CN115445076A - Catheter pump and method for folding pump head of catheter pump - Google Patents

Abstract

A catheter pump and a method of folding a pump head of a catheter pump are disclosed, the catheter pump comprising a collapsible pump head and radial gripping means adapted to compress the pump head in an unfolded state to a collapsed state. The radial crimping device includes a recompressible member made of a flexible and resilient material, and an operating member engaged with the recompressible member. The recompressing member has an axial passageway for receiving the pre-collapse path of the pump head, and the operating member has a first state in which a first force is applied to the recompressing member and a second state in which a second force is applied to the recompressing member, the first force being less than the second force. The first inner diameter of the pre-folding channel when the operation member is in the first state is at least not smaller than the outer diameter of the pump head in the unfolding state, and the second inner diameter of the pre-folding channel when the operation member is in the second state is smaller than the first inner diameter.

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 field of medical instruments.

Background

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

The distal pump head of the catheter pump is a self-expanding and expandable structure, and in order to deliver the catheter pump into a human blood vessel with a small interventional size, the pump head needs to be folded outside the body. Currently, the design method is to pre-install a tubular introducer at the proximal end of the catheter pump, and fold the pump head into the introducer tube by pushing the tubular introducer in the direction of the pump head. However, in this folding method, the pump head is subjected to an axial force during folding, the folding force is large, the operation by a doctor is inconvenient, the folding can be completed only by using a large force, and the pump head is easily damaged.

Disclosure of Invention

The invention aims to provide a catheter pump and a method for folding a 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 purpose, the invention provides the following technical scheme:

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 radial squeezing means adapted to compress the pump head in an expanded state to a collapsed state. The radial crimping device includes a recompressible member made of a flexible and resilient material, and an operating member engaged with the recompressible member. The re-compressible member has a pre-collapse channel in the axial direction for receiving the pump head. The operating member has a first state in which a first force is applied to the recompressible member and a second state in which a second force is applied to the recompressible member, the first force being less than the second force. The first inner diameter of the pre-folding channel when the operation member is in the first state is at least not smaller than the outer diameter of the pump head in the unfolding state, and the second inner diameter of the pre-folding channel when the operation member is in the second state is smaller than the first inner diameter.

In an embodiment of the first aspect, the catheter pump of the second aspect of the present invention further comprises an access sheath, the access sheath including an access channel adapted to receive the pump head. The distal end of the radial pressing and holding device can be operated to butt joint with the proximal end of the intervention sheath, the catheter is pushed forwards, and the pump head in a folding state is transferred into the intervention sheath from the pre-folding channel when the operating piece is in the second state.

Drawings

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

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

Fig. 3 is a sectional view of a partial structure of a catheter pump provided.

Fig. 4 is a perspective view of a catheter pump according to another embodiment of the present invention.

Fig. 5 is another perspective view of a catheter pump according to another embodiment of the present invention.

Fig. 6 is a partial perspective view of a catheter pump according to another embodiment of the present invention.

Fig. 7 is a sectional view of a partial structure of a catheter pump according to another embodiment of the present invention.

Detailed Description

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

The following will be described primarily with thecatheter pump 100 as a left ventricular assist as the primary scenario. It will nevertheless be understood that no limitation of the scope of the embodiments of the invention is thereby intended, as illustrated in the accompanying drawings.

Thecatheter pump 100 comprises a motor 1, acatheter 2, acollapsible pump head 3 deliverable through thecatheter 2 to a desired location of the subject's heart, such as the left ventricle, for pumping blood, and a coupler 4 connected to the proximal end of thecatheter 2 for detachable mating with the motor 1. Thecollapsible pump head 3 comprises apump housing 31 connected to the distal end of theconduit 2 and having aninlet end 311 and anoutlet end 312, and an impeller (not shown) disposed within thepump housing 31.

