herein.
Fig. 21 is an example of a shredder that may be used as part of any of the devices described herein.
Fig. 22 is an example of a shredder that may be used as part of any of the devices described herein.
Fig. 23 is an example of a shredder that may be used as part of any of the devices described herein.
Fig. 24 is another example of a shredder that may be used as part of any of the devices described herein.
Fig. 25 illustrates one example of an aspiration catheter as described herein.
Fig. 26 shows an example of a method of detecting a clot material.
Fig. 27A shows one example of a device for removing clot material that includes a shredder.
Fig. 27B shows an example of a device for removing clot material, the device comprising a shredder.
Fig. 28 shows an example of a method of detecting a clot substance using an optical sensor.
Fig. 29A-29B illustrate examples of devices for removing clot material using an optical sensor to detect the clot material. Fig. 29A shows a cross section through the distal region of the device. Fig. 29B shows a longitudinal section through the device.
Fig. 30A-30C illustrate a method of operating a device for removing clot material using an optical sensor.
Fig. 31A-31B illustrate examples of devices for removing clot material. Fig. 31A shows a device including an optical sensor. Fig. 31B shows an apparatus including a contact sensor based on optical detection of contact.
Fig. 31C to 31D show examples of the optical sensor.
Fig. 32 schematically shows an example of an optical sensor.
Fig. 33 schematically illustrates one example of a device for removing clot material that includes an optical sensor.
Fig. 34 shows an example of a method of detecting a clot material, the method comprising detecting a contact pressure.
Fig. 35A-35B illustrate examples of devices for removing clot material. Fig. 35A shows a device including a touch sensor. FIG. 35A shows the distal region of the device; fig. 35B shows an example of the proximal region of the device.
Fig. 35C shows another example of a device for removing clot material that includes a contact sensor.
Fig. 36 schematically illustrates one example of an optical contact sensor including an emitting fiber and a sensing fiber.
Fig. 37A-37D illustrate the operation of the device for removing clot material including a contact sensor.
Fig. 38A-38B illustrate examples of extraction inlets of a device that includes a sensor for detecting a substance entering an extraction chamber region of the device.
39A-39E illustrate a method of distinguishing clot material from a vascular lumen using a device as described herein.
Fig. 40 illustrates an example of a method of using suction to detect clot material and confirm that the clot material is extracted into the extraction chamber of the device.
Fig. 41 shows an example of a thrombectomy device that detects clot material within an extraction chamber region of the device to control operation of the device.
Fig. 42 illustrates another example of a thrombectomy device configured to detect substances within an extraction chamber (e.g., using aspiration) by monitoring a chopper and/or pressure within the extraction chamber.
Fig. 43 schematically illustrates an example of a shredder as described herein.
Fig. 44 illustrates an example of a method of controlling clot removal using a device configured to detect opening of a hole through a cover overlying an extraction chamber.
Fig. 45 schematically illustrates one example of a thrombectomy device configured to detect clot material and distinguish clot material from wall material, the thrombectomy device including a sensor for sensing the opening of a hole in a clot extraction region leading to the device.
Fig. 46A-46B illustrate operation of a thrombectomy device configured to detect opening of a hole into an extraction chamber.
Fig. 47 shows one example of a thrombectomy device as described herein.
Fig. 48A-48C illustrate examples of a thrombectomy device including an occlusion sensor configured as a deflectable member as described herein. FIGS. 48B-48C show the device with clot in the extraction chamber of the device.
Fig. 49 illustrates one example of a device (e.g., a thrombectomy device) that includes a suction catheter configured to include a plurality of deflectable members and a chopper.
Fig. 50 illustrates an example of a device (e.g., a thrombectomy device) that includes an aspiration catheter that includes a plurality of deflectable members and a chopper.
Fig. 51A schematically illustrates an example of a deflection sensing circuit for a deflectable member.
Fig. 51B schematically illustrates an example of a deflection sensing circuit for a deflectable member.
Fig. 52 is a graph illustrating different scenarios regarding the operation of a device using a deflectable member as an occlusion sensor as described herein.
Fig. 53 illustrates an example of a method of controlling clot removal using a device comprising one or more deflectable members as described herein.
54A-54C illustrate examples of deflectable members configured as spring elements that extend longitudinally (axially) within the aspiration lumen to detect clot material. Fig. 54A shows the deflectable member in a first (undeflected) configuration, while fig. 54B shows the deflectable member in a second (deflected) configuration, such as when clot material is trapped within the distal region of the aspiration lumen. Fig. 54C shows an example of a graph showing a change in electrical characteristics of a deflectable member in a deflected configuration.
Fig. 55 schematically illustrates an example of a deflectable member configured as an optical shape sensing bending sensor (shape-sensing bend sensor).
Fig. 56 schematically illustrates an example of a deflectable member configured as a resistive sensor, wherein the resistance varies as the deflectable member bends.
Fig. 57 schematically illustrates an example of a suction catheter including a deflectable member and a detection sensor (circuit) as described herein.
Fig. 58A schematically illustrates an example of a suction catheter including a universal impedance sensor similar to that described above.
Fig. 58B schematically illustrates an example of a suction catheter including a variation of an impedance sensor.
Fig. 58C schematically illustrates an example of a suction catheter including a second variation of the impedance sensor.
Fig. 59A-59B illustrate one example of an aspiration catheter device as described herein that includes a sensor (e.g., an impedance sensor) within a lumen to detect and/or track clot material within the lumen. Fig. 59B shows a cross section through the distal region of the catheter.
Fig. 60 schematically illustrates an example of an aspiration catheter including an internal distal electrical (e.g., impedance) sensor.
Fig. 61 schematically illustrates an example of a pair of ring electrodes that may be used as internal electrodes of any of the electrical sensors described herein.
Fig. 62 schematically illustrates an example of an aspiration catheter including an internal distal electrical (e.g., impedance) sensor and an internal proximal electrical (e.g., impedance) sensor, and is not drawn to scale.
Fig. 63A schematically shows an example of a pair of annular ring electrodes similar to the pair of ring electrodes of fig. 61.
Fig. 63B schematically illustrates an example of a pair of ring electrodes that extend only partially around a ring of the lumen of the aspiration catheter.
Fig. 63C schematically illustrates an example of a pair of spiral electrodes that may be functionally equivalent to the ring electrodes shown in fig. 63A-63B.
Fig. 64 is a graph showing impedance data over time according to operation of an aspiration catheter including an electrical sensor at a distal end of the catheter and an electrical sensor at a proximal end of the catheter as the aspiration catheter removes clot material.
Fig. 65 schematically illustrates an example of a device for sensing clot material, the device including a catheter (not shown to scale) having a suction lumen and an internal electrical impedance sensor, and a pair of impedance sensors at a distal suction opening.
Fig. 66 is a graph showing the change in impedance signal over time for each of three sets of internal impedance sensors (e.g., electrode pairs) within a lumen of a device such as the device shown in fig. 65.
Fig. 67 is a schematic example of a device including a suction opening sensor having two electrodes positioned at the edge of the suction opening of the suction catheter.
Fig. 68 schematically illustrates an example of a device that includes a suction opening sensor (having two electrodes positioned at the edges of the suction opening) and a set of internal impedance sensors that are slightly proximal to the suction opening sensor within the suction lumen.
Fig. 69A is an example of a schematic circuit of the impedance sensor.
Fig. 69B shows a trace of an example alternating current that may be applied for sensing impedance.
Fig. 70 schematically illustrates an example of an apparatus including a suction opening sensor including piezoelectric transducers (e.g., shown as a pair of piezoelectric transducers).
Fig. 71 schematically illustrates an example of a device including a suction opening sensor including an optical sensor as described herein.
Fig. 72 schematically illustrates an example of a device including a suction opening sensor including an electromagnetic sensor as described herein.
Fig. 73 schematically shows an example of a device comprising a suction opening sensor comprising an inductive sensor.
Fig. 74 schematically illustrates an example of a device including a suction opening sensor including a thermal sensor.
Fig. 75 schematically shows an example of a device comprising a suction opening sensor comprising a mechanical sensor.
Fig. 76 shows an example of a quaternary detector including four electrodes (two electrode pairs) spaced a predetermined distance apart within the aspiration lumen of the catheter described herein.
Fig. 77A-77C illustrate examples of impedance signals measured using a suction opening sensor of a first configuration that includes a pair of electrodes that measure electrical impedance at different frequencies when force is applied (e.g., by applying suction) to different substances (e.g., vena cava/wall or clot substances). In fig. 77A, the percent change in impedance versus blood impedance is shown for the vena cava/wall (left side in each pair of each frequency) and clot (right side in each pair of each frequency). Fig. 77B-77C show the impedance of the aspiration opening sensor with respect to blood (left), vena cava/wall (middle) or clot material (right) at different frequencies (120 Hz, 1kHz, 10kHz, 100kHz and 1 MHz) under different conditions.
Fig. 79A and 79B show examples of the internal impedance sensor.
FIG. 80 is an example of an internal impedance sensor with an inner loop.
Fig. 81A and 81B are examples of internal impedance sensors configured as quad detectors.
Fig. 82 illustrates one example of estimating clot volume using impedance measurements made according to various configurations of internal impedance sensors (similar to the internal impedance sensors shown in fig. 79A-79B, 80, and 81A-81B).
Fig. 83 is a graph showing impedance measurements over time from various internal impedance sensors that track clot material moving through the aspiration lumen of the device, wherein the clot material remains together.
FIG. 84 is a graph showing impedance measurements over time from various internal impedance sensors tracking clot material moving through the aspiration lumen of the device, wherein the clot material breaks as it moves through the aspiration lumen.
Fig. 85 illustrates one example of a device for aspirating substances, identifying/detecting substances at the aspiration opening, and tracking substances within the aspiration lumen of the device.
Detailed Description
Generally, methods and devices for removing clot material from a blood vessel are described herein. These methods and devices may be particularly suited for removing clot material while minimizing blood loss. These methods and devices may be used to track clots within and/or removed by an aspiration catheter, including, but not limited to, confirming that a clot has been removed, quantifying the amount of clot removed, estimating and/or quantifying the rate of clot removal, and/or determining and identifying a blockage of an aspiration catheter. In addition, these methods and devices may allow for more precise control of the aspiration and/or shredding of the clot and may aid in the automatic (or semi-automatic) removal of the clot.
Any of the methods and devices described herein may use one or more sensing modalities to detect the presence of and/or to detect the proximity of a clot material, and in particular to detect the presence and/or proximity of a clot material relative to a distal opening of and within an aspiration catheter. The methods and devices may use any suitable type (e.g., mode) of sensor, including, for example, electrical characteristics (e.g., impedance, e.g., bioimpedance spectroscopy, etc.), light (e.g., color), and/or ultrasound. Other types of sensors may also be used. One or more sensors may be positioned at the distal end (e.g., distal face) of the catheter, and/or may be present within the lumen of the aspiration catheter, and/or on the chopper. In some examples, the sensor may be configured as a deflection sensor that mechanically senses deflection of the deflectable member due to clot material contacting the deflectable member. In some examples, the sensor may extend radially around the lumen of the aspiration catheter at least partially around the circumference (e.g., between 30-360 degrees, between 40-350 degrees, between 60-350 degrees, between 90-360 degrees, between 45-360 degrees, etc.).
Thus, the devices and methods described herein can assist a user (e.g., doctor, surgeon, nurse, technician, etc.) in locating and engaging a thrombus to prevent unnecessary aspiration of whole blood or surrounding structures, such as a vessel wall or valve. These devices may provide improved spatial perception of the distal end of the aspiration catheter and/or other areas of the aspiration catheter or aspiration catheter lumen. Better spatial perception of the treatment site at the distal end of the aspiration catheter may be advantageous during thrombectomy procedures, for example, because it allows the user to establish proper engagement with the clot material before starting aspiration, while performing aspiration, and at the end of aspiration, thereby reducing blood loss during the procedure.
The devices described herein may generally include an aspiration catheter, which may include one or more sensors on the distal end of the aspiration catheter, and may include or may be used with an aspiration source (negative pressure). The device may also include an aspiration regulator as part of the controller or separate from the controller, which may include a valve for adjusting the aspiration source. In some examples, the apparatus may further comprise a positive pressure source, and the controller may further regulate operation of the positive pressure source.
For example, fig. 1A schematically illustrates one example of a device including an aspiration catheter 103 as described herein. Fig. 1A includes an elongated and flexible suction catheter 103 (not shown to scale). The aspiration catheter may be formed of any suitable material and may include a central (aspiration) lumen and a distal opening. The aspiration catheter may be formed of any suitable material. One or more (e.g., two are shown in fig. 1A) sensors 105, 105' are included at the distal end face of the aspiration catheter. The sensors are coupled to the controller 104, and the controller 104 can receive and process data from the sensors. One or more sensors (internal sensors or sensor groups) 106 may also be present within the lumen of the distal region of the aspiration catheter and/or within the more proximal region. All sensors may provide data input to the controller 104. The connection may be routed through the aspiration catheter and may be connected to the controller via one or more connectors.
The controller may control the suction applied through the suction conduit by directly controlling the pump and/or suction reservoir 109 or by indirectly regulating the pressure from the vacuum pump and reservoir via pressure regulator 111, the pressure regulator 111 may include one or more valves, manifolds, etc. to control the pressure within the suction conduit.
Fig. 1B shows an end view of the aspiration catheter of fig. 1A showing distally facing sensors 105, 105' on the outer edge of the aspiration catheter and the aspiration lumen 120 of the catheter. In fig. 1B, a pair of internal sensors 106 from inside the lumen is shown; in practice, the sensor may be flush with the inner wall of the catheter and/or may be recessed into the catheter wall.
The controller may include control circuitry for receiving and/or processing data from the sensors and for transmitting control signals to the pump regulator 111 or the pump 109. For example, the controller may include one or more processors, timing circuits, memory, and the like. In some examples, the controller may also include one or more outputs, such as a display, speakers, and the like. The controller may be connected to a remote processor or computer (e.g., notebook, desktop, etc.) wirelessly or via a cable or wire. The controller may indicate via the output when clot material is present in front of the lumen of the aspiration catheter or when in the lumen and/or when aspiration is being applied.
Any of these devices may include a chopper to help break up clot material for easier removal from the blood vessel (and through the lumen of the aspiration catheter). For example, fig. 1C and 1D schematically illustrate examples of devices that include a shredder 129, which shredder 129 can be positioned (including removably and/or adjustably positioned) within the lumen of the aspiration catheter 103, as shown. The device shown in fig. 1C is configured as a system that also includes a controller 104, the controller 104 receiving inputs from sensors 105, 105' at the distal face of the aspiration catheter and sensor 106 within the catheter. As shown in fig. 1C, the second set of sensors shown may also include one or more sensors 143 on the shredder 129. In fig. 1C, the shredder includes one or more windows through the elongate and flexible shredder body that expose the cutting members 133 (shown as rotating threads in fig. 1C). Any suitable cutting member may be used, including wires, blades, and the like. The shredder may be actuated by a drive 131 (shredder driver), which drive 131 rotates a flexible drive shaft 133 (shredder drive shaft). As will be described in more detail below, the controller 104 may control actuation of the shredder in addition to or instead of controlling suction through the suction catheter.
Fig. 1D shows a distal view of the aspiration catheter of fig. 1C. As in fig. 1B, the catheter may include one or more distally facing sensors (e.g., impedance electrodes in some examples). In fig. 1D, the chopper 129 is shown in the aspiration lumen. In this example, the sensor within the lumen is located at or near the distal portion. Fig. 1A-1D illustrate examples of aspiration catheters that include a sensor. Different types, sizes and sensitivities of sensors may be used.
Fig. 2 shows a schematic view of the distal region of the aspiration catheter. In fig. 2, the distal face of the catheter is covered by a membrane (e.g., a flexible and deformable polymer (e.g., silicone) cover 2). The sensors 5 in this example and in fig. 3-12 show the position and orientation of these sensors on the aspiration catheter. The suction catheter comprises an inner wall (not visible) and an outer wall 4. The flexible covering may comprise a small opening 3, which small opening 3 may be enlarged to allow the passage of clot material. In fig. 2, a pair of sensors 5 is included, and the pair of sensors 5 may provide input continuously or discretely.
Fig. 3-13 illustrate an alternative example of a distal end of an aspiration catheter that includes a sensor disposed on an outer surface (including a distally facing end) and a lumen. In all of the figures 3-13, the distal end of the aspiration catheter includes a cover 2, which cover 2 may be impermeable to blood, but may include an opening 3 (e.g., hole, slit, etc.), which opening 3 may expand when a clot is drawn into the lumen as a result of aspiration. This may limit the flow of lost blood into the aspiration catheter before and during aspiration when clot material is detected, as will be described in more detail below. In fig. 3, a single sensor 1 is shown. This example may be, for example, a monopolar bioimpedance sensor. Fig. 4 shows an example in which a bipolar bio-impedance sensor 8 is included on the distal face of the cover. In fig. 5, a plurality of sensors (e.g., eight sensors are shown in this example) are arranged around the cover, equidistantly spaced. In fig. 5, the sensor 1 is shown as a monopolar bioimpedance sensor (although other types of sensors may be used), whereas in fig. 6 the sensor 8 is a bipolar bioimpedance sensor. In fig. 7, a pair of radially spaced apart electrodes 8 (forming a larger bipolar bio-impedance sensor) is shown. Fig. 8 shows two pairs of radially spaced bipolar bio-impedance sensors 8 (opposing electrodes or adjacent electrodes may be used as bipolar pairs, or mating electrodes (partner electrodes) may be switched between these pairs).
Fig. 9-13 illustrate examples in which the distal region of the aspiration catheter includes one or more sensors within the lumen of the distal region of the aspiration catheter. In fig. 9, a single sensor 1 is shown within the lumen of a catheter. The sensor may be electrical (e.g., a bioimpedance sensor, which may be monopolar or bipolar). For example, fig. 10 shows an example of forming a bipolar electrode pair of the bio-impedance sensor 8 within a lumen of a distal end of an aspiration catheter. Fig. 11 shows an example of an aspiration catheter in which an annular ring (annual ring) of a sensor is disposed within the lumen of the distal end of the aspiration catheter, on the side wall of the lumen. One or more annular rings (longitudinal arrangements) of the sensor may be continuous or discrete; for example, the annular rings of electrodes may be electrically connected to each other to form a single electrical sensor having multiple contact points, as shown in fig. 11 and 12. These sensors may be monopolar bioimpedance sensors or bipolar bioimpedance sensors 8 as shown in fig. 12, for example. Fig. 13 shows an example in which a bipolar bio-impedance sensor is arranged, wherein two electrodes are arranged on opposite sides of the lumen of the aspiration catheter.
For simplicity, fig. 9-13 show examples where only a few sensors are shown, which are disposed within the distal region of the aspiration catheter. In some examples, a plurality of sensors may be disposed extending proximally along the length of the lumen, allowing for tracking of the clot material as it passes through the lumen.
Although fig. 9-13 only show the sensor within the lumen of the distal end of the aspiration catheter, in any of these embodiments, one or more sensors, including a bioimpedance sensor, may be positioned on the distal-facing end of the aspiration catheter (as shown in fig. 3-8). In some of these examples, one or more sensors for detecting clot material may be positioned proximally along the lateral length of the exterior of the distal end of the aspiration catheter, which may be used to indicate when clot material is to the lateral side of the aspiration catheter.
As mentioned, any suitable sensor may be used, including but not limited to impedance (e.g., bioimpedance) sensors. 2013 Lei et al describe one example of a bio-impedance sensor (e.g., electrode) that may be used with the methods and apparatus described herein. For example, for a bipolar configuration, the bio-impedance sensor may have an electrode spacing of about 1.8mm, and a titanium-aluminum alloy structure with a 1mm PDMS coating is associated with all of the impedance values and thresholds mentioned herein. Other bio-impedance sensors may be used in any of the methods and devices described herein.
As mentioned, the device may include an aspiration catheter having an elongate shaft including a lumen, a negative pressure source configured to fluidly couple the lumen of the aspiration catheter, and a controller. The elongate shaft may be flexible and may include a proximal portion configured to be positioned extracorporeal during treatment and a distal portion configured to be positioned intravascularly proximate to a clot material at a treatment site within a vascular lumen (e.g., a lumen of a pulmonary or other blood vessel). The aspiration catheter may include one or more sensors ("sensing devices") configured to sense and/or detect clot material. The sensor may be electrically coupled to the controller such that measurements obtained by the sensor may be processed by the controller. In some examples, the controller may be coupled to a negative pressure source and/or a connection between the negative pressure source (e.g., a pressure regulator) and the shaft of the aspiration catheter such that the controller may control the timing of aspiration applied through the shaft (and in some cases, the aspiration level).
Returning to fig. 1A, the sensor can include a plurality of sensing elements (in some examples electrodes, ultrasonic transducers, optical fibers, etc.) at a distal end region of the elongate shaft. The sensing element may be, for example, one or more electrodes. Any number of sensing elements (e.g., one, two, three, four, etc.) or composite sensing elements (e.g., electrode pairs) may be used. The sensing element can be positioned at the distal end portion of the elongate shaft such that the sensing element can enter the distal space of the elongate shaft unobstructed and can therefore contact and/or accurately sense clot material disposed in a lumen of a blood vessel distal of the shaft, including in contact with or near the distal end of the shaft (e.g., within 1mm, within 2mm, within 3mm, within 4mm, within 5mm, within 6mm, within 7mm, within 8mm, within 9mm, within 1cm, etc.). For example, as shown in the end view of fig. 1B, the sensing element can be positioned at a distally facing portion of a tubular sidewall of an elongate shaft forming the aspiration catheter. This may be true in both aspiration catheters that include a distal covering (e.g., an elastically deformable covering) and aspiration catheters that do not have a distal covering. In those examples where the system includes a distal cover (e.g., as shown in fig. 2), the sensing element may be positioned anywhere along the surface of the cover. The sensing element can be configured to sense the proximity of the tip of the elongate shaft of the aspiration catheter to clot material (e.g., thrombus, emboli (embolus), etc.) in a blood vessel, which can be used in conjunction with existing positioning systems and methods (e.g., fluoroscopy), and to manually or automatically control aspiration (aspiration) through the aspiration catheter. This may help reduce the amount of blood pumped during clot removal. The sensing mechanism may provide signals and indications that enable a user to discern clot material, whole blood, vessel walls, and other surrounding structures in the treatment zone. In some examples, the device may initially achieve partial engagement with the clot material. The sensor may be a sensor array that may include several electrodes (e.g., impedance sensors) or optical sensors circumferentially arranged around the distal face leading to a funnel-shaped or tubular opening in the aspiration catheter to provide point measurements of proximity to the clot material (and in some cases the lumen wall) and enable the physician to orient the device within the blood vessel to more fully engage the clot material. In some examples, the distal end of the aspiration catheter (e.g., a cylindrical or funnel-shaped opening) may include one or more ultrasound transducers; the ultrasound transducer may be positioned to achieve spatial perception of the end of the aspiration catheter.
The schematic diagrams shown in fig. 1A and 1C illustrate only one general configuration of a few examples of the devices described herein. The sensors shown in these examples, as well as the examples shown in fig. 2-13, are shown as electrical (e.g., impedance) sensors, however similar configurations and/or positioning may be used for other sensor types (or combinations of sensor types), including ultrasonic sensors and/or optical sensors. In some examples, the sensor may be an impedance sensing element that includes two electrodes electrically connected to a controller and/or other signal processing or power components (including sensing, signal processing, and control units) in a dipole configuration.
Optionally, the controller can be connected to one or more valves that regulate a path between the elongate shaft and the suction source (e.g., vacuum chamber) and/or, in some examples, the positive pressure source (e.g., pressure chamber). Alternatively, the controller may be directly connected to the suction source and/or the positive pressure source. For example, the controller may control the action of the suction source (on/off, pumping rate, etc.) without requiring an additional valve between the pump (suction source and/or positive pressure source) and the suction catheter.
Thus, in operation, the aspiration catheter may detect when the distal tip is in blood or near or in contact with clot material by one or more distally facing sensors (e.g., on the distal end of the aspiration catheter). For example, when these sensors are in contact with blood, when bioimpedance sensors are used, the alternating current through the blood between the sensing electrode pairs may experience a relatively low impedance, typically across the entire spectrum. The relatively low impedance may be processed and classified in a sensing and signal processing unit within the controller. If the impedance is low enough to statistically infer that there is no thrombus near the distal opening into the aspiration catheter, the control unit may keep the aspiration "off" or at a low level by directly controlling the negative pressure source or by regulating the valve (in or kept off state) so that the negative pressure is not transferred (or increased) to the aspiration catheter opening, thereby preventing or limiting aspiration of blood therein. As the clot material approaches the electrodes of the bioimpedance sensor, the impedance may increase and converge to a range of values indicative of the characteristic impedance (or impedance spectrum) of the clot material. The controller may distinguish a value indicative of a clot from a value indicative of a vessel wall or other structure that is not a clot material. Once the clot material is fully engaged with the sensor (and thus with the distal end of the aspiration catheter), the controller can turn on (or otherwise increase) the aspiration upon verifying that the sensor data indicates clot material. For example, in some cases (depending on the configuration of the bioimpedance sensor), impedance values of approximately 1000000 ohms and above 1000000 ohms may indicate to the controller that clot material is near and/or in contact with the distal end of the aspiration catheter. The controller may increase or turn on suction through the suction catheter. In some examples, once the thrombus is in sufficient contact with the sensor and the distal end of the aspiration catheter to aspirate the clot material, the system can initiate or increase the vacuum pressure. As the clot material is aspirated, the impedance may remain above the threshold until the clot material is all aspirated from the front of the aspiration catheter. Importantly, the suction of the clot material can be configured and tracked using a sensor within the lumen of the suction catheter.
The use of one or more sensors to detect clots within the lumen of the aspiration catheter has an unexpected effect in regulating aspiration and action of the aspiration catheter without relying on or requiring pressure or flow sensing. Although pressure and/or flow sensing may be used within the aspiration catheter, the use of one or more sensors that directly detect clot material is more robust and reliable for controlling negative pressure, and for controlling disruption of clot material within the lumen of the aspiration catheter by controlling shredding within the lumen of the aspiration catheter, as will be described in more detail below.
In some examples, the controller may continue to remain aspirated (e.g., in an open state or in a higher state) until clot material has been completely aspirated into the aspiration catheter, and until a sensor within the lumen of the aspiration catheter indicates that clot material has been removed from the distal region of the aspiration catheter. Once the clot material is removed, such as when using a bioimpedance sensor, the sensed impedance (or impedance spectrum) will drop back to a range of impedance values consistent with blood alone (e.g., less than 10000 ohms in some examples, depending on frequency), and the controller will shut down or reduce aspiration through the aspiration catheter (e.g., set one or more valves of the aspiration regulator to a closed state, shut down the aspiration pump, etc.).
In some examples, the suction regulator and/or suction source (e.g., pump) may be configured such that the standby/unpowered state is an off state to prevent unsafe, adverse suction in the event of sensor damage or contamination. For example, the valve in the suction regulator or suction source may be a normally closed solenoid. Anomaly detection (as known in the art) may be implemented in the controller to prevent accidental and/or undesired application of suction in the absence of clot material. In general, the controller may include sensing and signal processing for robustly confirming the presence of clot material from the sensor data.
When the apparatus comprises bio-impedance sensors, these sensors may be configured to comprise bipolar or monopolar electrodes. Monopolar electrodes and bipolar electrodes may be used almost equivalently, however in a monopolar configuration, each electrode may represent a separate signal, and the controller may combine these additional signals. The respective sensing ranges may be different for these electrodes. In any of these devices, the sensors may be distributed at appropriate locations (e.g., along the distal portion of the aspiration catheter), and data (e.g., impedance values of the bioimpedance sensor) may be provided for individual locations in order to provide spatial information about the clot material relative to the opening into the aspiration catheter. This information may be processed by the controller to further threshold the timing and/or level of applied attraction. In some examples, the controller may establish impedance thresholds for multiple (e.g., n) dimensions based on the number of available impedance sensors (monopolar or bipolar). This multiple signal configuration may be processed in the controller and output to an external display for providing additional spatial information to the physician regarding the medium near the distal end of the aspiration catheter.
