CN112791305A

CN112791305A - Blood pump and power transmission assembly thereof

Info

Publication number: CN112791305A
Application number: CN202110086567.5A
Authority: CN
Inventors: 张家良; 托马斯·乔治·罗根; 徐嘉颢; 徐博翎; 颜翊凡
Original assignee: Magassist Inc
Current assignee: Magassist Inc
Priority date: 2021-01-22
Filing date: 2021-01-22
Publication date: 2021-05-14
Also published as: CN113975624A; CN117839061A; CN113975624B; CN113856036B; CN116020050A; CN115999045B; CN114522338A; CN113856036A; CN117839062A; CN115999045A

Abstract

The invention discloses a blood pump and a power transmission assembly thereof, wherein the power transmission assembly of the blood pump comprises: the flexible shaft is used for driving an impeller of the blood pump to rotate; the flexible shaft is provided with a near end used for inputting power and a far end used for arranging the impeller; a first flow channel for flow of a perfusion fluid; the first flow channel has an output end adjacent the proximal end for outputting perfusion fluid, and an input end adjacent the distal end for inputting perfusion fluid. The blood pump and the power transmission assembly thereof can reduce the risk caused by the infusion liquid entering the body of a patient.

Description

Blood pump and power transmission assembly thereof

Technical Field

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

Background

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

The flexible shaft of the external motor type is arranged in the inner cavity of the catheter and is 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 heat generation caused by wear, a physiological fluid, such as a physiological saline or glucose solution, is often poured between the flexible shaft and the catheter.

Besides the above functions, the perfused liquid can also prevent the pump from driving blood to enter the bearing in the high-speed rotation process, thereby realizing the sealing function.

The prior art priming (purge) method is to provide a joint at the proximal end of the drive, connect the priming device, and allow the fluid to flow from the proximal end to the distal end, and finally enter the body, and further require a contact-type dynamic sealing device, such as a flood seal, at the proximal end of the joint.

A disadvantage of the prior art is that a large amount of perfusion liquid entering the patient may have a health-related adverse effect on the patient, since some abrasive particles may be entrained in the perfusion liquid; in addition, the contact dynamic seal fails due to long-term wear.

Disclosure of Invention

It is an object of the present invention to provide a blood pump and a power transmission assembly therefor that can reduce the risk of perfusion liquid entering the patient.

It is a further object of the present invention to provide a blood pump and power transfer assembly therefor to extend the useful life of the product.

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

a power transfer assembly for a blood pump comprising:

a shaft for rotating an impeller of the blood pump;

a first flow channel for flow of a perfusion fluid;

a coupling body provided with an axial passage communicating with the first flow passage; the shaft body penetrates through the axial channel to be connected with a driving assembly; the coupling body is also provided with an output interface which is communicated with the axial channel and is used for outputting the perfusion fluid in the first flow channel outwards;

wherein, a supporting body sleeved outside the shaft body is also fixedly arranged in the axial channel; the support body is located upstream of the output interface in a power transmission direction; a rotating gap is formed between the supporting body and the shaft body; the outer wall of the shaft body is also provided with a spiral structure; at least part of the spiral structure is sleeved in the support body.

In a preferred embodiment, the spiral structure has a direction opposite to a rotation direction of the shaft body.

In a preferred embodiment, the helical structure is left-handed when the rotation of the shaft body is clockwise or right-handed when the rotation of the shaft body is counterclockwise, as viewed from the proximal end to the distal end

As a preferred embodiment, the shaft body includes a connecting shaft located in the axial passage and a flexible shaft connected with the connecting shaft; the flexible shaft is provided with a near end connected with the connecting shaft and a far end used for arranging the impeller.

As a preferred embodiment, the helical structure is a helical groove or thread provided on the outer wall of the connecting shaft.

As a preferred embodiment, part of the helical structure is located within the support body and part of the helical structure is located outside the support body.

As a preferred embodiment, the spiral structure extends spirally downstream of the output interface in the power transmission direction.

