CN115999045A - Blood pump - Google Patents

Abstract

A power transmission assembly for a blood pump is disclosed, comprising a catheter and a drive shaft for rotating an impeller of the blood pump. An inner runner is arranged in the driving shaft, and an outer runner is formed between the driving shaft and the guide pipe. The outer flow passage has a first discharge port at the distal end of the catheter, and the inner flow passage has a second discharge port at the distal end of the drive shaft. One of the inner runner and the outer runner is communicated with a perfusate input part, a communication part for communicating the inner runner with the outer runner is arranged on the wall of the driving shaft, the perfusate input part inputs the perfusate into one of the inner runner and the outer runner, and the other of the two runners inputs the perfusate through the communication part. By constructing the inner part and the outer part which jointly convey the perfusion liquid to the far end, the multichannel conveying of the perfusion liquid is realized, the perfusion liquid can lubricate the bearing, and the damage caused by the blood entering the bearing can be avoided.

Description

Blood pump

The present application is a divisional application with the application number of "202111236050.6", the application date of "2021, 10, 22 days", and the name of "power transmission module and blood pump".

Technical Field

The present invention relates to the field of medical devices, in particular to a power transmission assembly of a catheter pump for heart assist use, and more particularly to a blood pump, a power transmission assembly and a foldable support.

Background

The known catheter pumps are divided into two categories: one type is a built-in motor, wherein a motor connecting shaft directly drives an impeller, and the motor enters a human body along with a catheter; the other type is an external motor, the impeller is driven by the flexible shaft, and the motor does not enter the human body along with the guide pipe and the impeller.

The flexible shaft of the external motor type is arranged in the inner cavity of the catheter and guided and limited by the catheter. To reduce wear between the flexible shaft and the catheter lumen, to reduce vibration caused by high speed rotation of the flexible shaft, and to reduce heating caused by wear, physiological fluids, such as saline or dextrose solution, are often infused between the flexible shaft and the catheter.

Besides the above functions, the liquid can also prevent the pump from driving blood into the bearing in the high-speed rotation process, so as to realize the sealing function.

The prior art infusion method is to provide a connector at the proximal end of the drive to connect the infusion device, the liquid flows from the proximal end to the distal end and finally enters the human body, and a contact type dynamic sealing device such as a universal plug seal ring is also required at the proximal end of the connector.

The disadvantage of the prior art is that the introduction of a large amount of perfusion liquid into the patient has a health-related adverse effect on the patient, since the perfusion liquid may be contaminated with some wear particles; in addition, the contact dynamic seal may fail due to prolonged wear.

Moreover, if the perfusion liquid enters the body at a relatively high perfusion pressure, adverse reactions of the patient are easily caused, uncontrollable adverse effects are generated, and then the perfusion liquid is required to enter the body at a relatively low pressure, so that adverse reactions of the human body are reduced.

In addition, the interventional pump assembly of the catheter pump requires excellent foldability so as to stably maintain the shape of the pump casing after being unfolded, and avoid adverse effects on the pump efficiency due to the fact that the pump casing cannot stably maintain the shape.

In addition, the pump assembly of the catheter pump needs to be folded into the sheath and unfolded at the desired position in the body before being inserted into the body, and needs to be re-inserted into the sheath when being removed from the body, but the current stent design has larger resistance when the sheath is inserted, is easy to encounter resistance, and increases the difficulty of removal.

Disclosure of Invention

It is an object of the present invention to provide a blood pump and power transmission assembly thereof that reduces the risk of perfusing fluids into a patient.

It is yet another object of the present invention to provide a blood pump and power transmission assembly thereof that reduces the perfusion pressure and the risk associated with large perfusion pressures.

In order to achieve at least one of the above objects, the present invention adopts the following technical scheme:

A power transmission assembly for a blood pump, comprising: the device comprises a driving shaft for driving an impeller of the blood pump to rotate, a first flow channel for perfusion fluid to flow, and a coupling body provided with an axial channel communicated with the first flow channel. The drive shaft passes through the axial channel to be connected with the drive assembly, and the coupling body is provided with an output interface which is communicated with the axial channel and used for outputting the perfusion fluid in the first flow channel outwards. The axial channel is internally provided with a support body which is sleeved outside the driving shaft and is positioned at the upstream of the output interface along the power transmission direction, and a rotating gap is arranged between the support body and the driving shaft. The outer wall of the driving shaft is provided with a spiral structure, and at least part of the spiral structure is sleeved in the supporting body.

Through setting up the spiral structure that spiral extending direction is opposite with the direction of rotation of drive shaft, at the rotatory in-process of drive shaft, the spiral structure can produce the thrust along power transmission direction to the liquid in the clearance of rotation, prevents the liquid of backward flow from flowing to drive assembly through the clearance of rotation from this, effectively guarantees that the liquid of backward flow can not enter into inside the drive assembly, promotes structural reliability, has prolonged the life of product.

In addition, by arranging the spiral structure, non-contact sealing is formed between the driving shaft and the coupling body, so that the abrasion influence generated during rotation can be reduced, the reliability of the structure is improved, and the service life is prolonged.

The direction of rotation of the helical structure is opposite to the direction of rotation of the drive shaft. The spiral structure is left-handed when the drive shaft rotates clockwise or right-handed when the drive shaft rotates counterclockwise, as viewed from the proximal end to the distal end.

The drive shaft includes a connecting shaft in the axial passage and a first shaft connected to the connecting shaft, the first shaft having a proximal end connected to the connected shaft and a distal end for positioning the impeller.

The spiral structure is a spiral groove or a thread arranged on the outer wall of the connecting shaft.

The part of the spiral structure is positioned in the support body, and the part of the spiral structure is positioned outside the support body.

The spiral structure extends spirally downstream of the output interface in the power transmission direction.

A second flow channel is also provided for flow of irrigation fluid, the second flow channel having an input adjacent the proximal end for inputting irrigation fluid and an output adjacent the distal end for outputting irrigation fluid. The first flow channel has an output end in communication with the output interface and an input end adjacent the distal end for inputting the perfusion fluid. The output part of the second flow channel is communicated with the input end of the first flow channel, and the coupling body is provided with an input interface communicated with the input part of the second flow channel.

The first shaft is sleeved with a guide pipe. The first flow channel is positioned between the outer wall of the first shaft and the inner wall of the conduit, and the second flow channel is positioned in the wall of the conduit to axially penetrate the wall of the conduit.

The second flow channel is communicated with an output gap sleeved outside the first shaft, and an outlet of the output gap is communicated with a pump cavity of the blood pump for accommodating the impeller, or the outlet of the output gap faces the power transmission direction of the first shaft.

The catheter is provided with a main pipe body and a front protruding pipe arranged at the front end of the main pipe body, a front step is arranged between the main pipe body and the front protruding pipe, and the input part is an input port positioned on the front step. The axial passage has a first passage section into which the front protruding tube extends, and a second passage section into which the main tube extends. The outer wall of the front protruding pipe is in sealing connection with the inner wall of the first channel section, and the outer wall of the end part of the main pipe body is in sealing connection with the inner wall of the second channel section. The output interface opens into the first channel segment and the input interface opens into the second channel segment.

The support body comprises a first bearing sleeved outside the connecting shaft, and the output interface is positioned on the far side of the first bearing.

The first shaft is sleeved with axially spaced second and third bearings, the third bearing being distal to the second bearing. And a spacing annular space communicated with the output part of the second flow passage is formed between the second bearing and the third bearing, an output gap for communicating the spacing annular space with the outside of the catheter is formed between the third bearing and the first shaft, and a communication gap for communicating the input end of the first flow passage with the spacing annular space is formed between the second bearing and the first shaft.

The guide pipe is provided with a rear protruding pipe arranged at the rear end of the main pipe body, and a bearing sleeve is sleeved on the rear protruding pipe. The bearing sleeve is provided with a fixing sleeve outside, and the second bearing and the third bearing are fixed in the bearing sleeve at intervals.

A power transmission assembly for a blood pump, comprising: the catheter and the driving shaft are rotatably arranged in the catheter in a penetrating way and are used for driving the impeller of the blood pump to rotate. The proximal end of the drive shaft passes out of the proximal end of the catheter to connect with the drive assembly and the distal end passes out of the distal end of the catheter to connect with the impeller. An outer flow passage is formed between the driving shaft and the guide pipe, and an inner flow passage is formed in the driving shaft. The wall of the driving shaft is provided with a communicating part which communicates the inner flow channel with the outer flow channel, one of the inner flow channel and the outer flow channel is communicated with a perfusate input part, the perfusate input part inputs the perfusate into one of the inner flow channel and the outer flow channel, and the other of the inner flow channel and the outer flow channel inputs the perfusate through the communicating part.

The infusion device has the advantages that the infusion device is constructed to jointly convey the infusion liquid to the inner and outer channels at the far end, the multi-channel conveying of the infusion liquid is realized, the infusion liquid input part is communicated with one of the outer channel and the inner channel, the input structure can be simplified, the manufacture is convenient, the flow area of the infusion liquid is increased through the communication part when the infusion device is input into one of the channels, the infusion pressure is reduced, adverse effects caused by overlarge infusion pressure are avoided, the infusion flow can be ensured, and the normal and smooth operation of an interventional operation is ensured.

The distal end of the outer runner is provided with a first discharge outlet positioned at the proximal side of the impeller, and the distal end of the inner runner is provided with a second discharge outlet positioned at the distal side of the impeller. The perfusate in the outer and inner flow paths is discharged through the first and second discharge ports, respectively.

