blood pump

Abstract

The blood pump (10) comprises a cannula assembly (100) having a fluid supply cavity (130), an impeller (200) rotatably disposed within the fluid supply cavity (130) and having a storage cavity (234) and a communication hole (232) that connects the fluid supply cavity (130) to the storage cavity (234), and a protrusion (320) fixedly connected to the impeller (200) and located at one end within the storage cavity (234). ), and a base (400) connected to the cannula assembly (100) and including a support shaft (420), wherein an end face (421) of the support shaft (420) surrounds a recess (421a) that engages with the protrusion (320), and a flow gap (240) is formed between the impeller (200) and the base (400), and the flow gap (240) communicates with the accommodating cavity (234).

Description

[Technical Field]

[0001] This application relates to the field of medical devices, and more particularly to blood pumps. [Background technology]

[0002] An intravascular blood pump is a blood pumping device that is inserted into a patient's heart through the patient's blood vessels, and is positioned within the opening of a heart valve so that blood can flow through the blood pump and into the arterial vessels. However, conventional intravascular blood pumps are prone to blood clot formation within the blood pump.

[0003] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to a Chinese patent application with application number 202210275303.9, filed with the State Intellectual Property Office of the People's Republic of China on March 21, 2022, the entire contents of which are incorporated herein by reference. Summary of the Invention [Problem to be solved by the invention]

[0004] Based on this, the present application provides a blood pump that can reduce the probability of thrombus formation. [Means for solving the problem]

[0005] An embodiment of the first aspect of the present application is a cannula assembly having a fluid delivery cavity; an impeller rotatably provided in the liquid feed cavity, the impeller having a receiving cavity and a communication hole communicating between the liquid feed cavity and the receiving cavity; a rotating shaft fixedly connected to the impeller and having a protrusion at one end positioned within the receiving cavity; The blood pump includes a base connected to the cannula assembly and including a support shaft, wherein an end surface of the support shaft surrounds a recess that engages with the protrusion, forming a flow gap between the impeller and the base, and the flow gap communicating with the accommodating cavity.

[0006] The details of one or more embodiments of the invention are set forth in the drawings and description which follow. Other features, objects, and advantages of the invention will become apparent from the description, drawings, and claims.

[0007] In order to more clearly explain the technical solutions in the embodiments of the present application, the drawings necessary for describing the embodiments or prior art will be briefly introduced below. It is obvious that the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without any creative efforts. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic perspective view of a blood pump according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the entire blood pump shown in FIG. [Figure 3] FIG. 2 is an exploded perspective view of a portion of the blood pump shown in FIG. 1. [Figure 4] FIG. 2 is a schematic perspective view of a first cannula in the blood pump shown in FIG. 1. [Figure 5] FIG. 2 is a schematic perspective view of an impeller in the blood pump shown in FIG. 1. [Figure 6] FIG. 2 is a plan cross-sectional view of the blood pump shown in FIG. [Figure 7] 2 is a top cross-sectional view of the blood pump shown in FIG. 1 after the cannula assembly has been removed. [Figure 8] FIG. 2 is a schematic perspective view of a support shaft in the blood pump shown in FIG. [Figure 9] FIG. 9 is a schematic perspective view of the support shaft shown in FIG. 8 at a different viewing angle. [Figure 10] FIG. 9 is a schematic cross-sectional view of the support shaft shown in FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0009] In order to more clearly understand the objectives, technical solutions and advantages of the present application, the present application will be described in more detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are only for the purpose of interpreting the present application, and do not limit the present application.

[0010] It should be noted that when an element is referred to as being "fixed" or "mounted" on another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being "connected" to another element, it may be directly connected to the other element or indirectly connected to the other element.

[0011] Furthermore, the terms "first" and "second" are for descriptive purposes only and should not be understood to denote or imply relative importance or the number of technical features shown. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "plurality" means two or more unless otherwise specified.

[0012] Hereinafter, the technical solution of the present application will be described with reference to specific drawings and examples.

[0013] 1, 2, and 3, a blood pump 10 according to one embodiment of the present invention is particularly directed to an intravascular blood pump, which may be placed in a human heart valve, such as the aortic valve, and suction of the blood pump 10 allows blood to flow through the blood pump 10 into an arterial blood vessel. The blood pump 10 includes a cannula assembly 100, an impeller 200, a rotating shaft 300, and a base 400.

[0014] 3, 4, and 6, in some embodiments, the cannula assembly 100 includes a first cannula 110 and a second cannula 120, both of which are coaxially arranged and detachably connected, and the second cannula 120 is arranged on the base 400, so that the first cannula 110 is farther from the base 400 than the second cannula 120. The first cannula 110 and the second cannula 120 may both be cylindrical, and the cavities of both cannulas may together form a fluid feed cavity 130. An inlet 131 is formed at the end of the fluid feed cavity 130 farther from the base 400, and the inlet 131 is located in the first cannula 110, and external blood flows into the fluid feed cavity 130 through the inlet 131. An outlet 121 is formed in the tube wall of the second cannula 120, and the outlet 121 is located close to the base 400 and communicates with the fluid supply cavity 130, so that blood in the fluid supply cavity 130 flows out of the entire blood pump 10 through the outlet 121.

