CN116251289A

CN116251289A - Catheter pump and method for folding pump head of catheter pump

Info

Publication number: CN116251289A
Application number: CN202211309783.2A
Authority: CN
Inventors: 屠攀; 张家良
Original assignee: Magassist Inc
Current assignee: Magassist Inc
Priority date: 2022-10-25
Filing date: 2022-10-25
Publication date: 2023-06-13
Anticipated expiration: 2042-10-25
Also published as: CN116251289B

Abstract

Disclosed are a catheter pump and a method of folding a pump head of the catheter pump, the catheter pump comprising: a catheter, a driving shaft rotatably penetrating the catheter, a pump head, a folding sheath, a transition sheath and an intervention sheath. At least the stent and impeller of the pump head are folded into the folded sheath first channel via the distal end of the folded sheath; pushing the catheter forward, at least part of the pump head being transferred from the first channel into the second channel of the transitional sheath in a collapsed state; the catheter is advanced and at least a portion of the pump head is transferred from the second channel into the third channel of the interventional sheath in a collapsed state. The pump head is folded step by using the folding sheath and the transition sheath, so that the folding difficulty is low, the pump head is not easy to damage in the folding process, the pushing process is smoother, the length of the folding sheath is shorter, and the strokes of folding the pump head into the folding sheath and transferring the pump head from the folding sheath to the transition sheath are correspondingly shortened, so that the damage of the pump head is further reduced; when the pump head is transferred from the transition sheath to the intervention sheath, the pump head is not further compressed and folded, so that the pain of a patient and the complication probability of a puncture opening are reduced.

Description

Catheter pump and method for folding pump head of catheter pump

Technical Field

The invention relates to a catheter pump and a method for folding a pump head of the catheter pump, and belongs to the technical field of medical appliances.

Background

Heart disease is a health problem with high mortality rates and physicians increasingly use mechanical circulatory support systems to treat heart failure. The treatment of acute heart failure requires a device that can quickly provide support to the patient and physicians desire to quickly and minimally invasively deploy a treatment regimen.

Mechanical Circulatory Support (MCS) systems and Ventricular Assist Devices (VADs) are increasingly accepted in the treatment of acute heart failure. For example, patients after cardiogenic shock are stabilized in the treatment of acute Myocardial Infarction (MI) or compensatory heart failure, or support is provided to the patient during high-risk Percutaneous Coronary Intervention (PCI). One example of an MCS system is a rotary catheter pump placed percutaneously via a catheter.

In conventional approaches, a catheter pump is inserted into the body and connected to the cardiovascular system (e.g., connecting the left ventricle and the ascending aorta) to assist the pumping function of the heart.

At present, catheter pumps in the field are divided into two types, namely a motor built-in pump head is not foldable and a motor external pump head is foldable. For the purposes of reducing patient pain and reducing complications of the puncture, catheter pumps are expected to be capable of smaller size interventions in the human body. As the catheter pump with the foldable pump head can achieve smaller wound when in intervention, the catheter pump has become a future development trend.

The distal pump head of the collapsible catheter pump is in a self-expanding, deployed configuration, requiring the pump head to be collapsed in vitro in order to deliver it into a human blood vessel with a small access size. The known embodiment as publication No. US9974893B2 provides the following solutions:

comprises a first sheath for receiving an expandable pump, the proximal end of the pump being connected to a catheter;

comprises a second sheath which is sleeved on the catheter and pulls the catheter, the expandable pump is pulled into the second sheath from the distal end of the second sheath, and the expandable pump is in a folded state in the second sheath;

the second sheath distal end is coupled to the first sheath proximal end, the expandable pump is advanced from the second sheath into the first sheath through the catheter, and the expandable pump remains in a compressed state, and the expandable pump expands as it is pushed out of the first sheath distal end.

Briefly, this known embodiment provides a solution comprising two sheaths, a first sheath as an interventional sheath and a second sheath as a folded sheath. By pre-folding the collapsible pump head into a folded sheath, the folded sheath is then directly coupled to the interventional sheath. The pump head is pushed from the folding sheath into the interventional sheath and finally enters the blood vessel for deployment.

The pump head folded by adopting the scheme has the following defects:

1. the pump head is expected to be folded once in vitro by adopting the folding sheath to realize the required folding size, so that the folding degree of the pump head is higher and the folding difficulty is higher. The performance is that the pump head is relatively blocked in the sheath, and the friction force is large.

2. In the interventional sheath, the pump head is further compressed and collapsed. However, in the interventional sheath, the pump head is in a forward pushing stage, and further folding of the pump head causes an increase in frictional resistance between the pump head and the interventional sheath, resulting in difficulty in pushing the pump head. In addition, the pump head which is further folded exerts strong reverse acting force on the intervention sheath, so that the intervention sheath can be expanded radially, further the puncture opening is expanded or even torn, and the pain of a patient and the complication probability of the puncture opening are increased.