Generally, as described above, the device may provide output to the user based on the aspiration, including a visual display (e.g., video), a numerical value (e.g., some indication of impedance at the distal end and/or within the aspiration catheter), and so forth.
For example, the device may include a bioimpedance sensor that operates as an dipole pair, located on a surface of the aspiration catheter (e.g., a distally facing surface and/or distal membrane). For example, in fig. 2, the dipole pair of the sensor may comprise two separate dipole electrodes 5 located on opposite halves of the distal membrane 2, which operate as one dipole pair. In a dipole configuration, AC current passes through local tissue surrounding the distal membrane and between the two electrodes. The effective resistance of tissue in direct contact with the electrode is the impedance of the tissue. Different tissue types exhibit different impedance characteristics. The impedance indicated in real time may be used to determine the type of tissue surrounding the distal face of the thrombectomy device and may be used to guide the user to the clot material once substantial access is established by non-invasive navigation (e.g., x-ray fluoroscopy). In this example, when the distal end of the aspiration catheter (e.g., the distal membrane cover in some examples) is in contact with only blood (e.g., whole blood, without substantial amounts of clot material) and the clot material is not nearby, the impedance detected by the bipolar impedance sensor may be the effective resistance of the blood as current passes through the blood. The volumetric sensitivity of the impedance measurement will be a function of the square of the current density in a given tissue volume, and the current arc in a dual electrode sensor can span a larger whole blood volume than the clot material. Thus, when a user guides an aspiration catheter to a clot material (e.g., using fluoroscopy or other guidance techniques), the impedance measurement may show a measurable increase in effective resistance despite the lack of contact with the clot material. Thus, in addition to contact with the clot material, the bioimpedance sensor may establish proximity to the clot material. In blood, at frequencies above 1kHz, the impedance sensor may always indicate an impedance value below 10000 ohms, whereas the clot material will return a value above 1000000 ohms. Note that the actual values of the impedance of the blood and/or clot and/or lumen wall may vary depending on the composition of the sensor (e.g., electrode material, etc.), however the relative differences and discrimination between these substances (blood, clot material, lumen wall, etc.) may remain. The difference between the impedance of the whole blood and the clot material may differ on average by about two orders of magnitude, which is sufficient to determine when there is complete contact with both electrodes. Similarly, the differences between the lumen wall and the blood and between the lumen wall and the clot material may be different, particularly at different frequencies within the impedance spectrum.
In any of these methods and devices, the device may include an aspiration catheter including a funnel carried by a distal portion of the aspiration catheter. Thus, the distal region of the aspiration catheter may be funnel-shaped, or may be expanded (having an enlarged diameter) relative to a more proximal portion of the aspiration catheter. As described above, the distal face extending across the distal end of the aspiration catheter (including the funnel-shaped aspiration catheter) may be covered with an elastically deformable material. In some examples, the distal face includes a fluid impermeable material (e.g., a sheet of elastically deformable material) having a single opening and/or slit. By causing suction at the outer proximal end of the aspiration catheter, the aspiration catheter can aspirate clot material within the blood vessel and can remove them (via aspiration) through the aspiration catheter to collect them in an outer containment chamber (e.g., a vacuum chamber). Real-time radiography may be used to guide an aspiration catheter to the location of clot material within a blood vessel in order to turn on aspiration. However, radiography is not accurate enough to control the application of suction, as it may not accurately reflect proximity, and as it suffers from information loss due to dimension reduction, it may not help to distinguish non-clot material from clot material. For example, the user may appear to position the distal face of the aspiration catheter proximal to the target thrombus, whereas the distal face may be improperly engaged with the thrombus in an orthogonal plane. To accurately begin aspiration, the user should determine the proper engagement with the thrombus. To establish proper engagement, the proximity measurement must indicate that a large portion of the distal surface of the funnel is in contact with the thrombus, such that a minimum amount of blood is aspirated before the thrombus enters the catheter.
In some examples, the apparatus may include an impedance sensor configured to measure impedance to discern a medium immediately beyond a distal end of the thrombectomy device. Each cell and tissue type in the body exhibits unique impedance and conductance characteristics. When a clot is formed in blood, normally conductive plasma is trapped in the fibrin network, which provides clot cohesiveness and thus the plasma is transformed from a conductive liquid to an insulating substance. Experimental results show that the impedance between whole blood and clotted blood increases significantly and that this impedance difference can be used to distinguish between thrombus at the treatment site and whole blood. The use of an impedance sensor placed at the distal end of the aspiration catheter and/or within the lumen of the aspiration catheter may allow the user to distinguish between engagement with blood and engagement with thrombus and allow for accurate tracking of removal of thrombus material, for example by relying on impedance alone, which eliminates the need to aspirate blood prior to identifying the state of the catheter engaged with clot material.
In some examples, the apparatus may include an ultrasonic sensor configured to obtain ultrasonic measurements to distinguish between clot material and blood at the distal end of the aspiration catheter. The clot material, blood and vessel wall tissue densities measurably vary, in part because the number of cells stored per unit volume varies for each tissue type, which may be determined by the structure of the cells and the manner in which they are bound together. Blood, as a heterogeneous mixture of cells and liquid, behaves like a low density fluid. However, clot material and vessel walls have a higher modulus cellular structure that is more compact and allows more cells to be present in the unit space therein. Ultrasound can use cell density to distinguish tissue types. Thus, any of these means may comprise one or more ultrasound sensors, for example at the distal end of the thrombectomy device, to identify clot material, blood and vessel walls. In some examples, the sensor on the distal end of the catheter includes one or more ultrasonic sensors, while the sensor within the lumen is a bioimpedance sensor (and in some examples, simply a bioimpedance sensor). The ultrasonic sensor may be used to detect engagement with the clot material prior to activating suction.
Alternatively or additionally, one or more optical sensors may be used, e.g. to obtain one or more optical measurements. For example, optical measurements may be obtained from the distal end of the aspiration catheter to distinguish between clot material, blood and vessel walls, for example, by processing light reflection and absorption characteristics (and comparing with known characteristics of each tissue). Blood, clot material and vessel wall tissue typically have significantly different optical qualities. This may be due to the difference in cellular structure, tissue and tissue cohesion for each material type. The light emitter and light detector, such as a photosensor, may be coupled to a detection/emission sensor on the distal end of the aspiration catheter. In some examples, the optical component may include a fiber optic material extending to the distal end of the aspiration catheter for emitting and/or detecting an optical signal. Such signals may be processed by the controller and the sensed signals may be used to distinguish between thrombus and surrounding medium without first causing aspiration. Optical sensing may also enable the user to establish proper engagement with the clot material prior to activating aspiration.
In any of these methods and devices, the device can include a controller (which can be configured to detect proximity to clot material), an aspiration catheter, a mounting surface (e.g., on the aspiration catheter), one or more electrodes, an oscillating voltage source, and a data processing unit. The voltage source and/or the data processing unit may be part of the controller or coupled to the controller.
Fig. 14-16 schematically illustrate examples of devices for controlling the operation of an aspiration catheter as described herein, which are similar to the examples shown in fig. 1A and 1C. In all of these examples, the device includes an elongate aspiration catheter 22, the elongate aspiration catheter 22 including one or more sensors 6 on a distal-facing end 31 of the aspiration catheter for sensing a clot. The sensor provides data to the controller 7. The controller may include one or more processors and processing hardware, software, and/or firmware for processing and analyzing sensor data received from the sensors. The controller may also control the suction regulator 13 that regulates suction from the suction source 14 (or in some examples, may directly control the suction source 14). The suction catheter may be connected to a suction source and/or suction regulator via one or more tubes 15.
For example, in fig. 14, the device includes an aspiration catheter 2, the aspiration catheter 2 having one or more clot sensors 6 disposed outside of the distal end 31. Any of these devices may also or alternatively include one or more clot sensors disposed within the lumen of the catheter, for example, at a known distance d from the distal end of the catheter (not shown in fig. 14).
These devices can be used to remove large or small clots, including clots that are less than length d when drawn into the catheter lumen. When a small clot is engaged at the distal end, one or more clot sensors 6 can be activated to indicate the presence of a clot. Because the diameter of the small clot may be less than or equal to the diameter of the catheter 2, not all clot sensors 6 for establishing proper engagement prior to aspiration may be activated, although sufficient conditions to aspirate the small clot are met. In this case, the controller may determine that aspiration should begin or increase in intensity based on determining from the sensor data that the signal is continuous over time (not an artifact) and consistent with the clot material. Alternatively, the user may decide to manually initiate aspiration by sending an override command signal (override command signal) to the controller.
Thus, any of these devices may include a user interface that includes one or more inputs (buttons, touch screens, knobs, dials, pedals, etc.) to allow a user to control and interact with the device, including the system. The user interface may be part of the controller 7 or may be separate from and coupled to the controller. For example, fig. 15 shows an example including the external unit 33. The external unit (or external interface unit) may include user controls such as, but not limited to, a suction on (e.g., valve open) override input (e.g., button) and a suction off (e.g., valve closed) override input (e.g., button) that may enable a user to manually override application of a control signal to initiate suction regardless of the indication of insufficient engagement or to cease suction regardless of the indication of sufficient engagement with the clot. Other user inputs may be included as part of the controller and/or external unit. For example, the user input may allow for operation of the control device, including level of attraction, turning on/off the shredder, etc.
Any of the devices described herein may also comprise a power supply control circuit 19 integrated into the control unit 7. The power control circuit may receive power from a wall power cord (e.g., plug) and/or may include a battery. The power control circuit may provide power to the controller and, in some cases, to the pressure source (e.g., pump and/or suction regulator) and the drive unit (e.g., motor) for driving the shredding. The power supply may be part of the controller and/or may be controlled by the controller.
The example apparatus illustrated in fig. 15 also includes a shredder assembly including a cutting member 12 and a shredder drive shaft 11 and a shredder driver 10. The shredder assembly may also be controlled by the controller 7 (and coupled to the controller 7). Any of the devices described herein may include a shredder assembly and may be configured to be controlled by a controller using sensor data from the sensor 6, the sensor 6 including sensors 6", 6'" within the lumen of the aspiration catheter 22.
In operation, in some examples, a small clot may be near, but not engaged with, the distal end 31 of the catheter 22. The (optional) external clot sensor 6 can indicate an approach signal that rises slightly in a manner characterized as approaching a clot due to the presence of clot material (e.g., when examining impedance or impedance spectra, including changes in impedance over time, the biological impedance can rise above the level of the wall and/or blood). In the engaged state, the distal end of the catheter may be in contact with the clot material such that the clot material (even small clots) is within, for example, half the diameter of the distal end of the aspiration catheter and aligned with the opening of the aspiration catheter. In some cases, the small clot may drift such that it remains near the distal end of the aspiration catheter in the engaged state, but is in substantially closer contact with a portion of the distal end than uniformly in contact with the entire distal end as described above. In some examples, the system may wait until the clot material is aligned with the distal opening of the catheter, and then the controller triggers the application of suction, which may help prevent fragmentation, slicing, or ejection of the clot in the treatment region. Alternatively, in some examples, the controller may be configured to apply an initial higher level of suction in order to center and position the clot. During improper engagement or partial engagement of clot material (e.g., when contacting a small clot), one or more sensors closest to the location of the small clot relative to the distal end of the catheter may indicate a measurably higher proximity signal to the controller than the proximity signal of more distant or other peripheral (forward looking) sensors, remaining sensors that do not contact or are not in close proximity to the small clot off-center ("misaligned"). In some cases, multiple sensors and/or additional sensing such as x-ray fluoroscopy may supplement the proximity sensor signals in order to guide repositioning of the distal end of the catheter relative to the clot material.
The example shown in fig. 16 shows a device similar to that shown in fig. 15, which also includes a positive pressure source 18, such as a pump. The controller 7 may directly control the positive pressure source 18, or the controller may indirectly control the positive pressure source by controlling the pressure regulator 13 for positive pressure. In fig. 16, two different pressure regulators (e.g., including valves, exhaust ports, manifolds, etc.) are shown; in some examples, the same pressure regulator may be used to control both negative and positive pressures. Both the negative pressure (e.g., suction) source 14 and the positive pressure source 18 may each include one or more sensors (e.g., pressure sensors 26, 26') for monitoring pressure from or within the device. The controller may receive data from these sensors and may adjust the pressure accordingly (including on/off, up/down adjustments). In some examples, the controller may adjust the final pressure or rate of pressure change by directly adjusting the negative pressure source and/or the positive pressure source and/or by controlling one or more pressure regulators 13.
For example, when suction is applied through the suction catheter, the controller may regulate the amount of suction (and in some cases regulate the positive pressure). When the suction regulator 13 is used instead of directly adjusting the suction source, the controller may hold the valve in an open state so that the suction source is in fluid communication with the suction catheter. When suction is applied through the suction catheter (during aspiration), the clot material may be located inside the catheter. In some examples, the controller may continuously monitor the reported vacuum source status and pressure source status in order to verify successful execution of the open and close commands. If the sensed state or states are inconsistent with the internal recorded state of the controller, an error may be generated and the device may temporarily cease applying vacuum (and/or trigger a reminder) as a safety measure. In some examples, the vacuum and pressure sources ("reservoirs" or pumps) may include a purge valve (purge valve) controllable by the controller such that during a device error, the controller may automatically (or a user may manually) execute a purge command (e.g., a user may trigger a button provided on an external unit) to actuate a purge valve provided for the vacuum and/or pressure reservoirs.
As described above, the aspiration catheter may include a clot access sensor disposed outside the distal end of the aspiration catheter and a clot detection sensor within the lumen of the aspiration catheter. In operation, these devices may detect that a clot is ingested (including complete ingestion) when a distally facing clot sensor no longer detects a clot. If the internal clot sensor within the lumen of the aspiration catheter still detects clot material, the clot has not been completely ingested and removed and the aspiration can remain open. The shredder may also remain open. Once the clot is no longer detected outside of the aspiration catheter or within the lumen of the aspiration catheter, the controller may close the aspiration until additional clot material is detected. In either of these cases, the device may cause the attraction to be on (and in some cases off), but may require manual input (e.g., via an input such as a switch, toggle, foot pedal, etc.) to turn the attraction on (or off). In some cases, the device may allow the user to select an automatic mode to automatically turn on (and/or off) the attraction based on the determination of the controller. For example, the device may include one or more distally facing external clot sensors and one or more internal clot sensors within the lumen of the aspiration catheter. The internal sensor may be, for example, at a distance d from the distal opening of the aspiration catheter. The one or more external sensors may send a baseline signal (indicating the absence of clot material) to the controller, while once clot material is fully ingested and within the distance d of the catheter opening, the one or more internal sensors will send a high proximity signal (indicating the presence of clot material) to the controller. In some examples, the proximity signal will be transmitted between the lumen of the catheter and an externally disposed sensor such that both the external sensor and the internal sensor send a high proximity signal to the controller, and the controller may jointly analyze the signals to determine the location of the clot material relative to the distal opening of the aspiration catheter. In some examples, if the controller determines that the location of the clot material inside the catheter lumen exceeds a known, predetermined distance (or is not present), and when no other clot material is detected to engage the distal opening of the aspiration catheter, the controller may send a shut-off or disconnect signal to a negative pressure source (e.g., pump) and/or aspiration regulator. The controller may also verify a successful detachment of the suction. When additional clot material engages the distal end of the aspiration catheter after aspiration of the clot material, the sequence may be repeated again until no additional clot material engages the distal end of the aspiration catheter.
The same general procedure can be performed for large and small clot materials. For example, an aspiration catheter having one or more externally distally facing clot sensors at the distal end and having one or more clot sensors disposed internally within the lumen (e.g., at a distance d from the distal end) may also control aspiration (and morcellation) based on an internal signal that senses clot material (e.g., bio-impedance, ultrasound, optics, etc. (even if no pressure or flow within the lumen is sensed)) and one or more external signals that sense a clot in contact with the distal opening. Any of these devices can determine the relative size of the clot. For example, a large clot may be defined as a clot having a length greater than or equal to d within the aspiration catheter. Because large clots may take on a narrow, elongated shape, some large clots may resemble small clots when engaged with the distal end of a catheter and interacting with a clot proximity sensor. When one or more external clot access sensors indicate a baseline access signal, the controller may detect that the large clot is fully ingested. In examples where the intraluminal includes a sensor, the controller may continue to operate the aspiration (or decrease the aspiration level, but not shut down) when the internal sensor indicates that the clot is still within the lumen of the aspiration catheter. For example, one or more external sensors may send a baseline signal interpreted by the controller to indicate that no clot is in close proximity to the distal end of the device, while one or more internal sensors send a high proximity signal to the controller indicating that a large clot is fully ingested and within the distance d of the opening of the catheter 2. In some examples, both the external sensor and the internal sensor may indicate a high proximity signal to the controller, and the controller may (using both sets of signals) determine the location of the large clot relative to the distal opening of the catheter 2 during ingestion and deliver the clot material to the collection container.
Although the devices described herein may operate without pressure sensing within the lumen of the catheter, in some examples, pressure sensors may be included. For example, one or more pressure sensors may be disposed within the aspiration catheter distal or proximal to the aspiration catheter. In this case, one or more pressure sensor signals may be sent to the controller to supplement one or more clot access sensors disposed inside or outside the aspiration catheter. The pressure indicated at the proximal end of the aspiration catheter may be approximately equal to the pressure applied by the pressure regulator or aspiration source. The pressure detected near the distal end of the aspiration catheter (e.g., within a known distance d from the distal opening) may exhibit a slightly higher level when there is no clot within the catheter, but may exhibit a higher pressure that is approximately equal to the pressure of the medium outside the distal end of the aspiration catheter when the clot material passes through or between the distal and proximal pressure sensors. The pressure signal from the end of the catheter may enable the controller to calculate a more accurate representation of the location of the clot material within the aspiration catheter, and this location may inform the pressure regulator or aspiration source in the form of a command, for example, to remain open in the event of insufficient displacement of the clot along the aspiration catheter.
As described above, in some examples, the controller may implement a method of delaying signal processing or delaying signal response in order to prevent feedback interference to the instantaneous or continuous control system. In these examples, the controller may include a known delay (represented by t 1) when the suction is stopped and/or when the suction is turned on and/or the shredding is stopped. Separate start and stop delays may be used. The controller may also introduce intentional delays before changing the speed of the shredder (e.g., turning the shredder on, turning the shredder off, increasing the shredder speed, decreasing the shredder speed, etc.). The controller may also impose intentional delays when updating the graphical user interface or external unit with status information. It may be beneficial to add an internal delay (e.g., 0.5 seconds, 1 second, 2 seconds, 3 seconds, etc., or more). For example, when the controller uses pressure-based internal sensors, changes in the intraluminal environment may initially cause pressure signal characteristics such as random noise or abnormal spikes. In this case, achieving the intentional delay may prevent the controller from reacting to a false or abnormal state by only allowing the controller to perform actions after the expected data artifact has resolved. The controller may modify the duration of the intentional delay. For example, the controller may modify the delay over time. In such examples, the controller may use continuous analysis of the data patterns and data buffering or recording to enable the controller to autonomously configure the delay duration. The controller may autonomously configure the delay duration or any other variable referred to herein by known statistical methods including, but not limited to, data signal processing, statistical analysis, thresholding, and artificial neural networks. For example, the value t 1 may be adjusted to minimize the delay t 1 while maximizing the reduction in noise and data artifacts. In some examples, the controller may control a rotating shredder drive shaft internally disposed at the distal end of the aspiration catheter and a drive motor 10 coupled to the drive shaft via an accessory to drive rotation (actuation) of the shredder. The controller may be responsible for adjusting the chopper speed by providing or denying (withholding) current to the motor and/or by applying control instructions (e.g., digital commands). In some examples, the controller may monitor fluctuations in the current drawn by the motor 10 in order to measure clot properties, including but not limited to volume, mass, density, or length. Based on such measurements, the controller may increase or decrease the speed and torque of the chopper to optimize chopping for a particular clot.
Similarly, the controller may modify the rate of the chopper based on one or more sensors within the lumen of the aspiration catheter that indicate the presence of clot material. The sensor output may be related to the integrity of the clot material, including the hardness or degree of densification of the clot material. Thus, the controller may be configured to set the speed and/or torque of the shredder based on the intensity of signals (e.g., bioimpedance, ultrasound, optics, etc.) from one or more sensors within the lumen of the aspiration catheter. In some examples, the controller may define time-dependent conditions including, but not limited to, clot-non-movement, rapid clot extraction, non-changing sensor inputs, and biased or contaminated sensor inputs, as determined by the controller continuously analyzing the sensor inputs after any change in state over a known interval t2 using any selected known analysis methods including, but not limited to, statistical inference, thresholding, signal enrichment (SIGNAL ENRICHMENT) analysis, noise detection, and data signal processing. For example, the controller may control, in part or in whole, the input to any component in electronic communication with the controller based on the time-dependent state. The activity of the adjustment components (such as valves, motors, and user interfaces) may enable the treatment of the clot according to continuously variable system properties at the distal end of the catheter. In some examples, the controller may bi-directionally communicate with all components (including, but not limited to, sensors, valves, motors, and external user interfaces) with which the controller may interface. The controller may monitor the signals generated by the interface component and may include signals acquired by monitoring the analysis and the action activation of the state change. in some examples, the controller may monitor components, peripherals, signals, or other electronic interfaces (including those not mentioned herein) such that the controller may continuously record input signals from the interface and all devices interfacing with the controller (which devices are capable of continuously self-reporting status and data signals, and may update the controller with measurement data or status at a regular, known frequency). By monitoring components (including, but not limited to, clot proximity sensors, pressure sensors, valves, external unit controls, and/or additional user interface controls), the controller can include additional information and incorporate the additional information into the control inputs for analysis, thresholding, state coordination, state verification, state change verification, emergency state override, and updating external indications of any states or measurements mentioned herein. In some examples, the vacuum and positive pressure reservoirs (e.g., pumps) may include pressure sensors disposed internally for continuously measuring and reporting the pressure within each reservoir. The controller may use pressure signals from the vacuum and pressure reservoirs, for example, to regulate the pressure (negative and/or positive) applied to the aspiration catheter, to change the valve state, to adjust the amount of time the valve remains open during aspiration, and/or to infer the pressure inside the distal portion of the aspiration catheter lumen. The controller may apply suction (e.g., by opening one or more valves) for a known time t 2 before automatically stopping suction (e.g., closing any open valves) and re-evaluating whether suction is reapplied (e.g., re-opening the valves) using any selection of available signals and status. This spacing approach may prevent contaminated sensors, dysfunctional sensors, old commands, or other errors that may occur during operation, thereby preventing valve operation. In some cases, the controller may fail to register a change in state in the system including the vascular region around the distal end of the aspiration catheter, and the interior of the distal end of the aspiration catheter of length d, which may result in adverse, unauthorized or excessive aspiration or damage to the vascular wall and components of the device. The controller may determine that the method of use and the electronic peripheral device in continuous data communication with the controller have met the necessary system conditions.
Fig. 17A-17E illustrate the operation of devices such as those schematically shown in fig. 1A, 1C, and 14-16. For example, the device shown in fig. 17A is similar to the device shown in fig. 16 and includes an aspiration catheter 22, the aspiration catheter 22 having a central lumen with an opening into the lumen at the distal end of the aspiration catheter. As described above, the aspiration catheter may include a distal cover. The device further comprises an aspiration (e.g., vacuum or negative pressure) reservoir 14 and a pressure regulator (e.g., aspiration regulator) 13 comprising one or more valves disposed between the aspiration reservoir and the central lumen of the aspiration catheter. The central lumen of the aspiration catheter is fluidly connected to the vacuum reservoir and (in this example) the pressure regulator by a connecting tube 15. One or more sensors 6 are provided on the distal end 1, and the distal end 1 may include, but is not limited to, a monopolar impedance sensor, a bipolar impedance sensor, a pressure sensor, an optical sensor, an acoustic sensor, or a force sensor. The suction reservoir may include a gas or fluid chamber and a pump for regulating the pressure within the chamber, and may be in communication with a controller (e.g., constant or periodic bi-directional reciprocal data communication). The controller, in turn, may be in communication with the attraction adjuster 13 and the remotely located sensor 6 (e.g., constant or periodic bi-directional reciprocal data communication). One or more sensors may be disposed internally within the lumen, for example, at a distal region within the aspiration catheter. In some examples, the internal sensor is separated from the suction catheter opening by a distance d. The external sensors 6 may be configured in a variety of arrangements including, but not limited to, forward and single, forward and proximal facing pairs, forward and multiple radial positioning around the catheter opening, and forward and multiple radial positioning around the distal opening, with each radial position being comprised of a proximal sensor pair as previously described. The internal sensors 6 may be configured in a variety of arrangements including, but not limited to, inward and single facing, inward and proximal facing pairs, inward and multiple radial placement around the catheter wall, and inward and multiple radial placement around the catheter wall, with each radial location consisting of a proximal sensor pair as previously described. The controller may supply power to various components of the system, including the sensors. An addressable motor chopper motor 10 is fixedly attached by a flexible drive shaft 11 with a chopper cutter 12 disposed at the distal end of the lumen. The user interface (e.g., external unit 13) may be coupled to (or part of) the controller and may include any selection of control interfaces and information displays (e.g., LED indicators, buttons, switches, and displays). The device in fig. 17A-17E further comprises a positive pressure reservoir 18 and a pressure regulator 13 for the positive pressure valve, both the positive pressure reservoir 18 and the pressure regulator 13 being in fluid communication with the lumen of the aspiration catheter through the connecting tube 15.
In fig. 17A, the device 1600 is shown within a blood vessel, such as within a pulmonary artery. The distal end of the aspiration catheter lumen is directly surrounded by blood 34. The vessel includes a large clot 13. A pair of forward facing impedance sensors 6 disposed on the distal end of the aspiration catheter are monitored by a controller 7. In this example, the sensor is configured as a bipolar bio-impedance sensor and operates by sending an electrical current 35 into the blood 14 of the blood vessel. In fig. 17A, the large clot 36 is beyond the sensing range of the clot sensor 6, so the impedance returned by the sensor approximates that of blood, and the aspiration and chopper 17 remains closed (e.g., without negative pressure through the aspiration catheter).
As the distal end of the catheter is closer to the clot 26, as shown in fig. 17B, the bioimpedance sensor 6 may detect clot material as it approaches and enters a region of relatively higher emission current 35 in close proximity to the distal end of the aspiration catheter. A large clot 36 proximal to the distal end; in this example, however, the clot material is relatively close to one of the sensors 6 in the sensor pair, indicating that the clot 36 is relatively misaligned with the aspiration catheter opening. In some examples, the controller may turn on the suction or may wait until the clot material is in a better position relative to the distal end of the suction catheter, which may be detected by a signal from the sensor. In some examples, the controller may turn on a brief pulse of higher attraction to help better locate the clot material.
In fig. 17C, the clot material 36 is proximal to the distal end 1 and is approximately equidistant from the two forward facing sensors 6. The distal opening is generally aligned with clot 13. In this example, the current 35 from the sensor on the distal end of the aspiration catheter passes through the large clot in front of the distal opening substantially symmetrically. The controller may then apply suction through the lumen of the suction catheter. Centering the clot as described above may allow the clot material to be aspirated without requiring too much blood to be drawn into the lumen of the aspiration catheter.
As shown in fig. 17D, the clot is aspirated into the lumen of the catheter. The clot material is in contact with the sensor in the lumen and with the forward facing sensor 6. In this configuration, clot material may be detected by bioimpedance signals from internal sensors emitting current 48 or fields, in addition to the current emitted by the distally facing sensor. The controller may activate the shredder such that the driver 10 causes the shredder drive shaft 11 to drive the rotation of the shredder cutter 12. In some examples, the chopper cutter may be positioned farther within the lumen of the aspiration catheter such that it may enhance the absorption of clot material.
