CN118215513A

CN118215513A - Systems and methods for ventricular assist support during epicardial oxygenation

Info

Publication number: CN118215513A
Application number: CN202280074842.4A
Authority: CN
Inventors: C·尼克斯; S·本施; K·伦茨
Original assignee: Abiomed Europe GmbH
Current assignee: Abiomed Europe GmbH
Priority date: 2021-09-10
Filing date: 2022-09-07
Publication date: 2024-06-18

Abstract

A controller for a blood pump, particularly a catheter-based intravascular blood pump, is configured to use detected or determined aortic pressure and left ventricular pressure to calculate a coupling factor, which is then used to determine how to adjust the rotational speed of the blood pump, such as when the blood pump is used in conjunction with an ECMO device.

Description

Systems and methods for ventricular assist support during epicardial oxygenation

Cross Reference to Related Applications

The present application claims priority from U.S. provisional patent application Ser. No.63/242,828 filed on 10 month 9 of 2021 and U.S. provisional patent application Ser. No.63/257,715 filed on 20 month 10 of 2021, the contents of which are incorporated herein by reference in their entireties.

Technical Field

The disclosed embodiments relate to a control system for in vitro membrane oxygenation.

Background

Cardiogenic shock (cardiogenic shock) is the main cause of death in patients with acute myocardial infarction (acute myocardial infarction, AMI) who have arrived in the hospital alive. Cardiogenic shock is caused by cardiac dysfunction or problems, which results in the heart failing to output sufficient blood to the body. Cardiogenic shock is sometimes referred to as obstructive shock.

External membrane oxygenation (Extracorporeal Membrane Oxygenation, ECMO) and external life support (Extra-Corporeal Life Support, ECLS) allow for blood gas exchange when the lungs are not working properly. For example, venous-arterial adventitia oxygenation (VA-ECMO) and venous-venous arterial adventitia oxygenation (VVA-ECMO) may involve the use of mechanical circulatory devices (e.g., for lung support) for patients experiencing oxygenation problems. In some cases, ECMO may be used in patients experiencing oxygenation problems due to cardiogenic shock or other forms of hemodynamic deterioration. In this case, the use of such a device may result in an increase in left ventricular afterload.

Ventricular assist devices (Ventricular ASSIST DEVICE, VAD) and catheter-based ventricular assist devices (such as intravascular blood pumps) may be used to mechanically unload the left ventricle (e.g., reduce left ventricular volume, thus resulting in a pressure drop) and/or decompress (decompression) the left ventricle (e.g., the volume of the left ventricle decreases, which may be driven by holes in the wall between the left atrium and the right atrium, resulting in a lower preload of the left ventricle). In some cases, this independent supporting flow may not be sufficient to treat the cardiogenic shock independently.

Disclosure of Invention

According to a first aspect of the present disclosure, a controller for a blood pump, such as an intravascular blood pump, includes a processor configured to control a rotational speed of a motor of a catheter-based intravascular blood pump using a first selectable mode of operation. The first selectable mode of operation includes the steps of: the method further comprises determining a coupling factor k using the detected or determined aortic pressure value and the detected or determined left ventricular pressure value, and adjusting the rotational speed of the motor based on the determined value of the coupling factor k. In general terms, the first selectable operating mode may make at least one adjustment to the rotational speed of the motor based on the determined value of the coupling factor k, the at least one adjustment being: increasing the rotational speed of the motor by a first amount when the coupling factor k is greater than a first threshold; when the coupling factor k is smaller than or equal to the first threshold value and larger than the third threshold value, the rotating speed of the motor is increased by a second amount, and the second amount is smaller than the first amount; reducing the rotational speed of the motor by a third amount when the coupling factor k is greater than or equal to the fourth threshold and less than the second threshold; when the coupling factor k is greater than or equal to the fifth threshold and less than the fourth threshold, reducing the rotational speed of the motor by a fourth amount, the fourth amount being greater than the third amount; when the coupling factor k is smaller than a fifth threshold value, reducing the rotation speed of the motor by a fifth amount, wherein the fifth amount is larger than the fourth amount; or a combination of the above. Optionally, the first selectable operation mode may be further configured to keep the rotational speed of the motor constant when the coupling factor is equal to the second threshold.

In some embodiments, in the first selectable mode of operation, the controller is configured such that when the coupling factor is outside of the target range, the controller will attempt to return the coupling factor to the target value and then not make any additional adjustments until the coupling factor is outside of the target range. The controller starts the speed adjustment process only if the coupling factor k is greater than the first threshold or less than the second threshold. Specifically, the speed adjustment is as follows:

When it is determined that the coupling factor k is greater than the first threshold, the controller starts a subroutine in which it steps up the rotational speed of the motor until the coupling factor k is below a predetermined value. Specifically, during the subroutine, when the coupling factor k is greater than a first threshold, the rotational speed of the motor is increased by a first amount, and when the coupling factor k is less than or equal to the first threshold but greater than a third threshold, the rotational speed of the motor is increased by a second amount, after which the pressure is measured and the coupling factor is determined. The loop repeats until the coupling factor k is determined to be less than or equal to the third threshold, at which point the subroutine is exited and the coupling factor is monitored back and only adjusted if the coupling factor is greater than the first threshold or less than the second threshold.

When it is determined that the coupling factor k is less than the second threshold, the controller starts a subroutine in which it gradually decreases the rotational speed of the motor until the coupling factor k is higher than a predetermined value. Specifically, during the subroutine, when the coupling factor k is greater than or equal to the second threshold and less than the fourth threshold, the rotational speed of the motor is reduced by a third amount; when the coupling factor k is greater than or equal to the fifth threshold and less than the second threshold, the rotational speed of the motor is reduced by a fourth amount, the fourth amount being greater than the third amount; and/or the rotational speed of the motor is reduced by a fifth amount when the coupling factor k is smaller than a fifth threshold, after which the pressure is measured and the coupling factor is determined. The loop repeats until it is determined that the coupling factor k is less than or equal to the third threshold, at which point the subroutine is exited and the monitoring of the coupling factor is returned and only adjustments are made if the coupling factor is greater than the first threshold or less than the second threshold.

The processor may be configured to adjust the rotational speed of the motor in the first selectable operating mode for a first predetermined time interval t (the first predetermined time interval t may be, for example, between every 5 seconds and 20 seconds, such as 10 seconds).

In some embodiments, the coupling factor k is determined within a second predetermined time interval (the second predetermined time interval may be, for example, between every 1 second and 5 seconds, such as 2 seconds).

In some embodiments, the coupling factor k is a quotient of an average of the detected or determined left ventricular pressure values and an average of the detected or determined aortic pressure values.

In some embodiments, the average of the detected or determined left ventricular pressure values and the average of the detected or determined aortic pressure values are determined within a third predetermined time interval (the third predetermined time interval may be, for example, between 8 seconds and 12 seconds, such as 10 seconds).

In some embodiments, the first threshold is 0.75, the second threshold is 0.55, the third threshold is 0.65, the fourth threshold is 0.65, and the fifth threshold is 0.15.

In some embodiments, the first threshold is the target coupling factor k value plus a limit value, the second threshold is the target coupling factor k value minus the limit value, the third target coupling factor k and the fourth target coupling factor k are the target coupling factor k values, and the fifth threshold is a value of 15% -35% of the target coupling factor k value.

In some embodiments, when the speed of the motor is adjusted by different amounts, the second and third amounts are 0.8% -1.9% of an operating range of rotational speeds of the motor (the operating range may be, for example, between 12,000rpm and 22,000rpm, determined as a difference between a maximum operating speed and a minimum operating speed at which the processor is configured to provide control), within which the processor is configured to execute the first selectable operating mode, the first and fourth amounts are 2% -4.5% of the operating range, and the fifth amount is 8% -19% of the operating range.

In some embodiments, the processor is further configured to detect pumping events and respond to such pumping events by: if the first pumping event is detected, the rotational speed of the motor is reduced by a fifth amount, if the second pumping event is detected, the rotational speed of the motor is reduced by a sixth amount, and after the second pumping event is detected within a predetermined time window (such as between 30 seconds and 5 minutes, or 2 minutes), the upper limit of the rotational speed of the motor is reduced by the sixth amount for a first period of time (such as, for example, between 10 minutes and 30 minutes, or 20 minutes).