A power transmission assembly for a blood pump includes a pump housing, and an impeller received in the pump housing. The power transmission assembly comprises a guide pipe and a driving shaft rotatably penetrating the guide pipe. The proximal end of the catheter is adapted to be coupled to a drive assembly and the distal end is adapted to be coupled to the pump housing. The proximal end of the drive shaft passes out of the proximal end of the catheter to be driven in rotation by the drive assembly and the distal end passes out of the distal end of the catheter to be connected to the impeller. An outer flow passage is formed between the driving shaft and the guide pipe, and an inner flow passage is formed in the driving shaft. The distal end of the outer runner is provided with a first discharge outlet positioned at the proximal side of the impeller, and the distal end of the inner runner is provided with a second discharge outlet positioned at the distal side of the impeller. The perfusion liquid in the outer runner is discharged through the first discharge port, and the perfusion liquid in the inner runner is discharged through the second discharge port. The second exhaust port is located within the distal bearing chamber and distal to the distal bearing.

By constructing the outer flow channel and the inner flow channel which jointly convey the perfusion liquid to the far end, the perfusion liquid can lubricate the near end bearing and the far end bearing, and can prevent blood from entering the bearing to be damaged and prevent hemolysis.

The power transmission assembly is also provided with a perfusate input part which is communicated with at least one of the inner runner and the outer runner. Preferably, the perfusate input part is communicated with the outer flow channel, a communication part for communicating the inner flow channel with the outer flow channel is arranged on the wall of the driving shaft, and the inner flow channel inputs perfusate in the outer flow channel through the communication part.

The communication portion communicates the inner flow passage and the outer flow passage by means of liquid permeation, and includes a wall of the drive shaft of at least a part of a length that is permeable to liquid within the conduit. Alternatively, the wall of the drive shaft at least partially within the conduit is of a liquid permeable construction to form the communication.

The proximal end of the catheter communicates with the perfusate input to communicate the proximal end of the outer flow channel with the perfusate input. The proximal end of the catheter is connected with the coupling body, the driving shaft is connected with the driving assembly through the coupling body, and the perfusate input part is arranged on the coupling body.

A blood pump, comprising: the device includes a drive assembly, a catheter having a proximal end connected to the drive assembly, a drive shaft rotatably disposed within the catheter, and a pump assembly that pumps blood through the catheter to a desired location of the heart. The pump assembly includes a pump housing having an inlet end and an outlet end, an impeller received within the pump housing, the impeller being driven in rotation by a drive shaft to draw blood into the pump housing from the inlet end and to discharge blood from the outlet end. The pump housing includes a stent and a cover partially covering the stent, the proximal end of the stent being connected to the distal end of the catheter. An outer flow passage is formed between the driving shaft and the guide pipe, and an inner flow passage is formed in the driving shaft. The distal end of the outer runner is provided with a first discharge outlet positioned at the proximal end of the bracket, and the distal end of the inner runner is provided with a second discharge outlet positioned at the distal end of the bracket.

When the blood pump is in an operating state in which the impeller rotates, perfusate in the outer flow channel and the inner flow channel is discharged from the proximal end and the distal end of the support through the first and second discharge ports, respectively, and the impeller is restrained between the first and second discharge ports.

The perfusate in the inner and outer flow channels flows out from the distal end and the proximal end of the impeller respectively, and forms a liquid high-pressure area at the distal end of the catheter and the proximal end of the distal bearing chamber, thereby preventing blood from entering the distal end of the catheter and the distal bearing chamber and thrombus.

The impeller is provided with a bearing mounting part on the near side and a far-end bearing chamber on the far side. The bearing mounting portion is a proximal bearing chamber. Alternatively, the bearing mount is formed by the distal portion of the catheter. Alternatively, the bearing mounting portion is formed by a proximal portion of the bracket. The bearing mounting part and the far-end bearing chamber are respectively provided with a near-end bearing and a far-end bearing for supporting the rotation of the driving shaft; the perfusion liquid of the outer runner and the inner runner respectively flows through the proximal end bearing and the distal end bearing to be discharged.

The first exhaust port is located distally of the proximal bearing. The second discharge port is positioned in the distal bearing chamber, and a perfusate discharge port is formed between the proximal inner wall of the distal bearing chamber and the distal outer wall of the drive shaft. The distal end of the drive shaft is internally provided with a diffuser section, the flow area of which gradually expands along the flow direction inside the diffuser section. The second discharge port is a distal port of the diffuser section.

The proximal bearing comprises a first and a second proximal bearing arranged at a distance from each other, and the outer wall of the drive shaft is provided with a stop member located between the first and the second proximal bearing. A flow gap is formed between the outer wall of the stop member and the inner wall of the bearing mounting portion.

The perfusion pressure in the first discharge port is greater than the blood pressure in the vicinity of the first discharge port, and the perfusion pressure in the second discharge port is greater than the blood pressure in the vicinity of the second discharge port.

The drive shaft includes a first shaft and a second shaft having a stiffness greater than the stiffness of the first shaft. The proximal end of the first shaft is connected to the drive assembly and the distal end is connected to the proximal end of the second shaft. The second shaft is connected with the impeller.

A communication part for communicating the inner flow channel with the outer flow channel is arranged on the wall of the first shaft, and the communication part extends from the proximal end to the distal end of the first shaft. The first shaft is of a woven construction, the walls of which are liquid permeable, and the communicating portions are woven slits extending over the walls of the first shaft. The first shaft comprises a plurality of braiding layers sleeved layer by layer, the spiral directions of two adjacent braiding layers are opposite, and the spiral direction of the braiding layer positioned on the outermost layer is opposite to the rotation direction of the first shaft.

The connection position of the bracket and the catheter is positioned at the proximal side of the second shaft. The proximal end of the bracket is provided with a connecting secondary pipe connected with the distal end of the catheter, and the proximal end of the second shaft does not extend out of the connecting secondary pipe.

A blood pump, comprising: the device includes a drive assembly, a catheter having a proximal end connected to the drive assembly, a drive shaft rotatably disposed within the catheter, and a pump assembly that pumps blood through the catheter to a desired location of the heart. The pump assembly includes a pump housing having an inlet end and an outlet end, an impeller received within the pump housing, the impeller being driven in rotation by a drive shaft to draw blood into the pump housing from the inlet end and to discharge blood from the outlet end. The pump housing includes a stent and a cover partially covering the stent, the proximal end of the stent being connected to the distal end of the catheter. The distal end of the bracket is connected with a distal bearing chamber, a distal bearing is arranged in the distal bearing chamber, and the distal end of the driving shaft extends through the distal bearing. The drive shaft is provided with a hollow inner cavity communicated with a distal bearing chamber, a blocking piece for blocking the position is arranged in the distal bearing chamber, and the blocking piece is positioned on the distal side of the distal end of the drive shaft.

Rotation of the impeller causes blood to be drawn into the pump housing from the distal inlet end, and the distal bearing chamber is closer to the inlet end of the pump housing. The existence of the plugging piece ensures that the perfusate conveyed by the hollow inner cavity of the driving shaft cannot continue to flow forwards, but can only be forced to flow back and flow out of the far-end bearing chamber, thereby effectively avoiding the possibility that the blood sucked into the pump shell through the inlet end enters the far-end bearing chamber, protecting the cells in the blood from being crushed and damaged by the far-end bearing and avoiding hemolysis.

The closure member is provided with a resealable channel for passage of the guidewire therethrough, the resealable channel being closed upon removal of the guidewire.

The distal end of the distal bearing chamber is provided with a non-invasive support having a hollow lumen leading into the distal bearing chamber, and the closure member is disposed proximal to the non-invasive support. The proximal end of the atraumatic support is positioned within a distal bearing chamber, a step is provided within the distal bearing chamber, and the closure member is clamped between the step and the proximal end of the atraumatic support.

Drawings

FIG. 1 is a schematic diagram of a blood pump according to an embodiment of the present invention;

FIG. 2 is a schematic view of the proximal portion of FIG. 1;

FIG. 3 is a schematic view of the distal portion of FIG. 1;

FIG. 4 is a schematic view of the coupling body and the connecting shaft of FIG. 2;

FIG. 5 is a schematic flow diagram of the perfusion fluid of FIG. 2;

FIG. 6 is a schematic view of the spiral structure of FIG. 2;

FIG. 7 is a schematic view of the flow of perfusion fluid at the front end of the catheter of FIG. 2;

FIG. 8 is a side view of a catheter;

FIG. 9 is a schematic view of a portion of the structure of FIG. 3;

FIG. 10 is an enlarged view of a portion of FIG. 9;

FIG. 11 is a schematic view of the foldable stand of FIG. 1;

FIG. 12 is an enlarged view of a portion of FIG. 11;

FIG. 13 is a schematic view showing a half of a foldable stand according to another embodiment of the present invention;

FIG. 14 is a schematic view of a blood pump according to another embodiment of the present invention;

FIG. 15 is a schematic view of the main intervening portion of FIG. 14;

FIG. 16 is an enlarged view of the distal portion (bearing mount) of the catheter of FIG. 15;

FIG. 17 is an enlarged view of the second shaft distal end portion (distal bearing housing) of FIG. 15;

FIG. 18 is a schematic view of a portion of a pump assembly of a blood pump according to another embodiment of the present invention;

FIG. 19 is an enlarged view of the distal portion (bearing mount) of the catheter of FIG. 18;

FIG. 20 is an enlarged view of the second shaft distal end portion (distal bearing housing) of FIG. 18;

fig. 21 is a schematic illustration of the inner and outer flow path fluid permeation flow of fig. 18.