In fig. 17E, the clot material has been fully attracted into the lumen of the aspiration catheter. The clot material can no longer be detected by the sensor on the distal end of the aspiration catheter and the signal from the first set of internal sensors 6 can be reduced or stopped as the clot moves proximally through the lumen. In some examples, additional sensors or sets of sensors may be included to track the progress of the clot material along the lumen. The controller may continue to chop and apply suction to pass the clot material proximally for collection.
Fig. 18A-18E illustrate another example of a device similar to that shown in fig. 1A, 1C and 14-16, also in the pulmonary artery, a small amount of clot material may be attracted to the device. In fig. 18A, the distal end of the device is within the pulmonary artery and the distal end is surrounded by blood 34. The small clot material 39 is outside the range of the sensor (here shown as a bioimpedance sensor, which emits current 25 for detecting impedance). In fig. 18B, the clot material is more closely adjacent to the distal end of the aspiration catheter. The clot material 39 is proximal of the distal end but is shown closer to one sensor 6 of the pair of distally facing sensors and the resulting bioimpedance signal indicates that the clot material is misaligned with the catheter opening. As previously described, the controller may initiate aspiration or may wait until the clot is closer (and the sensor indicates better centering) in order to minimize blood loss.
In fig. 18C, the clot material is proximal of the distal end and is approximately equidistant from the two forward facing sensors 6 such that the distal opening is approximately aligned with the clot material. The current 25 from the sensor passes approximately symmetrically through a small clot 39 in front of the distal opening. As shown in fig. 18D, the controller may aspirate clot material into the lumen. In fig. 18D, clot 21 is entirely within the lumen and, as described above, within the range D of the first set of internal sensors. In this case of fig. 18D, the clot material is in contact with the sensor inside the lumen 6 (for detection by the emitted current 48) as well as the forward facing sensor 6. Thus, the controller may continue to cause aspiration as clot material continues into the lumen.
Fig. 18E shows the clot material completely within the lumen and while still within the range of the internal sensor, has exceeded the range of the external distally facing sensor.
Fig. 19 shows one example of a control loop model of an apparatus such as that shown in fig. 1C, 15, 16, 17A-17E, and 18A-18E. In fig. 19, the controller may follow the control loop based on inputs 1901 from a clot-sensing sensor within the lumen of the aspiration catheter and from a clot-sensing sensor external to the distal end of the aspiration catheter. The sensor data may be analyzed to identify when the external sensor only identifies blood or vessel walls ("external baseline"), when clot material is near ("proximal"), or when clot material is present on the catheter ("engaged"). Similarly, the internal sensor may be analyzed to determine when clot material is present ("engaged"), near ("proximal") or absent, and only blood ("baseline"). In a simple example of this state diagram, the result of the combined external sensor and internal sensor data may set the state of attraction (on/off) or the state of the shredder (on/off). For example, if the external sensor indicates that the clot material is completely on the end of the catheter ("external engagement") and the interior is completely engaged with the clot material ("internal engagement") 1903, the aspiration may be "opened", e.g., by opening a valve in the aspiration regulator and/or by directly activating the aspiration source 1905. If the external sensor indicates that clot material is not present ("external baseline") or nearby but not yet in contact ("external proximal"), and clot material is present on the internal sensor ("internal engagement") 1907, suction may be applied to continue to remove clot material from within the catheter while the shredder is driven 1909. If the external sensor indicates that clot material is present ("external engagement"), and the internal sensor indicates that clot material is nearby or not present ("internal proximal/baseline") 1911, the controller can apply suction 1913 while driving the shredder. If the external sensor indicates that a clot is not present ("external baseline") and the internal sensor indicates that a clot is not present ("internal baseline") 1915, the controller may keep the suction off (or at a low level in some examples) while the chopper driver is also off 1917. If the external sensor indicates that the clot is nearby but not in contact ("external proximal"), while the internal sensor indicates that the clot is not present ("internal baseline") 1919, the controller may set or maintain suction off (or at a low level) while the shredder remains off 1921. Finally, if the external sensor indicates that a clot is not present ("external baseline") and the internal sensor indicates that a clot is nearby ("internal proximal") 1923, the controller may slow or stop the aspiration 1925 while continuing to drive the shredder.
In some examples, the states shown in fig. 19 may be interconnected in that transitions between states (not shown in fig. 19) may be predetermined, and the controller may determine the control state of the suction and/or shredder based on the previous state. Thus, the state diagram shown in fig. 19 is merely exemplary, and other state diagrams may be used and implemented by the controller. In some examples, the controller may also use data (e.g., feedback) from other components, which may inform the state diagram and control loop. For example, data from sensors on either the negative or positive pressure sources may be used, pressure sensors from within the catheter lumen may be used, user inputs (including user emergency override inputs) may be used, and so forth. The master control layer ("layer 1") may relate to any preliminary data collection or analysis from the peripheral components and is specifically related to the functionality of the controller. The secondary control layer ("layer 2") may be involved in establishing known system conditions including, but not limited to, clot out of range, clot proximal to distal, clot engaged with distal, clot within interval d, clot out of interval d, clot aspirated/returned to clot out of range condition, and the like. Control layer 3 ("layer 3") may be dedicated to control loop actions such as layer change or repeat steps, which in the case of the apparatus shown above may include returning to the master control layer. The model control loop described herein works interchangeably for small and large clot examples.
Any suitable chopper may be used. For example, FIGS. 20-24 illustrate examples of shredders that may be used. In general, the illustrated shredder, which may be referred to as a shaver (shavers), includes a housing 201, which housing 201 is shown as an insulated sleeve or bushing in fig. 20-24. The housing may be flexible such that the shredder can navigate within the curved suction catheter (navigate). The shredder of fig. 20-24 may also include an inner housing 202, for example, in fig. 20, the inner housing 202 is an insulated rotating sleeve. The rotating sleeve includes openings 203 and teeth forming a chopper cutter 204. In some examples, the shredder may comprise a single housing in which a flexible shredder drive shaft (e.g., wire) may rotate to drive rotation of the cutter of the shredder. In some examples, only a single (e.g., outer) housing is used, and may include a window (or windows) exposing the rotary cutter. Alternatively, in some examples, the cutter extends from the distal end of the housing, rather than being located within the window.
Any of the shredders described herein may include one or more sensors for detecting clot material. In any of these examples, the sensor may form the internal sensor or some (or part of) the internal sensor described above. These sensors may be clot detection sensors and may include bio-impedance sensors, ultrasonic sensors, optical sensors, and the like. For example, in some examples, the sensor may be configured as a bipolar bio-impedance sensor. In fig. 20, the shredder includes a monopolar impedance sensor 205, the monopolar impedance sensor 205 being disposed radially outside of the housing and proximally of the opening 203 (window exposing the cutter) of the inner rotating sleeve 202. In this configuration, the impedance sensor may emit a current 206, shown in fig. 20 by a dashed line representing the sensing field of the sensor. The current delivered from the monopolar impedance sensor 205 may return to the sensor 205 after being affected by the surrounding area. Thus, the sensor configuration has a low spatial specificity, enabling clot sensing within the entire volume of the distal end of the aspiration catheter (not shown in this example).
Fig. 21 shows another example of a shredder. In fig. 21, a second monopole impedance sensor 205 is disposed on an opposite side of the opening 203 and is radially outward of the housing 201. In this example, the current 206 delivered from each monopole impedance sensor 205 is also returned to each respective sensor 205. The sensor configuration combines low spatial specificity with multiple measurement locations radially disposed relative to the opening 203, enabling clot sensing across a volume within the aspiration catheter (e.g., the distal end of the aspiration catheter), as well as analysis including, but not limited to, clot approach triangulation and signal denoising.
Fig. 22 shows another example of a shredder similar to that shown in fig. 20, except that the bipolar impedance sensor 205 is used instead of a monopolar sensor. In this example, the current 206 delivered from one electrode in the bipolar impedance sensor 205 is returned through the opposite sensor 205' in the pair. The sensor configuration has a higher spatial specificity, enabling a more accurate analysis of the clot in the vicinity of the window opening 203. Multiple sensors (including multiple bipolar sensors) may be used.
Fig. 23 shows another example of a shredder in which the sensor includes a pair of electrodes 205, 205' forming a bipolar bio-impedance sensor that senses the area extending over the opening 202 of the exposure window 203. In this example, the current 206 delivered from one electrode in each bipolar impedance sensor is returned through the opposing sensor in the respective pair. The sensor configuration combines a high spatial specificity with a plurality of measurement positions radially arranged relative to the opening 203, enabling clot sensing and localization relative to the opening 203.
Fig. 24 shows an example of a shredder inserted through the suction lumen to the distal end of the suction catheter. As shown in fig. 24, the distal end of the aspiration catheter may include an expanded distal region into which the morcellator may be positioned. As described above, a cover 208 may be included, the cover 208 may be elastically deformable, and may include an opening or slit to allow the passage of clot material. In fig. 24, the shredder includes an electrode 207, which electrode 207 forms a sensing pair of a bipolar bio-impedance sensor with an electrode 207' located in the distal region of the lumen. Thus, the sensor pair 207, 207' is made between an electrode disposed radially proximal to the opening 202 in the housing of the shredder and an electrode residing on the wall of the aspiration catheter 209 (in this example, in an expandable "funnel" region). The sensor in this example may allow bipolar impedance sensing with high spatial specificity and long range current path 206 in order to provide sensing of the entire volume of the lumen that attracts the distal region of the catheter.
Fig. 25 shows an example of a distal region of a funnel as described herein, similar to the example schematically shown in fig. 24. In any of the devices described herein, the aspiration catheter may include an enlarged (larger diameter) distal region. The distal region may expand and contract from a compressed, unexpanded configuration (which may fit into the delivery catheter 305). The expandable distal region 303 may be referred to as a funnel region and may be formed of a material that self-expands when released from the delivery catheter 305. For example, the distal region may be formed of a knitted or woven material, such as a polymer or metal (e.g., nitinol), and may be laminated with a blood impermeable material. In fig. 25, the aspiration catheter 300 is shown in an expanded (deployed) configuration, with the distal funnel region shown expanded to a diameter 311, which diameter 311 is many times larger than the more proximal region 309.
The distal face of the expandable region may include a covering as described above. The cover may be an elastically deformable material that prevents blood from entering until suction is applied, which can deform it to allow clot material to enter. The cover may include one or more slits and/or holes that may resiliently expand as clot material is drawn into the funnel region. As described above, the outer distal surface (covering 307) may include one or more external sensors for sensing clots. The chopper can be inserted into the proximal end of the aspiration catheter and slid axially into the distally-flared (e.g., funnel) region, as shown in fig. 24. One or more internal sensors may be present inside the funnel region and/or the elongate body 309 of the aspiration catheter for detecting clot material within the aspiration catheter.
Fig. 26 illustrates a method of sensing a clot and distinguishing between clot material and non-clot (e.g., a vessel wall). In general, the methods and apparatus described herein may interrogate (interrogate) electrically, optically, pneumatically, and/or acoustically devices within a person's vasculature and surgical site to notify a clinician during removal of obstructive material (i.e., pulmonary embolism) from a blood vessel. Current techniques for removing obstructive material (e.g., pulmonary embolism) from a blood vessel require a clinician to navigate up through the heart and into the pulmonary artery and blindly seek and attempt to remove the obstructive material from the blood vessel. In some cases, when using the devices described herein to remove obstructive material from a blood vessel, a clinician accesses the pulmonary vasculature with a tubular catheter and guidewire and continuously aspirates blood from the body proximal of the blood vessel, desirably pulls the obstructive material toward the catheter and eventually out of the body through the catheter. This approach can result in significant blood loss, prolonged procedure time, and increased safety risks, such as hemodynamic failure and/or vascular dissection (vessel dissection). In some cases, the clinician will draw a vacuum at the proximal end of the catheter without drawing something back through the catheter. At this point, the clinician does not know whether they are stuck causing damage to the vessel wall or whether they are attached to a large obstruction, and they should wait and allow aspiration to pull the obstruction through the catheter. Because of these limitations, there is a need for an improved thrombectomy system that informs the clinician where the obstruction is located within the blood vessel, what is near and/or within the distal end of the system, and when to attempt to extract the obstruction. In the present invention, embodiments are described that address all of these limitations.
The methods and apparatus described herein may use at least one sensing element near or attached to the distal end of the system (e.g., within a predetermined distance (e.g., 10cm or less, 7.5cm or less, 5cm or less, 4cm or less, 3cm or less, etc.) to identify when the device encounters something more rigid than blood. When a stiffer object is sensed, the device may determine whether the obstruction is a clot material or a vessel wall, or some other obstruction. For example, the device may automatically and instantaneously apply negative pressure on the aspiration lumen or inform the clinician to do so. When pressure is applied, the system can interrogate (e.g., using at least another sensor within the aspiration lumen, or by otherwise detecting a substance within the aspiration lumen of the device) to determine whether the system is against an obstructive substance (e.g., clot substance) or a vessel wall. If an obstructive material is sensed, the system applies a continuous negative pressure and activates the chopping element to chop the obstructive material and extract the material from the body. If no obstructive material is sensed within the aspiration lumen, the device will not apply additional negative pressure and the clinician may be notified that the device is not experiencing obstructive material. In some embodiments, the device can monitor the removal of shredded and removed obstructive material and reduce or stop the negative pressure applied to the aspiration lumen to minimize blood loss.
For example, fig. 26 illustrates one example of a method of operating a thrombectomy device to detect and remove clot material. For example, in fig. 26, a general method may include moving a thrombectomy device 2601 within a blood vessel (e.g., advanced or withdrawn through a guidewire and/or diagnostic catheter) to position the device within the body. The device may be maneuvered with or without additional guidance (e.g., using fluoroscopy). The device may detect an obstruction 2603 within a distal region of an extraction inlet of the thrombectomy device ("extraction zone", e.g., at 0-5 cm) using, for example, a contact sensor, a pressure sensor, an optical sensor, a bioimpedance sensor, etc. Once the device determines that an occlusion is present, it may determine whether the occlusion is a clot material or a vessel wall (e.g., from an optical sensor, apply suction, and determine whether to be extracted into the extraction chamber by expanding a hole into the extraction chamber, etc.) 2605.
If the device (e.g., a controller of the device) determines that the occlusion is a clot material by directly sensing an attribute of the occlusion (e.g., electrical, light, tactile, etc.) or determining that the occlusion can be extracted into the extraction chamber and/or cut by a shredder (which typically can occur only if the occlusion material is a clot material based on the configuration of the device described herein), the device may manually or automatically trigger a clot detection response, e.g., alert/alarm, display, etc., and may turn on the extractor subsystem to extract; for example, the device may open the suction and/or mechanical extraction element (e.g., stent, capture tool, etc.) and/or in some examples may open and/or increase the chopper activity, etc 2607. Alternatively, if the device determines that the obstruction is not a clot material, it may signal this to the user and may continue to move the thrombectomy device.
In any of these methods, the method may further optimally include stopping the extractor subsystem from extracting the substance 2609 when the device determines that a clot is no longer detected. For example, the device may stop the extractor subsystem (e.g., turn off the suction and/or mechanical extraction element) 2611 when a clot is no longer detected within the extraction chamber, e.g., when one or more sensors configured to sense substances within the extraction chamber no longer detect clot substances, and/or when the device detects a change in chopper response (e.g., current/power usage, vibration or acoustics, suction lumen and/or pressure within the extraction chamber area, etc.).
Fig. 27A-27B illustrate examples of thrombectomy devices that may be configured to perform any of these methods. For example, fig. 27A shows one example of a device configured to aspirate a catheter that includes an elongated body 2713 with an aspiration lumen and an extraction chamber region 2703 at a distal end of the catheter. The opening 2721 into the extraction chamber region may be referred to as an extraction inlet, and may include one or more forward-facing obstruction sensors 2708, 2708', the one or more forward-facing obstruction sensors 2708, 2708' configured to detect or sense obstructions within the distal-facing extraction region 2704. The device also includes a shredder 2717 within the extraction chamber area and an internal sensor 2710 configured to detect substances within the extraction chamber. The device also includes a chopper driver 2717 and optionally includes an aspiration regulator 2719 and a controller 2715. The controller may receive input from the device (e.g., from an occlusion sensor, an internal sensor, and/or a shredder driver, a shredder sensor, and/or an attraction sensor). The controller may also include one or more inputs for a user to input control commands and/or data.
The controller may also output one or more outputs 2723 to the user based on the operation of the device, which may include an output (reminder).
In fig. 27A, the device may apply suction through and/or around the shredder. In operation, the device may control the application of suction and/or operation of the shredder based on input from one or more sensors and/or evidence (e.g., by observing the shredder driver) indicative of resistance of material within the extraction chamber that may affect operation of the shredder.
Fig. 27B illustrates another example of a device in which the apparatus includes an elongate body 4513 having a lumen extending along a length (e.g., an aspiration lumen). The distal region may include a tapered extraction chamber region 2703, which tapered extraction chamber region 2703 may include an extraction inlet 2721, which extraction inlet 2721 is at least partially covered by a cover 2729 that includes a hole 2743 (e.g., a slit) formed therethrough. The cover may be permanently placed over the distally facing extraction inlet and the aperture may be formed to allow clot material to be extracted. In the example shown in fig. 27B, the device includes a guide channel 2731 for passing a guidewire and/or guide 2735. The extraction chamber region 2711 may be configured to expand and contract, and may include an extraction chamber sensor 2748, which 2748 may be within or outside of the extraction chamber but configured to sense the chamber. The device may also include a shredder 2717 within the aspiration chamber. In this example, suction is drawn through the shredder and into the suction chamber. The device may also include a shredder driver 2717 for driving the shredder and, in some examples, an attraction modulator for modulating attraction applied by the device. The controller 2715 (including one or more inputs 2725 and outputs 2723) may also be included, and the controller 2715 may include one or more processors, communication circuitry, and the like. The controller may also include wireless circuitry and/or memory for storing and/or transmitting data regarding the operation of the device.
Fig. 28 illustrates another example of a method that may be implemented by the apparatus described herein. In this example, the method may include moving a thrombectomy device within the blood vessel, for example, optionally advancing or withdrawing the device through a guidewire and/or diagnostic catheter while preparing to detect the occlusion, and then removing the clot material 2801 once detected by the device and confirmed that the occlusion is a clot material.
In fig. 28, which shows a specific example of the method of fig. 26, the apparatus and method may be configured to optically detect contact 2803 with an occlusion in an extraction region (e.g., at one or more locations around an extraction inlet) of a thrombectomy device and determine if the occlusion is a clot material 2805. For example, the method or apparatus configured to perform the method may include determining whether the obstruction is a clot or a wall 2805, for example, by comparing reflectance spectral values obtained from one or more optical sensors configured to detect properties of a substance within the extraction chamber. If the obstructing material is not a clot material, the user may be alerted as such, and the position of the device may be adjusted (e.g., withdrawn away from the obstruction and the device advanced on). However, if, for example, based on reflectance spectral values, the occlusion material is determined to be a clot material, a clot extraction response may be triggered 2807. For example, a reminder/alarm, display, etc. may be triggered to indicate clot material, and the device may manually or automatically turn on/increase suction, manually or automatically turn on/increase a shredder, etc. The method or a device configured to perform the method may also stop the aspiration 2809 when clot material is no longer detected, e.g., by stopping the aspiration 2811 when clot material is no longer detected within the extraction chamber (e.g., a sensor within the aspiration chamber, resistance in rotation of the chopper, pressure within the aspiration lumen and/or extraction chamber, etc.). The suction and/or chopper may be stopped (or may be reduced) immediately and/or may optionally be stopped or reduced after a predetermined delay, e.g., to allow clot material within the device to clear from the elongate suction channel.
Fig. 29A-29B illustrate one example of a device configured to detect clot material within an extraction region forward of (distal to) a device extraction inlet 2921. In this example, the device is shown as a catheter device having an elongate body 2913 and a distal region. The optical sensor 2908 may be positioned distally forward (positioned distally forward-looking) at or near the distal end of the catheter. In some examples, the optical sensor may be formed from two (or more) optical fibers; a transmitting fiber 2947 and a sensing fiber 2913. As shown in fig. 29B, the apparatus may include a sensing fiber 2913 coupled to an optical detector 2938 and an emitting fiber 2947 coupled to one or more light sources 2948. The catheter may also include ports for coupling with the hemostatic port 2942, the aspiration port 2940, and/or the valve 2944. As described above, the apparatus may also include a controller (not shown), an attraction modulator (not shown), and an optional shredder and/or shredder driver (not shown). Fig. 29A shows a cross-section through the distal region (line A-A') of the device of fig. 29A, which includes the emitting fiber 2947 and the sensing fiber 2913, the emitting fiber 2947 and the sensing fiber 2913 being shown positioned on the inner surface of the lumen, but may be within the wall of the catheter and/or on the outer surface.
Fig. 20A-30C illustrate the operation of one example of an apparatus as described above. In fig. 20A, the device is guided through a blood vessel 3022 by a guidewire 3022 such that the distal end of the device may include a light emitter (or emitter/detector) that emits light 3015 of one or more wavelengths that may be used to distinguish between clot and wall materials as described above. In fig. 30B, the device is driven just proximal to obstruction 3020. In this example, the emitted/detected light may detect (or contact with) the obstruction and an attraction 3030 may be applied, as shown. Suction may remove clot material. Thereafter, as shown in fig. 30C, the device may be advanced distally through the guidewire, but may again encounter an obstruction, as shown in fig. 30C. In this case, the one or more indicators may indicate that the obstruction is not a clot material, but instead may be a vessel wall, as shown.
Fig. 31A-31B illustrate examples of two types of thrombectomy devices that include an elongated body having an extraction chamber region 3111. Chopper 3117 and/or chopper subsystems (e.g., chopper drivers, suction regulators, etc.) may also be included. Suction through the shredder can be applied via the suction lumen 3171. The distal face of extraction inlet 3157 may be completely or partially covered by a cover (e.g., membrane 3159) that includes a hole therethrough. The distal face may be slightly tapered. In fig. 31A, the device may include an optical sensor 3159 for sensing clot material and/or for distinguishing clot material as described above. The optical sensor may include an emitting fiber 3161 and a sensing fiber 3163 coupled to an optical detector 3146 and a light source 3148. A controller (not shown) may be used to coordinate the sensing/detection and the response of the device. Fig. 31A shows the diffuse reflectance spectrum optimally positioned to monitor the extraction area of the system while minimizing the impact on the pumping aperture cross-sectional area of the system.
Fig. 31B shows a similar arrangement, wherein the optical sensor 3169 is configured as a touch sensor, also comprising an emitting fiber 3161 and a sensing fiber 3163. The contact sensor in this example may protrude into the extraction region 3104. FIG. 31B illustrates a distal region comprised of a flexible contact sensing element protruding within an extraction region distal to a suction aperture and an interrogation sensor positioned to optically analyze an object entering the extraction region. The flexible contact sensing element in this embodiment comprises two flexible polymer optical fibers made of PMMA that are adjacently secured together. The fiber optic assembly is then wrapped with a protective polymer jacket. In other embodiments, those skilled in the art will envision simplifying it into a single optical fiber. The use of two optical fibers makes the proximal processing simpler and cheaper. The distal end of the optical fiber is cut and polished as above and the flexible optical fingers are secured over the distal end. The flexible optical fingers are designed to be 1-5mm long, range in diameter from 0.010-0.020 inches, and have a soft atraumatic distal tip. In this embodiment, the flexible optical fingers are made of a low durometer 20-40 shore a polymer, such as silicone, with a wire helically wound around the polymer. The proximal end of the optical fiber is cut and polished and attached to a light source and a photon sensor. In use, the light source transmits light into the flexible optical finger through the emission fiber. Light is shone into the flexible finger and a portion of the light is reflected back through the sensing fiber, where the photon sensor detects the signal. If the finger is touched, the amount of light reflected back will change, resulting in a change in the signal at the photon sensor. The elongate body of the fiber optic assembly is positioned within the aspiration lumen of the device. In some embodiments, the fiber optic assembly may have a dedicated lumen throughout the entire device. The interrogation sensor of the present embodiment is constructed similar to the sensor elements of fig. 1 above. The interrogation element is secured to a distal cone (DISTAL TAPER) of the shredding chamber and positioned such that a centerline of the optical lens passes through the extraction area. The example also includes an integrated reinforced molding catheter having a guidewire lumen, an expandable collapsed chopping chamber with a comfortable aspiration void, a resilient distal cone, and a proximal end secured to a catheter body that fluidly connects the chopping chamber to the aspiration lumen of the catheter body. Inside the shredding chamber, a shredder housing having a distal opening and at least one sidewall opening is positioned and secured to the distal end of the catheter body shaft so that there is still fluid communication between the shredding chamber and the aspiration lumen. Inside the shredder housing, the shredder element has at least one sidewall opening axially positioned such that the housing and element opening overlap. The shredder member is freely rotatable within the shredder housing and has a wire secured at a proximal end.
In use, the clinician sets up the system and inserts the distal end of the system into the lumen of the body according to standard minimally invasive protocols and advances the system through the lumen toward the obstructive material under fluoroscopic guidance. When an object impacts a touch sensing element, the element bends to change the intensity of light on the photon sensor. At this point, the system will use visible light, audible sound, or tactile sensations on the handle or an external base station to inform the clinician that something is in the extraction zone of the system. At the same time, the system will interrogate the object using the interrogating sensing element described above in the previous embodiment. If the object is an occlusive material and within the extraction zone, the system will apply negative pressure to the aspiration lumen, pull the occlusive material into the shredding chamber, and activate the shredding element to shred the material and allow it to pass through the catheter body and exit the body. Aspiration and shredding will continue until material is removed from the extraction zone. This process may be repeated as many times as desired.
For example, fig. 31C shows one example of an optical sensor or sensor subsystem that may be used. In this example, the apparatus includes an emitting fiber, a sensing fiber, and an optical lens at a distal end, as well as a light source coupled to the emitting fiber and a sensing element coupled to the sensing fiber. Fig. 31D shows another example of an optical sensor configured similar to the contact fiber shown in fig. 31C, but with an optical finger protrusion at the distal end to receive input from the emitting fiber and output from the sensing fiber. The distal finger region may comprise a flexible member.
Fig. 32 illustrates another example of an optical sensor configured to detect obstructions as described herein. In this example, the sensor includes an emitting fiber 3105 and a sensing fiber 3107 that terminate in the center of a spherical region having a first refractive index 3113. A region having a second refractive index 3111 may exist on an outer region of the sphere, and the optical sensor may detect a difference between the first refractive index and the second refractive index; contact with the blocking substance 3123 may change the shape of the spherical region, thereby changing the difference between the refractive indices. This may allow detection of contact with a substance. In some examples, the device may also detect changes in refractive index due to contact with an obstruction.
Fig. 33 shows an example of a device in which the emitting portion 3305 and sensing portion 3307 of the sensor are separated by the diameter of the elongate member 3325 at a distal opening into the extraction chamber. For example, the elongate member (elongate body) may be a suction catheter into which suction 3309 may be controllably applied.
The methods and apparatus described herein may electrically, optically, pneumatically, and/or acoustically sense the contents of a device within a lumen of a person and within an extraction region. As described above, examples of these devices may have at least one sensing element to detect when an occlusion is located within the extraction region of the aspiration aperture and interrogate the occlusion to determine if the occlusion should be extracted or bypassed (i.e., clot versus vessel wall). Other examples have at least two sensing elements for detecting when an occlusion is located within the extraction area of the aspiration aperture and interrogating the occlusion to determine if the occlusion should be removed or bypassed (i.e., clot and vessel wall).