The processor may be further configured to: detecting whether an ECMO device (such as VVA-ECMO or VA-ECMO) is operatively connected to the controller, and if no VA-ECMO device is detected, preventing selection or execution of the first selectable mode of operation; receiving a selection indicating that the processor should operate the blood pump using the first selectable mode of operation; or a combination of the above. In some embodiments, the processor may be configured to receive an input indicating that the user confirms that the ECMO device has been connected.

In some embodiments, a start-up procedure is used that quickly and safely brings the pump to the proper operating speed. To achieve this, the processor may be configured to, prior to executing the first selectable mode of operation: increasing the rotational speed of the motor from zero to a minimum rotational speed (such as between 5,000rpm and 50,000rpm, or between 20,000rpm and 40,000rpm, and/or between 25,000 and 31,000 rpm) that the processor is configured to use when executing the first selectable mode of operation; determining a coupling factor k using the detected or determined aortic pressure value and the detected or determined left ventricular pressure value; and adjusting the rotational speed of the motor based on the value of the coupling factor k. Specifically, the speed is adjusted by: if k.gtoreq.1, increasing the rotational speed by a sixth amount, and after a fixed period of time (such as, for example, between 5 seconds and 30 seconds, or 10 seconds), repeating the determining and adjusting steps; and if k <1, adjusting the motor speed according to the first selectable operation mode, and controlling the motor speed according to the first selectable operation mode after a fixed period of time.

In some embodiments, the sixth amount is between 5% and 30% of a range of rotational speeds of the motor within which the processor is configured to execute the first selectable mode of operation.

The controller may also be configured to allow the motor to operate in other modes, such as when the blood pump is not operating in parallel with the ECMO device. In some embodiments, the processor may be configured to operate in a second selectable operating mode, wherein the processor receives a selection of one of a plurality of predetermined operating speeds and adjusts the speed of the motor to the selected predetermined operating speed; and the processor may be configured to operate in a third selectable mode of operation wherein the processor is configured to increase the rotational speed of the motor to a maximum operating rotational speed at a predetermined rate.

In some embodiments, the controller is configured to exit the first selectable mode of operation if the pressure value for controlling the motor is determined to be unreliable. In some embodiments, when operating using the first selectable operating mode, the processor is further configured to determine whether the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both are unreliable, and to switch from the first selectable operating mode to the second selectable operating mode when the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both have been determined to be unreliable for a second period of time (such as, for example, between 30 seconds and 5 minutes, or between 1 minute and 3 minutes, or 2 minutes).

The processor may be further configured to cause the alarm notification to be activated if the coupling factor k is determined to be less than a fifth threshold until the coupling factor k is determined to be greater than or equal to a sixth threshold, the sixth threshold being greater than the fifth threshold and less than the fourth threshold. In some embodiments, the sixth threshold is between 20% and 15% of the target coupling factor k value.

In some embodiments, the controller further comprises a display controlled by the processor, a first port configured to operatively connect the processor with the catheter-based intravascular blood pump, an additional port configured to operatively connect the processor with an extracorporeal membrane oxygenation (ECMO) system; and a housing configured to contain at least the processor.

According to a second aspect of the present disclosure, a blood pump system includes a blood pump controller as described above, and a catheter-based intravascular blood pump operatively connected to the blood pump controller.

According to a third aspect of the present disclosure, an epicardial oxygenation (ECMO) system with ventricular assist comprises an epicardial oxygenation (ECMO) system and a blood pump system adapted to operate in parallel with the ECMO system, the blood pump system comprising a controller as described above and a catheter-based intravascular blood pump operably connected to the controller.

According to a fourth aspect of the present disclosure, a method for priming a blood pump, such as a catheter-based intravascular blood pump for use with an ECMO system. The method generally includes: increasing the rotational speed of the motor of the catheter-based intravascular blood pump from zero to a predetermined minimum rotational speed (such as, for example, between 5,000rpm and 50,000rpm, or between 20,000rpm and 40,000rpm, or 31,000 rpm); and determining a coupling factor k using the detected or determined aortic pressure value and the detected or determined left ventricular pressure value, and if k is ∈1, increasing the velocity by a fixed amount (such as, for example, between 5% and 30% of the operating range), and after a fixed period of time, repeating the steps of measuring the pressure and determining the coupling factor k until k <1.

In some embodiments, upon determining that the coupling factor k is less than 1, an automatic speed control mode suitable for use with an extracorporeal membrane oxygenation (ECMO) system is automatically switched.

A fifth aspect of the present disclosure is a method for operating a blood pump, such as a catheter-based intravascular blood pump for use with an extracorporeal membrane oxygenation (ECMO) system. The method generally includes: determining a coupling factor k using the detected or determined aortic position value and the detected or determined left ventricular position value; and adjusting a rotational speed of a motor of the catheter-based intravascular blood pump based on the determined value of the coupling factor k.

The method involves making at least one adjustment of the rotational speed of the motor based on the determined value of the coupling factor k, the at least one adjustment being: increasing the rotational speed of the motor by a first amount when the coupling factor k is greater than a first threshold; when the coupling factor k is smaller than or equal to the first threshold value and larger than the third threshold value, the rotating speed of the motor is increased by a second amount, and the second amount is smaller than the first amount; reducing the rotational speed of the motor by a third amount when the coupling factor k is greater than or equal to the fourth threshold and less than the second threshold; when the coupling factor k is greater than or equal to the fifth threshold and less than the fourth threshold, reducing the rotational speed of the motor by a fourth amount, the fourth amount being greater than the third amount; when the coupling factor k is smaller than a fifth threshold value, reducing the rotation speed of the motor by a fifth amount, wherein the fifth amount is larger than the fourth amount; or a combination of the foregoing. Optionally, the method may be further configured to keep the rotational speed of the motor constant when the coupling factor is equal to the second threshold.

In some embodiments, the rotational speed adjustment process may only be started when the coupling factor k is greater than the first threshold or less than the second threshold. Specifically, the speed is adjusted as follows:

In some embodiments, the speed is repeatedly adjusted at predetermined time intervals t, such as, for example, between every 5 seconds and 20 seconds, or 10 seconds.

As described herein, the coupling factor k is the quotient of the average of the detected or determined left ventricular pressure values and the average of the detected or determined aortic pressure values. In some embodiments, the average of the detected or determined left ventricular pressure values and the average of the detected or determined aortic pressure values are determined within a third predetermined time interval (the third predetermined time interval may be, for example, between 8 seconds and 12 seconds, such as 10 seconds).

In some embodiments, the first threshold is 0.75, the second threshold is 0.55, the third and fourth thresholds are 0.65, and the fifth threshold is 0.15.

In some embodiments, the first threshold is the target coupling factor k value plus a limit value, the second threshold is the target coupling factor k value minus the limit value, the third target coupling factor k and the fourth target coupling factor k are the target coupling factor k values, and the fifth threshold is a value between 15% and 35% of the target coupling factor k value.

In some embodiments, when adjusting the rotational speed of the motor by different amounts, the second and third amounts are 0.8% -1.9% of an operating range of rotational speeds of the motor in which the processor is configured to perform the first selectable operating mode (the operating range may be, for example, between 12,000rpm and 22,000rpm, determined as a difference between a maximum operating speed and a minimum operating speed in which the processor is configured to provide control), the first and fourth amounts are 2% -4.5% of the operating range, and the fifth amount is 8% -19% of the operating range.

According to one embodiment, the method may include detecting pumping events and responding to the pumping events by: if the first pumping event is detected, the rotational speed of the motor is reduced by a fifth amount, if the second pumping event is detected, the rotational speed of the motor is reduced by a sixth amount, and after the second pumping event is detected within the predetermined time window, the upper limit of the rotational speed of the motor is reduced by the sixth amount for a first period of time (such as, for example, between 10 minutes and 30 minutes, such as 20 minutes). This predetermined time window may be between 30 seconds and 5 minutes, and in one embodiment is 2 minutes.

The method may further comprise: detecting whether the ECMO device is operatively connected to the controller and if not, preventing selection or execution of the first selectable mode of operation; receiving a selection from the user interface indicating that the processor should operate the blood pump using the first selectable mode of operation; or a combination of the foregoing.

