CN116785584A - Catheter pump and method for folding pump head of catheter pump - Google Patents

Abstract

A catheter pump and method of folding a pump head of a catheter pump are disclosed, the catheter pump including an introducer having a pre-folded channel adapted to receive the pump head therein in an unfolded state. When the introducer is in a first assembled state slidably disposed over the catheter, the pump head is collapsed via the distal end of the introducer by pulling the catheter forward and/or rearward. When the introducer is in a second assembled state separate from the catheter pump, the distal end of the pump head may be inserted into the proximal end of the introducer, collapsing the pump head via the proximal end of the introducer by pulling the introducer rearward and/or pushing the catheter forward.

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. At present, a tubular introducer is preloaded at the proximal end of a catheter pump, and the pump head is folded into the introducer tube body by pushing the tubular introducer towards the direction of the pump head, but the introducer is likely to be erroneously operated during the operation process so as to slip off the distal end of the pump head, and because doctors have different operation habits, some doctors are more accustomed to folding the pump head from the distal end to the proximal end, so that the folding mode currently involved cannot meet the demands.

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 from the far end and the near end.

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

the catheter pump of the first aspect of the invention comprises a catheter, a drive shaft rotatably disposed through the catheter, a collapsible pump head, and an introducer. The collapsible pump head includes 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 a drive shaft, which is connectable to a motor to transfer rotation of the motor to the impeller. The introducer includes a pre-collapsed channel adapted to receive the pump head therein in an expanded state to switch the pump head to a collapsed state. The introducer has a first assembled state slidably disposed over the catheter and a second assembled state disposed apart from the catheter pump.

When the introducer is in the first assembled state, the pump head is collapsed into the pre-collapsed channel via the distal end of the introducer by pulling the catheter forward of the introducer and/or rearward.

When the introducer is in the second assembled state, the distal end of the pump head may be inserted into the proximal end of the introducer, collapsing the pump head into the pre-collapse channel via the proximal end of the introducer by pulling the introducer rearward and/or pushing the catheter forward;

the introducer may alternatively collapse the pump head into the pre-collapse channel in the first and second assembled states.

A method of folding a pump head of a catheter pump as described above, comprising:

when the introducer is in the first assembled state, at least one of the introducer and the catheter is operated to move the introducer and the pump head toward each other, the proximal end of the pump head is inserted into the distal end of the introducer, and finally collapsed into the pre-collapse channel.

When the introducer is in the second assembled state, at least one of the introducer and the pump head is operated to move the introducer and the pump head toward each other, the distal end of the pump head is inserted into the proximal end of the introducer, and finally collapsed into the pre-collapse channel.

The catheter pump of the second aspect of the invention comprises a catheter, a drive shaft rotatably disposed through the catheter, a collapsible pump head, an introducer, and an interventional sheath. The collapsible pump head includes 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 a drive shaft, which is connectable to a motor to transfer rotation of the motor to the impeller. The access sheath includes an access channel that receives the pump head. The introducer is operably interfaced with the interventional sheath and includes a pre-folded channel adapted to receive the pump head therein in a deployed state.

The introducer and the catheter pump are arranged separately, the distal end of the pump head can be in butt joint with the proximal end of the introducer, and the pump head is folded into the pre-folding channel through the proximal end of the introducer by pulling the introducer backwards and/or pushing the catheter forwards.

The distal end of the introducer is docked with the proximal end of the access sheath, and the pump head is transferred from the pre-folded channel into the access channel by pushing the catheter forward.

A method of folding a pump head of a catheter pump as described above, comprising:

at least one of the introducer and the pump head is operated to move the introducer and the pump head toward each other, the distal end of the pump head is inserted into the proximal end of the introducer, and finally collapsed into the pre-collapse channel.

The distal end of the introducer is butted with the proximal end of the interventional sheath, and the catheter is pushed forward, so that the pump head in the folded state is transferred into the interventional sheath through the pre-folded channel.

The pump head can be folded from the proximal end and the distal end of the introducer, and a doctor can select to fold the pump head from the proximal end or the distal end according to operation habits. When the pump head is folded from the distal end of the introducer, if the introducer slips from the distal end of the pump head due to misoperation, the pump head can be folded continuously from the proximal end of the introducer, and the operation is simple.

Drawings

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

Fig. 2 is another perspective view of a catheter pump provided by the present invention.