As a preferred embodiment, a second flow channel for the flow of the perfusion fluid is also provided; the second flow channel having an input adjacent the proximal end for inputting perfusion fluid, and an output adjacent the distal end for outputting perfusion fluid; wherein the first flow channel has an output end in communication with the output interface and an input end adjacent the distal end for inputting 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 also provided with an input interface communicated with the input part of the second flow passage.

As a preferred embodiment, the flexible shaft is sleeved with a guide pipe; the first flow passage is positioned between the outer wall of the flexible shaft and the inner wall of the guide pipe; the second flow passage is positioned in the pipe wall of the guide pipe and penetrates through the pipe wall of the guide pipe along the axial direction.

As a preferred embodiment, an output gap communicated with the second flow passage is further provided; the output clearance ring is sleeved outside the flexible shaft; the 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 to the power transmission direction of the flexible shaft.

As a preferred embodiment, the catheter has a main tube body and a front protruding tube arranged at the front end of the main tube body; a front step is arranged between the main pipe body and the front convex pipe; the input part is an input port positioned on the front step;

the axial channel is provided with a first channel section which is extended into by the front protruding pipe and a second channel section which is extended into by the main pipe body; the outer wall of the front protruding pipe is connected with the inner wall of the first channel section in a sealing mode; the outer wall of the end part of the main pipe body is hermetically connected with the inner wall of the second channel section; the output interface is communicated with the first channel section; the input interface is communicated with the second channel section.

As a preferred embodiment, the supporting body comprises a first bearing fixedly sleeved outside the connecting shaft; the output interface is located on a downstream side of the first bearing in a power transmission direction.

As a preferred embodiment, a second bearing and a third bearing which are spaced are sleeved outside the flexible shaft; the third bearing is positioned at the downstream of the second bearing along the power transmission direction of the flexible shaft; a communicating spaced annulus communicating with the output of the second flow passage is formed between the second bearing and the third bearing;

wherein an output gap for communicating the communication interval annulus with the outside of the conduit is formed between the third bearing and the flexible shaft; and a communication gap for communicating the input end of the first flow passage with the communication interval annulus is formed between the second bearing and the flexible shaft.

As a preferred embodiment, the catheter has a rear projecting tube provided at the rear end of the main tube body; a bearing seat sleeve is fixedly sleeved on the rear convex pipe; a fixed sleeve is fixedly sleeved outside the bearing seat sleeve; the second bearing and the third bearing are fixed in the bearing sleeve at intervals.

A blood pump, comprising:

the power transmission assembly according to any one of the above embodiments;

the impeller can be driven to rotate by the power transmission assembly.

Has the advantages that:

according to the power transmission assembly in one embodiment of the invention, the spiral structure with the spiral extending direction opposite to the rotating direction of the shaft body is arranged, so that in the rotating process of the shaft body, the spiral structure can generate thrust along the power transmission direction on liquid in the rotating gap, backflow liquid is prevented from flowing to the power assembly through the rotating gap, the backflow liquid is effectively prevented from entering the power assembly, the structural reliability is improved, and the service life of a product is prolonged. Moreover, through setting up this helical structure, form non-contact between axis body and the coupling body and seal, the wearing and tearing influence that produces when can reducing rotatory promotes structural reliability, increase of service life.

Specific embodiments of the present invention are disclosed in detail with reference to the following description and drawings, indicating the manner in which the principles of the invention may be employed. It should be understood that the embodiments of the invention are not so limited in scope.

Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments, in combination with or instead of the features of the other embodiments.

It should be emphasized that the term "comprises/comprising" when used herein, is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps or components.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

FIG. 1 is a schematic illustration of a blood pump configuration in one embodiment of the present invention;

FIG. 2 is a schematic structural 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 structural 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 helix structure of FIG. 2;

FIG. 7 is a schematic view of the forward end perfusion fluid flow 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 a partially enlarged view of fig. 9.