In some embodiments, the method is further configured to control the blood pump only when the pressure reading is reliable. In particular, the method may further comprise determining whether the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both are unreliable; and if the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both are determined to be unreliable for more than a second period of time (such as between 30 seconds and 5 minutes, and, in some embodiments, between 1 minute and 3 minutes, such as 2 minutes), stopping performing the method.

In some embodiments, the method is further arranged for the case where the coupling factor k is very low. Specifically, the method may further comprise causing the alarm notification to be activated when the coupling factor k falls below a fifth threshold value until the coupling factor k is determined to be greater than or equal to a sixth threshold value (such as, for example, a value between 20% and 50% of the target coupling factor k value), the sixth threshold value being greater than the fifth threshold value and less than the fourth threshold value.

Drawings

FIG. 1 is a schematic diagram of an embodiment of the disclosed controller as part of a system for providing ventricular assist support for epicardial oxygenation in use;

FIG. 2 is a schematic representation of a distal portion of an embodiment of a catheter-based intravascular blood pump;

FIG. 3 is a block diagram of the disclosed controller;

FIG. 4 is a flow chart illustrating an embodiment of a first alternative mode of operation;

FIG. 5 is a representative diagram showing the sensed or determined pressure used to calculate the coupling factor k;

FIG. 6 is a graphical depiction of the change in rotational speed value (N _set, bottom graph) of a motor versus coupling factor value (k _AIC, top graph) of a catheter-based intravascular blood pump;

FIG. 7 is a flow chart illustrating an embodiment of various security features embedded in a first alternative mode of operation;

FIG. 8 is a graphical depiction of an example of the rotational speed of a motor of a catheter-based intravascular blood pump being controlled when a pumping event is detected;

FIG. 9 is a flow chart illustrating an embodiment of a startup routine used prior to utilizing the first alternative mode of operation;

figure 10 is a graphical depiction of a catheter-based startup routine for an intravascular blood pump.

Detailed Description

Venous-arterial epicardial oxygenation (VA-ECMO) with Ventricular Assist Device (VAD) support has been tested for treatment of cardiogenic shock or other forms of hemodynamic deterioration, where the ECMO device maintains systemic circulation and the VAD unloads the left ventricle (sometimes referred to as LV decompression). However, in some cases, in such a configuration, the afterload of the heart may increase because the ECMO transfers blood back to the descending aorta, i.e. in a direction opposite to the normal blood flow. As afterload increases, the heart may need to work harder to overcome the pressure differential between the left ventricle and the aorta.

The performance of VADs may be challenged by these new conditions, such as decoupling of aortic and left ventricular pressures and higher afterloads. These two variations may affect the function of the safety features of the device, such as aspiration detection features based on differential pressure, aortic pressure, and pulsations thereof. While unloading the left ventricle, decoupling may result in the aspiration detection feature triggering an aspiration alert, some of which may be false positives, resulting in an automatic speed reduction when the speed is automatically controlled, a reduction in LV unloading by manually reducing the speed, or a sustained aspiration alert (resulting in noise/alert fatigue). Furthermore, due to the high afterload, it may be difficult to manually find the optimal speed of the pump, e.g. to avoid pumping, thus leading to the same problem.

In view of this, the inventors have recognized advantages of a controller for a blood pump, such as a catheter-based intravascular blood pump (catheter-based intravascular blood pump), that can be used in conjunction with an ECMO device. As described herein, the controller includes a particular start-up and operation mode to control the speed of the motor of the blood pump based on the coupling factor k.

As shown in fig. 1, a system 1 for such treatment according to the present disclosure may include a controller 100, a blood pump (blood pump) 50, an ECMO device 90, and an optional stand-alone oxygenator (oxygenator) 98. Both the ECMO device 90 and the blood pump 50 may influence the blood flow in the heart 3 of the patient 2. As shown, ECMO device 90 may have an input 91 for blood flow and an output 92, with output 92 being used to provide blood to heart 3. The blood pump 50 shown here has a distal-most portion in the left ventricle of the heart 3 and a proximal-most portion in the aorta, configured to deliver blood from the left ventricle to the aorta through the flow cannula. The blood pump 50 is a catheter-based intravascular blood pump. The ECMO device 90 may communicate with the controller 100 via, for example, one or more communication cables 115.

Although the controller 100 and the ECMO device 90 are shown as two separate devices in fig. 1, in some embodiments, the functions of the ECMO device and the functions of the controller may be combined into a single unit (e.g., the controller 100) capable of performing the ECMO process and controlling the blood pump 50.

It will be appreciated that while FIG. 1 illustrates an ECMO device and conduit configured for VA-ECMO, the ECMO device may be easily replaced or reconfigured in other ECMO processes, including, for example, VVA-ECMO.

An example of a blood pump 50 may be understood with reference to fig. 2. Specifically, fig. 2 illustrates a catheter-based intravascular blood pump (sometimes referred to as a "blood pump"), which is described herein as one exemplary embodiment of a VAD.

The blood pump 50 comprises a catheter 10 by means of which the blood pump 50 is temporarily introduced into the left ventricle of the heart through the aorta and the aortic valve. As shown in more detail in fig. 2, the blood pump further comprises a rotary pumping device (rotary pumping device) 70 fixed to the end of the catheter tube 20. The rotary pumping device 70 may include a motor portion 51 and a pump portion 52 axially spaced therefrom. A flow sleeve (flow channel) 53 may be connected to the pump portion 52 at a first end, extend from the pump portion 52, and have an inflow cage (inflow cage) 54 at an opposite second end. The inflow cage 54 may be attached to a soft and flexible atraumatic tip (atraumatic tip) 55. The pump portion 52 may include a pump housing having an outlet opening 56. Further, the pumping device 70 may include a drive shaft 57 extending from the motor portion 51 into the pump housing of the pump portion 52. Via the drive shaft 57, the electric motor of the motor part 51 can drive an impeller 58 as a thrust element, by means of which impeller 58, during operation of the rotary pumping device 70, blood can be sucked through the inflow cage 54 and discharged through the outlet opening 56.

The rotary pumping device 70 may also be adapted to pump in the opposite direction when required, for example when the blood pump 50 is placed in the right ventricle. In this regard and for completeness, fig. 1 shows one particular example of a VAD in which a blood pump 50 is located in the left ventricle and is used to assist the left ventricle.

In fig. 2, three lines, two signal lines 28A and 28B and a power supply line 29 for supplying electric current to the motor portion 51, may pass through the catheter tube 20 of the catheter 10 to the pumping device 70. The two signal lines 28A, 28B and the power line 29 may be attached to the controller 100 at their proximal ends. It should be appreciated that in other embodiments additional wiring for further functionality may be present. For example, a line (not shown) for cleaning liquid may also pass through the catheter tube 20 of the catheter 10 to the pumping device 70. Additional lines may be added based on different sensing technologies.

As shown in fig. 2, the signal lines 28A, 28B may be part of a blood pressure sensor having corresponding sensor heads 30 and 60, respectively, the sensor heads 30 and 60 being located outside the housing of the pump portion 52. The sensor head 60 of the first pressure sensor may be associated with the signal line 28B. The signal line 28A may be associated with the sensor head 30 of the second blood pressure sensor and connected to the sensor head 30. The blood pressure sensor may be, for example, an optical pressure sensor operating according to the Fabry-Perot (Fabry-Perot) principle described in us patent No.5,911,685A, wherein the two signal lines 28A, 28B are optical fibers. However, other pressure sensors may be used instead. Basically, the signals of the pressure sensors, which carry respective information about the pressure at the sensor locations and may have any suitable physical source, such as optical, hydraulic, or electrical, etc., may be transmitted via the respective signal lines 28A, 28B to the corresponding inputs of the data processing unit 110 of the control device 100. In the example shown in fig. 1, the pressure sensors may be arranged such that the main artery pressure (aortic pressure, AOP) is measured by the sensor head 60 and the left ventricle pressure (left ventricular pressure, LVP) is measured by the sensor head 30.

The controller may be connected with the respective signal lines 28A, 28B via input ports to receive the corresponding measurement signals AOP _meas for the aortic pressure AOP and LVP _meas for the left ventricular pressure LVP.