In some examples, optical sensing may detect and interrogate obstructions within the extraction region. An elongate flexible catheter body having a lumen (aspiration lumen) may have distal and proximal ends, a handle having an aspiration port and a hemostasis valve, and a sensing fiber optic assembly comprising an emitting fiber proximally connected to a light source, a sensing fiber connected to a photon sensor, and an optical lens attached to the distal end of the fiber optic assembly, as shown in fig. 29A-31B. The sensing fiber optic assembly may be secured to the lumen of the catheter body such that the optical lens of the assembly is aligned with the distal end of the aspiration lumen (e.g., within 5 mm) and extends proximally through the catheter body out of the handle with the proximal end of the optical fiber, which becomes the connector, connected to a light source and a photon sensor. The optical lens of the sensing fiber optic assembly may be positioned relative to the distal aperture of the aspiration lumen because blocking material within the aspiration region may be carried into the aspiration lumen when negative pressure is applied to the lumen. The fiber optic assembly can move freely independently of the catheter body and operate in a dedicated lumen of the catheter body or within an aspiration lumen of the catheter body. The optical fibers of the fiber optic assembly may be made of flexible glass or plastic, such as PMMA, with cladding having a diameter in the range of 50-500 microns, with each fiber preferably having a diameter of 125 microns. The optical fibers are combined and covered with an outer protective jacket. The distal ends of the two optical fibers are cut and polished to ensure that the distal ends are perpendicular to the center line of the optical fibers. The distal ends are then encapsulated together (potted) in a polyurethane or silicone material to form an optical lens. The optical lens has an atraumatic distal geometry. The proximal end of the optical fiber may be cut and polished like the distal end, and each fiber end may be packaged into a separate connector (i.e., SMA, ST, or MU connector). In some examples, the proximal end of the emitting fiber may be permanently affixed to a single LED and placed within the handle with a small electrical circuit and battery. The flexible catheter body of this example is a standard reinforced polymer shaft that is configured similar to the flexible elongate shaft disclosed in U.S. application No. 17/393,618, which is incorporated herein by reference in its entirety. The handle may be made of rigid to semi-rigid plastic, such as nylon, abs or polycarbonate, and may be injection molded or machined. The hemostatic valve may be made of an elastic material, such as silicone.
As shown in fig. 31C-31D and 32, optical sensing may utilize diffuse reflectance spectra using fiber optic assemblies to detect and interrogate obstructions within the extraction region. The light source used may emit a light range of 360-2500nm and the sensing fiber will be connected to at least one spectrometer to analyze the reflected light. In other examples, the emitting fiber may be fixed to a specific wavelength LED, e.g., 500nm, and the sensing fiber permanently fixed to a sensing element, e.g., a silicon diode. A3 or 4 fiber optic assembly may be used that utilizes two specific wavelengths, such as 480-520nm and 1530-1565nm.
In use, a clinician may insert the system into a lumen in the body and advance the system through the lumen toward the obstructive material according to standard minimally invasive protocols. When obstructive material enters the extraction zone or aspiration lumen near the lumen wall, the intensity of the returned light changes and the system will graphically display these changes to the clinician or compare the intensity readings to a look-up table, determine what is in the extraction zone, indicate to the clinician what is in the extraction zone, and/or apply negative pressure to the aspiration lumen.
The above examples may use light to detect contact; the contact sensing element may use an electromechanical element, such as a piezoelectric film, that converts mechanical motion into an electrical signal, or an excitation conductive element, such as a spring, and monitor the change in resistivity due to wire displacement.
Any of the methods and devices described herein may be configured to detect clot material based on contact pressure. For example, fig. 34 illustrates a method of identifying and distinguishing clot material from a vessel wall or other material using contact sensing. In fig. 34, the method can include inserting and/or advancing a thrombectomy device 3401 within a patient's blood vessel (e.g., through a guidewire, through a diagnostic catheter, etc.), and detecting contact with an occlusion at an extraction region of an extraction inlet of the thrombectomy device based on contact pressure. The contact pressure may be detected 3403 by a contact sensor (e.g., a pressure sensor), for example, using a contact balloon or other inflation member to detect changes in pressure on the substance within the contact balloon. Other contact sensors may include optical-based contact sensors such as those described above (see, e.g., fig. 31C, 32D, and 32). Other contact sensors may be based on impedance sensing, which may detect contact through changes in electrical impedance.
Once a contact is identified, the device (e.g., using a controller portion of the device) may trigger a reminder indicating the contact, and may also identify that the contact is with a clot material or with some other material including the vessel wall 3405. The step of distinguishing between clot material and other (e.g., vessel wall) material may be performed in a variety of ways. In some examples, as shown in fig. 34, if suction has not been applied, the device may turn on pulsed suction, e.g., suction, through the device and may detect that clot material has entered the extraction chamber from the extraction zone through the extraction inlet. In some examples, a closed or semi-closed extraction inlet, which may be at least partially covered by a cover (e.g., a membrane), may allow clot material to pass through the aperture, but may prevent lumen walls or other material from entering or entering the extraction chamber beyond a predetermined depth. Thus, the extraction chamber may be monitored to determine if a substance that is assumed to be a clot substance has entered 3406 during the application (e.g., pulsing) of suction/aspiration. In some examples, one or more sensors may be present within the extraction chamber or oriented to sense within the extraction chamber (even outside of the downstream of the extraction chamber), which may sense when a clot is present instead of the vessel wall 3408. In some examples, clot material within the extraction chamber may be optically detected (by one or more optical sensors within the extraction chamber), and typically the internal sensor may be oriented to sense at a desired internal proximal location, e.g., far enough from the extraction inlet to distinguish clot material from the vessel wall, e.g., 2mm or more (e.g., 3mm or more, 4mm or more, 5mm or more, 6mm or more, 7mm or more, 8mm or more, 9mm or more, 1cm or more, etc.) within the extraction chamber. In some examples, the methods and apparatus may be configured to detect clot material within the extraction chamber by detecting a change in the activity of the shredder. For example, the chopper may be activated continuously or when a clot is sensed (e.g., when suction (including suction pulses) is applied); interaction between clot material within the extraction chamber and the shredder may result in a change in shredder behavior that is detectable when compared to a baseline (e.g., operating without attraction or operating before contact is detected). In some examples, the device may detect contact between the shredder and the clot material within the extraction chamber by detecting a change in drive energy (e.g., applied current), and/or a change in activation rate (e.g., rotation, reciprocation, etc.), and/or a change in vibration, and/or a change in sound of operation of the shredder. The activity of the shredder can be detected remotely, e.g., at the proximal end of the device, such as by monitoring the applied energy (e.g., current), actuation resistance, etc.
The method or apparatus may trigger a clot detection response if clot material is detected within the extraction chamber. The method or apparatus may also indicate this if no clot material is detected. For example, if no clot material is detected, the device may determine a reminder that the occlusion may be a vessel wall, and/or may shut down (or reduce) the suction and allow the device to be repositioned. Similarly, if it is determined that clot material is present in the extraction chamber, the method and/or apparatus may trigger a clot detection response, which may include a reminder/alarm (e.g., audible, visual, including but not limited to, emitting or changing a tone, indicator light, display, etc.) to indicate that clot material is present and allow manual or semi-manual operation of the apparatus. Alternatively or additionally, the clot detection response can include manually or automatically opening or increasing suction, and/or opening or increasing a chopper or the like 3407 to remove clot material. The clot detection response can continue until clot material is no longer detected. For example, if a clot is no longer detected outside of the distal extraction chamber and/or within the extraction chamber, the clot detection response (e.g., aspiration and/or chopper activity) 3411 may be paused or reduced. In any of these cases, the clot detection response may be stopped or reduced immediately, or may be stopped or reduced after a delay. For example, the clot detection response may stop or decrease after a delay of a few seconds, minutes, etc., to allow clot material to clear through the lumen (e.g., aspiration lumen) of the device.
Fig. 35A and 35B illustrate examples of a distal portion (fig. 35A) and a proximal portion (fig. 35B) of a device 3500 configured for contact sensing as described above. In this example, the device includes an expandable extraction chamber region 3511 at a distal region of the device. The extraction inlet 3557 is covered by a cover (membrane 3559) in which holes (apertures) 3566 are present to allow the clot material to pass through. In this example, the covering 3559 is flexible and the aperture 3566 is configured as an incision or slit through the covering that can be expanded to pass (and hold) a larger clot while closing to limit or prevent blood loss when the clot is not present. The extraction chamber is formed on the distal end of an elongate catheter-like body that includes an aspiration lumen (aspiration lumen 3571). The chopper 3517 is positioned within the extraction lumen and can fit into and through the catheter body region such that the chopper extends distally into the extraction chamber region 3511. The drive shaft 3588 extends proximally; in this example, the shredder may be rotated by rotating a flexible elongate drive shaft. The distal end of the extraction chamber including extraction inlet 3557 may be angled (e.g., wedge-shaped), concave, or convex. In fig. 35, the device includes a guide channel 3531 for guiding an element 3533 (e.g., a guidewire and/or diagnostic catheter 3537, which guidewire and/or diagnostic catheter 3537 may include a pre-curved steering region).
The device shown in fig. 35A further comprises at least one contact sensor 3559. In this example, the contact sensor is a balloon element that can be connected to a pressure sensor to detect contact with the balloon region; the contact may increase the pressure of the fluid or other substance within the balloon and/or an elongate member (not shown) coupled to the balloon. The actual pressure sensor may be at the proximal end of the device (e.g., near the proximal end, e.g., fig. 35B).
Any of these devices may include a proximal handle 3571 coupled to an outer shaft 3558, the outer shaft 3558 enclosing an aspiration lumen 3571 and a chopper drive device 3588. In some examples including a pressure sensor as part of the external contact sensor 3559, the contact sensor may be positioned within the extraction zone 3504 at the distal end of the device, but the pressure sensor coupled to the contact sensor may be part of the controller 3780 at the proximal end of the device or in communication with the controller 3780.
In general, the controller may include circuitry for controlling the operation of the shredder, attracting and/or alerting the user. For example, the controller may be coupled to external sensors 3559 (in examples including them) and any sensors for sensing clot material within the extraction chamber; in fig. 35A, the apparatus includes a pressure lumen 3560, which pressure lumen 3560 can be coupled to a pressure sensor in communication with a controller 3780. The controller may also control the operation of the shredder driver (e.g., motor 3473, drive shaft 3588, etc.). The controller can also regulate the suction applied through the suction lumen 3571, for example, by coupling to the pump 3577, suction/aspiration canister 3375, and/or one or more valves (e.g., a bleed valve, etc.). As described above, the controller may also monitor the operation of the shredder driving device to detect a load on the shredder, which may be indicative of the clot material within the extraction chamber region, for example by monitoring the current applied to drive the shredder.
Fig. 35C shows an alternative version of a device including a touch sensor similar to that shown in fig. 35A. In this example, the contact sensor 3559' is configured as an annular balloon surrounding the extraction inlet and opening into the aperture 3566 in the extraction chamber 3511. This may allow for detection of contact around any portion of extraction inlet 3557 within extraction zone 3504. A pressure lumen (not shown) may couple an interior region of the contact sensing balloon 3559' with a pressure sensor, which may be monitored by a controller.
Fig. 36 shows another example of a touch sensor. In this example, the contact sensor is an optical contact sensor, which may be particularly suitable for detecting contact with a vessel wall or other tissue. For example, in fig. 35, the sensor includes an emitting optical fiber 3605 coupled adjacent to a sensing optical fiber 3607 such that light 3611 emitted from the sensing optical fiber can be reflected from tissue and detected by the sensing optical fiber. When the sensing and transmitting fibers are in contact with tissue 3613, a change in the characteristic of absorption, including oxygenation, can be detected based on the wavelength of the emitted light. For example, the sensor may be configured to detect pulsed oxygenation. The sensor may be positioned outside the extraction chamber and may detect contact with an obstruction. As described above, any suitable contact sensor may be used.
Fig. 37A-37D illustrate the operation of a device for detecting obstructions using a contact sensor, similar to the device illustrated in fig. 35A-35C. In fig. 37A, the device 3720 is advanced until the contact sensor 3759 in the extraction region distal to the extraction inlet into the extraction chamber indicates contact with the obstruction 3720. The controller may detect contact by comparing a contact sensor (e.g., a pressure sensor coupled to the balloon chamber at a distal region of the device, an optical sensor, an impedance sensor, etc.) to a baseline. For example, if the contact sensor is a pressure sensor, the controller may determine that the pressure indication is in contact with an obstruction (e.g., the pressure increases above a threshold). The controller may then trigger a reminder indicating an occlusion, and may determine whether the occlusion is a clot material by, for example, triggering or requesting the user to trigger an attraction pulse, as shown in fig. 37B. If the obstruction (as shown in this example) is a clot material, the material can be drawn into the extraction chamber 3711 as shown. The controller may detect the substance within the extraction chamber, for example, by one or more sensors configured to detect the substance within the extraction chamber, and may trigger a clot extraction response (e.g., suction, chopper, etc.).
Fig. 37C and 37D illustrate another possibility, wherein the obstruction 3720' is a portion of the vessel wall (e.g., bifurcation (bifurcation)). For example, fig. 37C may show the same device after removal of clot material after fig. 37B. After removal of the clot material, the contact pressure may drop, and the sensor sensing inside the extraction chamber may no longer register material (in some examples, chamber pressure may drop) and/or chopper drive current may drop, indicating that the clot material has been removed. The suction may be reduced or stopped and the device may continue to be advanced. In this example, the contact sensor 3759 in fig. 37D may detect the obstruction 3720' and may apply an attraction (e.g., a pulse or a low level of attraction), but may not detect the obstruction within the extraction chamber 3711 (or at a very far location within the extraction chamber 3711) because the wall material is not sufficiently pliable/pliable to be pulled into the extraction chamber very far, if at all. For example, the contact pressure on the contact sensor may increase, but the sensor (e.g., chamber pressure) within the chamber does not change beyond a threshold and/or the shredder driver does not indicate a significant change in drive energy (e.g., current), so the controller concludes that no occlusion is present and may alert the user to the presence of a non-clot occlusion (e.g., wall).
Fig. 38A-38B illustrate another example of a distal end of a device including an aspiration lumen 3803, the aspiration lumen 3803 including an extraction chamber 3811. The device schematically illustrates an example in which a sensor 3859 is positioned to sense pressure from a distal face (e.g., extraction region) of the device. In this example, the sensor is a pressure channel coupled to a pressure sensing element that can detect contact by sensing pressure changes in the area. Alternatively, the sensor may detect a change in flow if a small amount of positive or negative pressure is applied; pressure or fluid flow may be monitored to detect occlusions. The apparatus also includes a sensor configured as a pair of electrical sensors 3860, 3860' between which an impedance may be measured to detect a substance within the extraction chamber 3811. The electrodes are positioned at recessed locations (distance x within the extraction chamber) such that suction applied through the extraction chamber can draw more flexible clot material into the chamber, but less likely to draw wall material. Fig. 38B shows another similar example in which a pair of remote electrodes 3859, 3859' can detect contact with an occlusion.
39A-39E illustrate operation of another example of an apparatus as described herein. In this example, the controller may monitor the pressure and/or flow rate through the device surroundings and/or the impedance/resistance within the extraction chamber. For example, in fig. 39A, the flow around the device is relatively high, while the pressure is relatively low, and the electrical impedance/resistance is consistent with an unobstructed path (e.g., without a substance occluding chamber). As the device approaches the occlusion, as shown in fig. 39B, the flow and/or pressure may increase while the electrical impedance within the extraction chamber remains unchanged. As shown in fig. 39C, this may trigger the application of an attraction (or attraction pulse) drawing the occluding substance into the extraction chamber, resulting in a change in electrical impedance. The vacuum may remain high until no occlusion is detected any more distally and/or within the extraction chamber, resulting in an increase in flow and a decrease in pressure, and the electrical impedance returns to the occlusion value. Conversely, when the obstruction is a vessel wall, as shown in fig. 39E, the flow may decrease and the pressure may increase, but the sensed electrical impedance within the extraction chamber may remain substantially unchanged, indicating that the obstruction is not a clot material, but may be a wall.
The methods and apparatus described herein may also or alternatively include detection using only one or more internal sensors, e.g., sensing an area within the extraction chamber, rather than necessarily using a sensor that externally senses in front of the extraction chamber (e.g., within the extraction zone). Conversely, when advancing or positioning the distal end of the device, suction may be applied periodically or as desired, and one or more sensors may detect a substance (e.g., clot substance) within the extraction chamber. In some examples, the resistance to aspiration may be monitored to infer an occlusion (e.g., a high resistance to aspiration may indicate that the device is in contact with the occlusion). Alternatively, the device may monitor only the substances (clot substances) within the extraction chamber.
For example, fig. 40 illustrates a method of controlling clot removal using an attractive pulse. The method may include moving the thrombectomy device within a patient's blood vessel, which may include advancing the device 4001 through a guidewire and/or diagnostic catheter. By activating the chopper 4005 in the extraction chamber (which chopper may be activated prior to applying suction in order to obtain a baseline of chopper behavior for subsequent comparison), and applying suction pulses (which may be manually or automatically, periodically or intermittently triggered, etc.) 4007, clot material 4003 may be detected in the extraction zone of the extraction inlet of the device (e.g., in front of the extraction inlet). The pulses may be, for example, 100ms to 10 seconds long (e.g., between 200ms to 9 seconds, between 200ms to 8 seconds, etc.) or longer. During the suction pulse, the controller may determine whether clot material is present in the extraction chamber based on a change in chopper response (e.g., vibration, sound, current/load, etc.) by comparison to a baseline. If clot material is confirmed within extraction chamber 4011, a clot extraction response (e.g., reminder/alarm, display, etc., manually or automatically opening a mechanical extractor, e.g., suction, opening/controlling a chopper, etc.) 4013 can be triggered as described above.
Based on chopper response 4015, if a clot is no longer present in the extraction chamber, the clot extraction response may be turned off immediately or after a delay, such as stopping extraction (e.g., stopping or reducing aspiration or other mechanical extraction).
Fig. 41 illustrates one example of an atherectomy device (atherectomy apparatus) configured to perform the methods described above, including methods such as those described in fig. 40. In fig. 41, the device includes an elongated body having a distal end with an extraction chamber region 4103. The distal face of the elongate body may include an opening (extraction inlet 4121) into the extraction chamber region. Suction 4119 may be applied from the proximal end of the device under the control of a controller 4115, the controller 4115 may control the operation of a suction subsystem 4119, and the suction subsystem 4119 may include suction regulators, pumps, suction canisters, and/or valves. The pump or suction source may be independent and may be coupled to and regulated by the controller. The controller may also control and receive inputs from (and provide outputs to) a shredder subsystem that includes a shredder driver 4117, the shredder driver 4117 operating a shredder 4107 within the extraction chamber of the device or positionable within the extraction chamber region 4111. In this example apparatus, the controller may also receive input 4125 from the user and may provide output 4123, e.g., a notification as described above.
In operation, the device of fig. 41 may periodically (e.g., every few seconds or more) provide an attracting pulse to see if clot material is extracted from extraction inlet 4121 and extraction region 4104 into the extraction chamber region. When based on e.g. the action of the chopper, it is possible to confirm that the clot material is within the extraction chamber. For example, the chopper may indicate the presence of clot material by: the shredder is driven when suction is applied to determine if the response to the shredder is different from the response when suction is not applied because this difference may be a characteristic of the breaking of the clot material in the region of the extraction chamber due to the action of the shredder. For example, the chopper may require more power (e.g., current) to operate and/or may otherwise behave as if under load. In some examples, when clot material is present, the shredder may generate vibrations and/or sounds to indicate that a load is being applied.
Fig. 42 shows another example of a thrombectomy device similar to that described above, which may also be configured to detect clot material within the extraction chamber 4211 of the extraction chamber region 4203. In this example, the extraction chamber is covered by a cover that includes a hole that forms an inlet 4221 into the extraction chamber. The region distal to the inlet is an extraction region 4202, and the device may include a guide channel 4231 within which a guide device 4235 (e.g., a guidewire, diagnostic catheter, etc.) may be inserted and used to manipulate the device. A shredder subsystem 4219 may be included to drive the shredder 4207 within the extraction chamber for shredding. The shredder can be configured such that the suction 4219 is drawn through the shredder such that the clot material within the extraction chamber is drawn into the shredder and through the shredder. The apparatus of fig. 42 further includes a controller 4215, the controller 4215 may receive input 4225 from a user and/or from the shredder subsystem and/or from the suction subsystem 4219 including the suction regulator. The aspiration subsystem may be coupled to an aspiration source (e.g., pump, wall wire aspiration (wall line suction), aspiration canister, etc.) and may also include one or more valves. Thus, the controller may coordinate the application of suction and activation of the shredder, automatically or semi-automatically and/or manually. The controller may also include one or more outputs 4223 for outputting notifications (e.g., reminders, messages, etc.) to the user.
Any suitable shredder may be used, including reciprocating (e.g., biting) shredders or rotary shredders. For example, fig. 43 illustrates one example of a reciprocating shredder that may be used with any of the devices described herein. In fig. 43, the shredder includes a shredder housing 4335 which is closed about the periphery, but which may be open in one or more shredder windows 4327, and in some examples, at the distal end; in some examples, the distal end may be closed. The shredder housing may be elongate and may be flexible. In some examples, the shredder housing may be formed of a polymeric material or a laser cut hypotube (hypotube) that is flexible along its length. The housing can be configured to apply suction therethrough (e.g., it can enclose the suction lumen 4333). The shredder housing may enclose the rotating cutter 4329. In fig. 43, the cutter is a cylindrical cutter that includes one or more windows (cutter windows 4331) or openings therethrough. The cylindrical cutter may be configured to fit into the shredder housing and, in some examples, be retained within the distal region. For example, the distal region may include a channel or waist region (waisted region) that limits or prevents the cutter from moving proximally and/or distally away from a shredder window 4327 formed in the elongate housing. The cutter may be coupled to the proximal end of the drive shaft 4317. In fig. 43, the drive shaft is a wire that rotates eccentrically within the housing to rotate 4343 the cutter, such that the cutter window rotates relative to the shredder window, shearing, such as by attracting any clot material that is drawn into the window region when opened.
As described above, in any of the cutters described herein, the cutter activity may be monitored by monitoring inputs to the cutter subsystem, including power demand/load on the cutter drive. In some examples, a shredder sensor 4311 may be included to detect shredder response based on vibration (e.g., accelerometer), sound (microphone), etc. The sensor may be positioned near the cutter, including in some examples, adjacent the cutter.
In variations in which the extraction inlet is covered by a cover having apertures, any of the methods described herein may include detecting the presence of a clot and/or distinguishing clot material from other materials such as the wall of a blood vessel based on the status or response of the apertures leading into the extraction chamber region. The relative open state of the pores may reflect the presence or absence of a clot material. For example, fig. 44 illustrates one example of a method of detecting clot material and/or distinguishing between clot material and vessel wall material based on the open state or response of a hole through a cover of an extraction chamber.
In fig. 44, the method can include positioning (e.g., moving) a thrombectomy device within a patient's blood vessel, for example, by a guidewire and/or diagnostic catheter advancement device 4401. By detecting the opening of a hole through a cover covering the extraction inlet, clot material 4403 within the extraction zone of the extraction inlet (also referred to herein as a suction inlet) of a thrombectomy device can be detected. For example, the device may include applying an attracting pulse (e.g., manually or automatically, periodically or intermittently triggered, etc., as described above) 4405, and detecting separation between two or more sides of an aperture through a cover at least partially covering the extraction inlet before, and/or after, and/or during the attracting pulse. The separation between two or more sides, which may be gates, doors, etc., may be detected by any suitable technique. For example, the opening may be detected 4407 by an impedance sensor, an optical sensor, a magnetic sensor, or the like. The extent of the opening may be determined by comparing 4409 the separation of the sides of the hole to a value or range of threshold values (e.g., based on separation of the sides prior to approaching the clot material). If the separation is greater than threshold 4411, a controller (which may receive input from one or more sensors detecting the opening/position of the aperture) may determine that clot material is present based on the extent to which the aperture is opened; as described above, this may trigger a clot extraction response (e.g., alert/alarm, display, etc., manually or automatically opening a mechanical extractor, e.g., suction, opening/controlling a chopper, etc.) 4413. Optionally, the controller may also stop the clot extraction response (e.g., stop or reduce aspiration and/or other mechanical extraction, and/or shredding) 4415 when the separation of the sides of the aperture is less than a threshold or range.
Fig. 45 shows an example of a device similar to the device described above but configured to detect opening and/or separation of a hole. In fig. 45, the device includes an elongated body 4513 that encloses a suction lumen; the suction lumen may house a shredder 4507, and the shredder 4507 may also enclose the suction lumen to apply suction 4519 through the shredder in the extraction chamber 4511. The extraction chamber may extend from a distal region of the device and may be expandable/collapsible. The extraction chamber region 4503 may include a distal face forming an extraction inlet 4521, which may be angled, curved (concave or convex) or frontal (en face) (e.g., flat) with respect to the distal end of the device. The device may also include a guide channel 4531 for coupling to a guide device 4535 (e.g., a guidewire, a diagnostic catheter, etc.). The extraction inlet may be covered by a covering that includes a hole 4566, which hole 4566 may open or close to allow clot to pass when suction is applied. In the example shown in fig. 45, the aperture includes a pair of sensors 4505, 4505 'on either side of the example of the aperture, the pair of sensors 4505, 4505' can detect the opening of the aperture, including the extent to which it is open. In fig. 45, the holes are slits, but other holes may be used, including two or more (e.g., three, four, etc.) gates, valves, and the like. The device also includes a controller 4545 that may control aspiration via an aspiration subsystem 4519 (e.g., aspiration regulator, pump, etc., as described above). The controller may also control the shredder 4507 via a shredder subsystem 4517 (e.g., shredder driver, etc.). In addition to sensor inputs, such as aperture opening sensor inputs, the controller may also receive inputs 4525 (e.g., user inputs). The controller may also provide output 4523 (e.g., notifications, reminders, etc.) to the user as described herein.
Fig. 46A and 46B illustrate the operation of a pair of hole sensors on a cover 4612 of a device such as that shown in fig. 45. In fig. 46A, the aperture includes two sides, but an aperture having more than two sides may be used, and a pair of sensors (e.g., a first aperture sensor 4605 and a second aperture sensor 4605') are positioned on either side of the aperture 4666. In fig. 46A, the hole is mostly closed; this configuration may represent a baseline for the hole when suction is applied but no clot material (or other occlusion) is present. Some suction may be applied through the aperture resulting in minimal blood loss. However, when there is a clot, the sides of the hole may be separated more as shown in fig. 46B. Separation 4615 may represent the side as the clot passes and may hold the clot until it is all sucked through the aperture, allowing it to close back to baseline separation (fig. 46A). As described above, the sensor may be an optical sensor, an electrical sensor (e.g., an impedance sensor), a contact sensor, a magnetic sensor, or the like.
Fig. 47 illustrates another example of a device configured to detect and control capture of clot material. In fig. 47, the device includes an elongated body 4713 that encloses a suction lumen. The device also includes a guide channel (guide lumen 4735 is shown). In this example, an external/external sensor 4708 is also included for detecting obstructive material within the extraction zone 4707 forward of the extraction inlet 4721 into the extraction chamber 4703. Alternatively or additionally, the device may include an impedance sensor (e.g., a pair of electrodes 4758, 4758') configured as a suction opening sensor. The suction opening sensor may be on the edge of the suction opening 4721 or it may be slightly recessed into the suction lumen. In some examples, the suction opening sensor (electrode) may be recessed within the edge of the suction opening 4721; alternatively, in some examples, the suction opening sensor (e.g., electrode) is flush with or extends protruding from the edge.
One or more internal sensors (forming sensing subsystem 4710) may be included for detecting clot material within the extraction chamber. As described above, the controller 4715 may be used to coordinate the operation of the aspiration subsystem (e.g., aspiration modulator) 4719. The example shown in fig. 47 may be modified to embody any of the features and/or examples described above. For example, the extraction inlet 4721 may be covered by a covering that may include apertures. One or more sensors may detect the open state of the device. In some examples, the external sensor 4735 may not be present. The example shown in fig. 47 does not include a shredder; in some examples, the apparatus may be configured to include a shredder. The controller may receive input from sensors, including a suction opening sensor and/or one or more internal sensors (e.g., impedance sensing electrodes, mechanical sensors, etc.).