Description of reference numerals: 100. a power assembly; 101. a motor; 102. a motor housing;

200. a coupling body; 201. an input interface; 202. an output interface; 210. an axial channel; 220. a connecting shaft; 230. a support body; 211. a first channel segment; 212. a second channel segment; 213. connecting the steps; 215. a shaft clearance; 221. a helical structure; 222. a helical groove; 231. a rotational clearance;

300. a conduit; 301. an outer wall; 302. an inner wall; 311. a primary tube; 312. a front protruding pipe; 313. a rear projection tube; 315. a front step; 316. a rear step; 330. a bearing housing; 331. a second bearing; 332. a third bearing; 333. communicating the spaced annuluses; 334. communicating the gaps; 335. an output gap; 340. fixing a sleeve; 341. a flow passage is communicated; 342. a communicating hole; 350. a flexible shaft;

400. a pump housing; 401. coating a film; 402. an outlet of the pump; 403. a pump inlet; 404. a support; 405. a rear bearing seat; 410. an impeller;

500. a protective head; 600. a second flow passage; 700. a first flow passage; F. the power transmission direction.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the drawings in the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present 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 be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

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. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 to 10, a blood pump is provided according to an embodiment of the present invention. The blood pump has a power transmission assembly for transmitting power to the impeller 410 to drive the impeller 410 to rotate in the pump cavity, so that blood can be pumped out as a heart assist device.

Wherein the power transmission assembly of the blood pump comprises a shaft body for driving the impeller 410 of the blood pump to rotate. More specifically, the shaft body includes a flexible shaft 350 for driving the impeller 410 of the blood pump to rotate. The flexible shaft 350 has a proximal end for inputting power and a distal end for positioning the impeller 410.

The flexible shaft 350 may also be referred to as a flexible shaft, one end (proximal end) of the flexible shaft 350 may be connected to the power assembly 100 for inputting power, and the other end (distal end) of the flexible shaft 350 may be connected to the impeller 410 to rotate the impeller 410. The flexible shaft 350 may be advanced into a body vessel along with the impeller 410, bending according to the vessel configuration until it reaches a desired location in the heart.

The blood pump is provided with an external power assembly 100, and the external power assembly 100 utilizes a flexible shaft 350 to transmit power to an impeller 410 for pumping blood. In order to prevent the rotating flexible shaft 350 from contacting with the blood vessel, a guide tube 300 is further sleeved outside the flexible shaft 350. The catheter 300 is a flexible catheter 300 which can be bent and deformed together with the flexible shaft 350 to adapt to the structure of the blood vessel of the human body. Wherein, the flexible shaft 350 respectively penetrates out of the two ends of the conduit 300 to connect the power assembly 100 and the impeller 410.

As shown in fig. 2, the power assembly 100 includes a motor 101, and the motor 101 is accommodated in a motor case 102. The output end of the motor 101 is connected with the proximal end of the flexible shaft 350 through the connecting shaft 220. Correspondingly, the shaft body further comprises a connecting shaft 220 for connecting the flexible shaft 350 with the output end of the motor 101. The connecting shaft 220 may be a hard shaft (e.g., a steel shaft or other metal shaft). The connecting shaft 220 transmits the power output by the motor 101 to the flexible shaft 350, and then transmits the power to the far end through the flexible shaft 350, so as to drive the impeller 410 to rotate.

It should be noted that, in the present embodiment, the "far-near" position may be defined by a position relationship relative to the power assembly 100, and the power transmission direction F along the power assembly 100 to the impeller 410 may also be regarded as being transmitted from the near side to the far side, and accordingly, the near end of the flexible shaft 350 is closer to the power assembly 100 than the far end thereof, and of course, the far end and the near end of other components are also defined by referring to this definition.

In the present embodiment, the power assembly 100 and the guide tube 300 are connected by a coupling body 200. The shaft body passes through the coupling body 200 to be connected with the power assembly 100 (e.g., the motor 101). The proximal end of the coupling body 200 is inserted into the connecting end of the motor housing 102, and the connecting end of the motor housing 102 and the proximal end of the coupling body 200 are locked by a locking sleeve and threads outside the connecting end, so that the coupling body 200 and the motor housing 102 are fixedly assembled.