Detailed Description

In order to make the technical solution of the present invention better understood by those skilled in the art, the technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, shall fall within the scope of the invention.

It will be understood that when an element is referred to as being "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

The terms "proximal", "distal" and "anterior", "posterior" are used herein with respect to a clinician manipulating a blood pump. The terms "proximal", "posterior" and "anterior" refer to portions relatively closer to the clinician, and the terms "distal" and "anterior" refer to portions relatively farther from the clinician. For example, the extracorporeal portion is at the proximal or rear end and the intervening intracorporeal portion is at the distal or front end.

Referring to fig. 1 to 10, a blood pump according to an embodiment of the present invention has a power transmission assembly for transmitting power to an impeller 410 of the blood pump to drive the impeller 410 to rotate the blood. The power transmission assembly includes a driving shaft for driving the impeller 410 to rotate, and both ends of the driving shaft are respectively penetrated out of both ends of the guide tube 300 to be respectively connected with the driving assembly 100 and the impeller 410.

The drive shaft includes a first shaft 350, the first shaft 350 being a flexible shaft or shaft, which is coupled to the drive assembly 100 at a proximal end for inputting power and to a second shaft 355 at a distal end. The second shaft 355 is connected to the impeller 410 to rotate the impeller 410. The drive assembly 100 utilizes a first shaft 350 and a second shaft 355 to transfer power to the impeller 410.

To avoid contact between the rotating first shaft 350 and the blood vessel, the catheter 300 is sleeved outside the first shaft 350. Catheter 300 is a flexible catheter that can be bent and deformed with first shaft 350 to accommodate the curved configuration of the human vasculature.

As shown in fig. 2, the driving assembly 100 includes a motor 101 and a motor case 102 accommodating the motor 101. The output end of the motor 101 is connected to the proximal end of the first shaft 350 through the connection shaft 220, and the connection shaft 220 transmits the power output from the motor 101 to the first shaft 350 and then to the impeller 410 through the second shaft 355 to rotate.

In this embodiment, the "far and near" position may be defined by a positional relationship with respect to the driving assembly 100, and the power transmission direction F along the driving assembly 100 to the impeller 410 may be regarded as a near and far transmission. Accordingly, the proximal end of the first shaft 350 is closer to the drive assembly 100 than the distal end thereof, although the distal and proximal ends of other components are likewise defined with reference thereto.

The driving assembly 100 and the guide tube 300 are connected through the coupling body 200, and the driving shaft is connected to the motor 101 through the coupling body 200. The coupling body 200 may adopt any suitable existing structure, for example, a magnetic coupling structure to realize the transmission connection between the driving shaft and the motor 101, which is not limited in this embodiment.

As shown in fig. 4 and 5, the coupling body 200 is provided with an axial passage 210, and a drive shaft is connected to the motor 101 through the axial passage 210. The axial channel 210 is a linear channel that houses the connecting shaft 220, into which the proximal end of the first shaft 350 extends from the distal end port of the axial channel 210 for connection with the distal end of the connecting shaft 220.

The proximal end of the catheter 300 extends into the axial passage 210 and is fixedly sealingly connected to the inner wall of the axial passage 210. Specifically, the outer wall 301 of the proximal end of the catheter 300 is sealed and bonded to the coupling body 200, thereby achieving a fixed connection therebetween.

As shown in fig. 5 to 10, the power transmission assembly is provided with a first flow passage 700 for the perfusion fluid to circulate. The priming fluid can cool the drive shaft, avoid overheating during rotation, and lubricate the rotation of the drive shaft. The first flow channel 700 has an output for outputting perfusion fluid adjacent the proximal end of the first shaft 350 and an input for inputting perfusion fluid adjacent the distal end of the first shaft 350. In the first flow channel 700, the perfusion fluid flows in a direction from the distal end to the proximal end. By expelling irrigation fluid outwardly adjacent the output end of the proximal end of the first shaft 350, irrigation fluid is prevented from entering the body.

The output end of the first flow channel 700 that outputs irrigation fluid outwardly is adjacent to the proximal end of the first shaft 350, rather than opening at the distal end that opens into the body, thereby reducing or even avoiding the introduction of irrigation fluid into the body and reducing the risk of wear particles entering the body.

As shown in fig. 5 and 7, the first flow passage 700 extends with the first shaft 350 and the flow directions of the fluid therein are opposite. The first flow channel 700 is looped around the first shaft 350, and the outer wall of the first shaft 350 forms the flow channel wall of the first flow channel 700. Specifically, the first flow channel 700 is located between the catheter 300 and the first shaft 350. The inner wall 302 of the conduit 300 and the outer wall of the first shaft 350 constitute the flow channel wall of the first flow channel 700, and the first flow channel 700 has a circular cross section.

The power transmission assembly is further provided with a second flow passage 600 for the flow of irrigation fluid, the second flow passage 600 also being capable of cooling the first shaft 350. The second flow channel 600 is used to deliver a perfusion fluid (e.g., a cooling fluid, etc.). Further, the second flow channel 600 is used for delivering irrigation fluid from the proximal end to the distal end.

The second flow channel 600 has an input portion adjacent the proximal end for inputting the perfusion fluid and an output portion adjacent the distal end for outputting the perfusion fluid. The output of the second flow path 600 communicates with the input of the first flow path 700.

The first flow passage 700 and the second flow passage 600 are provided outside the first shaft 350 in a parallel manner, and the outer wall of the first shaft 350 constitutes the flow passage wall of the first flow passage 700 or the flow passage wall of the second flow passage 600, and the extending direction of the first flow passage 700 and/or the second flow passage 600 is parallel to the axial direction of the first shaft 350.

As shown in fig. 7 and 8, the second flow channel 600 is located between the outer wall 301 and the inner wall 302 of the conduit 300. The first flow channel 700 is located inside the inner wall 302 of the catheter 300, specifically between the outer wall of the first shaft 350 and the inner wall 302 of the catheter 300, and the second flow channel 600 is located inside the wall of the catheter 300 to axially penetrate the wall of the catheter 300.

The first flow channel 700 serves as a return flow channel for fluid to transport the abrasive dust generated during the power transmission to the outside of the body, thereby reducing the risk of entering the body. As shown in fig. 8, catheter 300 is a multi-lumen tube. The center of the catheter 300 has a main cavity that accommodates the first shaft 350. Cavities 601 and 602 forming the second flow channel 600 are formed in the pipe wall of the guide pipe 300, and the number of the cavities 601 and 602 is multiple, so that the overflow capacity of the second flow channel 600 is improved, and the cooling capacity is further improved.

As shown in fig. 9 and 10, to avoid the backflow of blood with the perfusion fluid, the power transmission assembly is further provided with an output gap 335, and the output gap 335 is looped around the drive shaft and is communicated with the second flow channel 600. The output gap 335 is located downstream of the first flow passage 700 in the power transmission direction F, between the conduit 300 and the drive shaft. The outlet of the output gap 335 opens into the pump chamber of the blood pump housing the impeller 410, thereby preventing blood flowing into the pump chamber from entering the catheter 300.

The outlet of the output gap 335 is directed toward the power transmission direction F of the first shaft 350 (i.e., is directed parallel to the power transmission direction F). By providing the output gap 335, the ingress of body fluid such as blood into the first flow channel 700 may be prevented from flowing back with the perfusion fluid. And, the priming fluid flows between the bearing and the drive shaft through the output gap 335, reducing wear between the drive shaft and the bearing, improving service life.

As shown in fig. 4 and 5, the coupling body 200 is provided with an output port 202 communicating with the output end of the first flow passage 700 and an input port 201 communicating with the input portion of the second flow passage 600. The input interface 201 and the output interface 202 are axially spaced, with the output interface 202 being closer to the drive assembly 100 than the input interface 201.

As shown in fig. 6, an axial gap 215 is formed between the connection shaft 220 and the inner wall of the coupling body 200, the output port 202 opens into the axial gap 215, and the axial gap 215 communicates with the output end (port) of the first flow passage 700.

To facilitate connection to the coupling body 200 and to avoid leakage of fluid, the proximal end of the catheter 300 is stepped. As shown in fig. 7, the catheter 300 has a main tube 311 and a front protruding tube 312 provided at the rear end of the main tube 311, and a front step 315 is provided between the main tube 311 and the front protruding tube 312, and the input portion is an input port (input port) located on the front step 315. The axial channel 210 has a first channel section 211 into which the front protruding tube 312 protrudes, and a second channel section 212 into which the main tube 311 protrudes. The first channel section 211 is located on the front side of the second channel section 212, closer to the connecting shaft 220 or the drive assembly 100.

The outer wall of the forward protruding tube 312 is sealingly connected to the inner wall of the first channel section 211, and the outer wall 301 of the end of the main tube body 311 is sealingly connected to the inner wall of the second channel section 212. The output interface 202 opens into a first channel section 211 and the input interface 201 opens into a second channel section 212.

As shown in fig. 4, the axial passage 210 is a stepped hole having a shaft passage section at the rear side of the first passage section 211, the inner diameter of the shaft passage section being smaller than the inner diameter of the first passage section 211. Accordingly, the inner diameters of the shaft passage section, the first passage section 211, and the second passage section 212 in the power transmission direction F are sequentially increased, and corresponding steps are formed. The shaft channel section, the first channel section 211, and the second channel section 212 are all cylindrical channels. The steps between the shaft channel section and the first channel section 211 are limiting steps, the front protruding pipe 312 stretches into the axial channel 210, and the end face of the front protruding pipe 312 contacts the limiting steps to be axially limited. The outer tube wall of the forward protruding tube 312 is sealingly bonded to the inner channel wall of the first channel section 211.