Thepump housing 31 includes ametal lattice support 313 made of nickel or titanium alloy and anelastic coating 314 covering thesupport 313. The metal lattice of thestent 313 has a mesh design, thecover 314 covers the middle and rear end portions of thestent 313, and the mesh of the portion of thestent 313 not covered by thecover 314 at the front end forms theinlet end 311. The rear end of thecoating 314 covers the distal end of thecatheter 2, and theoutlet end 312 is an opening formed at the rear end of thecoating 314.

The impeller comprises a hub and blades supported on the outer wall of the hub. The impeller can be driven to rotate to draw blood into thepump housing 31 from theinlet end 311 and expel the blood from theoutlet end 312.

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

The drive shaft includes flexible axle and the hard axle that is connected to the flexible axle distal end, and the flexible axle is worn to establish inpipe 2, and the hard axle is worn to establish in wheel hub.

The proximal and distal ends of thesupport 313 are connected to proximal and distal bearing chambers (not shown) and 32, respectively, and proximal and distal bearings (not shown) are disposed in the proximal anddistal bearing chambers 32, respectively. The near end and the far end of the hard shaft are respectively arranged in the near end bearing and the far end bearing in a penetrating way. Thus, the rigid shaft is supported at both ends by the two bearings, and the rigid shaft has a high rigidity, so that the impeller is preferably held in thepump 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 connected to the motor shaft. The coupler 4 includes a passive magnet attached to the proximal end of the drive shaft. The motor 1 is detached from thepipe 2 by detaching the plug and the coupling 4.

Thepump head 3 and the front end portion of thecatheter 2 are fed into and held in the subject, and it is desirable that the size of thepump head 3 and thecatheter 2 is as small as possible. The smaller size of thepump head 3 and thecatheter 2 can enter the body of the subject through the smaller puncture opening size, so that the pain of the subject caused by the interventional procedure can be reduced, and the complications caused by the oversize puncture opening can be reduced.

In the art, the size and hydrodynamic performance of thepump head 3 are two conflicting parameters. Thepump head 3 is desirably small in size from the viewpoint of alleviating pain of the subject and ease of intervention. However, a large flow rate is desired for thepump head 3 to provide a strong auxiliary function to the subject, and a large flow rate generally requires a large size of thepump head 3.

Therefore, in order to reduce the size of the puncture opening and ensure a large flow rate of thepump head 3, thepump head 3 is a collapsible pump having a collapsed state and an expanded state. In particular, in thepump head 3 corresponding to the access configuration, the pump housing and the impeller are in a collapsed state, and thepump head 3 is accessed and/or transported in the subject's vasculature with a first, smaller outer diameter dimension. In the corresponding operating configuration of thepump head 3, the pump housing and impeller are in an expanded state so 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 arranging thefoldable pump head 3, thepump head 3 has a smaller folded size and a larger unfolded size, so as to satisfy the requirements of relieving the pain of a subject in the process of intervention/transportation, ensuring easy intervention and providing large flow.

By the design of the multiple meshes, especially the diamond meshes, of thepump shell 31, folding can be achieved well, and unfolding can be achieved by means of 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 folding configuration and an unfolding configuration. The tip of the blade in the folded configuration is close to the hub and the tip of the blade in the unfolded configuration is far from the hub. The blades are folded to store energy, and after the external constraint is removed, the energy stored by the blades is released to unfold the blades.

In thepump head 3 corresponding to the access configuration, the vanes are in a collapsed configuration, wrapped around the outer wall of the hub and at least partially in contact with the inner wall of thepump housing 31. When thepump head 3 is in the corresponding operating configuration, the vanes extend radially outwardly from the hub and are spaced from the inner wall of thepump head 3 when in the extended configuration.

Thepump head 3 is folded by means of external constraint, and thepump head 3 is self-unfolded after the constraint is removed. In the present embodiment, the "collapsed state" refers to a state in which thepump head 3 is radially constrained, that is, a state in which thepump head 3 is radially compressed and folded into a minimum radial dimension by an external pressure. The "expanded state" refers to a state in which thepump head 3 is not radially constrained, that is, a state in which thebracket 313 and the radially outer side of the impeller are expanded to the maximum radial dimension.