An example of a controller may be understood with reference to fig. 3. In particular, the controller 100 may include several components. The first component may include one or more processors 110 (which include an associated non-transitory computer-readable medium including instructions for controlling the processors). The controller 100 may include various ports 111, 112, 113, and 114 operatively connected to the processor 110 to receive signals from and/or to transmit signals to various other components of the system. Not shown are various filters, converters, etc., that may allow signals to be encoded, decoded, formatted, or otherwise suitably modified for reading or transmission by a controller. The controller 100 may include at least one port 111, 112, 113 that operatively connects the processor with the blood pump 50. In some embodiments, the controller 100 may include one or more input ports 111, 112 to receive pressure signals from two or more pressure sensors (such as pressure sensors connected to the controller via, for example, optical fibers 28A, 28B to measure pressure in different chambers of the heart) and a port 113 for, for example, a power cord 29 to supply current to the motor portion 51 of the blood pump 50. In some embodiments, the controller 100 may include an additional port 114 configured to operatively connect the processor 110 with an in vitro membrane oxygenation (ECMO) system, such as a VA-ECMO system, via a communication cable 115 or some other suitable additional line.

The one or more processors 110 may be configured for acquiring external and internal signals for signal processing, such as calculating a difference between the two pressure signals as a basis for estimating the pump flow, for signal analysis, such as deriving an actual value of at least one characteristic parameter a, e.g. end-diastole left ventricular pressure (end-diastolic left ventricular pressure, EDLVP) or filling gradient (FILLING GRADIENT, FG) of the heart, which value may then be used for controlling the motor speed of the blood pump, i.e. the rotational speed of the motor unit 51 of the blood pump 50.

The controller 100 may also include other components. In some embodiments, the one or more processors 110 may be configured to control a display 130, such as a touch display. In some embodiments, the one or more processors 110 may be configured to control the audio speaker 140 (e.g., to generate an audible alert, etc.). In some embodiments, the one or more processors 110 may be configured to receive input from one or more buttons or switches 150.

In some embodiments, the controller may include a housing 160, the housing 160 being configured to contain at least the processor 110 (within the interior volume of the space defined by the outer walls of the housing). In some embodiments, the wall of the housing may define a plurality of openings through the wall. In some embodiments, at least a portion of the display 120 may be located in at least one of the plurality of openings of the housing 160. In some embodiments, the display may be operably connected to the processor 110, but not within the housing 160 or attached to the housing 160.

In some embodiments, the controller 100 may include a processor 110 configured to control the rotational speed of the motor of the blood pump 50 using the first selectable mode of operation. Fig. 4 illustrates an embodiment of a first alternative mode of operation, where the method 200 includes a first step 210 of detecting or determining pressure.

In one embodiment, the first step includes detecting or determining two pressure values—a left ventricular pressure value and an aortic pressure value. For purposes of this specification, a detected or determined left ventricular pressure value is the peak of a detected or determined left ventricular pressure value (LVP _max). Furthermore, for purposes of this specification, a detected or determined aortic pressure value is a peak of a detected or determined aortic pressure value (AOP _max).

These values may be measured based on signals provided by a pressure sensor (e.g., on the blood pump 50). In some embodiments, the signals received by the processor 110 from the pressure sensors may be used as variables in the calculation of determining the left ventricular pressure value or the aortic pressure value.

These values may be detected or determined at a frequency of, for example, 0.2Hz or greater or 0.5Hz or greater.

In some embodiments, the second step 220 of the first selectable mode of operation is to determine the coupling factor k using the detected or determined left ventricular pressure value and the aortic pressure value. In particular, the coupling factor k comprises a quotient of an average of at least some detected or determined left ventricular pressure values and an average of at least some detected or determined aortic pressure values over a predetermined time interval. In some embodiments, the predetermined time interval may be between 1 second and 5 seconds, such as 2 seconds. That is, in some embodiments, k is determined every 2 seconds.

In some embodiments, LVP _max and AOP _max are determined every 1 to 5 seconds (e.g., every 2 seconds). LVP _max,mean and AOP _max,mean can then be determined by averaging the previous 2 to 10 consecutive determinations of LVP _max and AOP _max, respectively. In some embodiments, LVP _max and AOP _max may be determined by averaging the previous 5 consecutive LVP _max and AOP _max determinations, respectively. The coupling factor k can then be calculated as k=lvp _max,mean/AOP_max,mean.

In one embodiment, the average of the detected or determined left ventricular pressure values used to determine the coupling factor and the average of the detected or determined aortic pressure values itself are determined within a predetermined time interval different from the period used to determine k. In some embodiments, this different time interval may be between 8 and 12 seconds, such as 10 seconds.

Fig. 5 is a schematic diagram of a graphical display 300 of left ventricular pressure and aortic pressure, as may occur on a screen of a controller. Left ventricular pressure 310 and aortic pressure 320 are shown as measured over time. The peak 311 of the left ventricular pressure is shown, as well as the peak 321 of the aortic pressure. These two values (peak 311, peak 321) can be used to calculate the coupling factor k. Using the graph shown in fig. 5, the value of the coupling factor k will be less than 1.

Referring to fig. 4, after determining the coupling factor k, the method 200 used by the one or more processors 110 may involve adjusting the rotational speed of the motor based on the determined value of the coupling factor k. As understood in the art, such "adjustment" may include indirect adjustment, wherein the processor 110 is configured to send a signal to one or more other components or modules, which then perform some action based on the signal, thereby adjusting the speed of the motor.

The processor 110 may be configured to adjust the rotational speed of the motor in the first selectable mode of operation over a predetermined time interval. In some embodiments, the predetermined time interval may be between every 5 seconds and 20 seconds.

In some embodiments, the controller 100 may be configured to adjust the motor speed once every 10 seconds based on the value of the coupling factor k. For example, in one embodiment, the coupling factor k is determined every 2 seconds based on the detected/determined pressure values within the previous 2 seconds, and the speed is adjusted based on the 5 th value of the coupling factor k every time the 5 th value of the coupling factor k is determined.

In some embodiments, the processor 110 may be configured to adjust the rotational speed of the motor in the first selectable mode of operation only after a predetermined time interval has elapsed since the previous speed adjustment. In some embodiments, the coupling factor k is calculated every 1 second-5 seconds (e.g., every 2 seconds), but the coupling factor k is used only every 5 seconds-20 seconds (e.g., every 10 seconds) after the previous adjustment of the speed.

After the coupling factor k is determined, the speed may then be adjusted based on the value of the coupling factor k (speed adjustment process 221), as shown in fig. 4. In one embodiment, this may be accomplished by comparing the coupling factor k to various thresholds (T ₁,T₂,…,T_n). In some embodiments, the threshold defines a range of coupling factors k of a particular type corresponding to motor speed adjustment.

In some embodiments, the control system is designed around a target coupling factor value or a range of target coupling factor values. The rotational speed of the motor may be automatically increased when the coupling factor k value is below the target k value(s), and the rotational speed of the motor may be automatically decreased when the coupling factor k value is above the target k value.

In some embodiments, at least one speed adjustment is made based on the determined value of the coupling factor k, wherein the at least one adjustment comprises or consists of: increasing the rotational speed of the motor by a first amount when the coupling factor k is greater than a first threshold; when the coupling factor k is smaller than or equal to the first threshold value and larger than the third threshold value, the rotating speed of the motor is increased by a second amount, and the second amount is smaller than the first amount; reducing the rotational speed of the motor by a third amount when the coupling factor k is greater than or equal to the fourth threshold and less than the second threshold; when the coupling factor k is greater than or equal to the fifth threshold and less than the fourth threshold, reducing the rotational speed of the motor by a fourth amount, the fourth amount being greater than the third amount; when the coupling factor k is smaller than a fifth threshold value, reducing the rotation speed of the motor by a fifth amount, wherein the fifth amount is larger than the fourth amount; or a combination of the foregoing. Alternatively, the first selectable operating mode may be further configured to maintain the rotational speed of the motor constant when the coupling factor is equal to the third threshold. A simplified description of this approach can be seen in table 1 below.