3. The distal end of the pump head is typically provided with a soft atraumatic Member, including a Pigtail (Pigtail Tip) as provided in US9833550B2 or a Tip Member (Tip Member) as provided in US9421311B 2. In order to allow the soft atraumatic member to smoothly penetrate the hemostatic valve in the proximal end of the access sheath, the atraumatic member is received within the folded sheath when the pump head is folded over the body to penetrate the hemostatic valve by means of the folded sheath so that the atraumatic member smoothly enters the access sheath. This results in the length of the folded sheath being configured so that it must be possible to receive both the pump head and the atraumatic member therein, i.e. the folded sheath is longer. Therefore, the pump head has longer moving travel in the folded sheath in the folded state in the process of folding the pump head into the folded sheath and transferring the pump head into the interventional sheath, and the pump head is extremely easy to damage.

Disclosure of Invention

The present invention is directed to a catheter pump and a method for folding a pump head of a catheter pump, which at least solves one of the above-mentioned problems.

In order to achieve the above purpose, the present invention provides the following technical solutions:

the catheter pump includes a catheter, a drive shaft rotatably disposed through the catheter, a collapsible pump head, a collapsible sheath, a transition sheath, and an access sheath.

The collapsible pump head includes a pump housing and an impeller. The pump shell comprises a bracket connected to the distal end of the catheter and a covering film covered on the bracket, wherein the front end of the covering film is connected to the bracket, and the rear end of the covering film is positioned at the rear side of the bracket. The impeller is received within the housing and is connected to a distal end of a drive shaft, which is connectable to a motor to transmit rotation of the motor to the impeller.

The folding sheath is slidably disposed over the catheter and has a first passageway. At least the stent and impeller of the pump head collapse into the first channel via the distal end of the collapsed sheath by pulling the catheter back and/or pushing the collapsed sheath forward.

The transition sheath proximal end is operably docked with the distal end of the folded sheath, having a second channel. By pushing the catheter forward, at least part of the pump head is transferred from the first channel into the second channel in a collapsed state.

The proximal end of the access sheath is operably docked with the distal end of the transition sheath, having a third passageway. By pushing the catheter forward, at least part of the pump head is transferred from the second channel into the third channel in a collapsed state.

Preferably, the inner diameter of the second channel is smaller than the inner diameter of the first channel.

Preferably, the inner diameter of the third channel is substantially equal to the inner diameter of the second channel.

Preferably, the distal end of the stent is connected with a protective tip; the length of the first channel is greater than the length of the stent but less than the sum of the length of the stent and the length of the guard tip.

Preferably, the pump housing has an inlet end for the inflow of blood and an outlet end for the outflow of blood. The front end of the tectorial membrane is connected to the support, and the rear end is located the rear side of support. The mesh of the portion of the front end of the stent not covered by the coating forms an inlet end, and the outlet end is an opening formed at the rear end of the coating. The length of the first passageway is greater than the distance between the inlet end and the outlet end, but less than the distance between the outlet end and the distal end of the guard tip.

Preferably, the sum of the lengths of the first channel and the second channel is greater than the sum of the lengths of the stent and the guard tip.

Preferably, a hemostatic valve is disposed at the proximal end of the third passageway; when the distal end of the folding sheath is in butt joint with the proximal end of the transition sheath and the bracket and the impeller of the pump head are still positioned in the first channel, the distal end of the protection tip is positioned in the second channel; when the distal end of the transition sheath is docked with the proximal end of the access sheath, the distal end of the transition sheath is inserted into the third passageway and through the hemostatic valve.

Preferably, the length of the second channel is greater than the sum of the length of the stent and the guard tip.

Preferably, a hemostatic valve is disposed at the proximal end of the third passageway; the distal end of the guard tip is positioned within the second channel when the holder and impeller of the pump head are transferred from the first channel into the second channel; the distal end of the transition sheath is inserted into the third channel and through the hemostatic valve when the distal end of the transition sheath is docked with the proximal end of the access sheath.

The method of folding the pump head of the catheter pump as above comprises:

pulling the catheter back and/or pushing the folded sheath forward, at least the stent and impeller of the pump head collapsing into the first channel via the distal end of the folded sheath;

abutting the distal end of the folding sheath against the proximal end of the transition sheath, pushing the catheter forward, at least a portion of the pump head being transferred from the first channel into the second channel in a collapsed state;

the distal end of the transition sheath is abutted against the proximal end of the interventional sheath, the catheter is advanced, and at least a portion of the pump head is transferred from the second channel into the third channel in a collapsed state.

Preferably, after the stent and impeller of the pump head are collapsed into the first channel via the distal end of the folded sheath, the stent and impeller are fully collapsed into the first channel, with the front end of the protective tip being located outside the front end of the first channel.

Preferably, the rear end of the cover is located outside the rear end of the first channel after the stent and impeller of the pump head are collapsed into the first channel via the distal end of the folded sheath.

Preferably, after the stent and impeller of the pump head are folded into the first channel via the distal end of the folded sheath, an inlet end formed by mesh of a portion of the stent front end not covered with the coating film and an outlet end formed at the rear end of the coating film are folded into the first channel.