Fig. 3 is a schematic perspective view of an introducer according to the present invention in a first assembled state slidably disposed over a catheter.

Fig. 4 is a schematic perspective view of the introducer provided in the present invention in a second assembled state separate from the catheter pump.

Fig. 5 is a partial structural sectional view of the catheter pump provided by the invention.

Fig. 6 is a partial enlarged view of fig. 5.

Fig. 7 is a schematic perspective view of a catheter pump according to another embodiment of the present invention.

Fig. 8 is another perspective view of a catheter pump according to another embodiment of the present invention.

Fig. 9 is a partial perspective view of a catheter pump according to another embodiment of the present invention.

Detailed Description

The terms "proximal", "posterior" and "distal", "anterior" as used herein are relative to a physician manipulating a catheter pump. The terms "proximal", "posterior" and "anterior" refer to portions relatively closer to the physician, and the terms "distal" and "anterior" refer to portions relatively farther from the physician. For example, the motor is at the proximal and rear ends and the protective head is at the distal and front ends.

The catheter pump of the present invention defines an "axial" or "axial direction of extension" of the drive shaft, the term "inner", "outer" being relative to an axially extending centerline, and the direction relatively closer to the centerline being "inner", and the direction relatively farther from the centerline being "outer".

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.

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 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 membrane 314 defines a blood flow path and may be an elastic membrane. 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 includes a drive shaft (not shown) rotatably disposed through catheter 2, the drive shaft being connected at a proximal end to motor 1 and at a distal end 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 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 "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 to 5, the catheter pump 100 further comprises an introducer 5, and the switching of the pump head 3 between the deployed state and the collapsed state can be achieved by the introducer 5. The introducer 5 comprises a pre-collapsed channel 51 adapted to receive the pump head 3 in its expanded state therein to switch the pump head 3 to its collapsed state.

It is clear that the inner diameter dimension of the pre-folded channel 51 defines the outer diameter dimension of the pump head 3 in the folded state, i.e. the inner diameter dimension of the pre-folded channel 51 is equal to the outer diameter dimension of the pump head 3 in the folded state.

The introducer 5 has a first assembled state slidably fitted over the catheter 2 and a second assembled state disposed apart from the catheter pump 100. That is, the introducer 5 may be provided as part of the structure of the catheter pump 100, slidingly disposed outside the catheter 2, or the introducer 5 may be provided separately as an accessory, without any assembly relationship with any portion of the catheter pump 100.

The introducer 5 is configured to alternatively collapse the pump head 3 into the pre-collapse channel 51 in the first and second assembled states. The pump head 3 can be folded into the pre-folded channel 51 of the introducer 5 by either of two assembly states. The proper assembled state may be selected in a desired manner for folding in a particular operation for better handling, rather than defining two assembled states to be taken together.

When the introducer 5 is in the first assembled state, the pump head 3 is collapsed into the pre-collapse channel 51 via the distal end of the introducer 5 by pulling the introducer 5 forward, or pulling the catheter 2 rearward while the introducer 5 is being pulled forward.

When the introducer 5 is in the second assembled state, the distal end of the pump head 3 may be inserted into the proximal end of the introducer 5 and the pump head 3 collapsed into the pre-collapse channel 51 via the proximal end of the introducer 5 by pulling the introducer 5 rearward, or pushing the catheter 2 forward, or pulling the introducer 5 rearward while pushing the catheter 2 forward.

External restraint imposed on the pump head 3 may be accomplished by the introducer 5. When the introducer 5 is in the first assembling state, the pump head 3 can be integrally contained in the introducer 5 when the introducer 5 moves distally, so that the pump head 3 is forcedly folded; then, when the introducer 5 is moved proximally, the radial restriction imposed on the pump head 3 is removed, and the pump head 3 is switched to the deployed state. When the introducer 5 is in the second assembling state, the pump head 3 can be integrally contained in the introducer 5 when the introducer 5 moves proximally, so that the pump head 3 is forcedly folded; then, when the introducer 5 is moved distally, the radial restriction imposed on the pump head 3 is removed, and the pump head 3 is switched to the deployed state.

The collapsing of the pump head 3 is achieved by means of the radial restraining force exerted by the introducer 5, whereas the impeller comprised by the pump head 3 is housed inside the pump housing 31. Thus, essentially, the folding process of the pump head 3 is: the introducer 5 applies a radial restraining force to the pump casing 31, and applies a radial restraining force to the impeller when the pump casing 31 is radially compressed.