Table 1 (example of possible k-value ranges and associated rotational speed adjustments)

In some embodiments, if the coupling factor is between the first threshold (or upper limit) and the second threshold (or lower limit) (threshold T ₁、T₂), no speed adjustment is made. That is, after the second step 220, if the value of the coupling factor k is between T ₁ and T ₂ (here, "between" is intended to include both upper and lower limits), no action is taken. These upper and lower limits may be centered on a target range for the coupling factor k, which is defined by two thresholds (threshold T ₃、T₄), or on a common target value for the coupling factor k value, which is defined by a common threshold (i.e., where T ₃＝T₄).

The amount by which the speed is increased or decreased may depend on how close the determined coupling factor k is to the target coupling factor k value, and whether the coupling factor k is greater or less than the target coupling factor k. A simplified description of this approach can be seen in tables 2 and 3 below.

TABLE 2 adjustment once it is determined that the coupling factor is greater than the first threshold

TABLE 3 (adjustment made once it is determined that the coupling factor is less than the second threshold)

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The above description and methods are intended to be non-limiting. As shown in tables 1 and 2, if the determined value of the coupling factor k is greater than the first threshold, the controller attempts to gradually increase the rotational speed in an attempt to decrease the coupling factor k until it is less than or equal to the target value or the target value range. If the value is less than the second threshold, the controller attempts to gradually decrease the rotational speed in an attempt to increase the coupling factor k until it is greater than or equal to the target value or range of target values.

In some embodiments, the first threshold T ₁ is the target coupling factor k value plus a limit value (e.g., 0.1, 0.15, or 0.2), the second threshold T ₂ is the target coupling factor k value minus the limit value, the third threshold T ₃ and the fourth threshold T ₄ are the target coupling factor k values, and the fifth threshold T ₅ is a value of 15% -35% of the target coupling factor k value. As a simple example, if the coupling factor k is 0.7, the limiting value is 0.15, and the fifth threshold is 20% of the target coupling factor k, the controller 110 may be configured to start increasing the speed when the coupling factor k >0.85, when the speed increases at a medium speed when k >0.85, increase at a small speed when the coupling factor k is between 0.7 and 0.85, and stop the speed increase after the coupling factor k reaches 0.7 or less. The controller will be configured to start reducing the speed when the coupling factor k is less than 0.55, at which time the speed will be reduced at a substantial speed when k <0.14, at a medium speed when k is between 0.14 and 0.55, and after the coupling factor k reaches 0.7 or more, the speed reduction will stop.

In one embodiment, the first threshold is 0.75, the second and fifth thresholds are 0.65, the third threshold is 0.15, and the fourth threshold is 0.55.

In some embodiments, the amount of speed adjustment may be based on a range of operating speeds of the motor (e.g., the difference between the maximum speed and the minimum speed that the motor is designed to operate in the first selectable operating mode). That is, if the motor is designed to be controlled in this operation mode while rotating between 31,000rpm and 46,000rpm, for example, the operation speed range may be 15,000rpm. In some embodiments, the range may be between 12,000rpm to 22,000 rpm. In some embodiments, the small speed increase (second amount) and/or decrease (third amount) may be an amount between 0.8% and 1.9% of the operating range, the medium speed increase and/or decrease (first amount and fourth amount) may be an amount between 2% and 4.5% of the operating speed, and the large speed decrease (fifth amount) may be an amount between 8% and 19% of the operating speed.

In some embodiments, the first amount (i.e., absolute amount) of speed adjustment is equal to the fourth amount (i.e., absolute amount). In some embodiments, the second amount (i.e., absolute amount) of speed adjustment is equal to the third amount (i.e., absolute amount).

In one embodiment, the second and third amounts are 200rpm, the first and fourth amounts are 500rpm, and the fifth amount is 2000rpm.

Fig. 4 illustrates a speed adjustment process 221 that the processor 110 is configured to use in some embodiments. In the speed adjustment process 221, the speed is adjusted only when the coupling factor k is determined to be greater than the first threshold T ₁ (step 230) or the coupling factor k is determined to be less than the second threshold T ₂ (step 231). If the coupling factor k is between the first threshold T ₁ and the second threshold T ₂, the speed adjustment process is essentially ignored and steps 210 and 220 are repeated.

Once the coupling factor k is determined to be greater than the first threshold (step 230), the first subroutine 232 is entered whereby (as previously disclosed) the speed is increased until the coupling factor is less than the third threshold T ₃. Specifically, in the first subroutine 232, if the coupling factor k is greater than the first threshold T ₁ (step 234), the rotational speed of the motor may be increased by a first amount (speed adjustment 235); when the coupling factor k is less than or equal to the first threshold T ₁ and greater than the third threshold T ₃ (step 236), the rotational speed of the motor may be increased by a second amount (speed adjustment 237). The second amount of motor speed increase (i.e., the absolute value of the motor speed change caused by the second amount) may be less than the first amount (i.e., the absolute value of the motor speed change caused by the first amount). After making the speed adjustments 235, 237, the pressure is measured and the coupling factor k is again determined (step 238), as previously described for steps 220 and 221. This subroutine 232 is repeated until the coupling factor k is less than or equal to the third threshold T ₃, at which point the subroutine 232 ends and the process returns to measuring pressure in step 210.

Once the coupling factor k is determined to be less than the second threshold (step 231), the second subroutine 233 is entered whereby the speed (as previously disclosed) is reduced until the coupling factor is greater than a fourth threshold T ₄, which may be the same as the third threshold T ₃ in some embodiments. Specifically, in the second subroutine 233, if the coupling factor k is less than the fourth threshold T ₄ and greater than or equal to the second threshold T ₂ (step 244), the rotational speed of the motor may be reduced by a third amount (speed adjustment 245); when the coupling factor k is greater than or equal to the fifth threshold T ₅ and less than the second threshold T ₂ (step 242), the rotational speed of the motor may be reduced by a fourth amount (speed adjustment 243); and if the coupling factor k is less than the fifth threshold T ₅ (step 239), the rotational speed of the motor may be reduced by a fifth amount (speed adjustment 240). The fourth amount of motor speed reduction (i.e., the absolute value of the motor speed change caused by the fourth amount) may be less than the fifth amount of reduction (i.e., the absolute value of the motor speed change caused by the fifth amount). The third amount of motor speed reduction (i.e., the absolute value of the motor speed change caused by the third amount) may be less than the fourth amount of motor speed reduction (i.e., the absolute value of the motor speed change caused by the fourth amount). After the speed adjustments 240, 243, 245 are made, the pressure is measured and the coupling factor k is again determined (step 241), as described above for steps 220 and 221. This subroutine 233 is repeated until the coupling factor k is greater than or equal to the fourth threshold T ₄, at which point the subroutine 233 ends and the process returns to measuring pressure in step 210.

This can be seen graphically with reference to fig. 6. As can be seen in this figure, near the beginning, where the value of the coupling factor k is between 1 and 0.75 (interval 601), the motor speed is increased stepwise, increasing the speed by a moderate amount each step (e.g., after each recalculation of the coupling factor k based on updated pressure) until the value of the coupling factor k is determined to be between 0.75 and 0.65 (interval 602), where each step speed is increased down to a smaller amount. Once the coupling factor k reaches 0.65 (interval 603), no further speed change occurs until the coupling factor k falls outside the range of 0.55-0.75. When the coupling factor k suddenly drops towards 0, the speed is first reduced by a moderate amount per step when the coupling factor k is determined to be less than 0.55 but greater than 0.15 (interval 604), but when the coupling factor k continues to be reduced and is determined to be less than 0.15 (interval 605), the speed will drop significantly per step until the coupling factor k is determined to be greater than 0.15 and less than 0.55 (interval 606), during which the speed continues to drop, but each step is reduced only by a moderate amount. Once the coupling factor k is determined to be between 0.55 and 0.65 (interval 607), the speed continues to drop, but only by a small amount per step, until the coupling factor k is again determined to be equal to or higher than 0.65 (interval 608). Again, no further speed change is made until the coupling factor k is above 0.75 (interval 609), wherein the speed increases by a medium amount per step until the coupling factor k is between 0.75 and 0.66 (interval 610), wherein the speed continues to increase by a small amount per step until the coupling factor k eventually returns to or below 0.65 (interval 611).