Deflection sensor
As described above, in any of the methods and apparatus described herein, one or more deflection sensors may be used. The deflection sensor may include a deflectable member coupled at one end to a wall of a lumen of the device (e.g., a suction lumen); the second end of the deflectable member is configured to move (deflect) from an initial position in the first (undeflected) configuration into the second (deflected) configuration. The deflectable member may be configured to be elastically deformable such that the deflectable member may transition from an undeflected configuration in an unloaded state to a deflected configuration when a force is applied by pushing on clot material of the deflectable member, and the deflectable member may return to the undeflected configuration when a load is removed from the deflectable member. Typically, the deflectable member is configured to protrude into the lumen of the aspiration lumen.
The deflection sensor (and the device comprising the deflection sensor) may also include sensing circuitry to detect deflection of the deflectable member and encode the deflection as a signal that the controller may use to detect clot material and/or distinguish between clot material and the wall of the lumen. In particular, the controller may be configured to use signals from the deflection sensor and/or from one or more other sensors (e.g., pressure, flow, etc.) to determine that clot material is trapped in the aspiration lumen.
For example, fig. 48A-48C illustrate one example of a device that includes a deflectable member 4855 configured to detect clot material within a distal region (e.g., extraction chamber region 4803) of an elongate body of an aspiration catheter 4800. The aspiration catheter includes an elongate body and an aspiration lumen 4813 extending from a distal end to a proximal end. In the example shown in fig. 48, the aspiration catheter includes an extraction inlet 4821 at the distal end, the extraction inlet 4821 being angled relative to the long axis of the catheter. The aspiration catheter also includes a guide channel 4831 within which guide means 4835 can be used to assist in navigating and positioning the device. The guide 4835 can also be used to pass a guidewire. In this example, the extraction inlet comprises a covering that partially covers the distal end (forming a lip region).
In fig. 48A-48C, deflectable member 4855 is configured as a tentacle configured to assume a first undeflected configuration at rest (shown as a solid line) that protrudes from the wall of the lumen and traverses the aspiration lumen. In the example of deflectable members shown in fig. 48A-48C, a deflection sensor including a deflectable member is configured to electrically detect displacement of the deflectable member. For example, the sensing circuit may include a first electrode 4856, the first electrode 4856 being positioned on an opposite side of the lumen from the base of the deflectable member. The second electrode 4857 is positioned on the distal end of the deflectable member 4855 and may be separated from (or, in some examples, may contact) the first electrode 4856 by a small distance in the undeflected configuration. Optionally, a third electrode (not shown) may be included in an axially (e.g., longitudinally) offset position, but on the same side of the lumen as the base of the deflectable member. As described in greater detail below in fig. 51A and 51B, deflectable members and electrodes may be used to detect deflection of the deflectable members in use.
For example, fig. 48B shows the apparatus of fig. 48A after suction (including suction pulses) is applied. In this example, clot material 4820 is shown to be trapped (stuck) within the distal end region of the device (e.g., extraction chamber region 4803). The deflectable member is shown fully deflected such that the second electrode on the distal end of deflectable member 4855 is pushed away from first electrode 4856. In this example, deflectable member 4855 (tentacle) is thin and extends virtually across the entire diameter of the lumen. In some examples, the deflectable member extends only partially across the diameter of the lumen. The deflection sensor may provide a signal indicative of deflection of the deflectable member for a long period of time, indicating that a clot is trapped in the distal region of the device. In some examples, the controller may determine that the clot is trapped and may prompt the user to manually deploy (or may automatically deploy) the shredder 4807 to assist in removing the clot material. In some examples, the shredder may be insertable/removable, as shown in fig. 48A-48C, or it may remain in place in the distal region (e.g., within an extraction chamber region, which may also be referred to herein as a shredder chamber). For example, in fig. 48C, the chopper 4807 can be driven distally through the aspiration catheter aspiration lumen until it reaches the stop 4857, which prevents it from cutting the deflectable member 4855. The shredding of the clot may be performed with continuous and/or pulsating suction.
In general, deflectable member 4855 can be positioned within the aspiration lumen at a location near the distal end that prevents it from being substantially deflected by the vessel wall, which can be partially withdrawn into the lumen of the aspiration catheter, but can allow the deflectable member to be forcefully deflected by the stiffer clot material. For example, in some examples, deflectable member 4855 is positioned within x mm distal from the distal opening (e.g., 20mm, 18mm, 15mm, 14mm, 12mm, 10mm, 9mm, 8mm, 7mm, 6mm, 5mm, 4mm, 3mm, 2mm, 1mm, etc., e.g., between 1mm and 25mm, between 2mm and 25mm, between 3mm and 25mm, between 4mm and 25mm, between 5mm and 25mm, between 2mm and 20mm, between 3mm and 20mm, between 4mm and 25mm, between 4mm and 20mm, between 3mm and 15mm, etc.). In examples where the distal opening is angled relative to the long axis of the catheter (e.g., as shown in fig. 48A-48C), deflectable member 4855 may be positioned within 5mm of the nearest positioned end of the opening. For example, deflectable member 4855 may be between 2mm and 20mm from the distal opening.
The examples shown in fig. 48A-48C illustrate the use of electrical sensing to monitor deflection of deflectable members within an aspiration lumen (e.g., aspiration lumen) of an aspiration catheter to more effectively remove a clot from a blood vessel. The device in this example includes an elongate shaft defining a lumen having distal and proximal ends, at least two electrodes 4857, 4856, and a proximal handle (not shown). The first pair of electrodes may be positioned axially within about 5mm from the distal end and radially in the same plane (e.g., transverse to the long axis of the catheter). The second electrode is exposed within the wall at the distal end of deflectable member 4855, including distal and proximal conductive portions and an insulator extending along the length of the elongate shaft of the deflectable member. The distal portion of the electrode then extends from the surface of the elongate shaft through the longitudinal axis of the lumen and is positioned within about 0.01mm-2mm from the first electrode on the inner surface of the inner suction lumen 4813. A small region of the distal portion of the second electrode proximate the first electrode may be electrically conductive, with the remainder of the electrode passing through the lumen and being insulated.
As mentioned, the deflectable member extending across the aspiration lumen may be configured to be flexible and, in some examples, may have a minimal surface area to minimize the area of obstruction within the lumen through which it passes. The flexibility of the deflectable member allows the second electrode to flex easily outwardly away from the first electrode on the opposing wall toward the inner surface of the lumen when sufficient force is applied; when the force is removed or reduced, the deflectable member may return to the starting position. The first electrode can be built into the inner surface of the aspiration lumen, and the conductive region of the first electrode can be positioned to encounter a fluid or object passing through the aspiration lumen. Thus, the first electrode 4856 can be flush with, recessed into, or can extend slightly protruding from the wall of the aspiration lumen. When the electrodes are energized and placed in a conductive solution (e.g., blood), the resistance between the electrodes increases as the electrodes separate. The change in resistance and the duration of such change may indicate whether there is east-west within the lumen, just attached to the distal end of the lumen, and/or through the lumen.
In some examples, the elongate shaft of the deflectable member is comprised of a polymeric inner liner (e.g., pebax, PTFE), a reinforcing layer (e.g., SS braided wire), and a polymeric outer sheath (e.g., pebax). The electrodes at the ends of the deflectable member may include 0.0005 to 0.003 inch round copper wire (magnet wire) coated with polyurethane and 0.003 to 0.015 inch nitinol wire. The wires may be placed together side-by-side and coupled together such that at least the distal ends are aligned. In one example, the wires are bonded together (head tgeater) by immersing at least 5mm of the distal portion into silicone and drying the silicone. In so doing, the two wires may have a thin coating around the wires, such as a coating less than 0.003 inches thick. The distal end of the magnet wire may then be exposed by removing the polyurethane and silicone coating, thereby creating a small conductive portion. In some embodiments, the exposed conductive portions may be just proximal to the distal end of the deflectable member, about 0.5mm apart. The first (e.g., lumen wall) electrode may comprise thin polyurethane coated copper wire (magnet wire) conductively affixed to a sheet (0.001-0.010 inches thick) of conductive material (e.g., copper). The electrode body may be integrated into the elongate shaft by placing an insulated electrode along the outer surface of the liner or reinforcement layer. The outer sheath may then be slid over the electrode and elongated reinforcement layer and shrunk using heat and thermal shrinkage to retain the electrode in place along the body of the shaft. The thin conductive film of the second electrode is folded around the distal end of the liner and compressed into the liner, securing it in place. The distal portion of the first electrode may then penetrate the liner adjacent the second electrode and be positioned through the longitudinal axis of the aspiration lumen such that the conductive portion of the first electrode is within about 2mm of the conductive portion of the second electrode. The proximal end of the electrode may then be extended to the distal end of the catheter (e.g., to the handle) to allow the electrical circuit to be completed and energized/monitored, for example, by a controller.
Fig. 49 shows a first example of a device comprising a suction catheter 4900, a shredder 4907 that can be inserted/removed from the suction catheter, and a controller 4915 that controls application of suction through the shredder and/or suction catheter. The device also includes a deflection sensor including a deflectable member 4955 for detecting when clot material is in the distal end of the aspiration catheter. In this example, the suction catheter further includes one or more additional deflection sensors (including a second or more deflectable members 4955') positioned along a length of the suction lumen 4913 of the suction catheter. The deflectable members 4855, 4855' are shown in solid lines in the undeflected configuration and in dashed lines in the deflected configuration.
In fig. 49, the aspiration catheter 4900 includes a distal opening 4921 into the aspiration lumen (a distal region extending proximally from the distal opening may be referred to herein as an extraction region of the aspiration lumen). As mentioned, deflectable member 4955 may be positioned slightly proximally relative to distal opening 4921 such that it will detect a clot that is drawn into the distal opening during an aspiration pulse, but will not deflect significantly from the vessel wall. For example, it may be recessed into the suction lumen 4913 between 2mm and 25 mm. The spacing may depend on the diameter and orientation of distal opening 4921. In examples where deflection of deflectable member 4855 is electrically detected as part of the detection circuit, the deflectable member may include an electrode at the deflection distal region, and the electrode may be positioned relative to electrode 4956 on the lumen wall. In some examples, one or more additional lumen electrodes (e.g., axially offset and on the same side of the lumen as the base of the deflectable member) may be included. The proximal end of the aspiration catheter may include a handle (not shown) and/or may include a hemostasis valve 4962, and the chopper 4907 may be manually or automatically (e.g., robotically) inserted into the hemostasis valve 4962, and the chopper 4907 may include an elongate body and a distal cutter, such as a rotatable cutter. The shredder may also include an aspiration lumen (shredder aspiration lumen) and may include a drive member, such as a drive wire (not shown), for driving the distal cutter in rotation.
In general, the controller may control the application of suction through the catheter 4900 and/or the chopper, for example, through a valve (such as a three-way valve 4963). Alternatively or additionally, the valve may be controlled manually. The valve may allow suction to be applied from vacuum pump 4919, vacuum pump 4919 may pass through clot reservoir 4964 to allow (e.g., through a transparent window) observation of clot material, and filter blood through one or more filters 4965 into blood collection reservoir 4966. The controller may also control (e.g., via a drive shaft, not shown) a driver 4917 that drives the shredder cutter in rotation. The driver may also or alternatively be controlled manually.
The controller may include one or more inputs (e.g., keyboard, touch screen, buttons, touch screen, dials, sliders, knobs, etc.) and one or more outputs (screen, lights/LEDs, speakers, etc.). In any of these devices, the controller may also receive input from one or more deflection sensors. The controller may determine whether clot material is within the lumen of the catheter 4900 based on the deflection of the deflectable members 4955, 4955', and may trigger one or more outputs (e.g., a clot extraction response). For example, in some cases, the controller may apply or coordinate the application of one or more suction pulses from the suction catheter 4900 and may determine whether clot material is drawn into the suction lumen through the distal end 4921. The continued deflection of the deflectable member at the distal end 4955 may indicate that a large clot is present at the distal end region, and the controller may be configured to trigger a reminder so that the user may apply a more continued aspiration and/or if clot material is trapped at the distal end of the aspiration catheter, a shredder 4907 may be inserted and used to remove the clot material.
Fig. 50 shows another example of a device that includes a suction catheter 5000 (shown within a blood vessel 5001). The catheter 5000 includes a catheter shaft 5013. A deflection sensor including a deflectable member 5055 (configured as a whisker W1 in this example) is positioned at a distal region within the aspiration lumen of the aspiration catheter. The aspiration catheter also includes a second deflection sensor including a deflectable member (W2) 5055' at the proximal end of the aspiration lumen. The catheter also includes a hemostatic valve 5062 through which a chopper shaft 5083 may be manually or automatically inserted through the hemostatic valve 5062. In fig. 50, a valve (e.g., a three-way valve) 5063 is included to switch between applying suction to the aspiration catheter or the chopper (or neither). The valve may be an electric three-way valve (MOT) and may couple the catheter and/or chopper to a vacuum blood reservoir 5066 through a filter 5065 and a clot reservoir 5064. The vacuum pump 5019 can be coupled to the catheter and/or chopper through a reservoir 5066. The controller 5015 may be used to coordinate the suction, chopper, and/or sensors.
In any of the devices described herein, the controller may also coordinate the application of suction through the aspiration catheter 5000 and/or the chopper 5083 based on patient respiration and/or local pressure within the blood vessel distal to the aspiration catheter. For example, during a blood pressure pumping cycle of a blood vessel, when (or only when) the local pressure is low, the suction may be applied in a pulsatile manner.
Thus, any of these devices may include a blood pressure transducer 5072 (P1). The pressure transducer may be on the catheter at or near the distal end or may be separate, including externally. Alternatively or additionally, a distal catheter shaft pressure transducer 5071 (P2) may also be included on the aspiration catheter. The catheter may also include a proximal pressure transducer 5073 (P3). Any of these devices may also include one or more flow sensors/flow transducers 5077 (F). In fig. 50, the flow transducer is near the proximal suction port. In addition to deflection sensors, the controller may also receive input from any or all of these sensors/transducers.
The shredder may also include a driver in the shredder handle 5081 or may be in communication with the handle (Mac), and the controller may also receive an input/direct output from the handle, allowing the driver to be turned on/off and/or increased/decreased.
In fig. 50, the controller may coordinate one or more suction pulses from the suction catheter based on the sensed pressure wave 5079 of the blood vessel, and may detect clot material entering and/or exiting the suction lumen via two deflection sensors.
Fig. 51A illustrates the operation of a system such as that shown in fig. 48 and 49. In fig. 51A, the deflection sensor detects a change in impedance according to a distance between the tips 5157, 5157x of the deflectable member 5155 and the electrode 5156. As the deflectable member (e.g., the "tentacles") deflects toward the axial position as the clot passes therethrough, the distance between the electrode on the opposing wall and the tip of the deflectable member 5157 increases and thereby increases the impedance between these two points, which is reflected in the impedance measurement Z5190. Impedance measurements may be performed at a single or multiple frequencies. The frequency range may be, for example, between 0Hz (DC measurement) and 100kHz, and more particularly from a few Hz to a few kHz, such as about a few hundred Hz (e.g., 100Hz-900Hz, 100Hz-700Hz, 100Hz-500Hz, 100Hz-400Hz, etc.). In any of these examples, the frequency may be further tuned to multiples of 50Hz and 60Hz to reduce the amount of power cord interference, especially when long cables are used in order to reach the distal end of the catheter. Some examples of such frequencies may include 300Hz, 600Hz, 900Hz, etc. Higher frequencies may be susceptible to long cable length stray capacitance/inductance and may experience cross-talk, however long cable lengths may be advantageous to reduce the effects of electrode/electrolyte interface impedance. Thus, for this type of measurement, an intermediate frequency (e.g., several hundred Hz) may be optimal.
Advantages of AC measurement compared to DC measurement include: the signal may be less sensitive to induced noise because the measurement may be performed at the same frequency using a lock-in amplifier or using synchronous demodulation (which has the advantage of being less costly to implement), the AC may be less susceptible to electrode/electrolyte interfaces, particularly double layer capacitances generated at such interfaces. Impedance measurements may be achieved by two-wire or four-wire techniques described herein.
Alternatively, in some examples, the sensing circuit may instead include a second wall electrode, as shown in fig. 51B. In this circuit, an electrode 5157 at the distal tip of the deflectable member 5155 moves between the first electrode 5156 and the second electrode 5156'. Thus, the sensing circuit allows sensing deflection (V Output of ) by observing the output voltage as a function of tip position. In this example, the deflectable member (e.g., tentacle) position acts as an impedance divider (IMPEDANCE DIVIDER) to divide the source AC signal into values proportional to the relative position of the tentacles with respect to the source electrode. This approach may be less sensitive to absolute impedance values of the medium (e.g., blood or blood clot), but may be relatively sensitive to the relative position of the deflectable member. Furthermore, the technique may be less sensitive to the accuracy of the impedance source voltage amplitude and frequency. This technique can convert absolute impedance measurements into ratio-metric (ratio-metric) measurements that are less sensitive to measurement variations. Furthermore, the AC signal may be sinusoidal, square wave, saw tooth or any other (including arbitrary) shape. The output may be calculated based on the RMS value of the signal.
Fig. 52 is a graph illustrating the use of deflectable members to determine characteristics of clot sensing in the distal end of a device. For example, in fig. 52, there are three possible aspiration conditions, and a graph is shown that schematically shows how each of these conditions is reflected in the deflection of the deflectable member at the distal end region of the aspiration catheter and the flow rate and pressure within the aspiration lumen. For example, in fig. 52, at the far left, the case is where no clot enters the catheter during an aspiration pulse (100 ms pulse) applied through the aspiration catheter comprising the deflectable member. The deflection in this example may be determined by sensing a change in impedance of the circuit (e.g., as shown in fig. 51A). During the pressure pulse, a slight increase in impedance is seen, but as the attraction is turned off, the impedance decreases. During the application of suction, the flow rate is maximized, while the catheter shaft pressure is moderately reduced during suction. As shown, the flow through the conduit is greatest during the 100ms period of time when the valve is fully open. Conversely, when the suction pulse causes a blockage of the material, as shown by the middle column in fig. 52, a large block or blocks of clot material may become lodged in the distal end of the catheter. In this case, the deflectable member (e.g., whisker) deflection signal remains on even after the valve is closed. In addition, much lower flow rates are seen, as well as considerable pressure differences. In contrast, if the vessel wall is engaged with the distal opening of the catheter, the deflectable sensor will not detect deflection of the deflectable member, as shown, similar to the case where no clot material is detected. However, in contrast, deflection of the deflectable member may have a similar flow and pressure profile as when the catheter is not occluded (left-most scenario). For example, the pressure may increase during aspiration, but the flow rate may remain relatively low.
In general, the controller may use the data as shown above, which may be collected using all or a subset of these components (e.g., sensors).
In some examples, the system may initially close the suction (e.g., three-way valve) to prevent any suction through the shredder or suction catheter, and may turn on and operate the vacuum pump until the reservoir vacuum pressure reaches a target range (e.g., -700 to-760 mmhg). At this point, the user may activate the valve by pressing a control (e.g., button) on the catheter shaft, and may pump saline through the catheter to prepare the system prior to inserting the catheter into the patient's blood vessel. Once the system has completed the initial setup (and any self-test steps), operation may begin.
The user may then insert a suction catheter into the patient's blood vessel and advance it until it reaches the target area in order to perform a thrombectomy procedure using these devices. At this point, the catheter tip may or may not be sufficiently close to the clot to capture it by aspiration. To limit blood loss, the system may activate the vacuum for a very short time interval (e.g., 20-100 ms) and then evaluate the sensor to see what is indicated by the combination of information from the pressure sensor and/or deflectable member. As shown in fig. 52, the first situation is that the tip of the catheter may be too far from the clot and thus not be able to capture the clot when the vacuum is activated. In this case, the valve is opened to its 100% open window and for a period of 100 ms. The catheter pressure measured by P2 is negative, but not the maximum vacuum pressure, because there is free flowing blood in the system. The deflectable member (e.g., whisker W1) moves a small amount due to the force exerted by the flowing blood on it, but not the maximum force.
In the second case, the large clot is caught at the tip of the catheter when the valve is open. The clot does not allow any flow other than some leakage around it, so the pressure is near maximum and the flow is minimal, but the deflectable member (e.g., whisker W1) signals to its maximum level in view of the clot pressing the deflectable member (e.g., whisker W1) against the side of the catheter lumen. Once the valve is closed, the whisker signal remains high because the clot is still present and needs to be chopped or otherwise forced to move.
In the third case, the tip of the catheter is placed against the wall of the blood vessel and when the valve is opened, the wall is sucked into the opening of the catheter and prevents any fluid flow, except for some possible leakage. In this case, the pressure approaches the maximum vacuum with a minimum flow signal and no tentacle signal other than the minimum amount due to leakage of blood into the catheter.
Fig. 54A-54C, 55, and 56 illustrate other examples of deflection sensors that include deflectable members. In any of these deflection sensors, the deflectable member is configured such that a first portion of the deflectable member is secured to the aspiration lumen and the deflection end extends at least partially into the lumen such that forces resulting from blood clots contacting it deflect it. In fig. 54A-54C, the deflection sensor includes a deflectable member 5455, the deflectable member 5455 configured as a deflectable spring within the aspiration lumen. The spring can move relatively easily within the lumen of the aspiration lumen, with the distal end fixed and the proximal end free to move. The sensing circuit may include an inductive sensor (e.g., an inductance to digital LDC sensor) 5447, which may be used to detect changes in impedance/inductance, as shown in fig. 54B. The change in inductance may be detected when the spring is pulled proximally (e.g., due to a clot entering the distal opening 5421 and pulling the spring proximally under suction, or when the clot is stuck in the distal region), as shown in fig. 54C.
Fig. 55 shows another example of a deflection sensor that includes a deflectable member 5555 in the aspiration catheter 5500, the deflectable member 5555 including a shape sensing fiber (e.g., a fiber optic bend sensor) near a distal opening 5521 into the aspiration lumen. Bending of the deflectable member causes the optical shape sensor 5549 to reflect a signal of the bending of the deflectable member 5555. In this example. As in any of these examples, the deflectable member may revert to the undeflected configuration when a force (e.g., clot) is released or removed, e.g., due to aspiration and morcellation.
Fig. 56 shows another example of an apparatus 5600, the apparatus 5600 comprising a deflection sensor having a deflectable member 5655 and a sensing circuit that provides a deflection signal to a controller. For example, the deflection member may comprise a material whose resistivity varies as it bends. Thus, bending of the elongated deflectable member 5655 results in an increase in resistance on the conductive element. The elongate deflectable member may be similar to the type of sensor available from Flexpoint sensor systems company of drager, utah. The deformable member 5655 may be secured to the side of the lumen within a predetermined distance from the distal opening 5621, as described above, for example, by adhesive, fasteners, or other suitable techniques. Alternatively, a current source may be used to drive the resistive element to produce a higher range signal.
Fig. 57 illustrates another example of a suction catheter device 5700, similar to the device illustrated in fig. 56, including a deflection sensor having a deflectable member 5755 and a sensing circuit providing a deflection signal to a controller. For example, the deflection member may comprise a material whose resistivity varies as it bends. Thus, bending of the elongated deflectable member 5755 results in an increase in resistance across the conductive element. The deformable member 5755 may be secured to the side of the lumen within a predetermined distance from the distal opening 5721, as described above, such as by adhesive, fasteners, or other suitable techniques. In this example, a current source 5793 may be used to drive the resistive element to generate a higher range signal. The controller may process the output voltage to detect deflection.
Fig. 53 illustrates one method of operating an apparatus including the described deflectable sensor. Alternatively, the device may be positioned within a patient's blood vessel in the vicinity of the clot material 5301. The device may then detect the clot material 5303 near the distal opening into the device by applying the attractive pulse 5305 and detecting the deflection of the deflectable member 5507 (e.g., by detecting the deflection of the deflectable tentacles based on the electrical signal between the tentacle tips and the reference (fixed) electrode in the lumen). The resulting signal may be analyzed to determine if there is clot material in the distal end of the device and/or if the aspiration catheter is against the vessel wall. For example, deflection signals from time periods before/during and after the pulse may be compared. Alternatively, pressure and/or flow may be analyzed. As illustrated in fig. 52, a clot can be distinguished from a vascular wall or non-clot condition. If an occlusion is detected and the occlusion is a clot 5311, the device may trigger a clot extraction response 5313, e.g., to alert the user that a clot is present (in some cases, the system may alternatively indicate that the vessel wall has been contacted), and/or to open suction and/or open shredding. Optionally, the method may include stopping extraction (e.g., aspiration) 5315 when the deflection sensor no longer detects deflection of the deflectable member indicating the presence of a clot.
Fig. 58A-58C illustrate examples of impedance-based sensing systems for detecting clot material within a lumen. In any of the devices described herein, the intraluminal sensor (generally referred to herein as an intraluminal sensor, shown as an impedance sensor in fig. 58A) includes a pair of sensing electrodes 5860, 5860'. These intraluminal sensors may be positioned within the lumen of the distal region of aspiration catheter 5800 at a specified distance from distal opening 5821 so that clot material may lodge in the distal region in contact with first electrode 5860 and second electrode 5860', changing the impedance between the two electrodes, including changing the impedance when measurements are made at different frequencies, as described above. The separation distance from the distal opening may be selected so that clot material may enter and lodge within the lumen, but the vessel wall may not extend sufficiently close within the lumen of the aspiration catheter and thus alter the impedance in a predictable and useful manner.
Fig. 58B and 58C illustrate examples in which a plurality of impedance electrodes 5860 on one side are distributed at different longitudinal locations along the inner wall of one side of the aspiration catheter 5800 lumen. In fig. 58B, this may allow for the acquisition of individual position signals using a single electrode 5860 and a single reference electrode 5860 in an electrode array. Alternatively, fig. 58C shows an example in which both sides of the lumen of aspiration catheter 5800 include multiple electrodes 5860, 5860', allowing for further refinement of the longitudinal position of an intra-lumen occlusion (e.g., clot) and/or helping to distinguish clot material from vessel walls based on signal and/or signal location when in use.
Also described herein are methods of performing pulmonary embolism excision using the devices described herein. In this example, the aspiration catheter is advanced through the pulmonary valve, bent or steered into the pulmonary artery, to a location where the clot may be located. In some examples, the aspiration catheter may be passed through an access vein (ACCESS VEIN) (e.g., right subclavian vein or jugular vein) into the superior vena cava, through the right atrium, tricuspid valve, right ventricle, and pulmonary valve, to a putative clot (thrombus or occlusive embolus) located in the pulmonary artery or branch of the pulmonary artery (e.g., left pulmonary artery or right pulmonary artery). In practice, capturing a clot from the left pulmonary artery by aspiration has proven to be particularly difficult, as the required navigation may tend to drive the tip of the aspiration catheter into the wall of the blood vessel, which is difficult or impossible for most devices to distinguish from the clot.
The method may further comprise applying suction (e.g., suction/negative pressure). If the aspiration catheter is occluded, for example, such that the flow through the aspiration catheter is occluded, the devices described herein can distinguish between an occlusion caused by clot material and an occlusion caused by vascular anatomy (e.g., a vessel wall, valve, etc.). The device may output this information (e.g., occlusion identity information) which may be used by the device to determine how to proceed with the method, including automatically or manually. In some cases, if the obstruction is a clot material, this information can be used to trigger a clot extraction response. In some examples, this information may be used to control aspiration (suction) by adding or changing suction if the occlusion is a clot material, or to shut off suction if the clot material is vascular anatomy. In some examples, the device may issue an output (e.g., a reminder) that the occlusion is a clot material or that the occlusion is a vascular anatomy.
The device can distinguish between clot material and vascular anatomy (e.g., a vessel wall) by any of the techniques described herein. In some examples, the device may distinguish between clot material and vascular anatomy based on an intraluminal sensor located at a predefined location within the lumen of the aspiration catheter. For example, the device may determine whether the occluding material is a clot material or a vessel wall by detecting deflection of a deflectable member at a predetermined location within a lumen of a vessel.
Any of the methods (including user interfaces) described herein may be implemented as software, hardware, or firmware, and may be described as a non-transitory computer-readable storage medium storing a set of instructions capable of being executed by a processor (e.g., a computer, a tablet, a smartphone, etc.), which when executed by a processor, cause the processor to control the performance of any steps, including, but not limited to: display, communicate with the user, analyze, modify parameters (including timing, frequency, intensity, etc.), determine, alert, etc.