That is, the pump housing 31 is folded directly under the action of the introducer 5, and the impeller is folded directly under the action of the pump housing 31. And as mentioned above, the impeller has elasticity. Therefore, although in the folded state, the impeller is folded and stored so as to have a tendency to be unfolded radially all the time, and the impeller is brought into contact with the inner wall of the pump casing 31 and applies a reaction force to the pump casing 31.

After the constraint of the introducer 5 is removed, the pump housing 31 expands under its own memory characteristics, supporting the elastic membrane 314, and the impeller expands itself under the released energy storage.

The introducer 5 is switchable between a first assembled state and a second assembled state. The introducer 5 may be switched from the first to the second assembly state, or the introducer 5 may be switched from the second to the first assembly state. That is, in the first assembled state, the pump head 3 is folded into the introducer 5 by pulling the catheter 2 rearward, which, when the catheter 2 is continued rearward, causes the introducer 5 to slip off the distal end of the pump head 3, the introducer 5 being in the second assembled state. By folding the pump head 3 into the introducer 5 by pushing the pump head 3 forward, continued pushing of the pump head 3 will cause the introducer 5 to be nested outside the catheter 2, with the introducer 5 in the first assembled state.

Thus, the pump head 3 can be folded from the proximal end and the distal end by the introducer 5, so that the operation of a doctor is facilitated, and the doctor can select to fold the pump head 3 from the proximal end or the distal end according to own operation habits. When the pump head 3 is folded in the first assembling state, if the introducer 5 slips off the distal end of the pump head 3 due to misoperation, the pump head 3 can be folded continuously in the second assembling state, and the operation is simple.

The introducer 5 includes an introducer catheter 52 defining a pre-folded channel 51, and an introducer sheath 54 disposed at a proximal end of the introducer catheter 52, the introducer sheath 54 defining a guide lumen 53 in communication with the pre-folded channel 51. The inner diameter dimension of the introducer catheter 52 defines the outer diameter dimension of the pump head 3 in the collapsed state, such that collapsing of the pump head 3 can be achieved by activating that pump head 3 into the introducer catheter 52.

Referring to fig. 6, the guide cavity 53 includes at least a proximal enlarged section 531, and the inner diameter of the enlarged section 531 is at least not smaller than the diameter of the pump head 3 in the deployed state. Thereby facilitating collapsing of the pump head 3 from the proximal end of the introducer 5 and guiding the pump head 3 to the pre-collapsed channel 51 by the enlarged segment 531. The difference between the inner diameter of the pre-folding channel 51 and the diameter of the pump head 3 in the unfolded state is avoided, so that the pump head 3 is prevented from being folded, and the operation is unsmooth and laborious.

The guide lumen 53 further includes a necked-down section 532 at the distal end, the necked-down section 532 having an inner diameter less than the inner diameter of the enlarged section 531 and at least not greater than the inner diameter of the pre-folded channel 51. The necked-down section 532 allows for smooth transfer of the pump head 3 in the collapsed state from the necked-down section 532 to the pre-collapsed channel 51.

The guide lumen 53 further includes a transition section 533 connecting the enlarged section 531 and the necked-down section 532, the inner wall of the transition section 533 being gradually tapered from the proximal end to the distal end. When the pump head 3 moves from the expanding section 531 and passes through the transition section 533, the inner diameter size is gradually reduced due to the gradual shrinkage of the transition section 533, the pump head 3 is slowly and gradually folded, the folding force is reduced, and the smoothness of the pump head 3 entering the introducer 5 is improved.

Referring to fig. 5 and 6, the introducer seat 54 is configured as an operating handle 54, and the guide cavity 53 is formed on the operating handle 54. An operating handle 54 is provided at the proximal end of the introducer catheter 52 to facilitate movement of the catheter forward or rearward by the physician by grasping the operating handle 54 to enhance its operability.

The introducer catheter 52 is made of PTFE. The PTFE material with a low friction coefficient can effectively reduce the conveying force of the pump head 3 during the relative movement in the introducer catheter 52 and improve the conveying compliance. In other embodiments, the introducer catheter 52 may be made of other low friction materials, not shown.