As shown in fig. 4 and 5, the coupling body 200 is provided with an axial passage 210 therethrough. The shaft is connected to the motor 101 through the axial passage 210. The axial channel 210 is a linear channel. A coupling shaft 220 is received in the axial passage 210 to couple the output of the motor 101 to the proximal end of the flexible shaft 350. Wherein, the proximal end of the flexible shaft 350 extends into the axial passage 210 from the distal end (port) of the axial passage 210 to be connected with the distal end of the connecting shaft 220.

The connecting shaft 220 transmits the rotation to the flexible shaft 350, and drives the flexible shaft 350 to rotate. The proximal end of catheter 300 extends into axial passage 210 of coupling body 200 and is fixedly and sealingly attached to inner wall 302 of axial passage 210. Specifically, the outer wall 301 of the proximal end of the catheter 300 is hermetically bonded to the coupling body 200, so as to achieve a fixed connection therebetween.

As shown in fig. 5 to 10, the power transmission assembly also has a first flow passage 700 for the flow of priming fluid. Wherein, the perfusion fluid can be used for cooling the shaft body and avoiding the overheating of rotation. The priming fluid may also lubricate the rotation of the shaft. The first flow channel 700 has an output end adjacent the proximal end of the flexible shaft 350 for outputting perfusion fluid, and an input end adjacent the distal end of the flexible shaft 350 for inputting perfusion fluid. In the first flow channel 700, the perfusion fluid (e.g., perfusion fluid) flows from the distal end to the proximal end, and is discharged through the output end adjacent to the proximal end of the flexible shaft 350, thereby preventing the perfusion fluid from entering the inside of the human body.

The power transmission assembly of the present embodiment has the first flow channel 700, and the output end of the first flow channel 700 for outputting the perfusion fluid outwards is adjacent to the proximal end of the flexible shaft 350, rather than being arranged at the distal end leading into the body, so that the perfusion fluid can be reduced or even prevented from being input into the human body, and the risk of the abrasion particles entering the body can be reduced.

As shown in fig. 5 and 7, the extending direction of the first flow channel 700 is parallel to the extending direction of the flexible shaft 350. The length direction of the first runner 700 is parallel to the flexible shaft 350. The first fluid channel 700 extends along with the flexible shaft 350, and the flow directions of the fluids inside the two fluid channels are opposite. The first runner 700 is sleeved outside the flexible shaft 350, and the outer wall 301 of the flexible shaft 350 can form a runner wall of the first runner 700. Specifically, the first flow channel 700 is located between the catheter 300 and the flexible shaft 350. The inner wall 302 of the guide tube 300 and the outer wall 301 of the flexible shaft 350 form a flow passage wall of the first flow passage 700, and the cross section of the first flow passage 700 is annular.

The power transmission flow passage is also provided with a second flow passage 600 for the flow of the priming fluid. The second flow channel 600 may also cool the flexible shaft 350. The second flow channel 600 is used to convey perfusion fluid (e.g., cooling fluid, etc.). Further, the second flow channel 600 is used for conveying the perfusion fluid from the proximal end to the distal end. The second flow channel 600 has an input for inputting perfusion fluid adjacent the proximal end and an output for outputting perfusion fluid adjacent the distal end. Wherein, the output part of the second flow channel 600 is communicated with the input end of the first flow channel 700.

The first flow channel 700 and the second flow channel 600 may extend in parallel. Specifically, the first flow channel 700 and the second flow channel 600 are disposed in parallel on the outer side of the flexible shaft 350. The outer wall 301 of the flexible shaft 350 forms a runner wall of the first runner 700 or a runner wall of the second runner 600. The extending direction of the first flow channel 700 and/or the second flow channel 600 is parallel to the axial direction of the flexible 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 conduit 300. The first flow channel 700 is located between the outer wall 301 of the flexible shaft 350 and the inner wall 302 of the catheter 300. The second flow channel 600 is located inside the wall of the conduit 300 and axially penetrates the wall of the conduit 300.