The step between the first channel section 211 and the second channel section 212 is a communication step 213, and a front step 315 between the main pipe body 311 and the front protruding pipe 312 and the communication step 213 are arranged at opposite intervals, so that an interval communication annulus is formed between the two, and the interval communication annulus communicates the input interface 201 on the coupling body 200 with the first flow channel 700 located on the front step 315. The outer wall surface of the rear end of the main pipe body 311 is sealed and bonded to the inner wall of the passage of the second passage section 212 (the portion located downstream of the input port 201 in the power transmission direction F).

As shown in fig. 4 to 6, a support body 230 sleeved outside the connecting shaft 220 is disposed in the axial channel 210, the support body 230 is located upstream of the output interface 202, a rotation gap 231 is formed between the support body 230 and the driving shaft, and the radial gap width of the rotation gap 231 is smaller than that of the shaft gap 215. The support body 230 is a first bearing fixed in the coupling body 200 and sleeved outside the connecting shaft 220, and the rotation gap 231 is located between the first bearing and the connecting shaft 220.

The outer wall of the driving shaft is provided with a spiral structure 221, the rotation direction of the spiral structure 221 is opposite to the rotation direction of the driving shaft, and at least part of the spiral structure 221 is sleeved in the supporting body 230.

In the embodiment shown in fig. 6, the spiral structure 221 is provided on the outer wall of the connection shaft 220. The helical structure 221 is left-hand thread in the case where the drive shaft rotates clockwise, as viewed from the drive end (the drive assembly 100) in the power transmission direction F. Alternatively, in the case of a counterclockwise rotation of the drive shaft, the helical structure 221 is a right-handed thread.

Through setting up spiral extending direction and the spiral structure 221 that the direction of rotation of drive shaft is opposite, at the rotatory in-process of drive shaft, spiral structure 221 can produce the thrust along power transmission direction F to the liquid in the clearance 231 that rotates, prevent the liquid that flows back from flowing back through the clearance 231 that rotates from this and flowing to drive assembly 100, effectively guaranteed that the liquid that flows back can not enter into drive assembly 100 inside, promoted structural reliability, prolonged the life of product.

In addition, by providing the spiral structure 221, a non-contact seal is formed between the driving shaft and the coupling body 200, so that abrasion effect generated during rotation can be reduced, the reliability of the structure can be improved, and the service life can be prolonged.

In this embodiment, the spiral structure 221 may be a spiral groove 222 or a screw thread provided on the outer wall of the connection shaft 220. The output interface 202 is located on the downstream side of the first bearing in the power transmission direction F. In particular, the spiral structure 221 may have a start end located within the support body 230, and a stop end located downstream of the start section in the power transmission direction F.

The end stop may be located outside the first bearing or inside the first bearing. That is, all of the spiral structures 221 may be located in the first bearing, or some of the spiral structures 221 may be located in the first bearing, and some of the spiral structures 221 may be located outside the first bearing. The spiral structure 221 extends helically from inside the first bearing to outside the first bearing. To enhance the sealing effect, the spiral structure 221 may extend on the outer wall of the drive shaft (the connecting shaft 220) downstream of the output port 202 in the power transmission direction F, preventing leakage of the return liquid.

The length of the spiral structure 221 in the axial direction (power transmission direction F) outside the first bearing is 1mm or more. More preferably, the axial length of the spiral structure 221 outside the first bearing is within 5mm, or the connection portion extending to the connection shaft 220 and the first shaft 350 is cut off. The axial length of the first bearing has a value ranging from 3 to 5mm and the depth of the helical groove 222 has a value ranging from 0.05 to 0.2mm.

As shown in fig. 9 and 10, the distal end of the drive shaft passes through the catheter 300 and is fixedly sleeved by the impeller 410, so that the impeller 410 can rotate together with the drive shaft. A pump housing 400 is provided at the distal end of the catheter 300, and the rear end of the pump housing 400 is fitted over the outer wall 301 of the catheter 300 and provided with a pump outlet 402.

The pump housing 400 may be formed by a membrane 401, and a foldable bracket 404 is provided in the pump housing 400, and the bracket 404 supports the membrane 401 to form a pump chamber. The distal end of the coating 401 is sleeved on a bracket 404, the proximal end is sleeved on the outer wall of the catheter 300, and the distal end of the bracket 404 which is not covered by the coating 401 forms a pump inlet 403.

The pump inlet 403 and pump outlet 402 are located on the front and rear sides of the impeller 410, respectively, the proximal end of the bracket 404 is connected to the distal end of the catheter 300, the distal end is provided on a rear bearing housing 405 (distal bearing housing) at the distal end of the drive shaft, and the distal end of the rear bearing housing 405 is connected to the atraumatic support 500.

As shown in fig. 11 and 12, the bracket 404 is made of a memory alloy material, and may be an integrally formed structure made of a nickel-titanium alloy material. After losing the constraint of the sheath, the stent 404 resumes its shape, stretching the covering membrane 401. The bracket 404 is integrally of a spindle body structure and is provided with a grid structure, and the multi-mesh design on the bracket is combined with the material of the memory alloy so as to facilitate the integral folding and unfolding. The impeller 410 is housed in the holder 404 and is positioned in the cover 401.

The impeller 410 is secured to an impeller shaft or second shaft 355 (which may be coupled to the first shaft 350 or integral with the first shaft 350), the impeller shaft 355 being positioned within the housing 404 and rotatably supported distally in the distal bearing housing 405.

The pump assembly is a collapsible pump assembly having a radially compressed state and a radially expanded state. In the corresponding access configuration of the pump assembly, the support 404 and impeller 410 are in a radially compressed state. At this point, the pump assembly may be delivered in the subject vasculature at a first, smaller radial dimension. In the corresponding operating configuration of the pump assembly, the support 404 and impeller 410 are in a radially expanded state. At this point, the pump assembly may pump blood at a desired location, such as within the left ventricle, at a second radial dimension that is greater than the first radial dimension.

From the standpoint of ease of intervention and pain relief for the subject, it is desirable that the pump assembly be small in size. While a large flow rate of the pump assembly is desirable for providing a strong need for ancillary functions to the subject, a large flow rate generally requires a large size of the pump assembly.

By providing a collapsible pump assembly, the pump assembly has a smaller collapsed size and a larger expanded size, which can both reduce pain for the subject during intervention/delivery and ease of intervention, as well as provide a large flow.

As shown in fig. 11, the support 404 includes a generally cylindrical body section 40, a generally tapered inlet section 41 and an outlet section 42 at opposite ends of the body section 40, the body section 40 having a mesh area smaller than the mesh area of the inlet section 41 and/or the outlet section 42. In the pump assembly deployed state, the outer wall of the body section 40 contacts the inner wall of the membrane 401, supporting the membrane 401 in deployment.

As shown in fig. 12, the (at least one) mesh of the body segment 40 has two first apexes 505 that are generally opposite in the axial direction, and two pairs of second apexes 504 that are generally opposite in the circumferential direction. The spacing between the two pairs of second vertices 504 is approximately equal but less than the spacing between the two first vertices 505.

The long axis direction of the mesh of the main body section 40 is consistent with the axial direction of the support 404, the mesh can be elongated along the long axis direction, the radial shrinkage of the support 404 is realized, the axial expansion deformation can be well adapted, the controllable smooth shrinkage of the support 404 and the tectorial membrane 401 is completed, the shrinkage is smoothly completed after the expected operation is completed in vivo, and the external body is conveniently removed.

The maximum dimension of the mesh of the body section 40 in the axial direction is greater than the maximum dimension in the circumferential direction thereof. In other irregular polygonal holes, or spaces between non-vertices, the circumferential maximum dimension of the mesh of the body segment 40 is 1.2-3 times its axial maximum dimension. Two points providing a circumferential dimension are generally circumferentially opposite and two points providing an axial dimension are generally axially opposite.

The mesh of the body section 40 is a plurality of support meshes 50, the support meshes 50 being closed polygonal holes to form a stable support structure, stabilizing the pump gap. The supporting mesh 50 is at least two polygonal holes with unequal side lengths, and the polygonal holes can be irregular polygonal holes or polygonal holes with mirror symmetry structures, which is not limited in the application.

For example, the support mesh 50 is a mesh of mirror-symmetrical structure, and the length direction of the smallest edge is parallel to the axial direction, and includes two parallel first edges 501 and two parallel second edges 502. The second vertex 504 is located at least one end of the second edge 502 and the first vertex 505 is located at least one end of the first edge 501.

The support mesh 50 may be a quadrangular hole such as a diamond hole or a hexagonal hole. In the diamond mesh embodiment, the support mesh 50 has two axial first peaks 505 forming front and rear peaks 510a, 510b of a saw tooth configuration for the first and second edges 501, 502, respectively. The two second peaks 504 are disposed opposite to each other in the circumferential direction, and the first and second edges 501 and 502 form left and right tooth tops of a saw-tooth structure, respectively.

In the embodiment of hexagonal holes, the support mesh 50 further comprises two third edges 503 parallel to the axial direction. A third edge 503 is connected between a first edge 501 and a second edge 502, the first edge 501, the second edge 502, and the third edge 503 enclosing a closed hexagonal support mesh 50.