The invention has the beneficial effects that:

when the foldable pump head is folded in vitro, the pump head is pre-folded by using the folding sheath, and then the pump head is further folded to a folded state by using the transition sheath. The step-by-step folding mode is used, the folding difficulty is small, the pump head is not easy to damage in the folding process, and the pushing process is smoother. Meanwhile, the length of the folding sheath is shorter, the support and the impeller of the pump head are folded into the folding sheath, the stroke of the pump head folded into the folding sheath and transferred from the folding sheath to the transition sheath is correspondingly shortened, and the damage of the pump head is further reduced.

When the pump head is transferred from the transition sheath to the intervention sheath, the intervention sheath is not further compressed and folded, so that the intervention sheath cannot be radially expanded due to the fact that the pump head enters the intervention sheath, the puncture opening is expanded or even torn, and pain of a patient and the complication probability of the puncture opening are reduced.

In addition, by means of the mode that the pump head is pre-folded in vitro by the double sheaths (the folding sheath and the transition sheath), the pump head, particularly the part with higher folding difficulty of the pump head, namely the support and the impeller are folded step by step and transferred, and the distance or the travel of the part with higher folding difficulty in the folding state is shorter by the size arrangement between the double sheaths and the support and the protection head, so that the damage to the pump head is reduced.

Drawings

Fig. 1 is a schematic perspective view of a catheter pump provided by the present invention.

Fig. 2 is a schematic perspective view of a part of the structure of the catheter pump provided by the invention.

Fig. 3 is a schematic perspective view of a catheter pump, folded sheath and transitional sheath provided by the present invention.

Fig. 4 is another perspective view of a catheter pump, folded sheath and transitional sheath provided by the present invention.

Fig. 5 is a schematic cross-sectional view of a catheter pump, folded sheath and transitional sheath provided by the present invention.

Fig. 6 is a schematic perspective view of a folded sheath and a transitional sheath provided by the present invention.

Fig. 7 is a schematic perspective view of a catheter pump and transition sheath provided by the present invention.

Fig. 8 is a schematic cross-sectional view of a stent and impeller of a folded sheath collapsible pump head provided by the present invention.

Fig. 9 is a schematic cross-sectional view of a folded sheath and transitional sheath interface provided by the present invention.

Fig. 10 is a schematic cross-sectional view of a transitional sheath and interventional sheath interface provided by the present invention.

FIG. 11 is a schematic cross-sectional view of a transition sheath and interventional sheath interface with the folded sheath removed provided by the present invention.

Detailed Description

The present invention will be described in detail below with reference to specific embodiments shown in the drawings. These embodiments are not intended to limit the invention and structural, methodological, or functional modifications of these embodiments that may be made by one of ordinary skill in the art are included within the scope of the invention.

The terms "proximal", "posterior" and "distal", "anterior" as used herein are relative to a clinician manipulating the catheter pump of the present embodiment. The terms "proximal", "posterior" and "anterior" refer to portions relatively closer to the clinician, and the terms "distal" and "anterior" refer to portions relatively farther from the clinician. For example, the motor is at the proximal and rear ends and the guard tip is at the distal and front ends; for another example, the proximal end of a member/assembly represents an end relatively close to the motor and the distal end represents an end relatively close to the guard tip.

The catheter pump of the present invention defines an "axial" or "axial extension" with the extension of the drive shaft. As used herein, the term "inner", "outer" is with respect to an axially extending centerline, and is "inner" with respect to a direction closer to the centerline and "outer" with respect to a direction farther from the centerline.

It will be understood that the terms "proximal," "distal," "rear," "front," "inner," "outer," and these orientations are defined for convenience in description. However, catheter pumps may be used in many orientations and positions, and thus these terms of expressing relative positional relationships are not limiting and absolute. For example, the above definition of each direction is only for the convenience of illustrating the technical solution of the present invention, and is not limited to the direction of the catheter pump of the present invention in other scenarios including, but not limited to, product testing, transportation and manufacturing, etc., which may cause the inversion or position change thereof. In the present invention, the above definitions should follow the above-mentioned explicit definitions and definitions, if they are defined otherwise.

In the present invention, the terms "connected," "connected," and the like should be construed broadly unless otherwise specifically indicated and defined. For example, the device can be fixedly connected, detachably connected, movably connected or integrated; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, the technical features of the different embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.

Referring to fig. 1 and 2, a catheter pump 100 according to an embodiment of the present invention may be at least partially inserted into a subject to assist in the pumping function of the heart and reduce the heart burden. Catheter pump 100 may act as a left ventricular assist, pumping blood in the left ventricle into the ascending aorta. It can also be used as a right ventricular assist to pump venous blood to the right ventricle.

The scenario will be described below primarily with catheter pump 100 as left ventricular assist. It will be appreciated from the foregoing that the scope of embodiments of the invention is not limited thereby.