The first flow channel 700 as a fluid backflow channel can convey wear generated in the power transmission process 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 catheter 300 has a main lumen in the center that houses a flexible shaft 350. A cavity forming the second flow channel 600 is formed in the wall of the catheter 300. The pipe wall can be provided with a plurality of

cavities

601 and 602 along the circumferential direction, so that the flow capacity of the second flow channel 600 is improved, and the cooling capacity is further improved.

To avoid blood backflow with the perfusion fluid, the power transmission assembly of the blood pump is also provided with an output gap 335, as shown in fig. 9, 10. Wherein the output gap 335 communicates with the second flow channel 600. The output gap 335 is sleeved outside the flexible shaft 350. Wherein the output gap 335 is located downstream of the first flow passage 700 in the power transmitting direction F. The output gap 335 may be located between the guide tube 300 and the flexible shaft 350. The outlet of the outlet gap 335 opens into the pump chamber of the blood pump housing impeller 410, thereby preventing blood flowing into the pump chamber from entering the conduit 300.

The outlet of the output gap 335 faces the power transmission direction F of the flexible shaft 350 (i.e., faces parallel to the power transmission direction F). Through setting up intercommunication clearance 334, can avoid body fluids such as blood to enter into first flow channel 700 along with the backward flow of perfusion fluid to, the perfusion fluid flows into between bearing and the flexible axle 350 through intercommunication clearance 334, reduces the wearing and tearing between flexible axle 350 and the bearing, promotes life.

The power transmission assembly has one end (proximal end) of the catheter 300 extending into the axial passage 210 and fixedly connected with the coupling body 200. The coupling body 200 is provided with an output port 202 communicating with an output end of the first flow channel 700 and an input port 201 communicating with an input end of the second flow channel 600. Wherein the input port 201 and the output port 202 are axially spaced apart. The output interface 202 is closer to the power assembly than the input interface 201. A shaft gap 215 is formed between the connecting shaft 220 and an inner wall 302 of the coupling body 200. The output interface 202 opens into the shaft gap 215. The shaft gap 215 communicates with the output end (port) of the first flow passage 700.

To facilitate connection with coupling body 200 and to avoid fluid leakage, the proximal end of catheter 300 is stepped. Specifically, the catheter 300 includes a main tube 311 and a front protruding tube 312 disposed at the front end of the main tube 311. A front step 315 is provided between the main pipe 311 and the front protruding pipe 312. The input portion is an input port (input port) located on the front step 315.

In the present embodiment, the axial channel 210 has a first channel section 211 extended by the front protruding tube 312, and a second channel section 212 extended by the main tube 311. The first channel section 211 is located on the front side of the second channel section 212, closer to the connecting shaft 220 or power assembly. Wherein the outer wall of the front protruding tube 312 and the inner wall of the first channel section 211 are sealingly connected. The outer wall 301 of the end of main tube 311 is sealingly connected to the inner wall of second channel section 212. The output interface 202 opens into the first channel section 211. The input interface 201 opens into the second channel section 212.

Specifically, the axial passage 210 is a stepped bore, and a shaft passage section is further provided at the front side of the first passage section 211. The inner diameter of the shaft passage section is smaller than that of the first passage section 211, and 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 to form corresponding steps. The shaft channel section, the first channel section 211, and the second channel section 212 are all cylindrical channels. The step between the shaft channel section and the first channel section 211 is a limiting step, the front protruding pipe 312 extends into the axial channel 210, and the end face of the front protruding pipe 312 contacts with the limiting step to be axially limited. The outer tube wall of the front protruding tube 312 is sealingly bonded to the channel inner wall 302 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. The front step 315 between the main tube 311 and the front protruding tube 312 is spaced apart from the communication step 213 to form a spaced-apart communication annulus. The spaced apart communication annulus communicates the input port 201 on the coupling body 200 with the first flow passage 700 located on the forward step 315. An outer wall 301 surface of the front end of the main pipe body 311 is sealingly bonded to a passage inner wall 302 of the second passage section 212 (a portion located downstream of the input port 201 in the power transmission direction F).