Referring to fig. 2 and 3, thecatheter pump 100 further comprises aradial squeezing means 5, and thepump head 3 is switchable between the expanded state and the collapsed state by theradial squeezing means 5. Theradial squeezing means 5 is adapted to compress thepump head 3 in the expanded state to the collapsed state.

Theradial crimping device 5 comprises arecompressible member 51 and an operatingmember 52 that cooperates with the recompressiblemember 51. Thecompressible element 51 is made of a flexible and resilient material, which deforms under the action of an external force and returns to its original shape after the external force is removed. The flexible elastic material can be silica gel, etc., which are not listed here.

There-compressible member 51 has apre-collapsed passage 511 in the axial direction for receiving thepump head 3. The operatingmember 52 exerts a force on therecompressible member 51 having a first state in which a first force is exerted on therecompressible member 51 and a second state in which a second force is exerted on therecompressible member 51.

It should be noted that the first inner diameter of thepre-collapse passage 511 when the operatingmember 52 is in the first state is at least not smaller than the outer diameter of thepump head 3 in the extended state. At this time, thepre-folding passage 511 facilitates thepump head 3 to smoothly enter therein.

The first force is less than the second force, and the second inner diameter of thepre-collapse passage 511 is less than the first inner diameter when the operatingmember 52 is in the second state. The second inner diameter of thepre-collapse channel 511 when the operatingmember 52 is in the second state defines the outer diameter of thepump head 3 in the collapsed state. That is, the second inner diameter dimension of thepre-collapse channel 511 is equal to the outer diameter dimension of thepump head 3 in the collapsed state. When thepre-collapsing channel 511 is switched from the first inner diameter to the second inner diameter, collapsing of thepump head 3 is thereby achieved.

For ease of operation, when the operatingmember 52 is in the first state, the first force applied by the operatingmember 52 to the recompressablemember 51 may be zero. Thus, without any manipulation, the operatingmember 52 is maintained in the first state and thepre-collapse passage 511 is maintained at the first inner diameter, at which time thepump head 3 can be easily introduced into thepre-collapse passage 511.

In the present embodiment, the operatingmember 52 is fitted in contact with theincompressible member 51 at an end portion in the axial direction, and the operatingmember 52 is switched between the first state and the second state by movement in the axial direction. Theoperation member 52 has anoperation passage 521 communicating with thepre-folding passage 511, and thepump head 3 is movable to thepre-folding passage 511 through theoperation passage 521. At least theoperation passage 521 is not smaller than the outer diameter of thepump head 3 in the expanded state to allow thepump head 3 to pass smoothly.

Theradial crimping device 5 further comprises asleeve 53 receiving the recompressiblemember 51 therein, thesleeve 53 maintaining the outer diameter of the recompressiblemember 51 when the operatingmember 52 is switched from the first state to the second state. That is, thesleeve 53 limits the outer diameter of the recompressingmember 51 to ensure that the inner diameter of the recompressingmember 51 is only changed when subjected to an external force.

In addition, the operatingmember 52 applies a force to the recompressiblemember 51 by moving in the axial direction, and in order to limit the axial movement of the recompressiblemember 51 under the force, thesleeve 53 is provided with astop end 531 at one end of the recompressiblemember 51 far away from the operatingmember 52, so that the force applied to the operatingmember 52 is saved, and the operation is convenient.

In order to facilitate the subsequent pushing of thepump head 3 in the collapsed state out of theradial clamping device 5, the inner wall of the stoppingend 531 is gradually tapered from the proximal end to the distal end. When thepump head 3 is moved out from thepre-folding channel 511, the stop end 531 gradually reduces, and the inner diameter gradually reduces, so that thepump head 3 is slowly and gradually folded, the folding force is reduced, and the smoothness of the movement of thepump head 3 out of the radial pressing and holdingdevice 5 is improved.