The third side edge 503 increases the axial dimension of the supporting mesh 50, so that the axial dimension of the supporting mesh 50 is the main dimension, and the supporting mesh can be smoothly folded along the axial direction when being taken into the sheath, and the resistance when being folded is reduced. Further, the length of the second edge 502 is equal to the length of the first edge 501, and the length of the third edge 503 is smaller than the length of the second edge 502. Third edge 503 is the smallest edge of support cell 50, providing the smallest edge of the cell.

The two axial end points of the third edge 503 form second vertexes 504, respectively, the axial rear end point of the third edge 503 is shared with a first edge 501, the shared end point forms a second vertex 504, the axial distal end point of the third edge 503 is shared with a second edge 502, and the shared end point forms another second vertex 504. The circumferential spacing of the two third edges 503 is the spacing of the two circumferentially opposite second vertices 504. The common end point of the first edge 501 and the second edge 502 forms a first vertex 505.

At least one of the first, second and third edges 501, 502, 503 is a straight line edge, the multiple edges of the mesh form a polygonal mesh, and the whole edge is a straight line, which may be a straight line without bending as shown in fig. 11 and 12. Alternatively, the edges may be straight edges that allow some slight curvature and still be intuitively considered as polygons, as shown in fig. 13.

Thus, in the present application, the edges of the polygonal mesh are of generally rectilinear configuration.

The length of the first edge 501 ranges from 1mm to 2mm, the length of the third edge 503 ranges from 0.15mm to 0.35mm, and the ratio of the lengths of the first edge 501 and the third edge 503 ranges from 3:1 to 5:1. The first vertex 505 and the second vertex 504 are provided with a first and a second rounded structure, respectively, so that a smooth transition between the hole edges of the support mesh 50 is achieved, and a stable support structure is constructed. The arc length of the first rounded structure is greater than the arc length of the second rounded structure.

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 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 length of the first edge 501 is illustrated as ranging from 1mm to 2mm, preferably from 1.1 to 1.9mm, more preferably from 1.2 to 1.8mm, and even more preferably from 1.3 to 1.7mm, for purposes of illustration of the non-explicitly recited values such as 1.4mm, 1.5mm, 1.6mm, etc.

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

The plurality of support cells 50 are sequentially arranged in the circumferential direction to form support rings (50 a, 50b, 50 c), and the plurality of support rings are axially arranged to form the main body section 40. As shown in fig. 12, the first edges 501 and the second edges 502 are alternately arranged along the circumferential direction to form zigzag rings 520 having a zigzag structure, and two axially adjacent zigzag rings 520 are opposite to each other to form a supporting hole ring.

As shown in fig. 11 and 13, the inlet section 41 is located on the front side of the main body section 40, at the distal end of the bracket 404, and the axial length of the mesh of the inlet section 41 is greater than the axial length of the support mesh 50.

The mesh of the inlet section 41 is an over-flow mesh for inflow of blood. The mesh of the inlet section 41 extends from the distal end of the mesh to the proximal end, and is not the radial projected length on the axis.

The axial length of the support mesh 50 in this embodiment is equal to its radial projected length on the axis.

The mesh of the inlet section 41 includes first and second through- flow mesh holes 52a and 52b alternately distributed in the circumferential direction, and the length of the first through-flow mesh hole 52a is smaller than that of the second through-flow mesh hole 52 b. The first through-flow net hole 52a is a closed hole, and the second through-flow net hole 52 is a non-closed hole.

The distal end of the inlet section 41 is provided with a front connection 44, the front connection 44 comprising a plurality of circumferentially dispersed connection legs 440. The connecting leg 440 has a T-shaped configuration with a distal end having a leg end 45 with a circumferential dimension greater than the leg body. The connecting legs 440 may snap into a snap-in groove in the outer wall of the distal bearing housing 405, the distal end of the snap-in groove communicating with an annular groove, the leg ends 45 snap into the annular groove, and secure the discrete plurality of connecting legs 440 to the distal bearing housing 405 via an outer collar.

In one embodiment, the collar is a heat shrink tubing that is secured over the distal bearing housing 405 by heat shrink fitting to retain the plurality of connecting legs of the bracket 404 within the receiving channel on the outer wall of the distal bearing housing 405.

The second through-flow net hole 52b extends from the inlet section 41 to the front connection part 44 until an opening 523 is formed at an end of the front connection part 44. A portion of the second through-flow apertures 52b are located in the inlet section 41 and a portion of the second through-flow apertures 52b are located in the front connection 44. The gap between the two connecting legs 440 forms part of the second flow-through web 52b at the front connection 44, which is filled with the outer wall projection of the distal bearing chamber 405 during installation.

The circumferential width of the first through-flow web 52a gradually decreases as it extends from the front tooth top 510a toward the junction, and the front junction 525 or the first through-flow web 52a does not exceed the transition between the inlet section 41 and the connecting sub-pipe 43. The second through-flow mesh 52b includes a front section 521 whose circumferential width extends in the axial direction and a rear section 522 whose circumferential width extends in the axial direction in a direction away from the main body section 40, which becomes gradually smaller. Wherein the front section 521 is located at the front connection 44.

In the embodiment shown in fig. 11 and 13, the circumferential width of the aft section 522 is substantially constant as it extends in the axial direction. The circumferential width of the section (the rear side section 522) of the second through-flow net hole 52b located between the front tooth top 510a and the junction varies by less than 10% at different positions in the axial direction. The circumferential width of the rear section 522 is greater than or equal to the circumferential width of the front section 521, and there is a transition between the rear section 522 and the front region that is approximately at the transition between the inlet section 41 and the front connection 44.

The inlet section 41 includes a plurality of front tensile ribs 528 extending from the front tooth top 510a toward the front connecting portion 44, with two adjacent front tensile ribs 528 meeting at an end remote from the main body section 40 to form a front junction 525, and the front junctions 525 are connected to or extend to the connecting leg 440 in a one-to-one correspondence. The number of front tensile ribs 528 is equal to the number of front tooth tops 510a of one serration ring 520 and is 2 times the number of connecting legs 440.

The outlet section 42 is substantially similar to the inlet section 41 except that the third and fourth through- flow mesh openings 51a, 51b are closed cells. Wherein the outlet section 42 is located at the proximal end of the support 404. The mesh of the outlet section 42 extends between the axial ends for a length greater than the axial length of the support mesh 50.

The mesh of the outlet section 42 includes third and fourth through- flow mesh holes 51a and 51b alternately distributed in the circumferential direction. Wherein, the third through-flow mesh 51a and the fourth through-flow mesh 51b are different in shape or area, and the length of the third through-flow mesh 51a is smaller than the length of the fourth through-flow mesh 51b.

The proximal end of the outlet section 42 is provided with a connecting sub-tube 43, the connecting sub-tube 43 being fixed to the catheter 300 or the bearing mounting part by means of hot melt or adhesive, achieving the proximal fixation of the support 404. The connecting secondary pipe 43 may further be provided with a fastening hole 431 for fastening the outer wall of the guide pipe 300 or the bearing mounting portion.

A fourth through-flow mesh 51b extends from the outlet section 42 to the connecting sub-pipe 43 and forms a closed bore end at the connecting sub-pipe 43. A portion of the fourth through-flow apertures 512 are located in the outlet section 42 and a portion of the fourth through-flow apertures 511 are located in the connecting secondary pipe 43. The fourth through-flow net hole 51b does not extend to the rear end beyond the catching hole 431 of the connection sub-pipe 43.

The outlet section 42 includes a plurality of rear tensile ribs 518 extending from the rear tooth top 510b toward the connecting secondary tube 43, with adjacent two rear tensile ribs 518 meeting at an end remote from the main section 40 to form a rear junction, the plurality of rear junctions being connected to or extending to the connecting leg 440 in a one-to-one correspondence. The number of rear tensile ribs 518 is equal to the number of rear tooth tips 510b of an serrated ring 520 and is 2 times the number of connecting legs 440.

The third through-flow web hole 51a gradually decreases in circumferential width as it extends from the rear tooth top 510b toward the rear junction, and the rear junction or the second through-flow web hole 52b does not exceed the transition between the outlet section 42 and the connecting sub-pipe 43. The circumferential width of the portion of the fourth through-flow mesh hole 51b located at the connecting sub-pipe 43 remains unchanged in the axial direction, and the rate of change in the circumferential width of the section of the fourth through-flow mesh hole 51b located between the rear tooth crest 510b and the rear intersection point at axially different positions is less than 10%.

Referring again to fig. 9 and 10, the drive shaft (specifically, the second shaft 355) is further sleeved with a second bearing 331 (first proximal bearing) and a third bearing 332 (second proximal bearing) at intervals, and the third bearing 332 is located downstream of the second bearing 331 in the power transmission direction F of the drive shaft. A spacer annulus 333 communicating with the output of the second flow passage 600 is formed between the second bearing 331 and the third bearing 332.

An output gap 335 is formed between the third bearing 332 and the drive shaft to communicate the spacing annulus 333 with the outside of the conduit 300, and a communication gap 334 is formed between the second bearing 331 and the drive shaft to communicate the input end of the first flow passage 700 with the spacing annulus 333. The flow direction of the communication gap 334 and the output gap 335 are opposite.

Catheter 300 has a rear protruding tube 313 provided at the rear end of main tube 311, with a rear step 316 between main tube 311 and rear protruding tube 313, and rear step 316, similar to front step 315, may be an annular step.