As shown in fig. 4 to 6, a supporting body 230 is fixedly disposed in the axial channel 210 and sleeved outside the shaft body. Wherein the support body 230 is located upstream of the output interface 202 in the power transmission direction F. The support body 230 and the shaft body have a rotation gap 231 therebetween. The outer wall 301 of the shaft body is also provided with a spiral structure 221. The spiral structure 221 rotates in the opposite direction to the shaft. At least a portion of the helical structure 221 is disposed within the support body 230. Wherein an annular shaft gap 215 is provided between the shaft channel section and the connecting shaft 220. The radial gap width of the rotation gap 231 is smaller than the radial gap width of the shaft gap 215.

Through the opposite helical structure 221 of the rotation direction who sets up spiral extending direction and axis body, and then at the rotatory in-process of axis body, this helical structure 221 can produce the thrust along power transmission direction F to the liquid in running clearance 231, borrow this and prevent the liquid of backward flow to power component 100 through running clearance 231, inside effectively having guaranteed that the liquid of backflow can not enter into power component 100, has promoted structural reliability, has prolonged the life of product. Moreover, through the arrangement of the spiral structure 221, non-contact sealing is formed between the shaft body and the coupling body 200, so that the abrasion influence generated in rotation can be reduced, the structural reliability is improved, and the service life is prolonged.

Further, the supporting body 230 may be a first bearing fixed in the coupling body 200 and sleeved outside the connecting shaft 220. A rotational gap 231 is located between the first bearing and the connecting shaft 220. The helical structure 221 is provided on the outer wall 301 of the connection shaft 220. When the shaft body (the connecting shaft 220) rotates clockwise as viewed from the drive end (the drive unit) in the power transmission direction F, the helical structure 221 is a left-handed thread; alternatively, when the shaft body rotates counterclockwise, the helical structure 221 is a right-handed thread.

In the present embodiment, the helical structure 221 may be a helical groove 222 or a thread provided on the outer wall 301 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. The support body 230 is located upstream of the output interface 202 in the power transmission direction F. Specifically, the helical structure 221 may have a start end located within the support body 230 and a stop end located downstream of the start end in the power transmission direction F.

The end stop may be located outside the first bearing or inside the bearing, that is, the whole spiral structure 221 is located inside the first bearing or a part of the spiral structure 221 is located inside the first bearing, and a part of the spiral structure 221 is located outside the first bearing. The helical structure 221 extends from within said first bearing to outside the first bearing. In order to improve the sealing effect and prevent the liquid return leakage, the spiral structure 221 may extend on the outer wall 301 of the shaft body (the connecting shaft 220) to the downstream of the output interface 202 along the power transmission direction F.

Specifically, the length of the spiral structure 221 in the axial direction (power transmission direction F) outside the first bearing is 1mm or more. Preferably, the axial length of the spiral structure 221 outside the first bearing is within 5mm, or extends to the connection position of the connection shaft 220 and the flexible shaft 350. The axial length of the first bearing ranges from 3 mm to 5 mm. The depth of the spiral groove 222 ranges from 0.05 to 0.2 mm.

As shown in fig. 9 and 10, the distal end of the flexible shaft 350 penetrates out of the catheter 300 and is fixedly sleeved by the impeller 410, so that the impeller 410 can rotate together with the flexible shaft 350. The impeller 410 is located in the pump chamber. A pump housing 400 is provided at the distal end of the catheter 300 and the flexible shaft 350. One end (front end) of the pump casing 400 is sleeved on the outer wall 301 of the guide pipe 300 and is provided with a pump outlet 402. The pump casing 400 may be formed by a film 401. Also within pump housing 400 is a collapsible bracket 404. The rear end of the pump casing 400 is fitted over the foldable support 404, and the foldable support 404 not covered by the pump casing 400 is expanded to form the pump inlet 403. The pump inlet 403 is located on the rear side of the impeller 410 and the pump outlet 402 is located on the front side of the impeller 410. The collapsible bracket 404 may support the pump housing 400 to form a pump chamber. The front end of the foldable bracket 404 is fixed to the rear end of the catheter 300, and the rear end of the foldable bracket 404 is fixed to a rear bearing block 405 sleeved at the rear end (end) of the shaft. A guard head 500 is also attached to the rear end of the rear bearing block 405.