As shown in fig. 7, the processor 110 may be configured to make other determinations and take corrective action if necessary when certain events occur. The processor may be configured to follow the method 400, wherein certain security features may be added prior to any of the previously described determining coupling factors (step 220) and speed adjustments (speed adjustment process 221). For example, the processor 110 may be configured to determine if the pump position is incorrect (step 410) (e.g., the blood pump is in the ventricle, or the blood pump is in the aorta), which may be based on the detected or determined pressure. In this case, automatic corrective action(s) 411 may be performed. This corrective action 411 may include, for example, suspending any speed adjustment as described above until no more incorrect pump position determinations are made, at which point the speed adjustment described above may optionally automatically resume. If the blood pump is properly placed but a pumping event is detected (step 420), an alternative corrective action may be automatically performed (step 421).

In some embodiments, the processor 110 may be further configured to detect one or more pumping events (step 420), and then automatically respond to these pumping events (step 421). In some embodiments, it may be by: if the first pumping event is detected, the rotational speed of the motor is reduced by a fifth amount, if the second pumping event is detected, the rotational speed of the motor is reduced by a sixth amount, and after the second pumping event is detected within a predetermined time window (e.g., 30 seconds to 5 minutes, or 2 minutes), the upper limit of the rotational speed of the motor is reduced by the sixth amount (sometimes referred to as a "pause") for a period of time (e.g., between 10 minutes to 30 minutes, or 20 minutes).

This process is schematically illustrated in fig. 8, and fig. 8 is a graph of motor speed over time. As shown, the rotational speed of the motor may increase from 0 through P-2 (preset speed option #2, approximately 31,000 rpm) to an initial maximum allowable speed P-9 (preset speed option #9, approximately 46,000 rpm) (interval 801). After the rotational speed passes P-2, the device is within the normal operating range of the device. During normal operation, there is a risk of aspiration (interval 802). In practice, a first pumping event 810 may be detected and the rotational speed may be rapidly reduced while the pumping event is cleared (interval 803). Once the pumping event is cleared 811, the rotational speed may be increased again. However, in a period of less than 2 minutes (interval 804), a second event 812 may be detected, at which time the rotational speed may again automatically decrease (interval 805) until the second suction event 813 is cleared. Since then, for a period of 20 minutes (interval 806), a new, lower maximum rotational speed (interval 807) may be set in place, which is less than P-9 (the previous maximum allowable speed). After 20 minutes, the maximum rotational speed may be adjusted back to P-9 (interval 808), and the motor may begin to slowly ramp back up without a third such pumping event.

In some embodiments, if the maximum speed is reduced, an alert is generated indicating that a reduction in rotational speed has occurred.

In some embodiments, if a puff is detected during a period of time (e.g., during a 10 to 30 minute window in which the maximum rotational speed has been reduced), the rotational speed may be further reduced until the puff is cleared, the pause counter may be reset, and another 10-30 minute pause may begin.

In some embodiments, if the pump motor speed reaches a lower speed at which the first selectable mode of operation is configured to operate using (e.g., 31,000 rpm), the rotational speed may not decrease further, but an alarm may be triggered. In one embodiment, this alert is different from an alert indicating that the maximum speed has been reduced.

In view of the need for ECMO and VAD to work in concert to provide a treatment for which the techniques described above are useful, the processor 110 may be configured to: (i) Detecting whether an ECMO device (e.g., VA-ECMO or VVA-ECMO device) is operatively connected to the controller and/or operational, and if the ECMO device is not detected and/or operational, preventing selection or execution of the first selectable mode of operation; (ii) Receiving a selection indicating that the processor should operate the blood pump using the first selectable mode of operation; or (iii) comprises both (i) and (ii). In some embodiments, the processor 110 may be further configured for (i) only-that is, the user cannot select the controller 100 to operate in the first selectable mode of operation unless the ECMO device 90 is detected as connected and/or operational.

In some embodiments, the controller 100 may be configured to receive a signal from a flow controller 99 associated with the ECMO device 90 indicating that the ECMO is in operation, alternatively or in addition to receiving a signal from the ECMO device 90. For example, in one embodiment, the controller 100 may not be allowed to operate in the first selectable mode of operation unless the controller 100 receives a signal from the ECMO device 90 indicating that the ECMO device 90 is connected, and also receives a signal from the flow controller indicating that blood is flowing through the ECMO device 90 and thus the ECMO device 90 is in operation.

Given the target coupling factor k, the processor can perform a priming process that quickly and safely brings the blood pump 50 to the proper operating speed. This can be described with reference to fig. 9. To complete the boot up, the processor 110 may also be configured to perform the boot up method 500 prior to executing the first alternative mode of operation 200. In some embodiments, the start-up method entails first increasing the rotational speed of the motor from zero to a minimum rotational speed (step 510). The minimum rotational speed should be the lowest rotational speed that the processor 110 is configured to use when executing the first selectable mode of operation. In some embodiments, the minimum speed is between 5,000rpm and 50,000rpm, such as between 20,000rpm and 40,000rpm, or 31,000rpm.

Once the minimum rotational speed is reached, the processor 110 may then determine a coupling factor k using the detected or determined aortic pressure value and the detected or determined left ventricular pressure value (step 520), as described above, wherein the coupling factor k is the quotient of the average of the detected or determined left ventricular pressure value and the average of the detected or determined aortic pressure value, the detected or determined left ventricular pressure value is the peak of the detected or determined left ventricular pressure value (LVP _max), and the detected or determined aortic pressure value is the peak of the detected or determined aortic pressure value (AOP _max).

Once the coupling factor k is determined, the speed can be adjusted.

As shown in FIG. 9, when the coupling factor k is not less than 1 (step 530), the rotational speed may be adjusted by a sixth amount, and then after a fixed period of time, the coupling factor k may be determined again and the speed may be adjusted again. In some embodiments, the fixed period of time may be between 5 and 30 seconds, for example between 10 seconds. In one embodiment, the sixth amount may be between 5% and 30% of a rotational speed range of the motor within which the processor is configured to execute the first selectable operating mode. As noted above, in some embodiments, this range may be between 12,000rpm and 20,000 rpm. For example, if the motor is designed to be controlled in this operating mode when rotating, for example, between 31,000rpm and 46,000rpm, the operating speed range is 15,000rpm, and thus, the sixth amount will be between 750rpm and 4,500 rpm. In one embodiment, the sixth amount is between 2,000rpm and 3,000 rpm.

However, once the coupling factor k <1, a different path may be followed. Specifically, if the coupling factor k is determined to be less than 1, the rotational speed of the motor may be adjusted according to the first selectable operating mode as described above (speed adjustment process 221). In one embodiment, and referring to FIG. 2, the speed is adjusted only if the coupling factor k is determined to be greater than the first threshold T ₁ (step 230) or the coupling factor k is determined to be less than the second threshold T ₂ (step 231). If the coupling factor k is between the first threshold T ₁ and the second threshold T ₂, the speed adjustment process is essentially ignored and steps 210 and 220 are repeated.

Once the coupling factor k is determined to be greater than the first threshold (step 230), the first subroutine 232 is entered whereby (as previously disclosed) the speed is increased until the coupling factor is less than the third threshold T ₃. Specifically, in the first subroutine 232, if the coupling factor k is greater than the first threshold T ₁ (step 234), the rotational speed of the motor may be increased by a first amount (speed adjustment 235); when the coupling factor k is less than or equal to the first threshold T ₁ and greater than the third threshold T ₃ (step 236), the rotational speed of the motor may be increased by a second amount (speed adjustment 237). The second amount of motor speed increase (i.e., the absolute value of the motor speed change caused by the second amount) may be less than the first amount (i.e., the absolute value of the motor speed change caused by the first amount). After the speed adjustments 235, 237 are made, the pressure is measured and the coupling factor k is again determined (step 238), as previously described for steps 220 and 221. This subroutine 232 may be repeated until the coupling factor k is less than or equal to the third threshold T ₃, at which point the subroutine 232 ends and the process returns to measuring the pressure in step 210.