Catheter pump 100 includes motor 1, catheter 2, a drive shaft (not shown) rotatably disposed through catheter 2, a collapsible pump head 3 that can be delivered through catheter 2 to the left ventricle of the subject's heart for pumping blood, and a coupler 4 connected to the proximal end of catheter 2 for releasable engagement with motor 1.

The collapsible pump head 3 includes a pump housing 31 connected to the distal end of the catheter 2 and having an inlet end 311 for blood to enter and an outlet end 312 for blood to exit, and an impeller (not shown) housed within the pump housing 31. The impeller comprises a hub and blades supported on the outer wall of the hub. The drive shaft is connected at a proximal end to the motor 1 and at a distal end to the hub of the impeller to transfer the rotation of the motor 1 to the impeller. The drive shaft comprises a flexible shaft which is flexible and a hard shaft which is connected to the distal end of the flexible shaft, the flexible shaft is penetrated in the catheter 2, and the hard shaft is penetrated in the hub.

In this embodiment, the pump housing 31 includes a support 313 made of nickel, titanium alloy in a metallic lattice and connected to the distal end of the catheter 2, and an elastic coating 314 covering the support 313. Wherein the front end of the covering film 314 is connected to the support 313, and the rear end is located at the rear side of the support 313. That is, the mesh of the portion of the front end of the support 313 not covered with the covering film 314 forms the inlet end 311. The rear end of the covering film 314 is covered outside the distal end of the catheter 2, and the outlet end 312 is an opening formed at the rear end of the covering film 314.

Specifically, the support 313 includes a cylindrical structure 3131 and tapered structures 3132 at both ends of the cylindrical structure. When the covering film 314 is covered on the support 313, the front end of the covering film 314 is connected to the cylindrical structure 3131 located in the middle, the tapered structure 3132 located at the front end is exposed, and the tapered structure located at the rear end is located in the covering film 314.

As described above, the impeller is housed in the pump casing 31. Specifically, the impeller is housed in a bracket 313. The proximal and distal ends of the support 313 are connected to a proximal bearing housing (not shown) and a distal bearing housing 32, respectively, and proximal and distal bearings (not shown) are provided in the proximal and distal bearing housings 32, respectively. The proximal end and the distal end of the hard shaft are respectively penetrated in the proximal end bearing and the distal end bearing. Thus, the two ends of the hard shaft are supported by the two bearings, and the high rigidity of the hard shaft allows the impeller to be preferably held in the pump housing 31.

The coupler 4 and the motor 1 may be detachably connected by means of a lock nut or a snap-on connection as provided in US9421311B 2. The motor 1 drives the driving part, a rotor is arranged in the coupler 4, the rotor comprises a rotor shaft and a driven part arranged on the rotor shaft, the proximal end of the driving shaft is connected to the rotor shaft, the driven part is coupled with the driving part to transmit the rotation power of the motor 1 when the motor is started to the driving shaft, and then the impeller is driven to rotate for pumping blood. The driven member and the driving member may be magnetically coupled, such as provided by CN203120810B or CN101820933B, i.e., the driven member and the driving member are both magnets. Alternatively, the follower and the driving member may employ an eddy current linkage (EddyCurrent Coupling) as provided by CN216061675U or CN114452527a, i.e. one of the follower and the driving member is a magnet and the other is a conductor.

The distal end of the support 313 is connected to a protective tip 5, the protective tip 5 being configured to be flexible so as not to injure the tissue of the subject, the protective tip 5 being made of any macroscopic material exhibiting flexibility. The flexible end part is supported on the inner wall of the ventricle in a noninvasive or atraumatic way, separates the suction inlet of the pump head 3 from the inner wall of the ventricle, avoids the suction inlet of the pump head 3 from being attached to the inner wall of the ventricle due to the reaction force of fluid (blood) in the working process of the pump head 3, and ensures the effective area of pumping.

The pump head 3 and the front end portion of the catheter 2 are fed into and held in the subject, and it is desirable that the size of the pump head 3 and the catheter 2 be as small as possible. The smaller size pump head 3 and catheter 2 can enter the subject's body through the smaller puncture size, reducing the pain of the subject caused by the interventional procedure, and reducing complications caused by oversized puncture.

Therefore, in order to reduce the size of the puncture and to ensure a large flow rate of the pump head 3, the pump head 3 is a collapsible pump having a collapsed state and an expanded state. In particular, in the corresponding insertion configuration of the pump head 3, the pump housing 31 and the impeller are in a collapsed state, the pump head 3 being inserted into and/or delivered in the subject's vasculature at a first smaller outer diameter dimension. In the corresponding operating configuration of the pump head 3, the pump housing 31 and the impeller are in a deployed state so that the pump head 3 pumps blood in the left ventricle of the heart at a second outer diameter dimension which is larger than the first outer diameter dimension.

By providing the collapsible pump head 3, the pump head 3 has a smaller collapsed size and a larger expanded size, so as to reduce pain of a subject and ease intervention in the intervention/transportation process, and provide a large flow.

