CN115430039B

CN115430039B - Catheter pump and method for folding pump head of catheter pump

Info

Publication number: CN115430039B
Application number: CN202210317581.6A
Authority: CN
Inventors: 张家良; 刘刚
Original assignee: Xinqing Medical Suzhou Co ltd
Current assignee: Xinqing Medical Suzhou Co ltd
Priority date: 2022-03-29
Filing date: 2022-03-29
Publication date: 2024-03-08
Anticipated expiration: 2042-03-29
Also published as: CN115430039A

Abstract

A catheter pump and method of folding a pump head of a catheter pump is disclosed, the catheter pump including a catheter, a foldable pump head, and a pre-folding assembly slidably disposed over the catheter. The pre-collapse assembly is configured to receive the pump head in the expanded state therein when slid distally to switch the pump head to the collapsed state. The pre-folding assembly includes an introduction tube having a first straight lumen, and an introduction sheath removably connected to a distal end of the introduction tube. The introducer sheath has a second straight lumen at the distal end with an inner diameter greater than the inner diameter of the first straight lumen. The introduction sheath is separated from the introduction tube after the pump head is transferred from the second straight chamber to the first straight chamber.

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, belonging to the field of medical appliances.

Background

The catheter pump is adapted to be inserted into a desired position of the heart of a heart failure patient to assist the pumping function of the heart. From the standpoint of alleviating pain for the patient and reducing complications of the puncture, it is desirable that the catheter pump be capable of being introduced into the human body in a smaller size.

The distal pump head of the catheter pump is in a self-expanding deployment 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. Currently, the design is that a tubular introducer is preloaded at the proximal end of the catheter pump, and the pump head is folded into the introducer tube by pushing the tubular introducer toward the pump head. However, in the folding mode, the pump head is subjected to axial force in the folding process, the folding force is large, the operation of doctors is inconvenient, the folding can be completed by using large force, and the pump head is easy to damage.

Disclosure of Invention

The invention aims to provide a catheter pump and a method for folding the pump head of the catheter pump, which can fold the pump head of the catheter pump more easily and safely.

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

the catheter pump of the present invention includes a catheter, a drive shaft rotatably disposed through the catheter, a collapsible pump head, and a pre-collapsible assembly. The pump head includes a pump housing connected to the distal end of the catheter, and an impeller disposed within the pump housing. The impeller is connected to a distal end of a drive shaft, which is connectable to a motor to transfer rotation of the motor to the impeller. The pre-folding component is slidably sleeved outside the catheter, and can accommodate the pump head in the unfolded state into the catheter when the pre-folding component slides towards the distal end, so that the pump head is switched to the folded state. The pre-folding assembly includes an introduction tube having a first lumen, and an introduction sheath removably coupled to a distal end of the introduction tube. The introducer sheath has a second straight lumen at the distal end with an inner diameter greater than the inner diameter of the first straight lumen. The introduction sheath is separated from the introduction tube after the pump head is transferred from the second straight chamber to the first straight chamber.

The method of folding the pump head of a catheter pump as described above comprises: the pre-folding assembly is pushed forward and/or the catheter is pulled backward, causing the proximal end of the pump head to be inserted into the second straight lumen. The pre-folding component is continuously pushed forwards and/or the conduit is pulled backwards until the pump head is folded and transferred into the first straight cavity from the second straight cavity. An operation of separating the introduction sheath from the introduction tube is performed.

The pre-folding component for folding the pump head comprises an ingress pipe and an ingress sheath which are detachably connected, so that the pump head is slowly and gradually folded, the folding force is reduced, the operation is more convenient and labor-saving, and the smoothness and smoothness of folding the pump head are improved.

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 pre-folding assembly according to the present invention

Fig. 3 is a structural cross-sectional view of a pre-folding assembly provided by the present invention.

Fig. 4 is a partial structural sectional view of the catheter pump provided by the invention.

Fig. 5 is a schematic perspective view of a catheter sleeved on a catheter pump by the pre-folding assembly provided by the invention.

Fig. 6 is a schematic perspective view of a pump head of a collapsible catheter pump of a pre-collapsible assembly according to the present invention.