In order to facilitate the switching of the operatingmember 52 between the first state and the second state, the operatingmember 52 and thesleeve 53 can be screwed, the operatingmember 52 can be switched to the second state by rotating the operatingmember 52 towards the front end, and the operatingmember 52 can be switched to the first state by rotating the operatingmember 52 towards the rear end, so that the operability of a user is improved.

In another embodiment, theoperation member 52 can circumferentially surround there-compressible member 51, and theoperation member 52 can be switched between the first state and the second state by moving in the radial direction, so as to switch thepump head 3 located in thepre-collapsing channel 511 between the expanded state and the collapsed state. The manner of interface between the operatingmember 52 and the recompressiblemember 51 is not particularly limited.

Theradial squeezing means 5 may be provided separately from thecatheter pump 100, theoperation member 52 at the proximal end, the introducingtube 55 at the distal end, and thepump head 3 may be switched to the collapsed state by pulling the radial squeezing means 5 backward, or pushing thecatheter 2 forward, or pulling the radial squeezing means 5 backward while pushing thecatheter 2 forward, the distal end of thepump head 3 being inserted into theoperation channel 521 and entering thepre-collapsing channel 511, switching theoperation member 52 to the second state, and switching thepre-collapsing channel 511 to the second inner diameter.

The external restraint applied to thepump head 3 is accomplished byradial squeezing means 5. When the operatingmember 52 is in the first state, thepump head 3 is entirely housed in thepre-folding passage 511. When the operatingmember 52 is switched to the second state, thecompressible member 51 is located at the second inner diameter, and thepump head 3 is subjected to a radial folding force, so as to forcibly fold thepump head 3. The folding force is small, the operation of a doctor is more convenient and labor-saving, and the operation efficiency is greatly improved. And because thepump head 3 is subjected to radial folding force, but not to axial folding force due to a pulling mode, thepump head 3 is not easy to damage, and the safety is high.

Thecatheter pump 100 comprises aprotective head 6 attached to the distal end of thepump head 3, theprotective head 6 extending along the axis of thepump head 3, i.e. theprotective head 6 is linear, in order for the radial squeezing means 5 to smoothly collapse thepump head 3 from the distal end, so that the distal end can smoothly enter theradial squeezing means 5. In addition, theprotection head 6 is configured to be soft so as not to damage the tissue of the subject, and theprotection head 6 may be made of any material that macroscopically exhibits flexibility, and the flexible end portion supports on the inner wall of the heart chamber in a non-invasive or non-invasive manner, and separates the suction port of thepump head 3 from the inner wall of the heart chamber, so as to prevent the suction port of thepump head 3 from adhering to the inner wall of the heart chamber due to the reaction force of the fluid (blood) during the operation of thepump head 3, and thus, ensure the effective pumping area.

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

pushing the catheter forward and/or pulling the radial crimping device backward, with the distal end of the pump head inserted into the pre-collapsed passage;

the operation member is switched from the first state to the second state, so that the pre-folding channel is switched to the second inner diameter, and the pump head is switched to the folding state.

The radial pressing device and the catheter pump are arranged separately, the operating piece is in a first state, the catheter is pushed forwards, or the radial pressing device is pulled backwards, or the catheter is pushed forwards and the radial pressing device is pulled backwards simultaneously, and the far end of the pump head enters the pre-folding channel through the operating channel. The specific operation of switching the pump head to the folded state is as described above, and is not further described herein. The pump head is collapsed for subsequent delivery to the vasculature of the subject.

Referring to fig. 4 to 7, acatheter pump 200 according to another embodiment of the present invention is substantially the same as thecatheter pump 100 provided in the above embodiment, and will not be described herein again, except that thecatheter pump 200 of this embodiment further includes aninterventional sheath 7, and theinterventional sheath 7 includes aninterventional channel 71 capable of receiving thepump head 3. Theradial crimping device 5 is operatively interfaced with theaccess sheath 7 so as to place theaccess channel 71 and thepre-collapse channel 511 in communication.