The support 313 of the pump housing 31 is preferably folded in a multi-mesh, in particular diamond-mesh, design, and is unfolded by means of the memory properties of the nitinol. The cover 314 is made of flexible material and can be folded and unfolded.

The blades of the impeller are made of flexible materials and can be bent relative to the hub, and the impeller has a folded configuration and an unfolded configuration. The blade tip of the blade in the collapsed configuration is proximate to the hub and the blade tip of the blade in the expanded configuration is distal to the hub. The energy storage of the blade is released after the external constraint is removed, so that the blade is unfolded, and the radially outer side of the blade is unfolded to be in a state of maximum radial dimension.

The pump head 3 is folded by means of external constraint, and after the constraint is removed, the pump head 3 is self-unfolded. In the present embodiment, the "collapsed state" refers to a state in which the pump head 3 is radially restrained, that is, a state in which the pump head 3 is radially compressed and collapsed to a minimum radial dimension by external pressure. The "deployed state" refers to a state in which the pump head 3 is not radially constrained, that is, a state in which the bracket 313 and the impeller are deployed radially outward to the maximum radial dimension.

Referring to fig. 3-11, catheter pump 100 is inserted into a subject, and may be implemented by an insertion assembly. In this embodiment, the interventional assembly comprises a folded sheath 6, a transitional sheath 7 and an interventional sheath 8.

In view of the above, it is desirable that the catheter pump 100 be capable of being inserted into a subject in a smaller size, that is, that the catheter pump 100 be inserted into the subject in a collapsed state, from the viewpoints of alleviating pain of a patient and reducing complications of a puncture. In this embodiment, the catheter pump 100 is folded in vitro by the cooperation of the folding sheath 6 and the transition sheath 7.

Specifically, referring to fig. 7 and 8, the folded sheath 6 is slidably disposed over the catheter 2 and has a first passageway 61. By pulling the catheter 2 back and/or pushing the folded sheath 6 forward, at least the support 313 and impeller of the pump head 3 are folded into the first channel 61 via the distal end of the folded sheath 6. The operation of pulling the catheter 2 backward and/or pushing the folded sheath 6 forward includes three cases, one is to pull the catheter 2 backward, one is to push the folded sheath 6 forward, and the other is to push the folded sheath 6 forward while pulling the catheter 2 backward.

Then, referring to fig. 9, the proximal end of the transition sheath 7 is operably docked with the distal end of the folded sheath 6, which has a second channel 71; by pushing the catheter 2 forward, at least part of the pump head 3 is transferred from the first channel 61 into the second channel 71 in a collapsed state, so as to switch the pump head 3 from the deployed state to the collapsed state.

In this embodiment, the inner diameter of the second channel 71 is smaller than the inner diameter of the first channel 61, and the inner diameter of the second channel 71 is approximately equal to the outer diameter of the pump head 3 in the collapsed state. The pump head 3 is folded step by step in vitro by the folding sheath 6 and the transition sheath 7. Specifically, after the support 313 and impeller of the pump head 3 enter the first channel 61, the folding sheath 6 folds the pump head 3 in a first stage. After the pump head 3 enters the second channel 71 from the first channel 61, the transition sheath 7 performs a secondary folding of the pump head 3. Compared with the one-time folding in the prior art, each folding in the step-by-step folding has lower folding degree of the pump head 3, lower folding difficulty, less damage to the pump head 3 in the folding process, smoother intervention pushing process and lower friction force.

It should be noted that, the strength of the support 313 is relatively high, and the difficulty of folding the support 313 is greater than that of folding the covering film 314. Therefore, the folding sheath 6 is finally folded to form the support 313 with greater difficulty, and the covering film 314 is folded by the folding sheath 6 when the catheter 2 is pushed forward to transfer the pump head 3 to the transition sheath 7.

In order to shorten the stroke of the pump head 3 in the folded sheath 6, the length of the folded sheath 6 is short. In one embodiment, the length of first channel 61 is greater than the length of support 313 but less than the sum of the lengths of support 313 and guard tip 5. When the folding sheath 6 folds the pump head 3, only the support 313 and the impeller fold into the first channel 61, the covering film 314 is not fully folded into the first channel 61, the covering film 314 is at least partially exposed, and the protective tip 5 is exposed outside the first channel 61. There is no need to protect the tip 5 from entering the primary channel 61, so that the stroke of folding the pump head 3 into the folded sheath 6 is shorter, and the stroke of transferring the pump head 3 from the folded sheath 6 to the transitional sheath 7 is shorter, thereby reducing the damage of the pump head 3.

Alternatively, in another embodiment, the length of the first channel 61 is greater than the distance between the inlet end 311 and the outlet end 312 of the pump housing 31, but less than the distance between the outlet end 312 and the distal end of the guard tip 5. When the folding sheath 6 folds the pump head 3, at least a portion of the structure of the pump head 3 (including the support 313, impeller, and part of the at least partial membrane 314) between the inlet end 311 and the outlet end 312 is folded into the first channel 61, but the protective tip 5 remains exposed outside the first channel 61. This embodiment increases the travel of the pump head 3 from the folded sheath 6 to the transitional sheath 7 compared to the previous embodiment, but the travel of the pump head 3 in the folded state is still partially shortened compared to conventional pre-folding schemes that require stowing into the folded sheath 6 along with the protective tip 5.