Fig. 7 is a schematic perspective view of the separation of the introduction tube and the introduction sheath in the pre-folding assembly according to the present invention.

Fig. 8 is a schematic perspective view of the pump head in a folded state transferred to the interventional sheath.

Detailed Description

Referring to fig. 1, 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 a motor 1, a catheter 2, a collapsible pump head 3 that can be delivered through catheter 2 to a desired location of a subject's heart, such as the left ventricle, 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 comprises a pump housing 31 connected to the distal end of the catheter 2 and having an inlet end 311 and an outlet end 312, and an impeller (not shown) provided within the pump housing 31.

The pump housing 31 includes a support 313 made of nickel, titanium alloy in a metallic lattice and an elastic coating 314 covering the support 313. The metal lattice of the support 313 has a mesh design, and the cover 314 covers the middle and rear end portions of the support 313, and the mesh of the portion of the front end of the support 313 not covered by the cover 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. The impeller comprises a hub and blades supported on the outer wall of the hub. The impeller can be driven in rotation to draw blood into the pump housing 31 from the inlet end 311 and out the outlet end 312.

Catheter pump 100 further comprises a drive shaft (not shown) rotatably disposed through catheter 2, the proximal end of the drive shaft being connectable to motor 1 and the distal end of the drive shaft being connected to the impeller to transfer rotation of motor 1 to the impeller for pumping blood. 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.

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 distal end of the distal bearing chamber 32 is provided with a protective head 5, which is configured to be flexible so as not to injure the tissue of the subject, the protective head 5 may be made of any macroscopic material exhibiting flexibility. Specifically, the protecting head 5 is a flexible protrusion with an arc-shaped or winding-shaped end, and the flexible end is supported on the inner wall of the ventricle in a non-invasive or non-invasive manner, so that the suction inlet of the pump head 3 is separated from the inner wall of the ventricle, the suction inlet of the pump head 3 is prevented from being attached to the inner wall of the ventricle due to the reaction force of blood in the working process of the pump head 3, and the effective pumping area is ensured.

The motor 1 has a motor shaft and a socket formed at the front end of the motor housing for mating with the coupler 4. The hub includes an active magnet coupled to the motor shaft. The coupler 4 comprises a passive magnet connected to the proximal end of the drive shaft. The disassembly of the motor 1 and the catheter 2 is realized by the disassembly of the connector and the coupler 4.

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.

The dimensions and the hydrodynamic properties of the pump head 3 are two mutually contradictory parameters in the art. From the viewpoints of alleviating pain of a subject and ease of intervention, it is desirable that the pump head 3 be small in size. However, in order to provide a strong assist function to the subject, it is desirable that the flow rate of the pump head 3 is large, and the large flow rate generally requires the pump head 3 to be large in size.

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 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 and the impeller are in a deployed state such that the pump head 3 pumps blood at a desired location with a second radial dimension that is greater than the first radial 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.

By the above, the design of the multi-mesh, especially diamond-shaped mesh, of the pump housing 31 can realize the preferable folding and unfolding by the memory property of the nickel-titanium alloy. The blades of the impeller are made of flexible materials or shape memory materials, can be bent relative to the hub, and have 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.

In the corresponding insertion configuration of the pump head 3, the blades are in a folded configuration, which wraps around the hub outer wall and is at least partially in contact with the inner wall of the pump housing 31. In the corresponding operating configuration of the pump head 3, the blades, when in the deployed configuration, extend radially outwardly from the hub and are spaced from the inner wall of the pump head 3.

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 "expanded 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 expanded radially outward to the maximum radial dimension.

The switching of the pump head 3 between the unfolded state and the folded state can be realized through the pre-folding component 6, the pre-folding component 6 is slidably sleeved outside the catheter 2, and the pump head 3 in the unfolded state can be accommodated in the pre-folding component when the pre-folding component 6 slides to the far end, so that the pump head 3 is switched to the folded state.