It is to be understood that all combinations of the foregoing concepts and additional concepts discussed in more detail below (provided that such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein and may be used to implement the benefits described herein.
Example
As described above, any of the methods and devices described herein may be used to detect and monitor (e.g., track) substances, including clot substances, within the lumen of an aspiration catheter. For example, a plurality of sensors (e.g., internal sensors) may be disposed along the length of the proximally extending lumen, allowing for tracking of clot material as it passes through the lumen. The controller of the device may transmit, store, analyze, and/or output (e.g., display) the tracking and/or detection of the substance within the lumen of the aspiration catheter. These methods and devices may improve removal of obstructive material from the vasculature by aspiration.
As noted above, the use of a large bore aspiration catheter to remove obstructive material from a blood vessel has been found to be effective, particularly in venous vasculature. Current techniques have limitations that increase the procedure time and present a safety risk of damaging the vessel walls of the vasculature. The cross-sectional area of obstructive material (e.g., clot) within the venous vasculature that needs to be removed may be greater than the cross-sectional area of the catheter for accessing the obstructive material. For example, a thrombus displaced from a peripheral vein of a leg and into a pulmonary artery may block blood flow through the pulmonary artery. Such thrombogenic material may be about 10-20mm in diameter and may be about 100mm in length or more. When the thrombus is dislodged, it is carried by the blood flowing to the lungs, and when the arteries begin to narrow and branch into various parts of the lungs, the thrombus may become wedged within the pulmonary arteries. Once wedged, the dislodged thrombus may span multiple vessels of the pulmonary artery, or may become lodged in a bolus and occlude the main pulmonary artery. Venous thrombi are composed of mainly erythrocytes and fibrin formed at low wall shear rates (WALL SHEAR RATES), imparting unique physical properties to the thrombus, allowing it to be compressed and elongated without tearing easily. The physical properties of the thrombus allow large pieces of thrombus to be removed from the vasculature through a smaller catheter. Current aspiration catheter technology typically relies on the compressibility of the thrombus and high aspiration flow rates, such as those produced by ultra high vacuum pressures (e.g., < -700 mmHg), to pull a large thrombus through a smaller aspiration lumen, which often results in the thrombus lodging within the aspiration lumen of the catheter, or even more dangerous, may result in the collapse of the vessel and the aspiration force of the catheter being applied to the thin wall of the vessel; the user is typically unable to evaluate either or which of these conditions is occurring. Instead, the user may see only that suction has been applied and little or no blood movement has been returned through the catheter. The user will typically wait to see if the thrombus continues to compress so that eventually the thrombus may be pulled through the catheter. While they are waiting, the user may try to increase the vacuum in the aspiration lumen multiple times. This procedure may take several minutes and typically does not result in a change, forcing the user to retract the catheter proximally and attempting to pull a thrombus with the catheter that may be stuck until the thrombus tears and blood flow begins to flush into the suction source. In some cases, the catheter must be retracted completely through the heart and pulled out of the patient, which requires the user to restart the procedure, meaning that the user must again pass through the heart and reenter the pulmonary artery being treated. The additional time and steps required increase the risk of the process. It would therefore be particularly advantageous to provide a system and method for removing obstructive material that enables a user to know what is happening in front of and/or within the lumen of the catheter (i.e., the aspiration lumen).
The methods and devices described herein may allow a user to monitor and/or track clot material within the lumen of an aspiration catheter, including identifying that the clot material (or in some cases the vessel wall) is occluded and/or its location of occlusion. The devices and methods may also allow the devices to distinguish between blockages of blood vessels, which may be cleared mechanically, and/or by adjusting (including increasing) the applied suction and collapse of blood vessels, which may instead require a decrease in the applied suction. Generally, these methods and devices can reduce the time and risk associated with removing thrombus from a blood vessel.
For example, such methods and devices, including aspiration catheters, may detect the presence of thrombus within the lumen of the catheter, measure at least one fluid parameter (e.g., flow rate, etc.) of the lumen of the catheter, may estimate the volume of clot material and/or blood within and/or through the lumen of the aspiration catheter, and may indicate this data to a user, store and/or transmit this data. In some examples, the devices and methods described herein can detect when an opening into the aspiration catheter (e.g., aspiration lumen) is aspirated onto the vessel wall and/or when the device is occluded by clot material.
Fig. 59A-59B illustrate one example of an apparatus as described herein. In this example, the device includes a catheter 5900, the catheter 5900 having a distal end 5901 and a proximal end 5902, with a flexible body 5903 extending between the ends. An internal (e.g., aspiration) lumen 5904 extends along the length of the catheter. At least one electrical property sensor (e.g., an impedance sensor) having at least one conductive surface, and in some examples preferably two conductive surfaces, is positioned within the lumen and configured to contact a substance (e.g., blood, clot, etc.) within the lumen. As described above, for example, fig. 1A, 11, 12, and 15-18E, a plurality of sensors (including surface electrodes) may be used. In fig. 59, the sensor includes two conductive surfaces that are spatially positioned relative to one another such that the impedance of a substance contacting the two surfaces can be measured and processed to determine contact with a clot substance or other substance within a lumen. The conductive surfaces of the sensing elements can be spatially radially aligned around the circumference of the inner lumen 5904 and/or axially aligned along the longitudinal axis of the inner lumen 5904, as shown herein. In this example, three sets of electrical (e.g., impedance) sensors are positioned longitudinally along the length of the lumen. The distal sensor (including the first sensing electrode 5905 and the second sensing electrode 5905') includes two conductive surfaces, each made of a conductive material (such as stainless steel), extending radially at least partially around the lumen of the aspiration catheter, for example extending between about 10-360 degrees (e.g., between about 20-360 degrees, between about 30-360 degrees, between about 40-360 degrees, between about 45-360 degrees, between about 60-360 degrees, above 10 degrees, above 20 degrees, above 30 degrees, above 45 degrees, above 50 degrees, above 60 degrees, above 70 degrees, above 80 degrees, above 90 degrees, etc.) relative to the inner diameter of the lumen. The electrode sensor may be secured to the body of the catheter such that the inward facing surface is exposed to objects passing through the interior lumen 5904 of the catheter. The conductive surface may form a continuous surface or may be a discrete surface that is electrically connected as a single sense electrode. In fig. 59A and 59B, the sensing electrode forming the sensor may be formed, for example, from a continuous strip of conductive material of a curved strip or ribbon about 1mm wide x about 0.13mm thick, forming a complete or partial loop extending around the lumen of the device, including at the distal end (e.g., distal region, extraction zone in some examples). Fig. 59B shows a cross section through the aspiration catheter of fig. 59A. In this example, the cross section shows the aspiration lumen 5904 as well as the guidewire lumen 5933 and the navigation lumen 5934.
As used herein, the ring sensor electrode ("ring electrode" or "ring sensor") may extend completely or partially around the inner wall of the aspiration catheter lumen. Thus, in some examples, the rings may be one or more annular rings arranged longitudinally, and may be continuous (as shown in fig. 59A), or may be discrete (see, e.g., fig. 11 and 12).
For example, in some variations, the ring electrode may be separated and pressed outwardly into the inner lumen of the catheter. The surface of the ring electrode may be thermally embedded or chemically bonded to the inner surface of the lumen. In some examples, small insulated wires may be mechanically secured to each conductive surface using a joining method (soldering). The insulated wire may extend through the length of the lumen and into the handle 5908 of the catheter. In fig. 59A, the device includes three sets (e.g., pairs) of sensing electrodes, one in each of the distal regions 5905, 5905', the proximal regions 5907, 5907', and at least one intermediate region 5906, 5906 '. In some embodiments, the wires may extend out of the handle 5908 and attach to an external signal processing source. In this example, the signal processing source 5909 may include a small battery powered PCB enclosed in the handle 5908, which is connected to the LED 5910 and the digital display 5911. The distal sensing electrodes 5905, 5905' may be distally located just proximal to the distal end 5901, e.g., at most 5mm from the distal opening, which may be a tapered or lateral (side-facing) suction opening in any of these suction catheters. In an aspiration catheter that includes a tapered or beveled distal end, the distal positioning may be relative to the proximal edge of the distal end 5901 of the device, as shown in fig. 59A. In this example, the conductive surfaces of the sense electrodes (ring electrodes) may be spaced apart by a distance of about 1-20mm, preferably about 2-5mm (edge-to-edge). The spacing of these surfaces can be selected to ensure that the passing thrombus will bridge across the conductive surface and allow for multiple sampling points during contact as the thrombus passes through the lumen. The distal sensor (including the sensing electrodes 5905, 5905') may be positioned distally relative to the distal end 5901 such that it may quickly detect substances that enter the interior lumen 5904, rather than substances (e.g., clots) that just touch or adhere to the distal end 5901 of the catheter. A second electrical sensor (including electrodes 5906, 5906') may be axially positioned along the interior lumen 5904 between the distal end 5901 and the proximal end 5902 of the catheter. In this example, the second sensor may be positioned between about 2-80cm, preferably about 30cm, proximal to the distal end 5901 of the catheter. This distance may be preferred because the thrombus passing through the lumen may move at a constant speed when completely withdrawn from the catheter. In some embodiments, this distance may also be preferred, as it may position the electrical sensor in a portion of the catheter proximal to the curved anatomy, for example, when accessing and treating the pulmonary vasculature. In some use cases of the invention, the user may use the sensing element as an indicator to stop aspiration power, which allows momentum to continue to move the thrombus through the lumen or allow the thrombus to stay in the lumen while more obstructive material is pursued. As noted above, this may help minimize blood loss during surgery. In this example, the conductive surface of the second electrical sensor (e.g., electrodes 5906, 5906 ') may be configured similarly to the distal sensor (e.g., electrodes 5905, 5905'), which is also shown spaced apart by about 2-5mm. Insulated wires may extend proximally from the sensor and may be attached to the same signal processing source 5909, for example in the handle 5908. proximal electrical sensor 5907 is positioned between second electrical sensor 5906 and a suction source (not shown) of the device. In this example, the proximal sensor (electrodes 5907, 5907') is positioned just distal to the proximal end 5902 of the catheter within the inner lumen 5904. A proximal sensor positioned in this location may detect when an obstructive material (e.g., a clot) has cleared the interior lumen 5904 of the catheter and may allow analysis of the material with the distal and second sensing elements to determine mechanical properties (e.g., mass and volume) of the obstructive material as well as mechanical properties of the catheter, such as a flow rate of the material (e.g., clot) through the device. the conductive surface of the proximal sensor (e.g., electrodes 5907, 5907 ') may be configured identically to the second sensor (electrodes 5906, 5906') and may be connected to a signal processing source 5909.
Fig. 60-63C illustrate examples of electrical sensors as described herein, particularly including sensors comprising annular ring electrodes. For example, fig. 60 shows an example of a device (e.g., system) that includes an embolectomy catheter having an elongate tubular catheter body 6004; an inner lumen 6006 through which a biological fluid or other substance (e.g., blood) and/or a solid or semi-solid substance (e.g., blood clot) can pass through the inner lumen 6006; a pair of conductive electrodes 6005, 6005' configured to substantially contact the biological fluid within the lumen; and an alternating current power supply (AC voltage) 6008 configured to establish and control a variable voltage between the sense electrodes, and also configured to sense, measure and record electrical impedance between the electrodes over time. In this example, the electrodes 6005, 6005' may operate as electrode pairs forming an electrical sensor, and may be configured to have a known fixed distance between the electrodes, as measured in the axial direction of the catheter, between about 0.5mm and 20mm, and more preferably between about 1mm and 10mm, for example between about 2mm and 5mm. The electrode pair may also be configured to be located proximal to the open inlet of the catheter, preferably between 0mm and 20mm from the open inlet, or more preferably between 1mm and 10mm from the open inlet of the catheter, measured in the axial direction of the catheter.
The system in fig. 60 is configured to allow the electrical impedance to be measured proximally of the electrode pair in the interior lumen of the catheter to detect changes in the time-varying content flowing through the catheter. In particular, the system may allow for detection of changes in substance density, composition and other characteristics that result in measurable changes in electrical impedance, such as the passage of blood clots. The apparatus may be configured to detect impedance, including amplitude and/or phase, from the sensor electrode at different frequencies.
Fig. 61 shows an example of a pair of conductive electrodes 6105, 6105', the pair of conductive electrodes 6105, 6105' shown being configured as two conductive annular rings through which a substance may pass. The electrodes may be connected to a variable power source 6108, for example to an AC voltage, AC current, or other electrical configuration that changes the voltage and/or current between the electrodes over time. The variable power supply is also configured to measure and record the electrical impedance between the two electrodes 6105, 6105'. In this example, the electrodes may measure primarily the fluid impedance in the axial space between the two ring electrodes.
In one example, as shown in fig. 62, an embolectomy catheter device (e.g., an aspiration catheter) can include a tubular catheter body 6204; an inner lumen 6206 through which biological fluids or other substances (e.g., blood) and/or solid or semi-solid substances (e.g., blood clots) may pass through the inner lumen 6206; a pair of distal conductive electrodes 6205, 6205', the pair of distal conductive electrodes 6205, 6205' being configured to be in substantial contact with the biological fluid and proximal to the open inlet of the catheter; a pair of proximal conductive electrodes 6207, 6207', the pair of proximal conductive electrodes 6207, 6207' being configured to remain a fixed distance from the pair of distal electrodes and in contact with biological fluid as measured in an axial direction of the catheter. The device may also include a first alternating current power source (e.g., AC voltage) 6208, the first alternating current power source 6208 being configured to establish and control a variable voltage between the sensors (e.g., distal electrodes 6205, 6205') and further being configured to sense, measure, and record electrical impedance between the electrodes of the distal electrode pair over time. The device may also include a second alternating current power source 6208 '(e.g., an AC voltage), the second alternating current power source 6208' being configured to establish and control a variable voltage between the proximal electrodes of the proximal electrode pair. The device may also be configured to sense, measure and record electrical impedance between the proximal electrodes over time.
In the example shown in fig. 62, the aspiration catheter may be configured to make impedance measurements at the distal electrode pair 6205, 6205 'and the proximal electrode pair 6207, 6207', allowing the system to cross-correlate signals to determine flow characteristics, for example: flow rate: the size and/or volume of the blood clot flowing through the catheter, etc.
During normal catheter use, the catheter tip at the location of the suction opening of the catheter may be occluded by venous tissue from the surrounding vessel wall, blocking flow and causing a certain amount of tissue to enter the open inlet region of the catheter. In this case, the distal electrode pair may detect a characteristic change in impedance indicative of the vein wall material entering the catheter, and the system may supply this information to the physician in real time.
Fig. 63A-63C illustrate another example of a set of electrodes forming an electrical sensor of an aspiration catheter, wherein the electrodes 6305, 6305' are configured as substantially annular partial ring segments. As mentioned, in any of these examples, the ring electrode may extend only partially around the ring of the aspiration lumen. For example, fig. 63B shows an example in which a pair of electrodes 6305", 6305'" forming an electrical (e.g., impedance) sensor are configured as a plate-like structure that extends only partially (e.g., between about 30-50 degrees) around a lumen and that may be mounted diametrically opposite one another on an inner surface of a catheter wall. In this example, the electrode pair may measure the electrical impedance across the catheter lumen when connected to a variable power source. The electrodes 6305", 6305'" may be configured as a set of two electrodes, a set of three electrodes or a set of any number of electrodes. In addition, multiple sets of ring segment electrodes may be employed at locations along the length of the catheter to measure and record additional flow characteristics, such as the flow rate, size, and mass of blood clots, etc.
Fig. 63C shows an alternative example of an electrical (e.g., impedance) sensor for attracting the lumen of a catheter. In this example, the electrode pair includes electrodes 6315, 6315', which electrodes 6315, 6315' are configured as spiral conductive elements with overlapping spiral pitches such that the resulting electrode pair appears substantially as an annular ring pair (where two electrode elements are axially adjacent to each other) and as an annular segment pair (where two electrodes are completely adjacent to each other). The electrodes may be mounted on the inner surface of the catheter wall in contact with the internal biological fluid within the catheter. The spiral electrode may be connected to a variable power source (as described above) and may be configured to measure and record the electrical impedance of the internal flow within the catheter over time. These spiral electrode pairs may be located at any axial location in the catheter, and the catheter system may be configured with one, two, or more electrode pairs located at different locations along the axial length of the catheter to measure and record additional flow characteristics, such as the flow rate, size, and mass of blood clots, etc. The ring electrode shown in fig. 63A-63B and the spiral electrode shown in fig. 63C are examples of ring electrodes that extend radially around the aspiration lumen.
Fig. 64 shows an example of the output of a device such as the device shown in fig. 62, showing the impedance output over time of a distal sensor comprising a first pair of distal inner ring electrodes extending almost entirely around a lumen and spaced apart from each other by about 5mm and a second pair of proximal ring electrodes extending almost entirely around a lumen and spaced apart from each other by about 5mm. As shown, the trace from the distal sensor (sensing electrode pair) 6455 shows an initial low impedance (in ohms) that rises sharply when a thrombus enters the interior lumen at about 11.75 seconds and initially remains in the distal region so that the impedance signal remains high when the thrombus is pulled into the lumen 6457. A proximal sensor (sensing electrode pair) 6459 is shown. At about 12.75 seconds, the first sensor at the distal region shows a rapid rise and fall in impedance, indicating that clot material is breaking within the interior lumen of the catheter 6461. After a short period of time (e.g., about 0.6 seconds), the proximal sensor (sensing electrode pair) signal shows a similar impedance fingerprint 6463 as the thrombotic material exits through the lumen of the catheter. As shown in the sample data of fig. 64, these devices can detect the presence of clot material within the lumen of the catheter and, based on the differential timing 6466 (e.g., 0.6 seconds) of the signals between the distal sensor signal and the proximal sensor signal, can estimate and present the rate at which clot material travels along the known length of the catheter. In addition, this data can also be used to determine the approximate size of the clot material. For example, the length of the thrombus may be estimated based on the magnitude (in time) 6468 of the proximal signal and the rate of travel of the clot through the catheter (based on the time between similar signals from the distal sensor to the proximal sensor 6466 and the length of the catheter lumen).
Fig. 65 illustrates another example of a device described herein, including a catheter (e.g., aspiration catheter) 6500 for removing a substance from a blood vessel, a vacuum/aspiration subsystem 6519 (e.g., including a vacuum/aspiration pump, a filter, etc.), and a controller 6515 for receiving sensor data from aspiration opening sensor 6558 and/or internal sensors 6505, 6505', 6507', 6509 '. In fig. 65, the suction opening sensor 6558 can include two or more (e.g., a pair of) electrodes on or adjacent to an edge of the suction opening 6521. For example, the electrodes forming the suction opening sensor may be slightly recessed into the suction opening, or they may be on the edge of the suction opening (flush, recessed into the edge, or extending protruding from the edge). In fig. 65, only a single electrode is shown. The suction opening is on the side of the catheter. Three internal electrical impedance sensors are shown. For example, the first internal electrical impedance sensor includes a first set of electrodes 6505, 6505' shown at the distal region (e.g., near or adjacent to the suction opening sensor) including a pair of ring electrodes extending partially or entirely around the inner diameter of the suction lumen, as described above. The second internal electrical impedance sensor is shown as including a second pair of ring electrodes 6507, 6507', the second pair of ring electrodes 6507, 6507' extending partially or entirely around the inner diameter of the aspiration lumen approximately midway along the catheter (note that fig. 65 is not shown to scale). In fig. 65 a third internal electrical impedance sensor with a third set of ring electrodes 6509, 6509' is shown. More or fewer internal electrodes may be included. The flexible elongate catheter 6500 has a suction lumen 6513 extending therethrough, and the internal electrical impedance sensor is within the suction lumen.
In fig. 65, the controller 6515 may be coupled to an internal electrical impedance sensor and a suction opening sensor. The controller may also include or be coupled to a power source for applying energy to the internal electrical impedance sensor and the suction opening sensor. For example, the controller may control the application of alternating current between two or more electrodes of each sensor. Each sensor may be individually energized, or energy (e.g., alternating current) may be applied to all or a subset of the sensors together. The controller may be configured to apply a single frequency or multiple frequencies (e.g., between 1Hz and 5MHz, e.g., between 100Hz and 3MHz, etc.). The internal electrical impedance sensor and the suction opening sensor may be used to determine an impedance spectrum using a plurality of different frequencies. The frequency of the alternating current applied to the internal electrical impedance sensor may be the same as or different from the frequency applied between the electrodes of the suction opening sensor. In general, the controller may receive signals (e.g., impedance signals) from the internal electrical impedance sensor and the suction opening sensor, and may store, analyze, and/or transmit electrical signals (impedance signals). For example, the controller may detect obstructive material (e.g., a clot) within the aspiration lumen based on electrical impedance signals from the internal electrical impedance sensor.
In any of the devices described herein, the internal electrical impedance sensor and the suction opening sensor may be connected to the controller 6515 via one or more wired or wireless connections. For example, in fig. 65, the device includes conductive traces (e.g., wires, etc.) extending from each electrode of the internal electrical impedance sensor and the suction opening sensor to a connector 6587. The connector may be directly or indirectly coupled to the controller 6515. In some examples, the catheter device may include circuitry to pre-process signals from the internal electrical impedance sensor and/or the suction opening sensor. For example, the catheter device may include circuitry that amplifies, filters, and/or combines signals from the internal electrical impedance sensor and/or the suction opening sensor. In some examples, the circuit may be part of connector 6587.
In the example device shown in fig. 65, as described above, the aspiration lumen 6513 of the device 6500 can be coupled to a vacuum subsystem 6519 and/or can be coupled 6538 to a guide channel or navigation channel (not shown).
Although fig. 65 is described as having three separate internal electrical impedance sensors and suction opening sensors, in some examples, the electrodes forming these sensors may be shared between different sensors (e.g., current may be applied to a first electrode of a distal internal electrical impedance sensor, and impedance may be measured from one or more electrodes of a second internal electrical impedance sensor and/or a third internal electrical impedance sensor). Alternatively or additionally, the signal may be applied and sensed only between a subset of the electrodes forming the internal electrical impedance sensor and/or the suction opening sensor.
The internal electrical impedance sensors described herein, such as those shown in fig. 65, may be used to reliably and stably detect obstructive material, such as clot material or neoplasms, from within the aspiration lumen of an aspiration catheter (vegetation). Impedance measurements may also be used to track movement of material within/through the lumen (including but not limited to the rate of movement), detect or determine occlusion of the aspiration lumen, and/or determine an estimate of the amount of material passing through the aspiration lumen (e.g., removed from a blood vessel), and may determine the extent to which the material is destroyed.
Fig. 66 illustrates an example showing detection and/or tracking of clot material through a lumen of a suction catheter similar to that shown in fig. 65, the suction catheter including three sets of internal electrical impedance sensors (distal tip, intermediate and proximal). Each internal electrode sensor includes a pair of ring electrodes that extend partially around the lumen of the aspiration catheter. The controller is configured to sense Vrms using an AC frequency initially set to1 MHz. The sample blood clot in physiological saline is aspirated through an aspiration opening at the distal end of the catheter and the impedance of each internal electrical impedance sensor (e.g., the impedance across each pair of electrodes forming the sensor) is detected. In this example, the distal internal electrical impedance sensor includes a pair of ring electrodes spaced about 2.5mm from the proximal end of the aspiration opening and about 3mm from each other. The inner diameter of the catheter was about 0.275 inches. Repeated tests showed a success rate of 100% in detecting and tracking clot material through the aspiration catheter. In fig. 66, an exemplary trace shows an impedance signal 6605 detected at a first internal electrical impedance sensor that first detects clot material in the vicinity of the first internal electrical impedance sensor from a start time 6606 for a first duration 6607. The impedance signal 6617 of the second internal electrical impedance sensor at the middle region of the catheter also shows that an impedance signal indicative of the clot material was detected at the start time 6618 (showing some fragmentation of the clot as the impedance rises and falls over time). Finally, from a start time 6630, the third internal electrical impedance sensor displays an impedance signal 6629, which impedance signal 6629 indicates the presence of clot material at the proximal end of the catheter. The controller may use these impedance signals to track movement of the obstructive material through the lumen of the catheter, including determining an estimate of the rate of movement through the lumen. In this example, the locations of the internal electrical impedance sensors are known, and the impedance measurements of each internal electrical impedance sensor may be used to determine the onset of the passage of material in the vicinity of each internal electrical impedance sensor. As is evident in fig. 67, the characteristic shape of each impedance measurement (at 1MHz in this example) may be correlated to confirm that a particular substance is passing through each internal electrical impedance sensor. The number of peaks in the impedance signal and the variation in spacing between peaks can also be used to determine fragmentation (e.g., chipping) of the material. The controller may also detect the onset (e.g., when the clot material begins to pass through the lumen), the rate of material passing through the lumen, and/or the end of detection, i.e., when the clot material has passed completely through the lumen, based on the threshold value of the impedance signal. The controller may also sense occlusion of the lumen based on the impedance signal. The controller may control the operation of the attraction to increase/decrease and/or turn the attraction on/off based on the impedance signal from the internal electrical impedance sensor. For example, if the clot material moves slowly through the lumen, the suction may be increased (or conversely, if the clot material moves too fast, which may increase the amount of unwanted blood loss, the suction may be decreased). The controller may also shut down or reduce the attraction when no more clot material is detected, for example, at the proximal internal electrical impedance sensor.
The device shown in fig. 65 (similar to the devices described in fig. 1A-1D, 2-13, 20-23, 27A, 39B, 45-46B, 47) may also include a suction opening sensor to detect when obstructive material is at or near the suction opening. The impedance-based aspiration opening sensors described herein may be used when a force is applied (e.g., by driving the aspiration opening against a substance and/or wall) to more clearly detect and distinguish between a target substance (e.g., clot substance) and a non-target substance (e.g., vessel wall). Thus, any of these devices can be configured (e.g., the controller can be configured) to detect clot material when a force is applied at the suction opening. In any of these examples, the applied force may be an attraction (e.g., suction) applied through the suction opening. Thus, in any of these devices, the controller can determine when a force (e.g., a threshold of force) is applied, and can analyze the resulting signal from the suction opening sensor only when that force is applied. For example, in any of these examples, the controller may analyze a signal (e.g., an impedance signal or other signal) from the suction opening sensor when the pressure within the lumen (and thus at the suction opening) is above a minimum threshold that indicates that the suction opening is held/driven against an occlusion (clot, wall, etc.) within the blood vessel. Surprisingly, during this period, the resulting suction opening sensor signal may be more reliable, possibly because the applied force may prevent the presence of more than one substance (e.g., wall and clot, or clot and blood, or wall and blood or wall, clot and blood) in close proximity to the suction opening sensor. Thus, the resulting signal from the suction opening sensor may be more characteristic of a clot, wall or blood than a combination of these signals.
The above method can be used with almost any type of sensor, including the electrical (e.g., impedance) sensors shown above. In general, the methods and devices can include the use of techniques for identifying tissue types (e.g., clots, vessel walls, or blood) that can be sensed and classified when sampled from the tip of an aspiration lumen as part of a thrombectomy procedure (e.g., for pulmonary embolism). As described above, these techniques may include electrical impedance, capacitance (e.g., transient electrical response), ultrasound, optical transmission (e.g., spectroscopy), optical reflectivity, inductive coupling, mechanical deflection, thermal conductivity, and elasticity.
For example, electrical impedance may be sensed between two or more electrodes located at the aperture of the aspiration lumen. The electrical impedance may be used to distinguish tissue types and may be measured at different frequencies (e.g., between about 100Hz and about 10 MHz) using alternating current (e.g., sinusoidal, sawtooth, square wave, etc.). One or more frequencies may be used, including a frequency spectrum. In any of the impedance techniques described herein, the amplitude and phase of the response can be measured to fully characterize the load impedance seen between the electrodes. In some examples, only amplitude may be used. The effective resistance, capacitance, and/or inductance of the tissue may be calculated at each frequency and compared to known thresholds to classify the tissue as clot, vessel wall, or blood. These thresholds may be different depending on the size and spacing of the sense electrodes.