Furthermore, this embodiment is such that, after pre-collapsing, at least the portion of the pump head 3 between the inlet end 311 and the outlet end 312 is collapsed into the first channel 61. Thus, after the priming and the venting of the catheter pump 100 are completed, the inlet end 311 to the outlet end 312 are prevented from being exposed to air, and the air is prevented from entering the pump head 3 again through the inlet end 311 and/or the outlet end 312, so that the pump head 3 is prevented from being subsequently inflated to be involved in a human body. This is critical for patient safety.

When the proximal end of the transition sheath 7 and the distal end of the folded sheath 6 are docked, the protection tip 5 is located within the transition sheath 7. In this embodiment, the protecting tip 5 extends along the axis of the pump head 3, i.e. the protecting tip 5 is straight, so that it can smoothly enter the transition sheath 7 from the distal end.

When the length of the second channel 71 is sufficiently long, the entire pump head 3 can be folded into the second channel 71. When the length of the second channel 71 is short, only the support 313 and the impeller can be folded into the second channel 71, and the cover 314 is located outside the second channel 71. This arrangement reduces the travel of the pump head 3 from the folded sheath 6 to the transitional sheath 7 to reduce damage to the pump head 3.

After the transition sheath 7 and the folding sheath 6 are docked, the catheter 2 is pushed forward to transfer at least part of the pump head 3 from the folding sheath 6 to the transition sheath 7. In order to avoid that the folded sheath 6 is separated from the transition sheath 7 when the pump head 3 is pushed forward, the transition sheath 7 and the folded sheath 6 need to be kept axially relatively fixed, so that the pump head 3 can be smoothly transferred into the transition sheath 7 in a folded state.

Referring to fig. 6, in this embodiment, the folding sheath 6 and the transition sheath 7 are detachably connected. Specifically, the distal end of the folded sheath 6 is provided with a first part 62, the proximal end of the transition sheath 7 is provided with a second part 72 cooperating with the first part 62, and the first part 62 and the second part 72 are detachably locked. The transition sheath 7 and the folding sheath 6 are subjected to a relative rotational movement to effect locking or unlocking of the first part 62 and the second part 72. The specific structure of the first member 62 and the second member 72 and the manner of fitting therebetween are not particularly limited, and may be set according to actual needs.

The access sheath 8 may partially access the vasculature of the subject through the puncture. The front end of the access sheath 8 enters the vasculature through the puncture and the back end remains outside the body for forming or establishing access for the device into the vasculature.

Referring to fig. 10 and 11, the proximal end of the access sheath 8 is operably docked with the distal end of the transition sheath 7, which has a third passageway 81. By pushing the catheter 2 forward, at least part of the pump head 3 is transferred from the second channel 71 into the third channel 81 in a collapsed state, so that the pump head 3 is delivered in a collapsed state through the interventional sheath 8 to the vascular system, enabling the pump head 3 to enter the subject's body with a smaller interventional size.

Wherein the inner diameter of the third channel 81 is substantially equal to the inner diameter of the second channel 71. When the pump head 3 enters the third channel 81, the pump head 3 is not compressed and folded any more, the friction resistance of the pump head 3 entering the third channel 81 is small, and the pushing is smooth. And the risk that the puncture opening is expanded or even torn due to radial expansion of the pump head 3 entering the puncture opening is avoided, and the pain of a patient and the probability of complications of the puncture opening are reduced.

A hemostatic valve 82 is provided proximally within the third passage 81. The hemostatic valve 82 prevents blood in the blood vessel from flowing out of the body through the hollow structure of the access sheath 8 when the access sheath 8 is accessed to the puncture. The hemostatic valve 82 may be a balloon, rubber or silicone flexible material.

Because the guard tip 5 is relatively soft, it cannot pass through the hemostatic valve 82. The distal end of the guard tip 5 is located within the second channel 71 as the pump head 3 is transferred from the transition sheath 7 to the access sheath 8. Specifically, in one embodiment, the sum of the lengths of the first channel 61 and the second channel 71 is greater than the sum of the lengths of the support 313 and the guard tip 5. With the distal end of the folded sheath 6 abutting the proximal end of the transition sheath 7 and the support 313 and impeller of the pump head 3 still located within the first channel 61, the distal end of the guard tip 5 is located within the second channel 71. Under the premise of ensuring that the folding sheath 6 is short enough, when the distal end of the transition sheath 7 is butted with the proximal end of the intervention sheath 8, the distal end of the transition sheath 7 is inserted into the third channel 81 and passes through the hemostatic valve 82, so that the protection tip 5 is pushed forward conveniently, and the protection tip 5 is prevented from being damaged.