The rear boss 313 is sleeved with a bearing sleeve 330 (proximal bearing chamber), the bearing sleeve 330 is sleeved with a retaining sleeve 340, and the rear step 316 provides positioning for the bearing sleeve 330 and retaining sleeve 340 when sleeved outside the rear boss 313. The third bearing 332 and the second bearing 331 are fixed in the bearing sleeve 330 at intervals, and a limiting sleeve is sleeved in the bearing sleeve 330 by the driving shaft and is positioned at the upstream of the second bearing 331 along the power transmission direction F to position the second bearing 331.

A plurality of (e.g., two) fluid cells circumferentially spaced apart from each other corresponding to the cavities forming the second fluid passages 600 are provided on the outer wall of the bearing sleeve 330, and the fixed sleeve 340 is sleeved on the outer wall of the bearing sleeve 330 to cover the fluid cells to form a communication fluid passage 341. At the rear end of the communication flow path 341 (the rear end bottom wall of the liquid tank), a communication hole 342 (one is provided for each of the two liquid tanks) is opened to the inside, and the communication hole 342 is located between the third bearing 332 and the second bearing 331, and further to the space annular space 333.

As shown by the flow arrows in fig. 10, liquid (priming fluid) enters the spacing annulus 333, a portion of the liquid enters the communication gap 334 in the opposite direction to the power transfer direction F until the first flow passage 700 is back-flowed, and another portion of the liquid enters the output gap 335 directly in the power transfer direction F, is output outwardly, enters the pump chamber, and is discharged into the body by the pump outlet 402.

As shown in fig. 14 to 17, in the power transmission assembly according to another embodiment of the present invention, an outer flow path 600 is formed between an outer wall of a driving shaft and an inner wall of a guide pipe 300, and an inner flow path 800 extending in parallel or in common with the outer flow path 600 is provided in the driving shaft. The outer flow passage 600 is provided with a first discharge port 605 at the distal end of the catheter 300 and the inner flow passage 800 is provided with a second discharge port 810 at the distal end of the drive shaft.

As shown in fig. 14, the power transmission assembly is further provided with a perfusate input 201, the perfusate input 201 being in communication with one of the outer flow channel 600 and the inner flow channel 800. The perfusate is inputted to the outer flow channel 600 and the inner flow channel 800 through the perfusate input part 201. The wall of the driving shaft is provided with a communication portion for communicating the inner flow path 800 with the outer flow path 600, and the outer flow path 600 and the inner flow path 800 are spaced apart by the wall of the driving shaft and communicate through the communication portion. The perfusate input part 201 inputs perfusate into one of the outer flow channel 600 and the inner flow channel 800, and the other of the outer flow channel 600 and the inner flow channel 800 inputs perfusate through the communication part.

For example, the outer flow channel 600 communicates directly with the perfusate input 201, and the inner flow channel 800 communicates indirectly with the perfusate input 201 via the communication. Alternatively, the inner flow path 800 communicates directly with the perfusate input 201, and the outer flow path 600 communicates indirectly with the perfusate input 201 via a communication.

As shown in fig. 16 and 19, the first discharge port 605 is located on the proximal side of the impeller 410, and the perfusate in the outer flow path 600 is discharged from the proximal end of the holder 404 through the first discharge port 605. As shown in fig. 17 and 20, the second discharge port 810 is located on the distal end side of the impeller 410, and the perfusate in the inner flow channel 800 is discharged from the distal end of the holder 404 through the second discharge port 810.

By flowing the perfusate in the outer and inner channels 600, 800 proximally and distally of the impeller 410, respectively, thrombus is avoided from entering the catheter 300, drive shaft or distal bearing chamber 405 at the proximal/distal end of the impeller 410.

In another embodiment, the perfusate input 201 communicates with at least one of the outer flow channel 600 and the inner flow channel 800. Further, the perfusate input 201 communicates with one of the outer flow channel 600 and the inner flow channel 800, in particular the perfusate input 201 communicates directly with the outer flow channel 600 and indirectly with the inner flow channel 800 via the communication.

When the blood pump is in an operating state in which the impeller 410 rotates, the impeller 410 is restricted between the first discharge port 605 and the second discharge port 810.

As shown in fig. 16 and 17, the impeller 410 is provided with a proximal bearing chamber 330 on the proximal side and a distal bearing chamber 405 on the distal side. The proximal bearing chamber 330 is provided with proximal bearings for supporting rotation of the drive shaft, such as a first proximal bearing 331, a second proximal bearing 332 (refer to the second bearing 331 and the third bearing 332 in the above embodiment) which are axially spaced apart.

Distal bearing housing 405 is provided with a distal bearing 4051 for supporting the rotation of the drive shaft. The perfusion fluid of the outer flow channel 600 is discharged through the proximal bearings 331, 332 and the perfusion fluid of the inner flow channel 800 is discharged through the distal bearing 4051.

To allow the perfusate to drain, and avoid blood backflow, the perfusate pressure in the first drain 605 is greater than the blood pressure near the first drain 605 and the perfusate pressure in the second drain 810 is greater than the blood pressure near the second drain 810. Thus, the perfusion liquid can lubricate the bearing and prevent blood from entering the bearing to damage, thereby preventing thrombus from forming in and near the bearing.

As shown in fig. 17, to slow down the flow rate of the perfusate entering the body, which is suitable for human acceptance, the distal end of the inner flow channel 800 is provided with a diffuser section, the end of which is a second discharge port 810. The diffuser section is flared in shape with a gradually increasing cross-sectional area extending from its proximal end to its distal end.

As shown in fig. 14-17, the communication includes a wall of the drive shaft within the conduit 300 that is permeable to liquid through at least a portion of the length. The walls of the drive shaft at least partially within the catheter 300 are of a liquid permeable construction. The outer flow channel 600 and the inner flow channel 800 are continuous flow channels, each extending from the proximal end to the distal end of the catheter 300.

The proximal end of the catheter 300 communicates with the perfusate input 201 to communicate the proximal end of the outer flow channel 600 with the perfusate input 201. The outer flow path 600 is a high pressure flow path, the inner flow path 800 is a low pressure flow path, and the perfusate is permeated into the inner flow path 800 through the wall of the driving shaft under the pressure difference.

The proximal end of the drive shaft is blocked or provided with a flow blocking structure proximal to the perfusate input 201. In this way, the perfusate is prevented from leaking proximally of the drive shaft and into the motor 101.

The perfusate input part 201 is a perfusate input port on the coupling body 200, and the perfusate input port is communicated with an input runner. The perfusate input port communicates with the lumen of catheter 300 through the input channel, the drive shaft passes through this site, and sealing means are provided proximal to the input channel to avoid proximal leakage of perfusate.

The present application is not limited to the embodiment in which the external flow path 600 communicates with the perfusate input 201. In one possible embodiment, the inner flow channel 800 may also be in communication with the perfusate input 201, with the perfusate in the inner flow channel 800 flowing radially outward into the outer flow channel 600. Specifically, the inner flow channel 800 of the driving shaft is communicated with the external perfusate input part 201, the proximal end of the driving shaft is connected with the output shaft of the motor 101 through the connecting shaft 220, the output shaft and the connecting shaft 220 are formed into a hollow structure, and the output shaft of the motor 101 penetrates out from the tail end thereof to provide a perfusate input interface.

The first shaft 350 is a flexible shaft that facilitates passage into a blood vessel to accommodate bending of the vascular structure and delivery of the distal pump assembly to a desired location. The second shaft 355 is connected to the impeller 410, specifically, the second shaft 355 is provided in the hub of the impeller 410. The second shaft 355, being rigid or stiff, has a stiffness greater than the first shaft 350, and cooperates with the proximal 331, 332 and distal 4501 bearings on either side to provide support for the impeller 410 to achieve a desired stability of the position of the impeller 410 in the pump housing.

The location of the connection of the distal end of the first shaft 350 and the proximal end of the second shaft 355 is within the distal end of the catheter 300, which may be connected by any suitable means, such as welding.

The connection location of the stent 404 to the catheter 300 is proximal to the second shaft 355. The proximal end of the bracket 404 is provided with a connection sub-tube 43, and the catheter 300 is connected with the connection sub-tube 43 by a hot melt or snap connection. Alternatively, the catheter 300 is connected to the connecting sub-tube 43 via the proximal bearing chamber 330, possibly by bonding the distal end of the catheter 300 to the proximal bearing chamber 330 and by snap-fitting the connecting sub-tube 43 to the proximal bearing chamber 330.

As described above, in order to provide sufficient strength support to the impeller 410 so that it is stably held in position within the pump casing, the second shaft 355 passing through the hub is a hard shaft, and is not easily deformed by bending. Thus, in order that the stiffer second shaft 355 does not affect the bending properties of the working portion of the front end of the blood pump (including the pump assembly and the portion of the front end catheter that is introduced into the human body), the proximal end of the second shaft 355 is located inside the proximal end of the stent 404 or inside the connecting sub-tube 43, but does not protrude out of the connecting sub-tube 43. That is, the proximal end of the second shaft 355 is positioned within the connecting sub-tube 43 and does not extend beyond the connecting sub-tube 43.

In the scenario where the pump assembly is introduced in a collapsed manner, the collapsed pump assembly is relatively rigid and generally inflexible. Then, during the interventional procedure, over-bending of the pump assembly needs to be accomplished by means of bending of the catheter 300 connected thereto. Through the above design, the proximal end of the second shaft 355 is located inside the proximal end of the bracket 404 or inside the connecting sub-tube 43, so that the proximal end of the second shaft 355 does not extend out of the connecting sub-tube 43 and enter the catheter 300 too much, and therefore, the rigidity of the catheter 300 cannot be increased due to the gain effect of the second shaft 355, and the distal end portion of the catheter 300 connected with the connecting sub-tube 43 still maintains better flexibility, so as to ensure the overstretching performance of the pump assembly during the intervention.