The catheter pump 100 includes a protective head 6 connected to the distal end of the pump head 3, and in order for the introducer 5 to collapse the pump head 3 smoothly from the distal end, the protective head 6 extends along the axis of the pump head 3, i.e., the protective head 6 is linear, so that it can be introduced into the introducer 5 smoothly from the distal end. In addition, the protective head 6 is configured to be flexible so as not to injure the tissue of the subject, the protective head 6 may be made of any material that macroscopically exhibits flexibility, the flexible end portion of which is supported on the inner wall of the ventricle in a non-invasive or atraumatic manner, separating the suction inlet of the pump head 3 from the inner wall of the ventricle, avoiding the suction inlet of the pump head 3 from adhering to the inner wall of the ventricle due to the reaction force of the fluid (blood) during operation of the pump head 3, ensuring the effective area of pumping.

The present invention also provides a method of folding (collapsing) a pump head of a catheter pump as shown above, comprising:

when the introducer is in the first assembled state, operating at least one of the introducer and the catheter to move the introducer and the pump head toward each other, inserting the proximal end of the pump head into the distal end of the introducer, and finally collapsing into the pre-collapse channel;

when the introducer is in the second assembled state, at least one of the introducer and the pump head is operated to move the introducer and the pump head toward each other, the distal end of the pump head is inserted into the proximal end of the introducer, and finally collapsed into the pre-collapse channel.

The pump head is folded (collapsed) to facilitate subsequent delivery to the vasculature of the subject.

Wherein when the introducer is in the first assembled state, operating at least one of the introducer and the pump head to move the introducer and the pump head toward each other comprises: the pump head is folded into the pre-folding channel via the distal end of the introducer by pulling the catheter forward, or backward, or both forward and backward, to switch the pump head to the folded state.

When the introducer is in the second assembled state, operating at least one of the introducer and the pump head to move the introducer and the pump head toward each other is performed by: the distal end of the pump head may be docked with the proximal end of the introducer and the pump head is switched to the collapsed state by pulling the introducer rearward, pushing the catheter forward, or pulling the catheter forward while pulling the introducer rearward, thereby collapsing the pump head into the pre-collapse channel via the proximal end of the introducer.

Referring to fig. 7 to 9, another embodiment of the catheter pump 200 according to the present invention is substantially the same as the catheter pump 100 according to the above embodiment, except that the catheter pump 200 according to the present embodiment further includes an insertion sheath 7, and the insertion sheath 7 includes an insertion channel for receiving the pump head 3. The introducer 5 is operably docked with the access sheath 7 so that the access channel and the pre-crimping channel are in communication.

Wherein the introducer 5 is disposed separately from the catheter pump 200, the distal end of the pump head 3 may be docked with the proximal end of the introducer 5 and the pump head 3 is collapsed into the pre-collapse channel via the proximal end of the introducer 5 by pulling the introducer 5 backward, either pushing the catheter 2 forward, or by a colleague pulling the introducer 5 backward, pushing the catheter 2 forward. The pump head 3 is folded by the introducer 5 as described above, and will not be described in detail here.

The distal end of introducer 5 is docked with the proximal end of access sheath 7 and pump head 3 is transferred from the pre-folded channel into the access channel by pushing catheter 2 forward.

Wherein the introducer 5 is operably docked with the access sheath 7 in such a way that the introducer 5 is at least partially operably threaded into the access sheath 7 to effect communication between the pre-folded channel and the access channel, as particularly shown in fig. 9.

Another way in which the introducer 5 may be operably docked with the access sheath 7 is by end-to-end docking of the distal end of the introducer 5 with the proximal end of the access sheath 7 to effect communication between the pre-folded channel and the access channel, as particularly shown in fig. 7 and 8.

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.

For fitting over the pump head 3 and the catheter 2, the inner diameter of the introducer 5 is larger than the outer diameter of the catheter 2 and the outer diameter of the pump head 3 in the collapsed state.

To achieve the interfacing of the introducer 5 and the interventional sheath 7, the inner diameter of the introducer 5 is less than or equal to the inner diameter of the interventional sheath 7. In an embodiment, the outer diameter of the introducer 5 may be less than or equal to the inner diameter of the access sheath 7 to achieve at least partial operable penetration of the introducer 5 into the access sheath 7.