In another embodiment, the length of the second channel 71 is greater than the sum of the length of the support 313 and the guard tip 5. The distal end of the guard tip 5 is located in the second channel 71 when the support 313 and impeller of the pump head 3 are transferred from the first channel 61 into the second channel 71. When the distal end of the transition sheath 7 is docked with the proximal end of the access sheath 8, the distal end of the transition sheath 7 is inserted into the third channel 81 and through the hemostatic valve 82, likewise protecting the tip 5 from damage.

Likewise, the distal end of the transition sheath 7 and the proximal end of the access sheath 8 may also be provided with cooperating locking assemblies (not shown) by which the relative locking or removal between the transition sheath 7 and the access sheath 8 is achieved. When the catheter 2 is pushed forward, the transition sheath 7 and the access sheath 8 are locked by the locking assembly, both remaining axially fixed relative to each other.

Referring to fig. 7 to 11, the present invention further provides a method for folding the pump head 3 of the catheter pump 100 as described above, comprising:

pulling the catheter 2 back and/or pushing the folded sheath 6 forward, at least the stent 313 and impeller of the pump head 3 collapsing into the first channel 61 via the distal end of the folded sheath 6;

abutting the distal end of the folding sheath 6 against the proximal end of the transition sheath 7, pushing the catheter 2 forward, at least part of the pump head 3 being transferred from the first channel 61 into the second channel 71 in a collapsed state;

the distal end of the transition sheath 7 is abutted against the proximal end of the insertion sheath 8, pushing the catheter 2 forward, at least part of the pump head 3 being transferred from the second channel 71 into the third channel 81 in a collapsed state.

Specifically, referring to fig. 7 and 8, the folding sheath 6 is slidably disposed over the catheter 2, and the catheter 2 is pulled back, or the folding sheath 6 is pushed forward while the catheter 2 is pulled back. Because the folded sheath 6 is short, only the support 313 of the pump head 3 and the impeller are folded into the primary channel 61. After the support 313 and impeller of the pump head 3 are collapsed into the first channel 61 via the distal end of the folded sheath 6, at least the support 313 and impeller are fully collapsed into the first channel 61, protecting the front end of the tip 5 from being outside the front end of the first channel 61, thereby reducing the collapsing stroke of the pump head 3 within the folded sheath 6.

In one embodiment, the length of the folded sheath 6 only supports the collapsing of the support 313 and impeller into the first channel 61, while the rear end of the cover 314 is located outside the rear end of the first channel 61, which is advantageous in reducing the travel of the support 313 and impeller under collapsing.

Of course, in another embodiment, to avoid re-entering the pump housing 31 through the inlet end 311 and/or the outlet end 312 of the pump head 3 after exhausting, the length of the folded sheath 6 is slightly longer than that of the previous embodiment, so as to support folding the portion of the pump head 3 between the inlet end 311 and the outlet end 312 into the first channel 61.

In both of the above embodiments, after the folding sheath 6 has completed the pre-folding of the pump head 3, it is ensured that the protection tip 5 is exposed outside the first channel 61. This is to reduce the moving distance of the support 313 and the impeller in the folded state, and to reduce damage to the pump head 3.

Referring to fig. 9, the distal end of the folded sheath 6 abuts the proximal end of the transition sheath 7, the guard tip 5 is positioned in the second channel 71, and the catheter 2 is pushed forward such that the support 313, impeller and guard tip 5 of the pump head 3 are positioned in the second channel 71, and the cover 314 may be positioned in the second channel 71 or in the first channel 71.

The folded sheath 6 and the transitional sheath 7 remain axially stationary during the transfer of the pump head 3 from the first channel 61 into the second channel 71. Which is achieved by the locking of the first part 62 and the second part 72.

Referring to fig. 10 and 11, the interventional sheath 8 is partially inserted into the vasculature of a subject through a puncture.

Likewise, the transition sheath 7 and the access sheath 8 remain axially stationary during transfer of the pump head 3 from the second channel 71 into the third channel 81, which is accomplished by the locking of the locking assembly.

To facilitate removal of the folded sheath 6, the folded sheath 6 has a lateral opening at the proximal end along which the folded sheath 6 can be peeled apart, saving labor and facilitating operation. The lateral openings may be provided in two, opposite sides of the proximal end of the interventional sheath 8. The folded sheath 6 has two handles 63 disposed opposite each other at the proximal end, which facilitates the operator to tear the folded sheath 6 by holding the two handles 63, improving the operability thereof. The structure of the folded sheath 6 is not particularly limited herein, but may be other structures that are convenient to remove, for example, the folded sheath 6 may be connected with a pre-pressing slit on two sides of the symmetrical position.

After at least a portion of the pump head 3 is transferred into the third channel 81 in the collapsed state, the method further comprises: the catheter 2 is pushed forward continuously, so that the pump head 3 is moved out of the distal end of the interventional sheath 8 in a folded state, after the constraint is removed, the pump shell supports the elastic covering film 314 to be unfolded under the action of the self memory property, the impeller is self-unfolded under the action of released energy storage, the pump head 3 is conveyed to the vascular system in an unfolded state and is intervened in the left ventricle, and the motor 1 and the catheter 2 are connected in a matched mode, so that the blood pumping working state of the catheter pump 100 is realized.