The manner in which thepump head 3 is collapsed by theradial squeezing means 5 is described above and will not be described further herein.

The distal end of theradial crimping device 5 is operably engaged with the proximal end of theaccess sheath 7, pushing thecatheter 2 forward, displacing thepump head 3 from the pre-collapsed state into theaccess sheath 7 through thepre-collapsed passage 511.

Wherein theradial crimping device 5 is operably interfaced with theaccess sheath 7 in such a way that the distal end of thesleeve 53 of theradial crimping device 5 and the proximal end of theaccess sheath 7 are end-on-end interfaced to enable communication of thepre-collapse channel 511 and theaccess channel 71.

To facilitate the docking of the radial squeezing means 5 with theaccess sheath 7, the radial squeezing means 5 further comprises anintroducer tube 55 defining astraight lumen 551, the proximal end of thestraight lumen 551 being in communication with the distal end of thepre-collapse passage 511, thepump head 3 being displaced from thepre-collapse passage 511 into thestraight lumen 551 and then into theaccess passage 71 when the operatingmember 52 is in the second state. The size of thestraight cavity 551 is equal to the outer diameter of thepump head 3 in the collapsed state.

The material of theintroduction tube 55 is PTFE. The PTFE material with low friction coefficient can effectively reduce the conveying force when thepump head 3 moves relatively in the introducingpipe 55, and improve the conveying compliance. In other embodiments, the material of the introducingpipe 55 may also be other materials with low friction coefficient, which is not listed here.

Another way in which theradial crimping device 5 may be operatively interfaced with theaccess sheath 7 may be that theintroducer tube 55 of theradial crimping device 5 is operatively threaded at least partially into theaccess sheath 7 to enable thepre-collapsed passage 511 and theaccess passage 71 to communicate through thestraight lumen 551 of theintroducer tube 55.

Yet another way in which theradial crimping device 5 may be operably interfaced with theaccess sheath 7 is to end-interface the distal end of theintroducer tube 55 of theradial crimping device 5 with the proximal end of theaccess sheath 7 to achieve communication between thepre-collapsed passage 511 and theaccess passage 71 via thestraight lumen 551 of theintroducer tube 55.

Thepump head 3 is delivered in a collapsed state through theaccess sheath 7 to the vascular system, enabling thepump head 3 to enter the subject with a smaller access size.

Theaccess sheath 7 has an inner diameter smaller than the outer diameter of the coupler 4 and is partially accessible to the vasculature of the subject through the puncture. Theaccess sheath 7 is advanced through the puncture into the vascular system at its forward end and is left at its rear end outside the body for forming or establishing a passage for the device into the vascular system.

The second inner diameter of thepre-collapsing channel 511 when the operatingmember 52 is in the second state is smaller than or equal to the inner diameter of theaccess sheath 7, thereby enabling thepump head 3 to be smoothly transferred from thepre-collapsing channel 511 into theaccess sheath 7. The inner diameter of thesame introducer tube 55 is also smaller than or equal to the inner diameter of theaccess sheath 7.

In the embodiment, the distal end of the introducingtube 55 and the proximal end of theinterventional sheath 7 are used for end face butt joint, and when thepump head 3 is intervened in the body of a subject, the introducingtube 55 does not enter the body, so that the size of theinterventional sheath 7 is reduced, related complications caused by interventional puncture are greatly reduced, and the operation safety is improved.

In one embodiment, the outer diameter of theintroducer tube 55 can be less than or equal to the inner diameter of theaccess sheath 7 to enable at least partial operable penetration of theintroducer tube 55 into theaccess sheath 7.

While thecatheter pump 200 is inserted into the subject to assist in pumping blood, thecatheter pump 200 is kept inserted into the subject, and theinsertion sheath 7 is kept in the puncture.