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 introducer 5 is a long sheath, the long sheath may interfere with coupler 4 and limit movement of pump head 3 within the vasculature of the subject because of its length and the inner diameter of the long sheath being smaller than the outer diameter of coupler 4. For this purpose, the long sheath is a tearable sheath, which is operatively peeled off after the pump head 3 has entered the vasculature, the intervention sheath 7 being pierced in the puncture, so that interference of the tearable sheath with the coupler 4 is avoided.

The method for operably stripping the tearable sheath comprises the following steps: the tearable sheath is torn while the tearable sheath is moved proximally.

Because the inner diameter of the tearable sheath is smaller than the outer diameter of the coupler 4, the two proximal parts of the tearable sheath formed in the process of being peeled off do not interfere with the coupler 4, so that the tearable sheath can be smoothly withdrawn from the puncture.

In order to achieve easy peel-off of the tearable sheath, without being affected by the coupler 4, the tearable sheath may have a lateral opening (not shown) at the proximal end along which the tearable sheath can be peeled off, with a labor-saving and convenient operation.

The lateral openings can be two, and the two lateral openings are oppositely arranged at two sides of the proximal end of the tearable sheath.

In another embodiment, the tearable sheath may be connected to a pre-pressed tear seam on each side of the symmetrical position. When the tearable sheath is peeled off, the tearable sheath can be torn into two halves along the pre-pressing tearing seam while withdrawing one edge towards the proximal end.

The tearable sheath can be made of polytetrafluoroethylene, and is manufactured into a tearable sheath pipe with two halves of symmetry completely consistent through a stamping process integrated into a whole, and the tearable sheath pipe with two halves of symmetry completely consistent is butted through a hot melting process, so that a pre-pressing tearing seam is formed at the butted position.

Referring to fig. 7 and 8, the proximal end of the insertion sheath 7 is provided with a first lock 71, the distal end of the introducer 5 is provided with a second lock 55, and the first lock 71 and the second lock 22 are detachably locked.

When the distal end of the introducer 5 and the access sheath 7 are docked, the pump head 3 is transferred from the pre-folded channel into the access channel by pushing the catheter 2 forward. At this time, the first lock 71 and the second lock 22 are locked, and the introducer 5 and the insertion sheath 7 cannot be separated from each other. Thereby preventing the transfer of the pump head 3 from the pre-folding channel to the intervention channel from being blocked due to the separation of the introducer 5 from the intervention sheath 7 caused by the backward movement of the introducer 5 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 transfer 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 structures of the first lock 71 and the second lock 22 are not particularly limited herein, and may be detachably locked.

The present invention also provides a method of folding a pump head of a catheter pump as described above, comprising:

operating at least one of the introducer and the pump head to move the introducer and the pump head toward each other, inserting the distal end of the pump head into the proximal end of the introducer, and finally collapsing into the pre-collapse channel;

the distal end of the introducer is butted with the proximal end of the interventional sheath, and the catheter is pushed forward, so that the pump head in the folded state is transferred into the interventional sheath through the pre-folded channel.

The folding of the pump head into the pre-folding channel is described above and will not be described in detail here.

In the process that the pump head is transferred into the intervention channel from the pre-folding channel, the introducer and the intervention sheath are axially kept fixed, and the pump head is concretely realized through the locking of the first lock catch and the second lock catch.

Wherein the interventional sheath is partially inserted into the vasculature of the subject through the puncture, the method further comprising, after the pump head is transferred into the interventional sheath: the catheter is continuously pushed forward, the pump head is moved out of the distal end of the intervention sheath, enters the vascular system of the subject in a unfolding state and is inserted to a target position, and the motor is connected with the catheter in a matched mode, so that the blood pumping working state of the catheter pump can be realized.

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

When the catheter pump assisted pumping is completed, the catheter pump is removed from the subject as: pulling the catheter proximally to house the pump in the deployed state within the insertion sheath to switch the pump head to the collapsed state; the catheter is continued to be pulled proximally, removing the pump head from the interventional sheath. Finally, the interventional sheath is pulled proximally to be removed from the body.

The introducer of the present invention is slidably disposed over the catheter or separately from the catheter pump. When the introducer is slidably positioned over the catheter, the pump head can be collapsed from the distal end of the introducer. When the introducer and catheter pump are separately positioned, the pump head may be collapsed from the proximal end of the introducer. The pump head can be folded from the proximal end and the distal end by the introducer, so that the operation of a doctor is facilitated, and the doctor can select to fold the pump head from the proximal end or the distal end according to own operation habits. When the pump head is folded from the distal end of the introducer, if the introducer slips from the distal end of the pump head due to misoperation, the pump head can be folded continuously from the proximal end of the introducer, and the operation is simple.