The external restraint imposed on the pump head 3 may be accomplished by a pre-folding assembly 6. When the pre-folding component 6 moves to the far end, the pump head 3 can be integrally accommodated in the pre-folding component, so that the forced folding of the pump head 3 is realized. Then, when the pre-folding assembly 6 moves proximally, the radial constraint imposed by the pump head 3 is removed and the pump head 3 is switched to the unfolded state.

The pre-folding assembly 6 includes an introduction tube 61 having a first straight lumen 611 and an introduction sheath 62 detachably connected to the distal end of the introduction tube 61. The inner diameter dimension of the first straight cavity 611 defines the outer diameter dimension of the pump head 3 in the collapsed state, i.e. the inner diameter dimension of the first straight cavity 611 is equal to the outer diameter dimension of the pump head 3 in the collapsed state. So that the pump head 3 enters the first straight cavity 611, and the pump head 3 is folded. It should be noted that, the first straight cavity 611 is a cavity channel with a constant inner diameter, and the pump head 3 is located in the first straight cavity 611 and keeps a folded state all the time.

The introduction pipe 61 is made of PTFE having a low friction coefficient, so that the conveying force of the pump head 3 during relative movement in the introduction pipe 61 can be reduced, and the conveying compliance can be improved. In other embodiments, the material of the inlet tube 61 may be other materials with low friction coefficient, which is not illustrated here.

The introducer sheath 62 provides for pre-collapsing of the pump head 3, with a second, distally located, straight lumen 621, the second, straight lumen 621 having an inner diameter at least not less than the diameter of the pump head 3 in the deployed state, thereby facilitating collapsing of the pump head 3 from the distal end of the introducer sheath 62. The second straight chamber 621 has an inner diameter larger than that of the first straight chamber 611, so that the second straight chamber 621 plays a guiding role to guide the pump head 3 to the first straight chamber 611. The difference between the inner diameter of the first straight cavity 611 and the diameter of the pump head 3 in the unfolded state is avoided from being too large, so that the pump head 3 is prevented from being folded.

The introducer sheath 62 also includes a guide lumen 622 located between the first straight lumen 611 and the second straight lumen 621, with the inner wall of the guide lumen 622 tapering proximally from the distal end. The distal inner diameter dimension of the guide cavity 622 is slightly greater than or equal to the outer diameter dimension of the pump head 3 in the deployed state, and the proximal inner diameter dimension is slightly greater than or equal to the outer diameter dimension of the pump head 3 in the collapsed state.

When the pump head 3 moves from the second straight cavity 621 and passes through the guide cavity 622, the inner diameter dimension is gradually reduced due to the gradual shrinkage of the guide cavity 622, the pump head 3 is slowly and gradually folded, the pre-folding of the pump head 3 is completed, the folding force is reduced, and the smoothness of the pump head 3 entering the first straight cavity 611 is improved. In this embodiment, the pump head 3 is gradually folded, but not folded by pulling, so that the pump head 3 is not easily damaged, and the safety is high.

The cross section of the guide cavity 622 is generally in a truncated cone shape, and the included angle of the conical surface of the truncated cone is between 5 degrees and 60 degrees. The design is more beneficial to folding the pump head 3 and reduces folding force. Practical verification shows that the included angle of the conical surface of the guide cavity 622 is an important parameter affecting the pre-folding effect, and the guide cavity 622 is arranged on the guide sheath 62, so that the included angle of the conical surface of the guide cavity 622 can be quite large to meet the requirement. The pump housing 31 includes a bracket 313 having a tapered proximal end. The cone angle of the truncated cone shape of the guide cavity 622 is smaller than the proximal cone angle of the support 313 to achieve smooth folding of the pump head 3.

It is to be noted that the above-mentioned numerical values include all values of the lower value and the upper value that are incremented by any one unit from the lower value to the upper value, and that there is at least two units of interval between any lower value and any higher value.

For example, the cone angle of the truncated cone is between 5 ° and 60 °, preferably between 10 ° and 55 °, more preferably between 15 ° and 50 °, further preferably between 20 ° and 45 °, further preferably between 25 ° and 40 °, further preferably between 30 ° and 35 °, for the purpose of illustrating the above-mentioned not explicitly recited values such as 6 °, 8 °, 12 °, 16 °, 18 °, 22 °, 24 °, 28 °, 32 °, 36 °, 39 °, 41 °, 43 °, 46 °, 49 °, 52 °, 56 °, 59 °.