Once the coupling factor k is determined to be less than the second threshold (step 231), the second subroutine 233 is entered whereby the speed (as previously disclosed) is reduced until the coupling factor is greater than a fourth threshold T ₄, which may be the same as the third threshold T ₃ in some embodiments. Specifically, in the second subroutine 233, if the coupling factor k is less than the fourth threshold T ₄ and greater than or equal to the second threshold T ₂ (step 244), the rotational speed of the motor may be reduced by a third amount (speed adjustment 245); when the coupling factor k is greater than or equal to the fifth threshold T ₅ and less than the second threshold T ₂ (step 242), the rotational speed of the motor may be reduced by a fourth amount (speed adjustment 243); and if the coupling factor k is less than the fifth threshold T ₅ (step 239), the rotational speed of the motor may be reduced by a fifth amount (speed adjustment 240). The fourth amount of motor speed reduction (i.e., the absolute value of the motor speed change caused by the fourth amount) may be less than the fifth amount of reduction (i.e., the absolute value of the motor speed change caused by the fifth amount). The third amount of motor speed reduction (i.e., the absolute value of the motor speed change caused by the third amount) may be less than the fourth amount of Yu Mada rotational speed reduction (i.e., the absolute value of the motor speed change caused by the fourth amount). After the speed adjustments 240, 243, 245 are made, the pressure is measured and the coupling factor k is again determined (step 241), as described above for steps 220 and 221. This subroutine 233 is repeated until the coupling factor k is greater than or equal to the fourth threshold T ₄, at which point the subroutine 233 ends and the process returns to measuring pressure in step 210.

Because the fifth threshold may be very low and generally indicates a potential problem, the processor 110 may be further configured to cause the alarm notification to be activated if the coupling factor k is determined to be less than the fifth threshold. The alert notification may remain until the coupling factor k is determined to be greater than or equal to another threshold that is greater than the fifth threshold and less than the fourth threshold. In some embodiments, the other threshold may be between 20% and 50% of the target coupling factor k value.

After a fixed period of time (e.g., the same fixed period of time as described above, after step 531), the processor may then automatically begin operation according to the first alternative method 200.

This start-up procedure is shown in fig. 10, and it can be seen that starting from 0, the rotational speed can be first increased to a minimum operating speed (here P-2). After a period of time (here 10 seconds) the coupling factor k can be determined to be greater than or equal to 1, thus increasing the speed by a sixth amount to P-3. This process may be repeated several times until the speed reaches P-6, after which time the coupling factor k is determined to be less than 1. During the period when the coupling factor k is less than 1 (interval 850), the speed may be adjusted according to the first alternative mode of operation, as shown in fig. 10, slowly until the coupling factor k=0.65.

The controller 100 may also be configured to allow the motor to operate in other modes than the first selectable mode of operation. That is, the controller 100 may be configured to be usable even if, for example, the blood pump 50 is not operated in parallel with the ECMO device 90. In one embodiment, the controller 100 may be configured to operate in at least one other mode of operation, for example, the controller 100 may be configured to operate in at least two other modes of operation.

In one embodiment, the processor 110 may be further configured to operate in the following: (i) A second selectable operating mode in which the processor 110 receives a selection of one of a plurality of predetermined operating speeds and then adjusts the speed of the motor to the selected predetermined operating speed; (ii) A third alternative mode of operation in which the processor 110 is configured to increase the rotational speed of the motor to a maximum operating rotational speed at a predetermined rate.

In some embodiments, if the pressure value for controlling the motor is determined to be unreliable, the controller 100 may be configured to exit the first selectable operating mode 200. It should be appreciated that the unreliability may be determined in any manner known to those skilled in the art, including, for example, whether the determined pressure is within a predetermined range of the expected pressure, or whether the standard deviation of the measured pressure is above a threshold.

In some embodiments, when operating using the first selectable operating mode 200, the processor may be further configured to determine whether the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both are unreliable, and when the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both have been determined to be unreliable for a period of time, switch from the first selectable operating mode to the second selectable operating mode. In some embodiments, the time period herein may be between 30 seconds and 5 minutes, such as 2 minutes. In some embodiments, switching from the first mode to the second mode may include automatically determining which of a plurality of preset speeds is closest to but not greater than the current motor speed, and then adjusting the speed to the determined preset speed. In some embodiments, an alarm or alert may be generated when the signal is determined to be unreliable.

The disclosed blood pump system may generally include a controller 100 as described above and a catheter-based intravascular blood pump 50 operatively connected to the controller.

The disclosed system (e.g., in combination with ECMO and VAD) may generally include two main sets of components. The first group is an external membrane oxygenation (ECMO) system, such as a VA-ECMO system (e.g., ECMO device 90, flow controller 99, and various associated tubing, fittings, etc.). The second group is a blood pump system adapted to operate in parallel with the ECMO system, the blood pump system comprising a controller 100 as described above and a catheter-based intravascular blood pump 50 operatively connected to the controller.

Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.

Embodiments of the present disclosure are described in detail with reference to the drawings, wherein like reference numerals designate like or identical elements. It is to be understood that the disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.

Claims

1. A controller for a blood pump, in particular a catheter-based intravascular blood pump, the controller comprising:

A processor configured to control a rotational speed of a motor of a catheter-based intravascular blood pump using a first selectable operating mode, wherein the first selectable operating mode includes the steps of:

Determining a coupling factor k using the detected or determined aortic pressure value and the detected or determined left ventricular pressure value; and

At least one adjustment of the rotational speed of the motor based on the determined value of the coupling factor k, the at least one adjustment being:

Increasing the rotational speed of the motor by a first amount when the coupling factor k is greater than a first threshold;

Increasing the rotational speed of the motor by a second amount when the coupling factor k is less than or equal to the first threshold and greater than a third threshold, the second amount being less than the first amount;

when the coupling factor k is greater than or equal to the fourth threshold value and less than the second threshold value,

Reducing the rotational speed of the motor by a third amount;

Reducing the rotational speed of the motor by a fourth amount when the coupling factor k is greater than or equal to a fifth threshold and less than the fourth threshold, the fourth amount being greater than the third amount;

Reducing the rotational speed of the motor by a fifth amount when the coupling factor k is less than the fifth threshold, the fifth amount being greater than the fourth amount; or alternatively

Combinations of the above.

2. The controller of claim 1, wherein the processor is further configured to maintain the rotational speed of the motor constant when the coupling factor is equal to the second threshold.

3. The controller of claim 1 or 2, wherein the processor is configured to adjust the rotational speed of the motor when the determined value of the coupling factor k is greater than the first threshold or less than the second threshold by:

When the coupling factor k is greater than the third threshold, repeating the steps of:

Increasing the rotational speed of the motor by the first amount when the coupling factor k is greater than the first threshold, and increasing the rotational speed of the motor by the second amount when the coupling factor k is less than or equal to the first threshold and greater than a third threshold; and

Reducing the rotational speed of the motor by a third amount when the coupling factor k is greater than or equal to a fourth threshold and less than a second threshold, reducing the rotational speed of the motor by a fourth amount when the coupling factor k is greater than or equal to a fifth threshold and less than the fourth threshold, the fourth amount being greater than the third amount, and reducing the rotational speed of the motor by a fifth amount when the coupling factor k is less than a fifth threshold, the fifth amount being greater than the fourth amount; and

The coupling factor k is determined using the detected or determined aortic pressure value and the detected or determined left ventricular pressure value.

4. A controller according to any one of claims 1 to 3, wherein the processor is configured to adjust the rotational speed of the motor at first predetermined time intervals in the first selectable mode of operation.

5. The controller of claim 4, wherein the first predetermined time interval is between 5 seconds and 20 seconds, optionally wherein the first predetermined time is 0 seconds.

6. The controller according to any of claims 1 to 5, wherein the coupling factor k is determined within a second predetermined time interval.

7. The controller of claim 6, wherein the second predetermined time interval is between 1 second and 5 seconds, optionally wherein the time interval is 2 seconds.

8. The controller according to any one of claims 1 to 7, wherein the coupling factor k is a quotient of an average of the detected or determined left ventricular pressure values and an average of the detected or determined aortic pressure values.

9. The controller of claim 8, wherein the average of the detected or determined left ventricular pressure values and the average of the detected or determined aortic pressure values are determined within a third predetermined time interval.

10. The controller of claim 9, wherein the third predetermined time interval is between 8 seconds and 12 seconds, optionally wherein the time interval is 10 seconds.

11. The controller of any one of claims 1 to 10, wherein the first threshold is 0.75, the second threshold is 0.55, the third and fourth thresholds are 0.55, and the fifth threshold is 0.15.