Further, a second bearing 331 and a third bearing 332 which are spaced apart from each other are sleeved outside the flexible shaft 350. The third bearing 332 is located downstream of the second bearing 331 in the power transmission direction F of the flexible shaft 350. A communication space annulus 333 communicating with an output portion of the second flow passage 600 is formed between the second bearing 331 and the third bearing 332.

Wherein, an output gap 335 for communicating the communication spacing annulus 333 with the outside of the guide tube 300 is formed between the third bearing 332 and the flexible shaft 350. A communication gap 334 for communicating the input end of the first flow passage 700 with the communication spacing annulus 333 is formed between the second bearing 331 and the flexible shaft 350. The flow direction of the communication gap 334 and the output gap 335 are reversed.

Like the forward end of the catheter 300, the distal end of the catheter 300 is a stepped configuration. The catheter 300 has a rear projecting tube 313 provided at the rear end of the main tube 311. Main tube 311 and rear projecting tube 313 have a rear step 316 therebetween. The rear step 316, like the front step 315, may be an annular step. The fixed sleeve 340 on the rear projecting pipe 313 is provided with a bearing sleeve 330. The bearing sleeve 330 is also provided with a fixed sleeve 340 outside the fixed sleeve 340. The rear step 316 provides a location for the bearing sleeve 330 and the retaining sleeve 340 to fit over the rear male tube 313. The first bearing and the second bearing 331 are fixed at intervals in the bearing sleeve 330. The flexible shaft 350 is also fixedly sleeved with a limiting sleeve 340 in the bearing sleeve 330. The stopper sleeve is positioned upstream of the second bearing 331 in the power transmission direction F, and positions the second bearing 331.

The outer wall 301 of the bearing sleeve 330 may have a plurality (e.g., two) of circumferentially spaced fluid slots formed therein corresponding to the cavities forming the second flow passage 600. The fixing sleeve 340 is sleeved on the outer wall 301 of the bearing seat sleeve 330 to cover the liquid tank to form a communicating flow passage 341. A communication hole 342 (one for each of the two liquid tanks) is provided at the rear end of the communication flow path 341 (the rear end bottom wall of the liquid tank) and opens into the inside. The communication hole 342 is axially located between the first bearing and the second bearing 331, and opens into the communication space annulus 333.

As shown by the liquid flow arrows in fig. 10, liquid (priming fluid) enters the communication space annulus 333, a part of the liquid enters the communication gap 334 in the opposite direction of the power transmission direction F until the first flow passage 700 forms a backflow, and another part of the liquid directly enters the output gap 335 in the power transmission direction F, is output outwards, enters the pump cavity, and is discharged into the body by the pump outlet 402.

Any numerical value recited herein includes all values from the lower value to the upper value, in increments of one unit, provided that there is a separation of at least two units between any lower value and any higher value. For example, if it is stated that the number of a component or a value of a process variable (e.g., temperature, pressure, time, etc.) is from 1 to 90, preferably from 20 to 80, and more preferably from 30 to 70, it is intended that equivalents such as 15 to 85, 22 to 68, 43 to 51, 30 to 32 are also expressly enumerated in this specification. For values less than 1, one unit is suitably considered to be 0.0001, 0.001, 0.01, 0.1. These are only examples of what is intended to be explicitly recited, and all possible combinations of numerical values between the lowest value and the highest value that are explicitly recited in the specification in a similar manner are to be considered.

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

All articles and references disclosed, including patent applications and publications, are hereby incorporated by reference for all purposes. The term "consisting essentially of …" describing a combination shall include the identified element, ingredient, component or step as well as other elements, ingredients, components or steps that do not materially affect the basic novel characteristics of the combination. The use of the terms "comprising" or "including" to describe combinations of elements, components, or steps herein also contemplates embodiments that consist essentially of such elements, components, or steps. By using the term "may" herein, it is intended to indicate that any of the described attributes that "may" include are optional.