As described above, the exemplary range in 5 ° intervals does not exclude the increase in the intervals in the appropriate units such as the numerical units of 1 °, 2 °, 3 °, 4 °, 6 °, 7 °, 8 °, 9 °, 10 °. These are merely examples that are intended to be explicitly recited in this description, and all possible combinations of values recited between the lowest value and the highest value are believed to be explicitly stated in the description in a similar manner.

Unless otherwise indicated, all ranges include endpoints and all numbers between endpoints. "about" or "approximately" as used with a range is applicable to both endpoints of the range. Thus, "about 20 to 30" is intended to cover "about 20 to about 30", including at least the indicated endpoints.

Other descriptions of the numerical ranges presented herein are not repeated with reference to the above description.

Introducer sheath 62 also includes a third straight lumen 623 at the proximal end, the third straight lumen 623 having an inner diameter less than the inner diameter of the second straight lumen 621 and at least no greater than the inner diameter of the first straight lumen 611. The third straight chamber 623 allows smooth transfer of the collapsed pump head 3 from the third straight chamber 623 to the first straight chamber 611.

The distal end of the introduction tube 61 is provided with a locking member 612, and the proximal end of the introduction sheath 62 is provided with a first member 624 which is engaged with the locking member 612, and the locking member 612 and the first member 624 are detachably locked. The introduction tube 61 and the introduction sheath 62 are subjected to a relative rotational movement to lock or unlock the locking member 612 and the first member 624, the rotational angle not exceeding 90 °.

Specifically, the first member 624 is one of a projection and a stopper wall, and the locking member 612 is the other of a projection and a stopper wall, which abut when the introduction tube 61 is locked with the introduction sheath 62. The number of the first parts 624 and the locking parts 612 is two, the two locking parts 612 are oppositely arranged at two sides of the ingress pipe 61, and the two first parts 624 are also arranged at two sides of the ingress sheath 62, so that the locking stability of the ingress pipe 61 and the ingress sheath 62 is improved.

In this embodiment, the locking member 612 is a T-shaped slot having two stop walls, the first member 624 is a protrusion, and the introduction tube 61 and the introduction sheath 62 can be rotated clockwise or counterclockwise when they are rotated relatively, and the protrusion can abut against the stop walls, thereby improving operability.

In the prior art, the inner wall of the distal end of the introducer for pre-folding the pump head is thinned to form a flared section, which is integrally formed. However, the folding effect of the introducer is difficult to ensure. Specifically, the distal inner wall is thinned and the material strength is weakened. When collapsed, the pump head is pulled back to exert a greater force on the weaker distal region, potentially resulting in collapse of its material and subsequent deformation of the distal end and even failure of the collapse.

In addition, in order to ensure a good gradual folding effect, the thickness is reduced, and a feasible approach is to make the taper angle of the reduced thickness region large or make the length long. But this aggravates the weakening of the distal material strength and is less conducive to collapsing.

And the manufacturing process of the importer is difficult. The distal wall thickness reduction treatment, relative to the percutaneous transluminal introducer, obviously increases the difficulty of manufacture.

In contrast, the introduction sheath 62 and the introduction tube 61 in this embodiment are two separate members, and are detachable therebetween. The pre-folding operation of the pump head 3 is performed by the introduction sheath 62 without having to be performed at the introduction tube 61 having a relatively thin wall thickness. In this way, introduction tube 61 does not need to be subjected to any material thickness reduction treatment, and introduction sheath 62 can be provided with a larger thickness as required to support the great strength required for pre-folding pump head 3. Thus, the material collapse does not occur in the introduction sheath 62, and the pre-folding of the pump head 3 can be completed more smoothly. The introduction sheath 62 and the introduction tube 61 can be manufactured separately, and the manufacturing process is simple.