The communication extends from the proximal end of the first shaft 350 to the distal end of the first shaft 350. The first shaft 350 is woven with a liquid permeable structure in the wall and the communication is a woven slit extending through the wall of the first shaft 350. The first shaft 350 is a multi-layer woven structure, e.g., a layer-by-layer wrap of 2, 3, 4, or more layers.

The plurality of braid layers of the first shaft 350 are in a layer-by-layer nested relationship, the braid layers being woven helically. Wherein the spiral directions of two adjacent braiding layers are opposite. The multi-layer braiding structure is a spiral twisting structure, and the rotation directions of the inner and outer adjacent braiding layers are opposite.

By providing the first shaft 350 with a braided twisted structure having opposite sense of rotation of the inner and outer adjacent braid layers, a helical groove or protrusion is formed on the outer surface of the first shaft 350, which has opposite sense of rotation of the drive shaft 300, to create a pumping effect, pumping perfusate distally, and preventing blood from entering at the distal end of the catheter 300, avoiding thrombus formation at the distal end of the catheter 300.

The communication extends over the circumference and the axial direction of the first shaft 350, and connects the outer flow path 600 and the inner flow path 800 by fluid permeation, and the wall of the drive shaft at least partially located in the guide tube 300 is a fluid permeable structure. The first shaft 350 is entirely of a liquid permeable structure, and the wall of the portion of the first shaft 350 sleeved by the conduit 300 constitutes a communication portion where the inner flow path 800 and the outer flow path 600 communicate. The connection between the inner flow path 800 and the outer flow path 600 extending to the first shaft 350 and the second shaft 355 is always in fluid communication or fluid penetration.

In the above described embodiment of the reflux of the perfusate, the drive shaft comprises a connecting shaft 220 with a screw structure 221 on the outer wall. It should be noted that in the embodiment illustrated in this embodiment wherein the perfusate does not reflux but is instead separately expelled from the distal end of catheter 300 and distal bearing housing 405, the outer wall of first shaft 350 contained by the drive shaft may likewise form spiral 221.

In this embodiment, the perfusate first flows forward within the outer flow path 600, i.e., the catheter 300 or outside the first shaft 350. During flow, a portion of the perfusate seeps into the first shaft 350, i.e., the inner flow channel 800. The spiral structure 221 of the outer wall of the first shaft 350 generates a forward force on the perfusate in the external flow channel 600 during rotation, so that the perfusion flow is smooth, and the perfusate congestion is avoided.

For the same purpose, the inner wall of the first shaft 350 may also be formed with such a spiral structure 221 in order to provide continuous forward flow of the perfusate in the inner flow channel 800.

The helical structure 221 formed by the outer and/or inner walls of the first shaft 350 may be formed by the helical braid described above. The braid is typically spiral braided from a single strand of material that is generally circular in cross-section to naturally form the spiral protrusions or grooves in the braid. Wherein the protrusions are the outer contour of the single strand of material and the grooves are formed between the woven materials.

Therefore, in order to form the spiral structure 221 conforming to the above description on the outer wall of the first shaft 350, in the case where the first shaft 350 adopts a spiral braid structure, it is only necessary to make the spiral direction of the outermost braid opposite to the rotation direction of the first shaft 350.

Likewise, the spiral direction of the innermost braid is opposite to the rotation direction of the first shaft 350, and it is possible to form a spiral structure conforming to the above description on the inner wall of the first shaft 350.

Thus, the spiral direction of the innermost and outermost braid is the same. In the case where the spiral directions of adjacent braid are reversed as set forth above, the number of braid layers included in the first shaft 350 should be an odd number of layers greater than 1, such as 3 layers or 5 layers.

Further, since the first shaft 350 needs to transmit torque, the outermost spiral braid tends to be tightened due to the torque in the rotation process by virtue of the structural design that the spiral direction of the outermost braid is opposite to the rotation direction of the first shaft 350, so that the outermost braid is prevented from loosening.

Thus, during rotation, the diameter of the braid, which is in the opposite direction of rotation of the first shaft 350, tends to decrease. If all of the spiral braid of the first shaft 350 is rotated in the opposite direction to the first shaft 350, the diameter of the first shaft 350 cannot be stably maintained as the working time is extended.

As described above, there are two adjacent braid layers in the first shaft 350 that are opposite in spiral direction. That is, the first shaft 350 includes a braid having a spiral direction identical to that of its rotation, which tends to increase in diameter or to loosen during rotation due to torque.

Then, the braid having the spiral direction opposite to the rotation direction of the first shaft 350 applies an inward compressive force to the inner braid, and the braid having the spiral direction identical to the rotation direction of the first shaft 350 applies an outward expansive force to the outer braid. Thereby, the diameter variations or forces of adjacent braid are at least partially compensated for, thereby allowing the diameter of the first shaft 350 to be stably maintained.

The stable maintenance of the diameter of the first shaft 350 is advantageous in that the shape of the outer flow path 600 is stable, thereby stabilizing the flow rate and the flow area of the perfusate.

The above-described arrangement of forming the helical structure 221 by means of the helical braiding configuration of the first shaft 350 is illustrative and not limiting in uniqueness. That is, in other alternative embodiments, it is also possible that the spiral structure 221 is formed by machining a spiral groove or protrusion, for example, in which the outer wall and/or the inner wall of the first shaft 350 is a flat or smooth wall.

The connection point of the first shaft 350 and the second shaft 355 is located proximal to the bearing mount 340. The bearing mounting portion 340 is sleeved outside the second shaft 355, and the proximal end bearing is sleeved outside the second shaft 355 to rotatably support the second shaft 355. A communication gap is formed between the bearing mounting portion 340 and the second shaft 355 to communicate the outer flow passage 600 with the first exhaust port 605.

The bearing mount 340 is located at the distal end of the catheter 300, incorporating proximal bearings 331, 332 (in other embodiments it is not excluded that the proximal bearings are 1 or more). The proximal bearings 331, 332 are sleeved outside the drive shaft (second shaft 355), and the first exhaust port 605 is located distally of the proximal bearing 332.

As shown in fig. 16 and 19, the proximal bearings include first and second spaced apart proximal bearings 331 and 332. The outer wall of the drive shaft is provided with a stop 356, the stop 356 being axially movable between the first proximal bearing 331 and the second proximal bearing 332.

The stopper 356 is a stopper ring provided on the outer wall of the drive shaft, or a stopper protrusion such as a bump provided on the outer wall of the drive shaft. A stopper flow gap is formed between the outer wall of the stopper 356 and the inner wall of the bearing mount 340.

The communication gap includes an internal flow gap of the first proximal bearing 331, a stop flow gap, and an internal flow gap of the second proximal bearing 332. Wherein the first and second proximal bearings 331, 332 themselves have flow gaps that are permeable to fluid and do not seal against fluid passage.

Of course, a first flow gap may also be formed between the first proximal bearing 331 and the outer wall of the second shaft 355, and a second flow gap may be formed between the second proximal bearing 332 and the outer wall of the second shaft 355, further facilitating fluid flow.

The stopper 356 and the first proximal bearing 331 have a first spacing therebetween, which communicates the stopper flow gap with the first proximal bearing 331. The stopper 356 and the second proximal bearing 332 have a second spacing therebetween that communicates the stopper flow gap with the second proximal bearing 332.

A tortuous perfusate output path is constructed by the first proximal bearing 331, stop flow gap, and second proximal bearing 332, slowing perfusate flow rate and impact pressure, avoiding damage or other adverse effects from rapid entry into the human body.

A first exhaust port 605 is located distally of the proximal bearing and opens into the proximal end of the bracket 404. Thus, as the perfusate in the outer flow channel 600 flows forward, it passes through the proximal bearings 331, 332, forming lubrication to the proximal bearings 331, 332.

Meanwhile, when the perfusion fluid is discharged through the first discharge port 605, a high-pressure region is formed in a certain range at the distal end of the catheter 300, thereby preventing the hemostatic fluid from entering the catheter 300 and preventing thrombus formation.

In some embodiments, bearing mount 340 includes a proximal bearing chamber 330 connected to the distal end of catheter 300. In other embodiments, the bearing mount 340 may also be formed by the distal portion of the catheter 300 or the connecting hypotube 43 of the stent 404, and the present application is not limited solely by the additional independent placement of the proximal bearing chamber 330.

The distal end of the second shaft 355 is rotatably supported within the distal bearing housing 405, and the distal end of the bracket 404 is connected to the distal bearing housing 405. A second discharge port 810 is located in the distal bearing housing 405, between the proximal end of the distal bearing housing 405 and the drive shaft, forming a perfusate discharge port.

The noninvasive support 500 connected to the distal end of the distal bearing chamber 405 is a flexible tube structure, and is characterized in that the end is a flexible protrusion in a circular arc shape or a winding shape, so that the flexible support 500 is supported on the inner wall of the ventricle in a noninvasive or atraumatic manner, separates the blood inlet 403 of the pump assembly from the inner wall of the ventricle, and avoids the suction inlet of the pump assembly from being attached to the inner wall of the ventricle due to the reaction force of fluid (blood) in the working process of the pump assembly, thereby ensuring the effective pumping area.