In any of these devices and methods, the sensing electrode may be located at the edge of the aperture (e.g., edge (rim)) or just slightly inward of the lumen, facing the interior of the shaft, e.g., recessed from the edge into the aspiration lumen. The one or more electrodes may be recessed solely into the material forming the edge and/or wall of the lumen, or they may be flush with or extend protruding from the edge or wall. Preferably, the electrodes may be slightly recessed and may be inwardly facing electrodes to help ensure that the tissue being measured is only the desired sample, and not other matter in the vicinity. For example, fig. 67 shows one example of a distal end of a catheter having a distally facing opening 6721, the distally facing opening 6721 forming a suction opening, and a pair of electrodes 6758, 6758' on the edge. The suction opening opens into the suction lumen 6713.
In any of the methods and devices described herein, the second sensor may be used in conjunction with a suction opening sensor to detect and/or identify clot material or to distinguish clot material from vessel walls and/or blood. For example, in fig. 68, the device includes a suction opening 6821, and the suction opening sensor includes a pair of electrodes 6809, 6809' at the distal end. The device also includes an internal impedance sensor comprising a pair of sensing electrodes 6807, 6807', the pair of sensing electrodes 6807, 6807' being positioned just proximal to the suction opening in fig. 68; alternatively, in variations in which the suction openings are on the slider of the catheter, they may be within the lumen and opposite the suction openings. Thus, in some examples, the device may use the electrical impedance of the second set of electrodes, as shown in fig. 68. For example, the controller may include information from an internal sensor at the time of the independent measurement to confirm whether the device is in contact with the vessel wall or clot material (e.g., when a force is applied to the tip, e.g., by applying suction from the suction lumen to the suction opening). This second pair of electrodes can be used to measure the impedance slightly deeper into the aspiration lumen and if the substance in contact with the aspiration opening shows a large change at those sensors it is more likely to be a clot substance, relatively the vessel wall cannot penetrate as far into the aspiration lumen even under negative pressure.
In any of these devices and methods, a transient electrical response may be used to help identify the type of substance in contact with the suction opening. For example, square wave pulses may also be used to evaluate the electrical properties of the tissue sample between the sensing electrodes described above and to measure the transient response of the electrode-tissue interface. This is shown in fig. 69A and 69B. The voltage rise time when exposed to square wave pulses through the series resistor can be used to quantify the effective capacitance of the electrode-tissue interface, another possible distinguishing characteristic between tissue types. In FIG. 69A, an exemplary circuit schematic shows an applied square wave pulse and a measured voltage (V Measurement of ) applied to the sense electrode. When square wave pulses are applied, the time constant of the rise time and/or the time constant of the fall time can be analyzed as shown in fig. 69B. The time constant may be characteristic of the substance being examined, such as clot material, blood and/or vessel walls.
Alternatively or additionally, in some examples, an ultrasonic transducer may be used to characterize the substance at the aspiration opening. For example, as shown in fig. 70, a pair (or more) of piezoelectric transducers 7028 can be used to distinguish tissue types at or near the aspiration opening 7021 (the opening to the aspiration lumen 7013) by observing acoustic impedance in continuous wave mode, or observing performance after discrete pings are performed on one transducer and measuring response, observing amplitude on the other transducer. For example, the controller may examine the response amplitude and threshold for each tissue type (e.g., blood, clot, vessel wall). As shown, the transducer may be placed at the tip of the catheter on either side of the aspiration opening.
Fig. 71 schematically illustrates an example of a catheter including an aspiration lumen 7213 in which light transmission/spectroscopy can be used to determine and/or confirm the presence of a particular type of substance (blood, vessel wall, clot, etc.) at the aspiration opening 7121 of the catheter. For example, the light transmission characteristics of tissue types may be another way of distinguishing them from each other. In particular, if an LED or other light source 7138 is placed at the tip of the catheter, and an optical detector 7139 can be positioned at the tip of the catheter on the opposite side from the emitter 7138, the detector 7139 can receive an optical signal from the light source that changes due to the transmission characteristics of the substance between the two (e.g., against the aspiration opening). This may be done at one frequency or a range of different electromagnetic frequencies to obtain spectral information about the optical transmission characteristics of the tissue sample. The tissue type may then be classified by a threshold in the transmission characteristics at certain frequencies.
Fig. 72 shows a similar configuration using optical reflectivity/spectroscopy. In this example, the catheter includes a suction opening 7221 leading to the suction lumen 7213, and optical reflection characteristics of tissue types can be used to distinguish them from one another. For example, an LED or other light source (emitter 7238) may be placed at (or within) the edge of the aspiration opening and may be integrated with an optical detector 7239, the optical detector 7239 also being placed at or on the edge of the aspiration opening near the emitter (LED or light source), and the optical reflectance properties of the substance in front of the sensor may be used to characterize the substance. One or more of these light sources/sensors at the tip of the catheter may be used to determine the average "color" of the substance in front of the aperture. In some examples, a single frequency, a distribution of several frequencies, or a broad spectrum may be used to find the reflection amplitude. The type of substance may then be determined based on the category by a threshold value of the reflection characteristic at a particular optical frequency.
Fig. 73 shows an example of a catheter including a suction opening sensor configured as an inductive coupling coefficient sensor. For example, the inductive coupling coefficient may be used to distinguish tissue types based on how much the tissue changes the coupling coefficient between two inductive coils 7328, 7328' placed, for example, near the tip of the catheter (e.g., on either side of the suction opening 7321 leading into the suction lumen 7313). When different substances are placed between coils, the coupling coefficient between coils (which may be based on the originally designed geometry) may vary. Thus, the coupling coefficient can be measured and a threshold value of this value can be used to distinguish the type of substance. The configuration of these coils may be embedded as traces in a flexible board that is wrapped around the end of the catheter.
Any of the devices and methods described herein may alternatively or additionally use thermal conductivity to help identify substances adjacent to (and/or in contact with) the aspiration lumen. The thermal conductivity can be used to distinguish the type of substance at the end of the conduit by determining the extent to which the substance is thermally conductive. For example, as shown in fig. 74, a heat source 7428, such as a resistor, may be used at the end of the catheter, and one or more heat sensitive elements 7329, such as a thermistor or thermocouple, may be used to measure the temperature at a nearby location (which requires heat to pass through the unknown substance). For example, the heat source 7428 and thermal sensor 7429 may be part of the suction opening (or simply recessed within the suction lumen 7413 relative to the suction opening 7421). Thermal conductivity can be measured to see how fast the temperature can rise when the heat source is turned on. The thermal conductivity may be used to characterize the type of substance (e.g., blood, clot material, vessel wall) between the heat source and the temperature sensor.
Alternatively or additionally, the elasticity of the substance at the aspiration aperture may be used to identify the substance. For example, the elasticity of a substance may be used to distinguish between blood, clots, and blood vessel walls based on the amount of force that the substance pushes back when facing an impact force. The type of tissue can be distinguished by pressing a known force (spring force or air or saline) into the substance and measuring the amount of force pushed back by the substance, in part because different substances (blood, clot, wall) can be liquids, gels and fibrous solids, which have very different elastic force pushing back characteristics when subjected to the mechanical force of an impact. For example, fig. 75 shows a device with one or more mechanical members 7528, 7528 'at a distal aspiration opening 7521 into the aspiration lumen 7513, which mechanical members 7528, 7528' can apply force in a first direction and measure response force in the opposite direction pushed back by the substance.
As described above, generally any of these sensor types and methods may be combined with force and/or pressure sensors to detect forces acting on the aspiration opening and/or negative pressure in the aspiration lumen, which may indicate something is occluding the aspiration opening; in general, the blockage may be due to clotting material or vessel wall.
Alternatively or additionally, any of these methods may be used as part of an internal sensor within the aspiration lumen. For example, fig. 76 shows a pair of internal sensors positioned within the lumen 7613 of the catheter proximal to the distal aspiration opening 7621. The first internal lumen sensor 7638 in this example can be an electrical (e.g., impedance) sensor including a first electrode and a second electrode. The second internal lumen sensor 7638' is shown just proximal to the first internal lumen sensor 7638, separated by, for example, 5cm or less. For example, two pairs of electrodes in close proximity within the lumen can measure the speed of the clot as it passes through the lumen by observing the time difference in the onset of the signal. The duration of the signal can be used with the velocity to determine the distance of the clot within the lumen and thus determine a volume estimate. This may allow for an estimation of clot volume even in cases where the speed of the clot within the lumen is not constant.
As described above, when impedance is used to determine a property of a substance at the distal end (e.g., at the aspiration opening) and/or within the aspiration lumen, or multiple frequencies may be used to distinguish between types of substances near or in contact with the electrode. For example, fig. 77A-77C illustrate the effects of different frequencies of alternating current applied when measuring the magnitude of the impedance of the aspiration opening sensor on either side of the aspiration lumen. For example, FIG. 77A shows the effects of applying 120Hz, 1kHz, 10kHz, 100kHz, and 1MHz when the aspiration opening (and sensing electrode) is in contact with the vena cava (model of the vessel wall) 7768 or clot material 7769. For each frequency, the percent change (% change) in impedance of each substance relative to blood is shown. In fig. 77B, the measured impedance (in ohms) for each of blood 7767, vena cava (wall) 7768, or clot 7769 is shown for each frequency (120 Hz, 1kHz, 10kHz, 100kHz, 1 MHz). Similarly, in fig. 77C, the impedance measured for each substance at different frequencies is shown. In fig. 7A-7C, the electrode is part of a suction opening sensor, wherein the electrode is located on an edge of the suction opening and suction is applied to secure the substance to the suction opening sensor.
Similar results can be seen when using different impedance sensor electrodes, as shown in fig. 78A-78C. In this example, the electrode is a flat head probe, rather than a ring electrode as shown in fig. 55 or 76, for example. In fig. 78A, the percent of impedance change of a vessel wall 7869 (e.g., vena cava test tissue) or clot material 7868 compared to blood at 120Hz, 1kHz, 10kHz, 100kHz, and 1MHz is shown. In fig. 78B, the measured impedance (in ohms) for each of blood 7867, vena cava (wall) 7868, or clot 7869 is shown for each frequency (120 Hz, 1kHz, 10kHz, 100kHz, 1 MHz). Similarly, in fig. 78C, the impedance measured for each substance at different frequencies is shown.
In general, in any of these devices and methods, the impedance level may vary due to the sensor geometry (e.g., flat probe versus tip electrode), but the overall trend remains unchanged, and when sensing across the aspiration opening, frequencies between about 100Hz (e.g., 120 Hz) and 100kHz (less than 1 MHz) appear to work best, with the largest delta (delta) seen at 100kHz (most like a real model), regardless of the geometry of these distal electrodes.
In general, the configuration of the sensor may provide more robust and efficient sensing when measuring impedance in any of the devices and methods described herein. Fig. 79A-79B, 80, and 81A-81B illustrate examples of different configurations of internal impedance sensors that may be used to sense and/or track substances within a lumen. For example, fig. 79A shows a first configuration of an internal electrical impedance sensor that includes two or more electrodes within the aspiration lumen. In this example, each sensor is coupled to a wire that extends proximally to a coupler that may be coupled to a controller for processing, storing, and/or transmitting impedance values. In each of these examples, the suction lumen has an inner diameter of about 0.25 inches (0.635 cm). In fig. 79A, a pair of at least partially annular electrodes surrounds a lumen; the first electrode is spaced about 1mm from the second electrode. In fig. 79B, a similar arrangement is shown, but with a much greater separation (e.g., 3 mm) between the first and second electrodes, and in this example, the first and second electrodes may be ring electrodes that extend completely (or nearly completely) around the lumen. FIG. 80 shows another example of an internal electrical impedance sensor in which a pair of ring electrodes extend as a complete ring around the suction lumen wall and the electrodes are spaced apart by about 5mm.
Any of these internal electrical impedance sensors may be configured as a quad detector, as shown in fig. 81A-81B, with four electrodes divided into two groups of two electrodes (e.g., two pairs of electrodes) each separated by a small distance. In fig. 81A, the first electrode and the second electrode of the first pair of ring electrodes are spaced about 3mm apart and the first electrode and the second electrode of the second pair of ring electrodes are spaced about 3mm apart. The first pair of ring electrodes is spaced about 10mm from the second pair of ring electrodes. Such a configuration may allow for detection of the rate of movement of a substance (e.g., clot substance) within the aspiration lumen from a single quaternary detector (internal electrical impedance sensor). Fig. 81B is similar to fig. 81A, but with a separation of about 5mm between the ring electrode pairs.
Various configurations of the internal electrical impedance sensors shown in fig. 79A-79B, 80, and 81A-81B were tested to estimate clot volume based on impedance measurements made with the internal electrical impedance sensors, and the results are shown in the graph of fig. 82. In this example, configuration a corresponds to the example shown in fig. 79A, configuration B corresponds to the example shown in fig. 79B, configuration D corresponds to the example shown in fig. 81A, and configuration E corresponds to the example shown in fig. 81B. As can be seen in fig. 82, all of these variants have similar results.
Fig. 83 and 84 illustrate the tracking of clot material using different internal electrical impedance sensors similar to those shown in fig. 79A-79B, 80 and 81A-81B. In fig. 83, the change in impedance over time is monitored using differently configured internal impedance sensors as the device removes clot material through the aspiration lumen. For example, signals 8301, 8401 from an internal impedance sensor such as shown in fig. 79A are similar to signals shown as signals 8303, 8403 from an internal impedance sensor such as shown in fig. 79B. Each internal impedance sensor configured as a quad detector/sensor returns two signals (reflecting travel time) that are slightly delayed in time. For example, the internal impedance sensor of fig. 81A returns slightly offset signals 8305, 8405 and 8307, 8407. Similarly, impedance sensor return signals 8309, 9409 and 8311, 8411, such as shown in fig. 81B. In this example, the impedance shows the removal of clot material, which remains quite organized as it travels along the length of the aspiration lumen. In contrast, in fig. 84, clot material rupture during travel along the aspiration lumen can be observed. In this example, the clot volume estimate may be highly variable when the clot breaks, as the clot volume determination may depend in part on the rate of travel of the clot material and the spacing of the electrodes. In addition, clot build-up may affect the ability to estimate clot volume and transport speed, and the impedance amplitude may be higher when the clot breaks, as shown in fig. 84.
In any of the devices and methods described herein, the size of the clot material (which may be further estimated from the known cross-sectional area of the aspiration lumen and the length of the clot material), the rate of travel of the clot material within the lumen, the presence or absence of clot material occluded within the aspiration catheter, etc. may be determined and output to a user, stored, transmitted, and/or further processed.
Fig. 85 illustrates one example of an apparatus as described herein, including many of the features described above. For example, fig. 85 includes a flexible elongate body 8513 (shown in two parts), the flexible elongate body 8513 including a distal region 8577, the distal region 8577 having a guide channel 8531 for a diagnostic catheter 8537 (and/or guidewire), the guide channel 8531 extending from a distal opening through the length of the elongate body. The distal region may include an extraction chamber region having a suction opening 8521 into a suction lumen extending along the length of the flexible elongate body. In this example, the suction opening at the distal end region of the flexible elongate body is side-facing (e.g., on the tapered distal end region). The distal region may also include one or more openings (not visible in fig. 85) into the aspiration lumen on a side of the distal region opposite the aspiration opening.
The distal end of the device also includes a suction opening sensor comprising two electrodes 8558, 8558' positioned at the edges of the suction opening. In this example, the electrodes are positioned at the 2 o 'clock and 10 o' clock positions, generally toward the proximal end of the aspiration opening. The electrodes of the suction opening sensor may be between about 0.1cm and 3cm long (about the perimeter of the suction opening) (e.g., between about 0.5cm and 2cm, etc.). Typically, positioning these electrodes in the proximal half (e.g., proximal 40%, proximal 35%, proximal 30%, etc.) may help sense matter in contact with the suction opening, e.g., between 9 o 'clock and 3 o' clock, or more preferably between 10 o 'clock and 2 o' clock, or between 11 o 'clock and 1 o' clock positions, as this is the area of highest flow density into the suction opening. The second set of internal impedance sensing electrodes 8507, 8507 'are positioned just proximal to the suction opening and suction opening sensor electrodes 8558, 8558'. The second set of internal impedance sensing electrodes may be configured to detect a substance (e.g., a clot substance) within the aspiration lumen and may be used in conjunction with (or in concert with) the aspiration opening sensor electrodes to confirm that the aspiration opening is in contact with the clot substance or to distinguish from the vessel wall when a force (e.g., suction) is applied to drive a distal region including the aspiration opening into the substance. The internal impedance sensing electrode may be spaced between about 0.1mm and 30mm (e.g., between about 1mm and 20mm, between about 1mm and 10mm, etc.) from the suction opening (proximal end). The internal impedance sensing electrode in this example comprises two ring electrodes extending partially around the wall of the aspiration lumen, but any shape of electrode may be used. The internal impedance sensing electrodes may be spaced from each other by any suitable distance, such as between about 0.1mm and 10mm (e.g., between about 0.5mm and 5mm, between 0.5mm and 3mm, etc.). The internal impedance sensing electrodes shown in fig. 85 each have a diameter (in the proximal-to-distal direction) of about 1 mm.
The internal impedance sensing electrode and the suction opening sensor electrode may each be electrically coupled to a wire, lead, trace, or the like, extending proximally along the length of the flexible elongate body and into the proximal handle 8509. In the example apparatus illustrated in fig. 85, the second internal impedance sensor is configured as a quad detector/sensor, comprising two sets of two internal impedance sensing electrodes 8536, 8536', 8537'. The second internal impedance sensor is still within the aspiration lumen, but is positioned within a portion of the aspiration lumen in the handle. The suction lumen may extend from the elongate body into the handle and may include a suction port 8597 at a proximal end.
In fig. 85, the apparatus further includes a controller 8515, the controller 8515 being coupled or connected (via a connector 8587) to each electrode of the internal impedance sensor (e.g., the first internal impedance sensor and the second internal impedance sensor) and the suction opening sensor. The controller in this example includes one or more outputs (e.g., display/LED, lights, tone/sound, etc.) and is configured to track the substance within the aspiration lumen. The controller may indicate (via the first LED) that the substance is within the distal end of the aspiration lumen and/or at the aspiration opening. For example, the controller may process the impedance signal (received after applying current to the distal internal impedance sensor and/or the suction opening sensor) to determine if or when the impedance in the internal impedance sensor and/or the suction opening sensor is greater than a threshold value indicative of a likelihood of being a substance (e.g., clot substance) other than blood and/or vessel wall. The controller may also indicate (e.g., by a second LED) that the substance has passed through (or is positioned proximal to) a proximal sensor, such as the quad detector/sensor shown in fig. 85. In some examples, the controller may indicate that a substance has passed and/or is nearby when a change in impedance (relative to the impedance in blood) exceeds a threshold. In some examples, the controller may determine the flow rate of the clot material by tracking the impedance change between the two pairs of electrodes at a known (e.g., 10 mm) distance, and may estimate the total volume of material passing through the proximal end (and out of the device) based on the flow rate and the total size of the clot material (e.g., the product of the time and flow rate at which the clot material was detected and the known cross-sectional area of the aspiration lumen at the region of the second internal impedance sensor). The controller may display an estimate of the volume and/or may store, transmit, or otherwise process this information.
When a feature or element is referred to herein as being "on" another feature or element, it can be directly on the other feature or element or intervening features and/or elements may also be present. In contrast, when a feature or element is referred to as being "directly on" another feature or element, there are no intervening features or elements present. It will also be understood that when a feature or element is referred to as being "connected," "attached," or "coupled" to another feature or element, it can be directly connected, attached, or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being "directly connected," "directly attached," or "directly coupled" to another feature or element, there are no intervening features or elements present. Although described or illustrated with respect to one embodiment, the features and elements so described or illustrated may be applied to other embodiments. Those skilled in the art will also recognize that a reference to a structure or feature that is disposed "adjacent" another feature may have portions that overlap or underlie the adjacent feature.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. For example, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items, and may be abbreviated as "/".
Spatially relative terms, such as "under", "below", "lower", "upper" and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" may include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms "upwardly ()", "downwardly (vertical)", "vertical", "horizontal", and the like are used herein for purposes of explanation only, unless otherwise specifically indicated.
Although the terms "first" and "second" may be used herein to describe various features/elements (including steps), these features/elements should not be limited by these terms unless otherwise indicated by the context. These terms may be used to distinguish one feature/element from another feature/element. Thus, a first feature/element discussed below could be termed a second feature/element, and, similarly, a second feature/element discussed below could be termed a first feature/element, without departing from the teachings of the present invention.
Throughout this specification and the claims which follow, unless the context requires otherwise, the term "comprise" and variations such as "comprises" and "comprising" will be understood to mean that the various components may be used in both methods and articles of manufacture (e.g. compositions and apparatus, including devices and methods). For example, the term "comprising" will be understood to imply the inclusion of any stated element or step but not the exclusion of any other element or step.
In general, any of the devices and methods described herein should be understood to be inclusive, but that all or a subset of the elements and/or steps may alternatively be referred to as being "consisting" or, alternatively, "consisting essentially of, the various elements, steps, sub-elements, or sub-steps.
As used herein in the specification and claims, including as used in the examples, and unless otherwise expressly stated, all numbers may be read as though there was a word of "about" or "approximately" before, even if the term does not expressly appear. The phrase "about" or "approximately" may be used in describing the magnitude and/or position to indicate that the value and/or position being described is within a reasonably expected range of values and/or positions. For example, a value may have a value of +/-0.1% of the stated value (or range of values), +/-1% of the stated value (or range of values), +/-2% of the stated value (or range of values), +/-5% of the stated value (or range of values), +/-10% of the stated value (or range of values), etc. Any numerical values set forth herein should also be understood to include about or approximate such values unless the context dictates otherwise. For example, if the value "10" is disclosed, then "about 10" is also disclosed. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. It is also to be understood that when a value is disclosed as being "less than or equal to" the value, "greater than or equal to the value" and possible ranges between the values are also disclosed, as will be properly understood by those of skill in the art. For example, if the value "X" is disclosed, then "less than or equal to X" and "greater than or equal to X" are also disclosed (e.g., where X is a numerical value). It should also be understood that throughout this application, data is provided in a variety of different formats, and that the data represents endpoints and starting points and ranges for any combination of the data points. For example, if a particular data point "10" and a particular data point "15" are disclosed, it should be understood that greater than, greater than or equal to, less than or equal to, and equal to 10 and 15, and between 10 and 15, are considered disclosed. It should also be understood that each unit between two particular units is also disclosed. For example, if 10 and 15 are disclosed, 11, 12, 13, and 14 are also disclosed.
While various illustrative embodiments have been described above, any of several modifications may be made to the various embodiments without departing from the scope of the invention as described in the claims. For example, in alternative embodiments, the order in which the various described method steps are performed may generally be changed, and in other alternative embodiments, one or more method steps may be skipped altogether. Optional features of the various device and system embodiments may be included in some embodiments and not in others. Accordingly, the foregoing description is provided primarily for illustrative purposes and should not be construed to limit the scope of the invention as set forth in the claims.
The examples and descriptions included herein illustrate by way of illustration, and not by way of limitation, specific embodiments in which the subject matter may be practiced. As noted, other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. Such embodiments of the inventive subject matter may be referred to, individually or collectively, herein by the term "application" merely for convenience and without intending to voluntarily limit the scope of this application to any single application or inventive concept if more than one is in fact disclosed. Thus, although specific embodiments have been illustrated and described herein, any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.
Claims (111)
1. An apparatus, comprising:
a flexible elongate catheter having an aspiration lumen extending therethrough;
An internal electrical impedance sensor comprising two or more electrodes within the aspiration lumen; and
A controller coupled to the internal electrical impedance sensor and configured to apply an alternating current between the two or more electrodes and detect obstructive material within the aspiration lumen based on an electrical impedance signal from the internal electrical impedance sensor.
2. The apparatus of claim 1, wherein the internal electrical impedance sensor is configured to operate at a frequency of 50kHz or higher.
3. The device of claim 1, wherein the internal electrical impedance sensor is within about 20mm of a suction opening to the suction lumen at a distal region of the flexible elongate catheter.
4. The device of claim 1, wherein the controller is further configured to output a signal indicative of obstructive material within the aspiration lumen.
5. The apparatus of claim 1, wherein the controller is configured to apply the alternating current after beginning aspiration through the aspiration lumen.
6. The device of claim 1, further comprising a second internal electrical impedance sensor comprising two or more electrodes at a proximal region of the aspiration lumen.
7. The apparatus of claim 1, further comprising a current generator configured to apply the alternating current.
8. The device of claim 1, wherein the two or more electrodes comprise a ring electrode extending at least partially radially around the suction lumen.
9. The apparatus of claim 8, wherein the ring electrode comprises a spiral electrode.
10. The device of claim 8, wherein the ring electrodes are spaced from each other by 0.1mm to 20mm.
11. The device of claim 8, wherein each of the ring electrodes extends radially 30 degrees or more around the suction lumen.
12. An apparatus, comprising:
a flexible elongate catheter having an aspiration lumen extending therethrough;
an internal electrical impedance sensor comprising two or more electrodes within the aspiration lumen between the proximal and distal ends of the flexible elongate catheter; and
A controller coupled to the internal electrical impedance sensor and configured to apply an alternating current between the two or more electrodes to detect obstructive material within the aspiration lumen based on electrical impedance signals from the internal electrical impedance sensor and to output a signal indicative of obstructive material within the aspiration lumen.
13. An apparatus, comprising:
a flexible elongate catheter having an aspiration lumen extending therethrough;
A suction opening at a distal region of the flexible elongate catheter;
A first internal electrical impedance sensor comprising two or more electrodes extending at least partially around the aspiration lumen at a distal region of the aspiration lumen;
A second internal electrical impedance sensor comprising two or more electrodes extending at least partially around the aspiration lumen at a proximal region of the aspiration lumen; and
One or more connectors at a proximal end region of the flexible elongate catheter, wherein the one or more connectors are in electrical communication with the first and second internal electrical impedance sensors, further wherein the one or more connectors are configured to be coupled to a controller to provide an electrical impedance input to detect obstructive material within the aspiration lumen based on electrical impedance signals from the first and second internal electrical impedance sensors.
14. The device of claim 13, wherein the first internal electrical impedance sensor is within about 20mm of a suction opening into the suction lumen.
15. The device of claim 13, further comprising a proximal suction port in communication with the suction lumen.
16. The device of claim 13, wherein the aspiration opening is on a tapered side of the distal region of the flexible elongate catheter.
17. The apparatus of claim 13, wherein the two or more electrodes of the first internal electrical impedance sensor comprise ring electrodes.
18. The apparatus of claim 17, wherein the ring electrode of the first internal electrical impedance sensor comprises a spiral electrode.
19. The apparatus of claim 17, wherein the ring electrodes of the first internal electrical impedance sensor are spaced apart from each other by a distance of between 0.1mm and 20 mm.
20. The device of claim 17, wherein each of the ring electrodes of the first internal electrical impedance sensor extends radially 30 degrees or more around the aspiration lumen.
21. A method of detecting obstructive material within a lumen of an aspiration catheter, the method comprising:
Applying suction through a lumen of the aspiration catheter;
Applying a variable current between two or more electrodes of a first internal electrical impedance sensor within the lumen of the aspiration catheter between a proximal end and a distal end of the aspiration catheter to generate an impedance signal; and
Based on the impedance signal, the obstructive material within the lumen of the aspiration catheter is detected.
22. The method of claim 21, wherein detecting the obstructive material comprises distinguishing obstructive material from blood within the lumen of the aspiration catheter based on the impedance signal.
23. The method of claim 21, further comprising outputting a signal indicative of obstructive material within the lumen of the aspiration catheter.
24. The method of claim 21, further comprising analyzing the impedance signal to detect a change in impedance, the change in impedance being indicative of an obstructive material being in proximity to the first internal electrical impedance sensor.