The thickness of the wall of the introduction sheath 62 defining the second straight chamber 621 is greater than the thickness of the wall of the introduction tube 61 defining the first straight chamber 611. Further, the thickness of the wall of the introduction sheath 62 defining the guide chamber 622 is also greater than the thickness of the wall of the introduction tube 61 defining the first straight chamber 611. Thereby ensuring the strength of the pre-folding component 6 and improving the folding success rate of the pump head 3.

The wall thickness of the first straight lumen 611 is typically 0.3mm, and if the wall thickness is less than 0.3mm by making the inner wall thinner at the distal end, it is difficult to ensure that collapse does not occur when collapsing the pump head 3.

The pre-folding assembly 6 further comprises a handle 63 arranged at the proximal end, so that a doctor can conveniently move to the front end or the rear end by holding the handle 63, and the operability is improved.

Referring to fig. 5 to 8, the introduction sheath 62 is separated from the introduction pipe 61 after the pump head 3 is transferred from the second straight chamber 621 to the first straight chamber 611. That is, after the pump head 3 is folded in the introduction sheath 62 and transferred to the introduction tube 61, the introduction sheath 62 and the introduction tube 61 are separated.

Introduction tube 61 may be coupled with access sheath 7 after introduction sheath 62 is separated therefrom to transfer pump head 3 from first straight lumen 611 of introduction tube 61 into the access straight lumen of access sheath 7. The distal end of the introduction tube 61 is abutted against the proximal end of the insertion sheath 7, and the catheter 2 is pushed forward, so that the pump head 3 in the collapsed state is transferred from the first straight lumen 611 into the insertion sheath 7. Wherein the introduction tube 61 is operably docked with the access sheath 7 in such a way that the distal end of the introduction tube 61 and the proximal end of the access sheath 7 are end-docked to achieve the first straight lumen 611 and the access straight lumen communication.

Another way in which the introduction tube 61 may be operably docked with the access sheath 7 may be for the introduction tube 61 to be at least partially operably threaded into the access sheath 7 to provide communication between the first lumen 611 and the access lumen.

The introduction tube 61 and the insertion sheath 7 are also detachably connected. Specifically, as described above, the distal end of the introduction tube 61 is provided with a locking member 612, and the proximal end of the insertion sheath 7 is provided with a second member 71 that mates with the locking member 612. The first member 624 and the second member 71 are identical in structure. And the locking or unlocking of the second member 71 with the locking member 612 is identical to the locking or unlocking of the first member 624 with the locking member 612.

The pump head 3 is delivered to the vasculature through the access sheath 7 in a collapsed state, enabling the pump head 3 to enter the subject with a smaller access size. The insertion sheath 7 has an inner diameter smaller than the outer diameter of the coupler 4 and is partially inserted into the vasculature of the subject through the puncture. The interventional sheath 7 has a forward end that enters the vasculature through the puncture and a rearward end that remains outside the body for forming or establishing access for the device into the vasculature.

The first straight lumen 611 is smaller than or equal to the inner diameter of the interventional sheath 7, so that a smooth transfer of the pump head 3 from the first straight lumen 611 into the interventional sheath 7 is achieved.

In this embodiment, the distal end of the introducing tube 61 and the proximal end of the insertion sheath 7 are used for end-face butt joint, and when the pump head 3 is inserted into the body of the subject, the introducing tube 61 does not enter the body, so that the size of the insertion sheath 7 is reduced, the related complications caused by insertion puncture are greatly reduced, and the operation safety is improved.

When the catheter pump 100 is inserted into the body of the subject to assist in pumping blood, the catheter pump 100 is kept in the body of the subject, and the insertion sheath 7 is kept in the puncture. When the distal end of the introduction tube 61 and the intervention sheath 7 are butted, the pump head 3 is transferred from the first straight lumen 611 into the intervention straight lumen by pushing the guide tube 2 forward. At this time, the first member 624 and the second member 71 are locked with the locking member 612, and the introduction tube 61 and the insertion sheath 7 cannot be separated from each other. Thereby preventing the process of transferring the pump head 3 from the first straight cavity 611 to the intervention straight cavity from being blocked due to the separation of the introducing pipe 61 and the intervention sheath 7 caused by the backward movement of the introducing pipe 61 due to the reaction force of the pump head 3 when the catheter 2 is pushed forward, and also preventing the intervention sheath 7 from moving at the puncture under the action of external force to destroy the puncture during the transferring process of the pump head 3. Ensuring the size of the puncture opening, being beneficial to the healing of the puncture opening and reducing the complication probability of the puncture opening, and simultaneously relieving the pain of the subject.