The proximal end of the atraumatic support 500 is inserted into the distal bearing compartment 405 and the distal end of the second shaft 355 slidably extends into the distal bearing 4051. The proximal end face of the atraumatic support 500 is spaced from the distal end face of the second shaft 355 and is adapted to provide a margin of movement of the second shaft 355 relative to the axial movement of an external sheathing member, such as the stent 404, during the pump assembly intervention.

As shown in fig. 17, a seal 550 is disposed within the distal bearing housing 405 between the distal end of the second shaft 355 and the proximal end of the atraumatic support 500. A step 551 is provided in the distal bearing chamber 405, and the occluding component 550 is clamped between the step 551 and the proximal end of the atraumatic support 500.

Thus, the perfusate in the inner flow channel 800 is discharged from the second discharge port 810 into the distal bearing chamber 405, flows only in reverse due to the presence of the blocking member 550, and further lubricates it by flowing through the distal bearing 4501, and then is discharged from the perfusate discharge port out of the distal bearing chamber 405 into the support 404 and finally into the human body. Thus, the perfusate discharged from the perfusate discharge port may form a high pressure zone within a range at the proximal end of the distal bearing chamber 405, thereby preventing hemostatic liquid from entering the distal bearing chamber 405 and preventing thrombus formation.

The occluding member 550 is a flexible check valve, such as a check valve, provided with a resealable channel through which the guidewire may pass, the resealable channel being closed upon removal of the guidewire threading to maintain the occluded state of the site. The flexible hemostatic valve can be made of plugging rubber or silica gel, when the guide wire passes through the resealable channel, the flexible hemostatic valve is attached to the guide wire to maintain a plugging state, and after the guide wire is withdrawn, the flexible hemostatic valve resets to close the wire penetrating hole, and the plugging state of the position is still maintained.

The occluding component 550 occludes the proximal end of the non-invasive support 500, preventing blood from entering the non-invasive support 500 in the operational state of the pump assembly.

The atraumatic support 500 has a hollow lumen 555, the hollow lumen 555 and the hollow lumen of the drive shaft forming a guidewire traversing path having an inner diameter equal to or slightly larger than the outer diameter of the guidewire. For example, the inner diameter of hollow lumen 555 is 1-1.2 times the diameter of the guidewire.

As shown in fig. 17, the occluding component 550 is distal to the distal end of the second shaft 355. The flexible seal 550 is spaced from the distal end of the second shaft 355 to provide a margin of axial movement of the second shaft 355 for axial movement of the second shaft 355.

The blocking member 550 may constitute an axial stop for the second shaft 355, defining a far dead center position of the axial movement of the blocking member 550. Of course, in the presence of the stop 356 described above, the distal end of the second shaft 355 is not in contact with the closure member 550 when the stop 356 is in contact with the second proximal bearing 332, and is spaced apart to avoid damage to the closure member 550 by axial movement of the second shaft 355.

18-21, in some embodiments, no closure 500 may be provided between the second vent 810 and the atraumatic support 500, with the interior of the distal bearing chamber 405 communicating the second vent 810 with the hollow lumen 555. The distal port of the atraumatic support 500 constitutes a perfusate discharge outlet. At this time, since the perfusate pressure is high, the distal bearing 4051 may also form a perfusate discharge path, forming a perfusate discharge port on the proximal side of the distal bearing 4051, at which time perfusate may be discharged out of the distal port of the atraumatic support 500 and the proximal side of the distal bearing 4051 at the same time.

The perfusate exits through the second discharge port 810 and enters the non-invasive support 500 and exits proximally of the distal port of the non-invasive support 500 and distal bearing 4051, while blood is prevented from entering the non-invasive support 500 and distal bearing chamber 405 in the operating state of the pump assembly.

It is to be understood that the above description is intended to be illustrative, and not restrictive. Many embodiments and many applications other than the examples provided will be apparent to those of skill in the art upon reading the above description. The scope of the present teachings should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated herein by reference for the purpose of completeness. The omission of any aspect of the subject matter disclosed herein in the preceding claims is not intended to forego such subject matter, nor should the inventors regard such subject matter as not be considered to be part of the disclosed subject matter.

Claims (12)

1. A blood pump, comprising:

a conduit;

a drive shaft;

A pump assembly, comprising: a pump housing having an inlet end and an outlet end, an impeller received within the pump housing; the impeller is driven to rotate by the drive shaft to draw blood into the pump housing from the inlet end and to discharge blood from the outlet end;

the pump housing includes: a stent attached to the distal end of the catheter and a cover partially covering the stent; the distal end of the bracket is provided with a distal end bearing chamber, and a distal end bearing for supporting the rotation of the driving shaft is arranged in the distal end bearing chamber; a blocking piece is arranged in the distal bearing chamber and is positioned on the distal side of the distal end of the driving shaft; the closure member is provided with a resealable channel for passage of a guidewire therethrough, the resealable channel being closed upon removal of the guidewire;

an inner runner is formed in the driving shaft, a second exhaust port is arranged at the far end of the inner runner, and the second exhaust port is positioned in the far end bearing chamber and is positioned at the far side of the far end bearing; the perfusion liquid in the inner flow channel is discharged from the second discharge port and enters the far-end bearing chamber, and can only flow reversely due to the existence of the plugging piece, so that the perfusion liquid can be lubricated by flowing through the far-end bearing.

2. The blood pump of claim 1, wherein a distal end of the distal bearing chamber is provided with a non-invasive support, and the occlusion member is provided proximal to the non-invasive support.

3. The blood pump of claim 2, wherein the proximal end of the atraumatic support is positioned within a distal bearing chamber, the distal bearing chamber having a step therein, the occluding component being clamped between the step and the proximal end of the atraumatic support.

4. The blood pump of claim 1, wherein the distal end of the catheter is provided with a bearing mounting portion, a proximal bearing for supporting the rotation of the drive shaft is provided in the bearing mounting portion, and the proximal bearing comprises a first proximal bearing and a second proximal bearing which are arranged at intervals; the outer wall of the drive shaft is provided with a stop member located between the first proximal bearing and the second proximal bearing.

5. The blood pump of claim 1, wherein the distal end of the catheter is provided with a bearing mount having a second proximal bearing disposed therein for supporting rotation of the drive shaft, and wherein the outer wall of the drive shaft is provided with a stop member, and wherein the distal end of the second shaft is not in contact with the occluding member when the stop member is in contact with the second proximal bearing.

6. The blood pump of claim 4 or 5, wherein a stop flow gap is formed between an outer wall of the stop and an inner wall of the bearing mount; a first spacing space is arranged between the stop piece and the first proximal bearing, and the first spacing space communicates the stop flow gap with the first proximal bearing; a second spacing space is provided between the stop and the second proximal bearing, the second spacing space communicating the stop flow gap with the second proximal bearing.

7. The blood pump according to claim 4 or 5, wherein an outer flow channel is formed between the drive shaft and the catheter, and a communication part for communicating the inner flow channel with the outer flow channel is provided on a wall of the drive shaft, and the communication part communicates the inner flow channel with the outer flow channel by liquid permeation;

the proximal end of the catheter is communicated with the perfusate input part so as to communicate the proximal end of the outer flow channel with the perfusate input part;

the external flow channel is directly communicated with the perfusate input part, and the internal flow channel is indirectly communicated with the perfusate input part by means of the communication part;

the perfusate flows forward within the outer flow channel, and during flow, a portion of the perfusate seeps into the inner flow channel.

8. The blood pump of claim 7, wherein the inner and outer flow paths cooperate to distally deliver perfusate.

9. The blood pump of claim 7, wherein the distal end of the outer flow path is provided with a first discharge port at the proximal end of the stent, the first discharge port being distal to the proximal bearing; and when the perfusion liquid in the outer runner flows forwards, the perfusion liquid passes through the proximal bearing to lubricate the proximal bearing.

10. The blood pump of claim 9, wherein the perfusion pressure in the first outlet is greater than the blood pressure in the vicinity of the first outlet, and wherein the perfusion pressure in the second outlet is greater than the blood pressure in the vicinity of the second outlet.

11. The blood pump of claim 1, wherein a perfusate outlet is formed between the proximal inner wall of the distal bearing chamber and the distal outer wall of the drive shaft; the distal end of the inner runner is provided with a diffusion section, and the port of the diffusion section is a second discharge port.

12. A blood pump, comprising:

a conduit;

a drive shaft;

a pump assembly, comprising: a pump housing having an inlet end and an outlet end, an impeller received within the pump housing; the impeller is driven to rotate by the drive shaft to draw blood into the pump housing from the inlet end and to discharge blood from the outlet end;

the pump housing includes: a stent attached to the distal end of the catheter and a cover partially covering the stent;

an outer flow passage is formed between the driving shaft and the guide pipe, and an inner flow passage is formed in the driving shaft; the far end of the outer flow channel is provided with a first discharge outlet, and the far end of the inner flow channel is provided with a second discharge outlet;

the wall of the driving shaft is provided with a communication part for communicating the inner flow channel with the outer flow channel, and the communication part is communicated with the inner flow channel and the outer flow channel in a liquid permeation mode;

the proximal end of the catheter is communicated with the perfusate input part so as to communicate the proximal end of the outer flow channel with the perfusate input part;

the external flow channel is directly communicated with the perfusate input part, and the internal flow channel is indirectly communicated with the perfusate input part by means of the communication part;

The perfusate flows forward within the outer flow channel, and during flow, a portion of the perfusate seeps into the inner flow channel.

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