25. The method of claim 21, wherein applying the variable current comprises applying a variable current having a frequency of 50kHz or greater.
26. The method of claim 21, further comprising determining whether the obstructive material is occluded within the lumen based on the impedance signal.
27. The method of claim 21, wherein applying the variable current between two or more electrodes comprises applying a plurality of frequencies to obtain an impedance spectrum, wherein detecting the obstructive material within the lumen comprises detecting the obstructive material using the impedance spectrum.
28. The method of claim 21, further comprising determining a rate of movement of the obstructive material within the lumen.
29. The method of claim 21, further comprising applying the same or different variable current between two or more electrodes of a second internal electrical impedance sensor within the lumen of the aspiration catheter and detecting obstructive material within the lumen of the aspiration catheter in proximity to the second internal electrical impedance sensor.
30. An apparatus, comprising:
a flexible elongate body having an aspiration lumen extending therethrough;
a suction opening into the suction lumen at a distal region of the flexible elongate body;
A suction opening sensor comprising two or more electrodes positioned at an edge of the suction opening; and
A controller coupled to the suction opening sensor and configured to distinguish between a clot and a vessel wall based on an impedance signal between two or more electrodes when a force is applied to the flexible elongate body or through the suction lumen.
31. The device of claim 30, wherein the controller is configured to distinguish between a clot and a vessel wall when a negative pressure within the aspiration lumen exceeds a threshold.
32. The apparatus of claim 30, wherein the controller is configured to distinguish between a clot and a vessel wall when a mechanical force exerted on the aspiration opening is above a threshold.
33. The device of claim 30, wherein the suction opening is on a tapered side of the distal region of the flexible elongate body.
34. The device of claim 30, wherein the two or more electrodes of the suction opening sensor are recessed from the edge.
35. The device of claim 30, wherein the two or more electrodes of the suction opening sensor are recessed into the suction lumen at the edge.
36. The apparatus of claim 30, wherein the two or more electrodes of the suction opening sensor are equally spaced from each other on the edge of the suction opening.
37. The apparatus of claim 30, wherein the two or more electrodes of the suction opening sensor are positioned opposite each other across the suction opening.
38. The device of claim 30, wherein the two or more electrodes of the suction opening sensor are positioned opposite each other across the suction opening at a region of minimum diameter.
39. The device of claim 30, further comprising a plurality of smaller flow regulating openings into the suction lumen positioned adjacent the suction opening.
40. The apparatus of claim 39, further comprising a second impedance sensor comprising two or more electrodes positioned adjacent to the plurality of smaller flow regulating openings.
41. An apparatus, comprising:
a flexible elongate body having an aspiration lumen extending therethrough;
a suction opening into the suction lumen at a distal region of the flexible elongate body;
A suction opening sensor comprising two or more electrodes positioned at an edge of the suction opening; and
A controller coupled to the suction opening sensor and configured to distinguish between a clot and a blood vessel wall based on an impedance signal between the two or more electrodes when a negative pressure applied through the suction lumen exceeds a threshold.
42. An apparatus, comprising:
a flexible elongate body having an aspiration lumen extending therethrough;
a suction opening into the suction lumen at a distal region of the flexible elongate body;
a suction opening sensor comprising two or more electrodes positioned at an edge of the suction opening;
a proximal suction port in communication with the suction lumen; and
One or more connectors at a proximal end region of the flexible elongate body, wherein the one or more connectors are in electrical communication with the two or more electrodes of the suction opening sensor, further wherein the one or more connectors are configured to be coupled to a controller to provide electrical impedance input when a force is applied to the flexible elongate body or through the suction lumen to distinguish between a clot and a vessel wall.
43. The device of claim 42, further comprising a second set of two or more electrodes proximal to the suction opening sensor within the suction lumen, further wherein the one or more connectors are in electrical communication with the second set of two or more electrodes to provide differential electrical impedance input from the two or more electrodes of the suction opening sensor when a force is applied to the flexible elongate body or through the suction lumen to distinguish between a clot and a vessel wall.
44. The device of claim 42, wherein the suction opening is angled.
45. The device of claim 42, wherein two or more electrodes of the suction opening sensor are recessed from the edge.
46. The device of claim 42, wherein two or more electrodes of the suction opening sensor are recessed into the suction lumen at the edge.
47. The apparatus of claim 42, wherein two or more electrodes of the suction opening sensor are equally spaced from each other on the edge of the suction opening.
48. The device of claim 42, wherein two or more electrodes of the suction opening sensor are positioned opposite each other across the suction opening.
49. The device of claim 42, wherein two or more electrodes of the suction opening sensor are positioned opposite each other across the suction opening at a region of minimum diameter.
50. The device of claim 42, further comprising a plurality of smaller flow regulating openings into the suction lumen positioned adjacent the suction opening.
51. The apparatus of claim 50, further comprising a second impedance sensor comprising two or more electrodes positioned adjacent to the plurality of smaller flow regulating openings.
52. A method of distinguishing between a blood clot and a blood vessel wall, the method comprising:
Applying suction through a lumen of a flexible elongate catheter, wherein the flexible elongate catheter comprises a suction opening at a distal region and two or more electrodes at or adjacent the suction opening; and
When the force at the suction opening exceeds a threshold, it is determined whether the suction opening is engaged with a blood clot or the vessel wall based on impedance measured from two or more electrodes at or adjacent to the suction opening.
53. The method of claim 52, wherein the force at the aspiration opening comprises a negative pressure within the lumen.
54. The method of claim 52, further comprising transmitting a reminder indicating whether the suction opening is engaged with one or both of a blood clot and a blood vessel wall.
55. The method of claim 52, further comprising applying an alternating current having a frequency between about 1kHz and 1 MHz.
56. The method of claim 55, wherein the alternating current has a frequency between about 10kHz and 100 kHz.
57. The method of claim 52, further comprising delaying the step of determining whether the suction opening is engaged with a blood clot or with the vessel wall for a delay period after the force exceeds the threshold.
58. The method of claim 52, wherein determining whether the aspiration opening is engaged with a blood clot or a blood vessel wall is based on the following differences: the difference in impedance measurements from two or more electrodes at or adjacent to the suction opening and the impedance measurements from a second set of two or more electrodes positioned proximal to the two or more electrodes at or adjacent to the suction opening.
59. The method of claim 52, further comprising adjusting suction through the lumen based on impedance measured from two or more electrodes at or adjacent to the suction opening.
60. A method of removing obstructive material from a blood vessel, the method comprising:
Applying negative pressure to an aspiration lumen of a flexible elongate catheter, the flexible elongate catheter having an aspiration opening and two or more electrodes at or adjacent the aspiration opening;
While applying the negative pressure, making impedance measurements from the two or more electrodes at or adjacent to the suction opening; and
The negative pressure is adjusted based on the impedance measurements made.
61. An apparatus, comprising:
a flexible elongate body having an aspiration lumen extending therethrough;
A first pair of electrodes within the aspiration lumen;
a second pair of electrodes proximal to the first pair of electrodes; and
A controller coupled to the first and second pairs of electrodes and configured to track clot material within the aspiration lumen based on electrical impedance signals from the first and second pairs of electrodes.
62. The device of claim 61, wherein the first pair of electrodes comprises a pair of ring electrodes extending at least partially radially around the aspiration lumen.
63. The device of claim 62, wherein the pair of ring electrodes comprises ring electrodes extending radially around the aspiration lumen.
64. The apparatus of claim 62, wherein the pair of ring electrodes comprises spiral electrodes.
65. The device of claim 62 wherein the pair of ring electrodes are spaced apart from each other by a distance of between 0.1mm and 20 mm.
66. The device of claim 62 wherein each of the pair of ring electrodes extends radially 30 degrees or more around the suction lumen.
67. The apparatus of claim 61, wherein the first and second pairs of electrodes comprise a quad detector.
68. The device of claim 67, wherein the first pair of electrodes is spaced between 0.1mm and 20mm from the second pair of electrodes along a distal-to-proximal length of the suction lumen.
69. The apparatus of claim 61, further comprising an alternating current power source coupled to the first pair of electrodes and configured to apply a variable voltage.
70. The apparatus of claim 61, wherein the controller is further configured to determine the size of the clot material based on electrical impedance signals from the first and second pairs of electrodes.
71. The apparatus of claim 61, wherein the controller is configured to determine a flow rate of the clot material within the aspiration lumen based on electrical impedance signals from the first and second pairs of electrodes.
72. The apparatus of claim 61, wherein the controller is configured to distinguish between clot material and vessel walls based on electrical impedance signals from the first and second pairs of electrodes.
73. The apparatus of claim 61, wherein the controller is further configured to adjust the suction through the suction lumen based at least in part on the electrical impedance signal from the first pair of electrodes.
74. An apparatus, comprising:
a flexible elongate body having an aspiration lumen extending therethrough;
a suction opening into the suction lumen at a distal region of the flexible elongate body;
a first pair of electrodes within and extending at least partially around the aspiration lumen;
A second pair of electrodes proximal to and extending at least partially around the first pair of electrodes within the aspiration lumen;
a proximal suction port in communication with the suction lumen; and
One or more connectors at a proximal end region of the flexible elongate body, wherein the one or more connectors are in electrical communication with the first and second pairs of electrodes, further wherein the one or more connectors are configured to be coupled to a controller to provide electrical impedance input to track clot material within the aspiration lumen based on electrical impedance signals from the first and second pairs of electrodes.
75. The device of claim 74 wherein the first pair of electrodes comprises a pair of ring electrodes extending at least partially radially around the aspiration lumen.
76. The device of claim 75 wherein the pair of ring electrodes comprises ring electrodes extending radially around the aspiration lumen.
77. The device of claim 75 wherein the pair of ring electrodes comprises spiral electrodes.
78. The device of claim 75 wherein the pair of ring electrodes are spaced apart from each other by a distance of between 0.1mm and 20 mm.
79. The device of claim 75 wherein the pair of ring electrodes each extend radially 30 degrees or more around the suction lumen.
80. The apparatus of claim 74, wherein the first and second pairs of electrodes comprise a quad detector comprising two pairs of electrodes.
81. The device of claim 80, wherein the first and second pairs of electrodes are spaced apart from each other along a distal-to-proximal length of the aspiration lumen by a distance of between 0.1mm and 20 mm.
82. A method of tracking clot material within an aspiration lumen of a catheter, the method comprising:
Receiving a first impedance signal from a first pair of electrodes within the aspiration lumen;
receiving a second impedance signal from a second pair of electrodes within the aspiration lumen; and
One or more of a flow rate of a clot material and a volume of the clot material is estimated from the first impedance signal and the second impedance signal.
83. The method of claim 82, further comprising outputting one or more of a flow rate of the clot material and a volume of the clot material.
84. The method of claim 82, further comprising detecting occlusion of the catheter based on the first impedance signal and the second impedance signal.
85. The method of claim 82, further comprising adjusting suction through the suction lumen based on the first impedance signal and the second impedance signal.
86. The method of claim 82, wherein estimating one or more of a flow rate of clot material and a volume of clot material comprises correlating the first impedance signal and the second impedance signal.
87. The method of claim 86, wherein estimating one or more of a flow rate of clot material and a volume of clot material comprises determining a time difference between correlations of the first impedance signal and the second impedance signal.
88. A method, comprising:
Moving the thrombectomy device within the vessel;
detecting an occlusion within an extraction region distal to an extraction inlet of the thrombectomy device using a sensor configured to sense an occlusion within the extraction region of the thrombectomy device;
Determining whether the occlusion is a vessel wall or a clot material;
Triggering a clot extraction response if the occlusion is a clot material, wherein the clot extraction response includes one or more of: signaling to a user that the thrombectomy device is in contact with a clot material, activating an extractor to remove the clot material from the extraction inlet, and/or activating a shredder within an extraction chamber region of the thrombectomy device; and
Stopping the extractor when clot material is no longer within the extraction chamber region based at least in part on one or more of: a sensor configured to sense a change in the response of the chopper and the clot material within the extraction chamber region.
89. An apparatus, comprising:
an elongate body having an aspiration lumen extending therethrough;
An extraction chamber region in fluid communication with the aspiration lumen at a distal end region of the elongate body;
an extraction inlet opening into the extraction chamber region at a distal end of the extraction chamber region;
An obstruction sensor configured to sense an obstruction in an extraction zone distal to the extraction inlet; and
A controller configured to detect an occlusion within the extraction area using the occlusion sensor to determine whether the occlusion is a vessel wall or a clot material and trigger a reminder indicating a property of the occlusion, wherein the controller is further configured to manually or automatically activate aspiration within the extraction chamber area when the controller determines that the occlusion is a clot material.
90. An apparatus, comprising:
an elongate body having an aspiration lumen extending therethrough;
An extraction chamber region in fluid communication with the aspiration lumen at a distal end region of the elongate body;
a shredder within the extraction chamber region configured to shred the clot material within the extraction chamber region;
an extraction inlet opening into the extraction chamber region at a distal end of the extraction chamber region;
An obstruction sensor configured to sense an obstruction within an extraction zone distal to the extraction inlet; and
A controller configured to detect the occlusion within the extraction region using the occlusion sensor to determine whether the occlusion is a vessel wall or a clot material and trigger a reminder indicating a property of the occlusion, wherein the controller is further configured to manually or automatically activate aspiration within the extraction chamber region when the controller determines that the occlusion is a clot material;
wherein the controller is further configured to stop the drawing through the extraction chamber region when the controller determines that there is no more clot material in the extraction chamber region.
91. A method, comprising:
Moving the thrombectomy device within the vessel;
detecting an occlusion within an extraction region distal to an extraction inlet of the thrombectomy device using an optical sensor on the thrombectomy device;
Determining whether the occlusion is a vessel wall or a clot material based on the reflectance spectral values of the occlusion;
Triggering a clot extraction response if the occlusion is a clot material, wherein the clot extraction response includes one or more of: signaling to a user that the thrombectomy device is adjacent to clot material, applying suction from the extraction inlet, and/or activating a chopper within an extraction chamber region of the thrombectomy device; and
When clot material is no longer detected in the extraction chamber region, suction is stopped.
92. A method, comprising:
detecting an occlusion in an extraction area within a blood vessel adjacent to an extraction inlet of a thrombectomy device using an optical sensor on the thrombectomy device;
Determining whether the occlusion is a vessel wall or a clot material based on the reflectance spectral values of the occlusion;
Triggering a clot extraction response if the occlusion is a clot material, wherein the clot extraction response includes one or more of: signaling to a user that the thrombectomy device is in contact with a clot material, activating an extractor to capture the clot material, and/or activating a chopper within an extraction chamber region of the thrombectomy device; and
The extractor is stopped when the clot material is no longer detected within the extraction chamber region.
93. An apparatus, comprising:
an elongate body having an aspiration lumen extending therethrough;
An extraction chamber region in fluid communication with the aspiration lumen at a distal end region of the elongate body;
an extraction inlet opening into the extraction chamber region at a distal end of the extraction chamber region;
an optical sensor configured to sense obstructions within an extraction region distal to the extraction inlet;
A light source coupled to the optical sensor;
an optical detector coupled to the optical sensor; and
A controller coupled to the optical detector and configured to detect the occlusion within the extraction region and determine whether the occlusion is a vessel wall or a clot material based on a reflectance spectral value of the occlusion, wherein the controller is further configured to trigger a reminder indicating a property of the occlusion and provide manual or automatic activation of attraction within the extraction chamber region when the controller determines that the occlusion is a clot material.
94. An apparatus, comprising:
an elongate body having an aspiration lumen extending therethrough;
An extraction chamber region in fluid communication with the aspiration lumen at a distal end region of the elongate body;
a shredder within the extraction chamber region configured to shred the clot material within the extraction chamber region;
an extraction inlet opening into the extraction chamber region at a distal end of the extraction chamber region;
an optical sensor configured to sense obstructions within an extraction region distal to the extraction inlet;
A light source coupled to the optical sensor;
an optical detector coupled to the optical sensor; and
A controller coupled to the optical detector and configured to detect an occlusion within the extraction area and determine whether the occlusion is a vessel wall or a clot material based on a reflectance spectrum value of the occlusion, wherein the controller is further configured to trigger a reminder indicating a property of the occlusion and provide manual or automatic activation of attraction within the extraction chamber area when the controller determines that the occlusion is a clot material;
Wherein the controller is further configured to stop the aspiration based at least in part on one or more of the following when clot material is no longer detected within the extraction chamber region: a sensor configured to sense clot material within the extraction chamber region and a change in response of the shredder.
95. A method, comprising:
Moving the thrombectomy device within the vessel;
Detecting contact with an obstruction within an extraction zone adjacent an extraction inlet of the thrombectomy device using a sensor within or on a distal end of the thrombectomy device adjacent the extraction zone;
Determining whether the occlusion is a vessel wall or a clot material by applying suction from the extraction inlet and detecting the occlusion within an extraction chamber region of the thrombectomy device;
Triggering a clot extraction response if the occlusion is a clot material, wherein the clot extraction response includes one or more of: signaling to a user that the thrombectomy device is in contact with a clot material, applying or increasing suction, and/or activating a chopper within an extraction chamber region of the thrombectomy device; and
When clot material is no longer detected in the extraction chamber region, suction is stopped.
96. A method, comprising:
Moving the thrombectomy device within the vessel;
Detecting contact with an occlusion in an extraction region distal to an extraction inlet of the thrombectomy device using a sensor on a distal end of the thrombectomy device within or adjacent to the extraction region;
Determining whether the occlusion is a vessel wall or a clot material by applying suction from the extraction inlet and detecting the occlusion within an extraction chamber region of the thrombectomy device;
Triggering a clot extraction response if the occlusion is a clot material, wherein the clot extraction response includes one or more of: signaling to a user that the thrombectomy device is in contact with a clot material, activating an extractor to capture the clot material, and/or activating a shredder within an extraction chamber region of the thrombectomy device; and
Extraction is stopped when clot material is no longer detected in the extraction chamber region.
97. An apparatus, comprising:
an elongate body having an aspiration lumen extending therethrough;
An extraction chamber region in fluid communication with the aspiration lumen at a distal end region of the elongate body;
An extraction inlet opening into a distal end of the extraction chamber region;
A contact sensor adjacent to the extraction inlet within an extraction zone, wherein the contact sensor is configured to detect a contact pressure;
A sensing subsystem configured to detect clot material within the extraction chamber region; and
A controller coupled to the contact sensor and the sensing subsystem and configured to detect contact with an occlusion within the extraction area based on the contact sensor and to determine whether the occlusion is a vessel wall or a clot material based on the sensing subsystem, wherein the controller is further configured to trigger a reminder indicating a property of the occlusion and provide manual or automatic activation of attraction within the extraction chamber area when the controller determines that the occlusion is a clot material;
Wherein the controller is further configured to stop the aspiration when clot material is no longer detected within the extraction chamber region.
98. A method, comprising:
Detecting clot material within an extraction region distal to an extraction inlet of an intravascular thrombectomy device by applying an aspiration pulse through the extraction inlet;
Confirming that a clot material is within an extraction chamber region of the thrombectomy device by detecting the clot material within the extraction region during or immediately after the aspiration pulse;
Triggering a clot extraction response if clot material is confirmed within the extraction zone, wherein the clot extraction response comprises one or more of: signaling to a user that the thrombectomy device is in contact with a clot material, activating an extractor to capture the clot material, and/or activating a chopper within an extraction chamber region of the thrombectomy device; and
Extraction is stopped when clot material is no longer detected in the extraction chamber region.
99. A method, comprising:
Moving the thrombectomy device within the vessel;
detecting clot material within an extraction zone adjacent to an extraction inlet of the thrombectomy device by applying an aspiration pulse through the extraction inlet of the thrombectomy device while operating a chopper within an extraction chamber region of the thrombectomy device during or immediately after the aspiration pulse and confirming that clot material is within the extraction zone based on a change in chopper response;
Triggering a clot extraction response if it is confirmed that a clot material is within the extraction zone, wherein the clot extraction response comprises one or more of: signaling to a user that the thrombectomy device is in contact with the clot material, activating a mechanical extractor to capture the clot material, and/or activating a shredder within an extraction chamber region of the thrombectomy device; and
Based on the change in chopper response, extraction is stopped after clot material is no longer detected in the extraction chamber region.
100. An apparatus, comprising:
an elongate body having an aspiration lumen extending therethrough;
An extraction chamber region in fluid communication with the aspiration lumen at a distal end region of the elongate body;
An extraction inlet opening into a distal end of the extraction chamber region;
a shredder within the extraction chamber region; and
A controller configured to be coupled to an aspiration modulator and to control application of an aspiration pulse from the aspiration modulator through the extraction inlet when the shredder is operating, and to confirm the presence of clot material within the extraction chamber region by detecting a change in shredder response during the aspiration pulse, further wherein the controller is configured to perform one or more of: signaling the presence of a clot substance, activating suction to capture the clot substance, activating the chopper and/or stopping suction after clot substance is no longer detected within the extraction chamber region based on the chopper response during capture of the clot substance.
101. A method, comprising:
Moving the thrombectomy device within the vessel;
detecting clot material within an extraction zone adjacent to an extraction inlet of the thrombectomy device by applying an aspiration pulse through the extraction inlet of the thrombectomy device and detecting separation between two or more sides of a hole through a cover over the extraction inlet of the thrombectomy device;
triggering a clot extraction response if the separation between the two or more sides exceeds a threshold, wherein the clot extraction response comprises one or more of: signaling to the user that the thrombectomy device is in contact with a clot material, activating suction to capture the clot material, and/or activating a chopper within the extraction zone.
102. An apparatus, comprising:
An extraction chamber region in fluid communication with the aspiration lumen at a distal region of the elongate body;
an extraction inlet opening into the extraction chamber region;
a cover covering the extraction inlet;
a hole through the cover, the hole having two or more sides;
A sensor configured to detect separation between two or more sides of the aperture; and
A controller configured to be coupled to an aspiration modulator and control application of an aspiration pulse from the aspiration modulator through the extraction inlet and trigger a clot extraction response if separation between the two or more sides exceeds a threshold, wherein the clot extraction response comprises one or more of: signaling contact with clot material, activating suction to capture the clot material, and/or activating a chopper within the extraction chamber region.
103. An apparatus, comprising:
an elongate body having an aspiration lumen extending therethrough;
A deflection sensor extending at least partially into the aspiration lumen, the deflection sensor comprising a deflectable member having a first region coupled to a wall location within the aspiration lumen and a second region spaced from the first region by a length of the deflectable member, wherein the deflectable member has an undeflected configuration and a deflected configuration, wherein in the deflected configuration the second region has an axial offset relative to the wall location that is different than an axial offset between the second region and the wall location in the undeflected configuration; and
A controller configured to detect an occlusion within the aspiration lumen based on a signal from the deflection sensor indicative of deflection of the deflectable member.
104. An apparatus, comprising:
an elongate body having an aspiration lumen extending therethrough;
A deflectable whisker extending from a wall of the suction lumen;
a first electrode at a distal region of the deflectable whisker;
a second electrode on a wall of the suction lumen opposite the deflectable whisker, wherein the deflectable whisker has a first configuration in which the deflectable whisker extends through the suction lumen such that the first electrode is proximate the second electrode and a second configuration in which the deflectable whisker is deflected such that the first electrode is spaced farther from the second electrode than the first configuration; and
A controller configured to detect an occlusion within the aspiration lumen based on an electrical signal between the first electrode and the second electrode indicative of deflection of the deflectable whisker.
105. An apparatus, comprising:
An elongate body having an aspiration lumen extending therethrough, wherein a distal region of the aspiration lumen is configured as an extraction chamber region;
a deflectable whisker extending from a wall of the extraction chamber region;
a first electrode at a distal region of the deflectable whisker;
A second electrode on a wall of the aspiration lumen opposite the deflectable whisker,
Wherein the deflectable whisker has a first configuration in which the deflectable whisker extends to protrude across the extraction chamber region such that the first electrode is proximate the second electrode, and a second configuration in which the deflectable whisker is deflected such that the first electrode is spaced apart from the second electrode compared to the first configuration; and
A controller configured to detect an occlusion in the extraction chamber region based on the electrical signal between the first electrode and the second electrode and determine whether the occlusion is a vessel wall or a clot material.
106. A method, comprising:
Moving the device within the blood vessel;
Applying suction through a suction lumen of the device;
Detecting an occlusion within an extraction chamber region at a distal region of the suction lumen through the device using deflectable tentacles extending at least partially across the extraction chamber region;
Determining whether the occlusion is a vessel wall or a clot material based on an electrical signal between a first electrode at a distal end of the deflectable whisker and a second electrode in communication with a wall of the extraction chamber region;
triggering a clot extraction response if the occlusion is a clot material, wherein the clot extraction response includes one or more of: signaling to the user that the device is adjacent to clot material, applying continuous suction through the suction lumen, and/or activating a shredder within the extraction chamber region of the device.
107. A method, comprising:
applying suction intravascularly through a suction lumen of the device;
Detecting deflection of a deflectable member extending at least partially within an extraction chamber region at a distal end region of the aspiration lumen;
Determining whether the deflection is caused by clot material captured in the extraction chamber region;
Triggering a clot extraction response if clot material is captured in the extraction chamber region, wherein the clot extraction response comprises one or more of: signaling to the user that the device is adjacent to clot material, applying continuous suction through the suction lumen, and/or activating a shredder within the extraction chamber region of the device.
108. A method, comprising:
Moving the device within the blood vessel;
Applying suction through a suction lumen of the device;
Detecting an occlusion within an extraction chamber region at a distal region of the suction lumen through the device using deflectable tentacles extending at least partially across the extraction chamber region;
Determining whether the occlusion is a vessel wall or a clot material based on an electrical signal between a first electrode at a distal end of the deflectable whisker and a second electrode in communication with a wall of the extraction chamber region;
triggering a clot extraction response if the occlusion is a clot material, wherein the clot extraction response includes one or more of: signaling to the user that the device is adjacent to clot material, applying continuous suction through the suction lumen, and/or activating a shredder within the extraction chamber region of the device.
109. A method of performing pulmonary embolism excision, the method comprising:
advancing the aspiration catheter into the left pulmonary artery;
Applying suction through the suction catheter;
when flow through the aspiration catheter is occluded, determining whether the identity of the occlusion is a clot material or a vascular anatomy; and
An indicator of the identity of the clot material is output.
110. An apparatus, comprising:
an elongate body having an aspiration lumen extending therethrough;
a first internal impedance sensor at a distal region of the aspiration lumen;
A second internal impedance sensor at a proximal region of the aspiration lumen; and
A controller configured to track clot material within the aspiration lumen based on signals from the first and second internal impedance sensors.
111. An apparatus, comprising:
an elongate body having an aspiration lumen extending therethrough;
A first internal impedance sensor at a distal region of the aspiration lumen, the first internal impedance sensor comprising a first pair of ring electrodes extending proximally at least partially around the aspiration lumen;
A second internal impedance sensor at a proximal region of the aspiration lumen, the second internal impedance sensor comprising a second pair of ring electrodes extending proximally at least partially around the aspiration lumen; and
A controller configured to track clot material within the aspiration lumen based on the time-varying impedance signal from the first internal impedance sensor and the time-varying impedance signal from the second internal impedance sensor and to determine a size estimate of the clot material.
Applications Claiming Priority (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US63/202,880 | 2021-06-28 | ||
| US63/203,672 | 2021-07-27 | ||
| US63/287,049 | 2021-12-07 | ||
| US63/310,989 | 2022-02-16 | ||
| US202263345028P | 2022-05-23 | 2022-05-23 | |
| US63/345,028 | 2022-05-23 | ||
| PCT/US2022/035392 WO2023278495A2 (en) | 2021-06-28 | 2022-06-28 | Apparatuses and methods for controlling removal of obstructive material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118251183A true CN118251183A (en) | 2024-06-25 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202280058428.4A Pending CN118251183A (en) | 2021-06-28 | 2022-06-28 | Apparatus and method for controlling removal of obstructive material |
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| Country | Link |
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| CN (1) | CN118251183A (en) |
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2022
- 2022-06-28 CN CN202280058428.4A patent/CN118251183A/en active Pending
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