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 (14)

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;

an introducer comprising a pre-collapsed channel adapted to receive the pump head in an expanded state therein to switch the pump head to a collapsed state; the introducer has a first assembled state in which the introducer is slidably sleeved outside the catheter and a second assembled state in which the introducer is separated from the catheter pump;

folding the pump head into the pre-folding channel via the distal end of the introducer by pushing the introducer forward and/or pulling the catheter backward when the introducer is in the first assembled state;

when the introducer is in the second assembled state, the distal end of the pump head may be inserted into the proximal end of the introducer and the pump head collapsed into the pre-collapsed channel via the proximal end of the introducer by pulling the introducer back and/or pushing the catheter forward;

the introducer may alternatively collapse the pump head into the pre-collapse channel in the first and second assembled states.

2. The catheter pump of claim 1, wherein the introducer is switchable from the first to the second assembled state or the introducer is switchable from the second to the first assembled state.

3. The catheter pump of claim 1, wherein the introducer comprises an introducer catheter defining the pre-collapsed channel, an inner diameter of the introducer catheter defining a diameter of the pump head in a collapsed state.

4. The catheter pump of claim 3, wherein the introducer further comprises an introducer hub disposed at a proximal end of the introducer catheter, the introducer hub defining a guide lumen in communication with the pre-collapsed channel, the guide lumen including at least a proximally located enlarged section having an inner diameter at least not less than a diameter of the pump head in the deployed state.

5. The catheter pump of claim 4 wherein the guide lumen further comprises a necked down section at the distal end, the necked down section having an inner diameter less than an inner diameter of the enlarged section and at least no greater than an inner diameter of the introducer catheter.

6. The catheter pump of claim 5, wherein the guide lumen further comprises a transition segment connecting the enlarged segment and the necked segment, an inner wall of the transition segment being gradually tapered from the proximal end to the distal end.

7. The catheter pump of claim 4, wherein the introducer is a tearable sheath, the introducer housing being configured as an operating handle.

8. A method of folding the pump head of the catheter pump of any of claims 1 to 7, comprising:

operating at least one of the introducer and the catheter to move the introducer and the pump head toward each other when the introducer is in the first assembled state, the proximal end of the pump head being inserted into the distal end of the introducer and eventually collapsed into the pre-collapsed channel;

when the introducer is in the second assembled state, at least one of the introducer and the pump head is operated to move the introducer and the pump head toward each other, with the distal end of the pump head inserted into the proximal end of the introducer and eventually collapsed into the pre-collapsed channel.

9. 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;

an access sheath comprising an access channel receptive of the pump head;

an introducer operably interfacing with the interventional sheath, comprising a pre-folded channel adapted to receive the pump head therein in a deployed state;

wherein the introducer is disposed separately from the catheter pump, the distal end of the pump head being adapted to interface with the proximal end of the introducer, and collapsing the pump head into the pre-collapsed channel via the proximal end of the introducer by pulling the introducer back and/or pushing the catheter forward;

the distal end of the introducer is docked with the proximal end of the interventional sheath, and the pump head is transferred from the pre-folded channel into the interventional channel by pushing the catheter forward.

10. The catheter pump of claim 9, wherein an inner diameter of the introducer is less than or equal to an inner diameter of the interventional sheath.

11. The catheter pump of claim 9, wherein the proximal end of the access sheath is provided with a first lock and the distal end of the introducer is provided with a second lock, the first lock and the second lock being removably locked.

12. A method of folding a pump head of a catheter pump as claimed in any one of claims 9 to 11, comprising:

operating at least one of the introducer and the pump head to move the introducer and the pump head toward each other, the distal end of the pump head being inserted into the proximal end of the introducer and eventually collapsed into the pre-collapse channel;

and butting the distal end of the introducer with the proximal end of the interventional sheath, and pushing the catheter forward to transfer the pump head in the folded state from the pre-folded channel into the interventional sheath.

13. The method of claim 12, wherein the introducer remains axially stationary with the interventional sheath during transfer of the pump head from the pre-folded channel into the interventional channel.

14. The method of claim 12, 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.