The distal end of theradial crimping device 5 is provided with afirst part 56, the proximal end of theintervention sheath 7 is provided with asecond part 72 which is matched with thefirst part 56, and thefirst part 56 and thesecond part 72 are detachably locked.

Theradial crimping device 5 and theintervention sheath 7 are subjected to a relative rotational movement to lock or unlock thefirst part 56 and thesecond part 72; wherein the angle of rotation does not exceed 90 °.

Specifically, one of thefirst member 56 and thesecond member 72 is a projection, and the other of thefirst member 56 and thesecond member 72 has a stop wall that cooperates with the projection, the projection and the stop wall abutting when theintroducer tube 55 is locked with theaccess sheath 7.

The number of thefirst parts 56 and thesecond parts 72 are two, respectively, the twofirst parts 56 are oppositely arranged on both sides of the introducingtube 55, and the twosecond parts 72 are also arranged on both sides of theintervention sheath 7, so as to improve the locking stability of the radialpressing device 5 and theintervention sheath 7.

In this embodiment, thefirst member 56 is a T-shaped slot having two stop walls, and when theradial crimping device 5 and theaccess sheath 7 are rotated relative to each other, the radial crimping device can be selected to rotate clockwise or counterclockwise, and thesecond member 72 can be abutted against the stop walls, thereby improving operability.

When the distal end of theradial crimping device 5 is docked with theaccess sheath 7, thepump head 3 is displaced from thepre-collapsed passage 511 into theaccess passage 71 by pushing thecatheter 2 forward. At this point, thefirst part 56 and thesecond part 72 are locked, and the radial-direction crimping device 5 and theintervention sheath 7 cannot be separated relatively. Therefore, when thecatheter 2 is pushed forwards, the radial pressing and holdingdevice 5 moves backwards due to the counterforce of thepump head 3 and is separated from theintervention sheath 7, so that the process that thepump head 3 is transferred from thepre-folding channel 511 to theintervention channel 71 is prevented from being blocked, and the phenomenon that theintervention sheath 7 moves at the puncture port under the action of external force to damage the puncture port in the transfer process of thepump head 3 is also avoided. The size of the puncture opening is ensured, the puncture opening can be healed conveniently, the probability of puncture opening complications is reduced, and meanwhile, the pain of a testee can be relieved.

Theradial crimping device 5 is operatively peeled off after thepump head 3 has entered the vascular system, and theaccess sheath 7 is inserted into the puncture, thereby avoiding interference of theradial crimping device 5 with the coupler 4.

Theinlet pipe 55 has a pre-pressure slit or a side opening on its axis, and the operatingmember 52 and thesleeve 53 may be designed as a two-lobe structure to facilitate peeling.

The operatingmember 52 and thesleeve 53 may be made of teflon, and are integrally formed by a stamping process to form two symmetrical and completely consistent structures, and the two symmetrical and completely consistent structures are butted by a hot melting process to form a pre-pressing tearing seam at the butted position.

Asleeve 54 is further sleeved on thesleeve 53 to ensure the circumferential fixation of the operatingmember 52 and thesleeve 53 in a two-piece structure, and prevent the operatingmember 52 and thesleeve 53 from moving circumferentially.

The proximal end of theaccess sheath 7 is provided with anintroducer hub 73, theintroducer hub 73 serving to secure and seal thecatheter 2. Theintroduction seat 73 is provided with a three-way extension pipe 74, and the three-way extension pipe 74 is prior art and will not be described herein.

The proximal end of theaccess sheath 7 has ahemostatic valve 75, by whichhemostatic valve 75 blood in the vessel is prevented from exiting the body through the hollow structure of theaccess sheath 7 when the pump head is operably threaded into theaccess sheath 7.

The hemostatic valve can be made of flexible materials such as a balloon and rubber, and is of an existing structure, and the description is omitted.