A plurality of elements, components, parts or steps can be provided by a single integrated element, component, part or step. Alternatively, a single integrated element, component, part or step may be divided into separate plural elements, components, parts or steps. The disclosure of "a" or "an" to describe an element, ingredient, component or step is not intended to foreclose other elements, ingredients, components or steps.

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 should instead 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 hereby incorporated by reference for all purposes. The omission in the foregoing claims of any aspect of subject matter that is disclosed herein is not intended to forego such subject matter, nor should the inventors be construed as having contemplated such subject matter as being part of the disclosed subject matter.

Claims

1. A power transfer assembly for a blood pump, comprising:

a shaft for rotating an impeller of the blood pump;

a first flow channel for flow of a perfusion fluid;

2. The power transfer assembly of claim 1, wherein the helical structure is rotated in a direction opposite to the rotation direction of the shaft body; alternatively, the first and second electrodes may be,

viewed from the near end to the far end, the spiral structure is left-handed when the rotation of the shaft body is clockwise rotation or right-handed when the rotation of the shaft body is counterclockwise rotation.

3. The power transfer assembly of claim 1 or 2, wherein the shaft body includes a connecting shaft located in the axial passage and a flexible shaft connected to the connecting shaft; the flexible shaft is provided with a near end connected with the connecting shaft and a far end used for arranging the impeller.

4. A power transmission assembly as defined in claim 1 or 2, wherein the helical formation is a helical groove or thread provided on an outer wall of the connecting shaft.

5. A power transfer assembly as defined in claim 1 or 2, being characterized in that part of the helical structure is located inside the support body and part of the helical structure is located outside the support body.

6. The power transfer assembly of claim 1 or 2, wherein the helical structure extends helically in the power transfer direction downstream of the output interface.

7. The power transfer assembly of claim 3, further comprising a second flow passage for flow of priming fluid; the second flow channel having an input adjacent the proximal end for inputting perfusion fluid, and an output adjacent the distal end for outputting perfusion fluid; wherein the first flow channel has an output end in communication with the output interface and an input end adjacent the distal end for inputting 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 also provided with an input interface communicated with the input part of the second flow passage.

8. The power transfer assembly of claim 7, wherein the flexible shaft is sleeved with a guide tube; the first flow passage is positioned between the outer wall of the flexible shaft and the inner wall of the guide pipe; the second flow passage is positioned in the pipe wall of the guide pipe and penetrates through the pipe wall of the guide pipe along the axial direction.

9. The power transfer assembly of claim 8, further providing an output gap in communication with the second flow passage; the output clearance ring is sleeved outside the flexible shaft; the 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 to the power transmission direction of the flexible shaft.

10. The power transfer assembly of claim 8, wherein the conduit has a main tubular body, and a forward protruding tube disposed at a forward end of the main tubular body; a front step is arranged between the main pipe body and the front convex pipe; the input part is an input port positioned on the front step;

11. The power transfer assembly of claim 3, wherein the support body includes a first bearing fixedly sleeved outside the connecting shaft; the output interface is located on a downstream side of the first bearing in a power transmission direction.

12. The power transfer assembly of claim 10, wherein the flexible shaft is further sleeved with a second bearing and a third bearing that are spaced apart; the third bearing is positioned at the downstream of the second bearing along the power transmission direction of the flexible shaft; a communicating spaced annulus communicating with the output of the second flow passage is formed between the second bearing and the third bearing;

13. The power transfer assembly of claim 12, wherein the conduit has a rear projecting tube disposed at a rear end of the primary tube; a bearing seat sleeve is fixedly sleeved on the rear convex pipe; a fixed sleeve is fixedly sleeved outside the bearing seat sleeve; the second bearing and the third bearing are fixed in the bearing sleeve at intervals.

14. A blood pump, comprising:

the power transfer assembly of any one of claims 1 to 13;

the impeller can be driven to rotate by the power transmission assembly.