The method of folding the pump head 3 of the catheter pump 100 includes:

referring to fig. 5 and 6, the pre-folding assembly 6 is pushed forward and/or the catheter 2 is pulled backward, so that the proximal end of the pump head 3 is inserted into the second straight cavity 621;

continuing to push the pre-folding assembly 6 forward and/or pull the catheter 2 backward until the pump head 3 is folded and transferred into the first straight cavity 611 by the second straight cavity 621;

referring to fig. 7, an operation of separating the introduction sheath 62 from the introduction tube 61 is performed.

The specific operation of switching the pump head 3 to the folded state is described above, and will not be described herein. The pump head 3 is collapsed for subsequent delivery to the vasculature of the subject.

During the transfer of the pump head 3 from the second straight chamber 621 into the first straight chamber 611, the introduction tube 61 and the introduction sheath 62 remain axially fixed. Which is achieved by the locking of the first member 624 and the locking member 612.

Referring to fig. 7 and 8, after the step of separating the introduction sheath 62 from the introduction tube 61, the method further includes: the distal end of the introduction tube 61 is abutted against the proximal end of the insertion sheath 7, and the catheter 2 is pushed forward, so that the pump head 3 in the collapsed state is transferred from the first straight lumen 611 into the insertion sheath 7.

During the transfer of the pump head 3 from the first straight lumen 611 into the access sheath 7, the introduction tube 61 and the access sheath 7 remain axially fixed. Which is achieved by the locking of the locking member 612 and the second member 71.

The access sheath 7 is partially inserted into the vasculature of the subject through the puncture, and after the pump head 3 is transferred into the access sheath 7, the method further comprises: continuing to advance catheter 2, pump head 3 is moved out of the distal end of access sheath 7 to enter the subject's vasculature in the deployed state and is accessed to the target site, and the pump operation of catheter pump 100 is achieved by mating connection of the motor and catheter 2.

It should be noted that, the insertion sheath 7 is partially inserted into the puncture, so as to facilitate the subsequent removal operation of the pump head 3 from the subject.

When the catheter pump 100 is assisting in pumping blood to completion, the catheter pump 100 is removed from the subject as follows: pulling the catheter 2 proximally to house the pump in the deployed state within the insertion sheath 7 to switch the pump head 3 to the collapsed state; the catheter 2 is continued to be pulled proximally, removing the pump head 3 from the interventional sheath 7. Finally, the interventional sheath 7 is pulled proximally to be removed from the body.

The pre-folding component 6 for folding the pump head comprises an ingress pipe 61 and an ingress sheath 62 which are detachably connected, so that the pump head 3 is slowly and gradually folded, the folding force is reduced, the operation is more convenient and labor-saving, and the smoothness and smoothness of folding the pump head 3 are improved.

In the embodiment where the guide cavity 622 with the gradually decreasing inner diameter of the guide sheath 62 is provided, the pump head 3 is gradually folded, rather than folded in a pulling manner, so that the pump head 3 is not easily damaged and the safety is high. The guide cavity 622 is provided on the introduction sheath 62 instead of the introduction tube 61, the introduction tube 61 does not need to be subjected to any material thickness reduction treatment, and the introduction sheath 62 can be provided with a larger thickness as required to support the great strength required for pre-folding of the pump head 3. Thus, the material collapse does not occur in the introduction sheath 62, and the pre-folding of the pump head 3 can be completed more smoothly.

The foregoing is merely a few embodiments of the present invention and those skilled in the art may make various modifications or alterations to the embodiments of the present invention in light of the disclosure herein without departing from the spirit and scope of the invention.