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

pushing the catheter forward and/or pulling the radial crimping device backward, with the distal end of the pump head inserted into the pre-collapsed passage;

the operation piece is switched from a first state to a second state, so that the pre-folding channel is switched to a second inner diameter, and the pump head is switched to a folding state;

the distal end of the radial pressing and holding device is butted with the proximal end of the intervention sheath, the catheter is pushed forwards, and the pump head in the folding state is transferred into the intervention sheath from the pre-folding channel when the operating piece is in the second state.

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

During the process that the pump head is transferred from the pre-folding channel into the intervention sheath, the radial pressing and holding device and the intervention sheath are axially kept fixed, and particularly, locking of the first part and the second part is achieved.

Wherein the access sheath is partially accessed to the vasculature of the subject through the puncture, and after the pump head is transferred into the access sheath, the method further comprises: the catheter is pushed forward continuously, the pump head is moved out from the far end of the intervention sheath to enter the vascular system of the subject in a deployment state, and the vascular system is intervened to a target position, and the motor and the catheter are connected in a matching mode, so that the blood pumping working state of the catheter pump can be achieved.

After the pump head is transferred within the access sheath, the method further comprises: the radial crimping devices are operatively peeled apart. The cutting sleeve is moved out firstly, the operating part and the sleeve of the two-petal structure and the lead-in pipe with the prepressing tearing seam or the lateral opening can be peeled off under the action of external force, the structure of the external part of the body after the catheter pump is inserted into the human body is simplified, and the post-operation nursing of a doctor is facilitated.

It should be noted that the access sheath is always partially inserted into the puncture to facilitate the subsequent removal of the pump head from the subject.

When the catheter pump-assisted blood pumping is complete, removing the catheter pump from the subject is performed by: pulling the catheter towards the proximal end, and accommodating the pump in the unfolding state into the intervention sheath so as to switch the pump head to the folding state; continued proximal pulling of the catheter causes the pump head to move out of the access sheath. And finally, pulling the intervention sheath to the proximal end to remove the intervention sheath from the body.

Through the cooperation of operating parts and recompression piece, the operating parts exert the effort to the recompression piece to make the internal diameter of the passageway of rolling over in advance of recompression piece change, from at least not being less than the external diameter of the pump head under the state of expansion to reducing, thereby reduce the external diameter that is located the pump head in the passageway of rolling over in advance thereupon, fold up with the realization to the pump head, this method of folding up, radial folding up power is received to the pump head, it is little to fold up the power, doctor's operation is convenient and laborsaving more, improve operating efficiency greatly. And because the pump head receives radial folding force, but not receives axial folding force because of pulling the mode, the pump head is difficult to be impaired, and the security is high.

The above description is only a few embodiments of the present invention, and those skilled in the art can make various changes or modifications to the embodiments of the present invention without departing from the spirit and scope of the present invention based on the disclosure of the application document.

Claims (14)

1. A catheter pump comprising:

a conduit;

a drive shaft rotatably disposed through the conduit;

foldable pump head, comprising: a pump housing connected to a distal end of the catheter, an impeller disposed within the pump housing; the impeller is 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 radial squeezing means adapted to compress the pump head in an expanded state to a collapsed state, comprising:

a re-compressible member made of a flexible elastic material having a pre-collapsed channel in an axial direction for receiving the pump head;

an operating member cooperating with the recompressible member to apply a force thereto, having a first state in which a first force is applied to the recompressible member, and a second state in which a second force is applied to the recompressible member; the first acting force is less than the second acting force;

wherein a first inner diameter of the pre-collapse channel when the operating member is in the first state is at least not smaller than an outer diameter of the pump head in the expanded state, and a second inner diameter of the pre-collapse channel when the operating member is in the second state is smaller than the first inner diameter.

2. The catheter pump of claim 1, wherein the radial crimping device further comprises: a sleeve receiving the recompressable member therein; the operating member is in contact fit with the compressible member along the axial end, and the operating member is switched between the first state and the second state by moving along the axial direction; the sleeve maintains an outer diameter of the recompressable member when the operating member is switched from the first state to the second state.