12. The controller according to any one of claims 1 to 11, wherein the first threshold value is a target coupling factor k value plus a limit value, the second threshold value is the target coupling factor k value minus the limit value, the third and fourth threshold values are the target coupling factor k value, and the fifth threshold value is a value of 15% -35% of the target coupling factor k value.

13. The controller of any of claims 1-12, wherein the second amount is 0.8% -1.9% of an operating range of the rotational speed of the motor in which the processor is configured to perform the first selectable operating mode, the first and fourth amounts are 2% -4.5% of the operating range, and the third amount is 8% -19% of the operating range.

14. The controller of claim 13, wherein the operating range of the rotational speed of the motor is between 12,000rpm and 22,000 rpm.

15. The controller of any one of claims 1 to 14, wherein the processor is further configured to detect a pumping event and respond to the pumping event by:

reducing the rotational speed of the motor by a fifth amount if a first pumping event is detected;

reducing the rotational speed of the motor by a sixth amount if a second pumping event is detected; and

After detecting the second pumping event within a predetermined time window, reducing the upper limit of the rotational speed of the motor by the sixth amount for a first period of time.

16. The controller of claim 15, wherein the first period of time is between 10 minutes and 30 minutes and the predetermined time window is between 30 seconds and 5 minutes.

17. The controller of any one of claims 1 to 16, wherein the processor is further configured to:

Detecting whether an external membrane oxygenation (ECMO) device is operatively connected to the controller, and if the ECMO device is not detected, preventing selection or execution of the first selectable mode of operation;

receiving a selection indicating that the processor should operate the blood pump using the first selectable mode of operation; or alternatively

Combinations of the above.

18. The controller of any one of claims 1 to 17, wherein the processor is further configured to, prior to executing the first selectable mode of operation:

increasing the rotational speed of the motor from zero to a minimum rotational speed that the processor is configured to use when executing the first selectable mode of operation;

Determining the coupling factor k using the detected or determined aortic pressure value and the detected or determined left ventricular pressure value; and

Adjusting the rotational speed of the motor based on the value of the coupling factor k by:

If k is more than or equal to 1, increasing the rotating speed by a sixth amount, and repeating the steps b-c after a fixed period of time; and

If k <1, adjusting the rotational speed of the motor according to the first selectable operating mode, and after the fixed period, controlling the rotational speed of the motor according to the first selectable operating mode.

19. The controller of claim 18, wherein the sixth amount is between 5% and 30% of a range of the rotational speed of the motor within which the processor is configured to execute the first selectable mode of operation.

20. The controller according to any one of claims 1 to 19, wherein,

The processor is further configured to operate in a second selectable operating mode, wherein the processor receives a selection of one of a plurality of predetermined operating speeds and adjusts the speed of the motor to the selected predetermined operating speed; and

The processor is further configured to operate in a third selectable mode of operation wherein the processor is configured to increase the rotational speed of the motor to a maximum operating rotational speed at a predetermined rate.

21. The controller of claim 20, wherein the processor is further configured to:

Determining whether the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both are unreliable when operating using the first selectable mode of operation; and

Switching from the first selectable operating mode to the second selectable operating mode when the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both have been determined to be unreliable for a second period of time.

22. The controller of claim 21, wherein the second period of time is between 30 seconds and 5 minutes.

23. The controller of any of claims 1 to 22, wherein the processor is further configured to cause an alarm notification to be activated if the coupling factor k is determined to be less than the fifth threshold until the coupling factor k is determined to be greater than or equal to a sixth threshold that is greater than the fifth threshold and less than the fourth threshold.

24. The controller of claim 23, wherein the sixth threshold is between 20% and 50% of a target coupling factor k value.

25. The controller according to any one of claims 1 to 24, further comprising:

A display controlled by the processor;

a first port configured to operatively connect the processor with the catheter-based intravascular blood pump;

A second port configured to operably connect the processor with an external membrane oxygenation (ECMO) system; and

A housing configured to contain at least the processor.

26. A blood pump system, comprising:

the controller according to any one of claims 1 to 25; and

A catheter-based intravascular blood pump operably connected to the controller.

27. A system, comprising:

An external membrane oxygenation (ECMO) system; and

A blood pump system adapted to operate in parallel with the ECMO system, the blood pump system comprising a controller according to any one of claims 1 to 25 and a catheter-based intravascular blood pump operatively connected to the controller.

28. A method for activating a catheter-based intravascular blood pump for use with an extracorporeal membrane lung oxygenation (ECMO) system, the method comprising:

Increasing the rotational speed of the motor of the catheter-based intravascular blood pump from zero to a predetermined minimum rotational speed; and

The coupling factor k is determined using the detected or determined aortic pressure value and the detected or determined left ventricular pressure value, and if k is greater than or equal to 1, the speed is increased by a fixed amount, and after a fixed period of time, this step is repeated until k <1.

29. The method of claim 28, wherein upon determining that the coupling factor k is less than 1, automatically switching to an automatic speed control mode suitable for use with an extracorporeal membrane oxygenation (ECMO) system.

30. The method of claim 28, wherein the fixed amount is between 5% and 30% of an operating range of speeds of the motor.

31. A method for operating a catheter-based intravascular blood pump for use with an extracorporeal membrane oxygenation (ECMO) system, the method comprising:

Determining a coupling factor k using the detected or determined aortic position value and the detected or determined left ventricular position value; and

At least one adjustment of the rotational speed of the motor of the catheter-based intravascular blood pump based on the determined value of the coupling factor k, the at least one adjustment being:

Reducing the rotational speed of the motor by a third amount when the coupling factor k is greater than or equal to a fourth threshold and less than a second threshold;

Combinations of the above.

32. The method of claim 31, further comprising maintaining the rotational speed of the motor constant when the coupling factor is equal to the second threshold.

33. The method of claim 31 or 32, wherein the at least one adjustment of the rotational speed of the motor comprises:

34. The method of any one of claims 31 to 33, wherein the adjusting step is repeated at predetermined time intervals.

35. The method of claim 33, wherein the predetermined time interval is between 5 seconds and 20 seconds.

36. The method of any one of claims 31 to 35, wherein the first threshold is 0.75, the second threshold is 0.55, the third and fourth thresholds are 0.65, and the fifth threshold is 0.15.

37. The method of any of claims 31 to 36, wherein the first threshold is a target coupling factor k value plus a limit value, the second threshold is the target coupling factor k value, the fourth threshold is the target coupling factor k value minus the limit value, and the third threshold is a value of 15% -35% of the target coupling factor k value.

38. The method of any of claims 31-37, wherein the second amount is 0.8% -1.9% of an operating range of the rotational speed of the motor, the first and fourth amounts are 2% -4.5% of the operating range, and the third amount is 8% -19% of the operating range.

39. The method of claim 38, wherein the operating range of the rotational speed of the motor is between 12,000rpm and 22,000 rpm.

40. The method of any one of claims 31 to 39, wherein the method further comprises:

detecting one or more pumping events within a predetermined time window;

Reducing the rotational speed of the motor by a fifth amount after detecting a first pumping event of the one or more pumping events;

The upper limit of the rotational speed of the motor is reduced by the sixth amount for a first period of time after the second one of the one or more pumping events is detected.

41. The method of claim 40, wherein the first period of time is between 10 minutes and 30 minutes and the predetermined time window is between 30 seconds and 5 minutes.

42. The method of any one of claims 31 to 41, further comprising:

Detecting whether an external membrane oxygenation (ECMO) device is operatively connected to the controller, and if the ECMO device is not detected, preventing selection or execution of a first selectable mode of operation;

Receiving a selection from a user interface indicating that the blood pump should be operated using the first selectable mode of operation; or alternatively

Combinations of the above.

43. The method of any one of claims 31 to 42, further comprising:

Determining whether the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both are unreliable; and

If the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both are determined to be unreliable for more than a second period of time, the method is stopped.

44. The method of claim 43, wherein the second period of time is between 30 seconds and 5 minutes.

45. The method of claim 44, wherein the second period of time is between 1 minute and 3 minutes.

46. The method of any of claims 31-45, further comprising causing an alarm notification to be activated when the coupling factor k falls below the fifth threshold until the coupling factor k is determined to be greater than or equal to a sixth threshold that is greater than the fifth threshold and less than the fourth threshold.

47. The method of claim 42, wherein the sixth threshold is between 20% and 50% of a target coupling factor k value.