Claims

1. A catheter pump comprising:

a conduit;

a drive shaft rotatably penetrating the guide tube;

a collapsible pump head comprising: a pump housing connected to the distal end of the catheter, an impeller disposed within the pump housing; the impeller is connected to a distal end of the drive shaft, the proximal end of the drive shaft being connectable to a motor to transmit rotation of the motor to the impeller;

a pre-folding assembly slidably sleeved outside the catheter and configured to accommodate the pump head in an unfolded state therein when slid distally, so as to switch the pump head to a folded state; the pre-folding assembly includes:

an ingress pipe having a first straight cavity;

an introduction sheath removably connected to a distal end of the introduction tube, having a second straight lumen at the distal end, the second straight lumen having an inner diameter greater than an inner diameter of the first straight lumen;

wherein the introducing sheath is separated from the introducing pipe after the pump head is transferred from the second straight cavity to the first straight cavity;

the thickness of the wall of the ingress sheath defining the second straight lumen is greater than the thickness of the wall of the ingress tube defining the first straight lumen.

2. The catheter pump of claim 1, wherein an inner diameter of the second straight lumen is at least no less than a diameter of the pump head in the deployed state.

3. The catheter pump of claim 1, wherein the introducer sheath further comprises a guide lumen between the first and second straight lumens, an inner wall of the guide lumen tapering proximally from the distal end.

4. The catheter pump of claim 3, wherein the thickness of the wall of the introducer sheath defining the guide lumen is also greater than the thickness of the wall of the introducer tube defining the first straight lumen.

5. The catheter pump of claim 3, wherein the guide lumen has a generally frustoconical cross-section, the frustoconical taper having an included angle of between 5 ° and 60 °, the pump housing comprising: a membrane defining a blood flow passageway, a stent supporting the membrane; the proximal end of the bracket is tapered.

6. The catheter pump of claim 5, wherein the cone angle of the frustoconical shape is less than the proximal cone angle of the stent.

7. The catheter pump of claim 1, wherein the introduction tube is couplable with an insertion sheath after the introduction sheath is separated therefrom to transfer the pump head from the first lumen of the introduction tube into the insertion lumen of the insertion sheath.

8. The catheter pump of claim 7, wherein a distal end of the introduction tube is provided with a locking member, and proximal ends of the introduction sheath and the access sheath are provided with a first member and a second member, respectively, which cooperate with the locking member.

9. The catheter pump of claim 8, wherein the first and second components are identical in construction.

10. The catheter pump of claim 8, wherein the introduction tube and the introduction sheath or access sheath are subjected to relative rotational movement to effect locking or unlocking of the locking member with the first member or second member; wherein the angle of rotation does not exceed 90 °.

11. The catheter pump of claim 8, wherein the first and second members are one of a projection and a stop wall, and the locking member is the other of a projection and a stop wall, the projection and stop wall abutting when the introduction tube is locked with the introduction sheath or insertion sheath.

12. A method of folding a pump head of a catheter pump as claimed in any one of claims 1 to 11, comprising:

pushing the pre-folding assembly forward and/or pulling the catheter backward to insert the proximal end of the pump head into the second straight lumen;

continuing to push the pre-folding component forwards and/or pull the catheter backwards until the pump head is folded and transferred into the first straight cavity by the second straight cavity;

an operation of separating the introduction sheath from the introduction tube is performed.

13. The method of claim 12, wherein after the step of separating the introducer sheath from the introducer tube, the method further comprises: and butting the distal end of the ingress pipe with the proximal end of the intervention sheath, and pushing the catheter forwards to enable the pump head in the folded state to be transferred into the intervention sheath from the first straight cavity.

14. The method of claim 13, wherein the introduction tube remains axially stationary with the introduction sheath during the transfer of the pump head from the second straight lumen into the first straight lumen; during the process that the pump head is transferred into the intervention sheath from the first straight cavity, the ingress pipe and the intervention sheath are axially kept fixed.

15. The method of claim 13, wherein after the pump head is transferred into the interventional sheath, the method further comprises: continuing to advance the catheter, the pump head is removed from the distal end of the interventional sheath.