3. The catheter pump of claim 1, wherein the second inner diameter of the pre-collapse channel when the operating member is in the second state defines an outer diameter of the pump head in the collapsed state.

4. The catheter pump of claim 1, wherein the radial crimping device further comprises an introducer tube defining a straight lumen, a proximal end of the straight lumen communicating with a distal end of the pre-collapse channel, the pump head transitioning from the pre-collapse channel into the straight lumen when the operator is in the second state.

5. A method of folding a pump head of a catheter pump as claimed in any one of claims 1 to 4, comprising:

pushing the catheter forward and/or pulling the radial crimping device backward, the distal end of the pump head being inserted into the pre-collapsed passage;

the operating piece is operated to be switched from the first state to the second state, so that the pre-folding channel is switched to a second inner diameter, and the pump head is switched to a folding state.

6. A catheter pump comprising:

a conduit;

a drive shaft rotatably disposed through the conduit;

foldable pump head includes: a pump housing connected to a distal end of the catheter, an impeller disposed within the pump housing; the impeller is 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;

an access sheath including an access channel receivable of the pump head;

a radial crimping device operably interfacing with the access sheath adapted to compress the pump head in an expanded state to a collapsed state, comprising:

a re-compressible member made of a flexible elastic material having a pre-collapse channel in axial direction and in communication with the access channel, the pre-collapse channel for receiving the pump head;

an operating member cooperating with the recompressible member to apply a force thereto, having a first state in which a first force is applied to the recompressible member and a second state in which a second force is applied to the recompressible member; the first acting force is less than the second acting force;

wherein a first inner diameter of the pre-collapse channel when the operating member is in the first state is at least not smaller than an outer diameter of the pump head in the expanded state, and a second inner diameter of the pre-collapse channel when the operating member is in the second state is smaller than the first inner diameter;

the distal end of the radial pressing and holding device can be operated to butt against the proximal end of the intervention sheath, the catheter is pushed forwards, and the pump head in a folding state is transferred from the pre-folding channel into the intervention sheath.

7. The catheter pump of claim 6, wherein the second inner diameter of the pre-collapse channel when the operating member is in the second state is less than or equal to the inner diameter of the access sheath.

8. The catheter pump of claim 6, wherein the distal end of the radial crimping device is provided with a first component and the proximal end of the interventional sheath is provided with a second component that mates with the first component.

9. The catheter pump of claim 8, wherein the radial crimping device and the interventional sheath are performed relative rotational movement to effect locking or unlocking of the first component and the second component; wherein the angle of rotation does not exceed 90 °.

10. The catheter pump of claim 8, wherein one of the first and second components is a protrusion, the other of the first and second components having a stop wall that cooperates with the protrusion, the protrusion and stop wall abutting when the introducer tube is locked with the interventional sheath.

11. A method of folding a pump head of a catheter pump as claimed in any one of claims 6 to 10, comprising:

pushing the catheter forward and/or pulling the radial crimping device backward, the distal end of the pump head being inserted into the pre-collapsed passage;

operating the operating member to switch from the first state to the second state, so that the pre-folding channel is switched to a second inner diameter, and the pump head is switched to a folding state;

and abutting the distal end of the radial pressing and holding device with the proximal end of the interventional sheath, pushing the catheter forward, and transferring the pump head in a folded state into the interventional sheath from the pre-folding channel when the operating piece is in the second state.

12. The method of claim 11, wherein the radial crimping device remains axially fixed with the interventional sheath during translation of the pump head from the pre-collapsed channel into the interventional sheath.

13. The method of claim 11, wherein after the pump head is transferred within the access sheath, the method further comprises: continuing to push the catheter forward, the pump head is removed from the distal end of the access sheath.

14. The method of using the introducer assembly of claim 11, wherein after the pump head is transferred within the access sheath, the method further comprises: peeling off the radial pressing device.

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