In a comprehensive way, when the foldable pump head is folded in vitro, the pump head is pre-folded by using the folding sheath, and then the pump head is further folded to a folding state by using the transition sheath, a step-by-step folding mode is used, the folding difficulty is small, the pump head is not easy to damage in the folding process, the pushing process is smoother, meanwhile, the length of the folding sheath is shorter, the support and the impeller of the pump head are folded into the folding sheath, and the strokes of folding the pump head into the folding sheath and transferring the pump head from the folding sheath to the transition sheath are correspondingly shortened, so that the damage of the pump head is further reduced;

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The foregoing examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. A catheter pump comprising:

a conduit;

a drive shaft rotatably penetrating the guide tube;

a collapsible pump head comprising: a pump housing and an impeller; the pump housing includes: a stent attached to the distal end of the catheter, a cover over the stent; the front end of the tectorial membrane is connected to the bracket, and the rear end is positioned at the rear side of the bracket; the impeller being received within the housing and connected to a distal end of the drive shaft, a proximal end of the drive shaft being connectable to a motor to transmit rotation of the motor to the impeller;

a folding sheath slidably sleeved outside the catheter and provided with a first channel; at least the stent and impeller of the pump head are collapsed into the first channel via the distal end of the folded sheath by pulling back the catheter and/or pushing the folded sheath forward;

a transition sheath having a proximal end operably interfacing with a distal end of the folded sheath, with a second passageway; at least part of the pump head is transferred from the first channel into the second channel in a collapsed state by pushing the catheter forward;

an access sheath having a proximal end operably interfacing with a distal end of the transition sheath, with a third passageway; at least part of the pump head is transferred from the second channel into the third channel in a collapsed state by pushing the catheter forward.

2. The catheter pump of claim 1, the second channel having an inner diameter that is smaller than an inner diameter of the first channel.

3. The catheter pump of claim 1, wherein an inner diameter of the third channel is approximately equal to an inner diameter of the second channel.

4. The catheter pump of claim 1, said stent distal end being connected to a protective tip; the length of the first channel is greater than the length of the stent but less than the sum of the lengths of the stent and the guard tip.

5. The catheter pump of claim 4, said pump housing having an inlet end for ingress of blood, an outlet end for egress of blood; the front end of the tectorial membrane is connected to the bracket, and the rear end is positioned at the rear side of the bracket; the mesh of the part of the front end of the bracket, which is not covered by the coating, forms the inlet end, and the outlet end is an opening formed at the rear end of the coating;

the length of the first passageway is greater than the distance between the inlet end and the outlet end, but less than the distance between the outlet end and the distal end of the guard tip.

6. The catheter pump of claim 4, the sum of the lengths of the first and second channels being greater than the sum of the lengths of the stent and the guard tip.

7. The catheter pump of claim 6, wherein a hemostatic valve is disposed proximally within the third passageway;

the distal end of the guard tip is positioned within the second channel while the distal end of the folded sheath is docked with the proximal end of the transition sheath and while the stent and impeller of the pump head are still positioned within the first channel;

the distal end of the transition sheath is inserted into the third channel and through the hemostatic valve when the distal end of the transition sheath is docked with the proximal end of the access sheath.

8. The catheter pump of claim 4, the length of the second channel being greater than the sum of the lengths of the stent and the guard tip.

9. The catheter pump of claim 8, a hemostatic valve disposed proximally within the third passage;

the distal end of the guard tip is positioned within the second channel when the holder and impeller of the pump head are transferred from the first channel into the second channel;

10. A method of folding the pump head of the catheter pump of any of claims 1 to 9, comprising:

pulling back the catheter and/or pushing forward the folded sheath, at least the stent and impeller of the pump head collapsing into the first channel via the distal end of the folded sheath;

abutting the distal end of the folding sheath with the proximal end of the transition sheath, pushing the catheter forward, at least a portion of the pump head being transferred from the first channel into the second channel in a collapsed state;

abutting the distal end of the transition sheath with the proximal end of the access sheath, pushing the catheter forward, at least a portion of the pump head being transferred from the second channel into the third channel in a collapsed state.

11. The method of claim 10, wherein after the stent and impeller of the pump head are collapsed into the first channel via the distal end of the folded sheath, at least the stent and impeller are fully collapsed into the first channel, the front end of the guard tip being located outside the front end of the first channel.

12. The method of claim 10 or 11, wherein the trailing end of the membrane is located outside the trailing end of the first channel after the stent and impeller of the pump head are collapsed into the first channel via the distal end of the folded sheath.

13. The method of claim 10 or 11, wherein after the stent and impeller of the pump head are folded into the first channel via the distal end of the folded sheath, an inlet end formed by mesh of a portion of the stent front end not covered by the coating and an outlet end formed at the rear end of the coating are folded into the first channel.