[0015] First cannula 110 includes cannula body 111 and inner fins 112. Cannula body 111 is connected to second cannula 120, and the cavities of cannula body 111 and second cannula 120 together form liquid feed cavity 130. The number of inner fins 112 is plural, and for example, there may be three, four, or the like inner fins 112. Inner fins 112 are provided on the inner wall surface of cannula body 111 (i.e., the cavity wall of liquid feed cavity 130) at a position of cannula body 111 close to second cannula 120. Each inner fin 112 has a free end and a fixed end, and is fixed to the inner wall surface of cannula body 111 so that the inner fin 112 protrudes a certain distance radially from the inner wall surface of cannula body 111. The fixed end is fixed to the inner wall surface of cannula body 111, and a gap is maintained between the free end and the inner wall surface in the radial direction of cannula body 111. Since the free ends of each inner fin 112 do not contact each other, the free ends of all inner fins 112 surround mounting cavity 113, and the central axis of mounting cavity 113 overlaps the central axis of cannula body 111. The diameter of mounting cavity 113 gradually decreases in the direction from second cannula 120 to first cannula 110.

[0016] The cannula assembly 100 is configured in a segmented manner, including a first cannula 110 and a second cannula 120 that are removably connected, thereby facilitating attachment of the impeller 200. The cannula assembly 100 includes, but is not limited to, a first cannula 110 and a second cannula 120 that are removably connected. In some embodiments, the first cannula 110 and the second cannula 120 are a non-removable, one-piece structure, i.e., the first cannula 110 and the second cannula 120 are configured as a single unit, i.e., the first cannula 110 and the second cannula 120 are replaced by a single cannula, and the fluid delivery cavity 130 is the cavity of that cannula.

[0017] 3, 5, and 7, in some embodiments, the impeller 200 is rotatably mounted within the liquid feed cavity 130. The rotation axis of the impeller 200 overlaps with the central axis of the liquid feed cavity 130, and the rotation axis of the impeller 200 overlaps with the central axis of the impeller 200.

[0018] The impeller 200 includes a first blade 210, a second blade 220, and a rotor 230, and both the first blade 210 and the second blade 220 are fixed to the rotor 230. The rotor 230 includes a rotor 233, which is a permanent magnet. Specifically, the rotor 233 is housed inside the rotor 230, and the rotor 233 may be a Halbach array magnet. The rotor 233 rotates due to a rotating magnetic field generated by the base 400, causing the rotor 230 to rotate, and both the first blade 210 and the second blade 220 rotate following the rotor 230. The rotor 230 is formed with a communication hole 232 and a storage cavity 234. The communication hole 232 communicates the storage cavity 234 with the liquid feed cavity 130, and blood in the liquid feed cavity 130 can flow into the storage cavity 234 through the communication hole 232. Specifically, the storage cavity 234 extends along the central axis of the impeller 200, and the communication hole 232 extends in a direction inclined relative to the central axis of the impeller 200.

[0019] 6 and 7, for convenience of explanation, the central axis of the communicating hole 232 is referred to as a first central axis, and the central axis of the impeller 200 is referred to as a second central axis. The first central axis forms an acute angle with the second central axis. If the direction of blood flow in the communicating hole 232 is referred to as a reference direction, the diameter of the communicating hole 232 gradually decreases along the direction of blood flow in the communicating hole 232, and the distance from the first central axis to the second central axis gradually decreases. Generally speaking, since the communicating hole 232 is substantially conical, the communicating hole 232 has a small-diameter opening and a large-diameter opening, and the small-diameter opening communicates with the storage cavity 234 and the large-diameter opening communicates with the fluid feed cavity 130. In this way, the communication hole 232 has an excellent flow-guiding effect on the blood, and the blood in the fluid-feeding cavity 130 flows into the storage cavity 234 at a reasonable flow rate.

[0020] Referring to Figures 5, 6 and 7, the first blade 210 may be spiral-shaped and extend generally along the axial direction of the rotating body 230. The first blade 210 is positioned within the fluid supply cavity 130, and when the first blade 210 rotates following the rotating body 230, the first blade 210 generates a suction force, introducing external blood into the fluid supply cavity 130 through the inlet 131 and discharging it through the outlet 121.

[0021] The rotor 230 further has a mounting surface 231, which faces the base 400. The mounting surface 231 and the base 400 are spaced apart along the axial direction of the rotor 230. A gap is formed between the mounting surface 231 and the base 400. If the gap is defined as a flow gap 240, the flow gap 240 communicates with the accommodating cavity 234. Specifically, the position of the flow gap 240 corresponds to the position of the outlet 121. The second blade 220 is provided on the mounting surface 231 and extends along the radial direction of the rotor 230. At least a portion of the second blade 220 is accommodated in the flow gap 240. In the illustrated embodiment, the entire second blade 220 is located in the flow gap 240. There may be a plurality of second blades 220, and the second blades 220 may be arranged at intervals in the circumferential direction of the rotor 230. Mounting surface 231 is perpendicular to the central axis of impeller 200. When second blade 220 rotates following rotor 230, second blade 220 also generates a suction force, and the blood in accommodating cavity 234 is quickly discharged from outlet 121 through flow gap 240 by the suction force.

[0022] 6 and 7, when the entire impeller 200 rotates, external blood flows into the liquid feed cavity 130 through the inlet 131. The blood in the liquid feed cavity 130 is divided into two parts. The first part of the blood is discharged directly from the outlet 121. The flow trajectory of the first part of the blood may be represented as liquid feed cavity 130-outlet 121. The second part of the blood flows into the storage cavity 234 through the communication hole 232, passes through the flow gap 240, and is discharged from the outlet 121. The flow trajectory of the second part of the blood may be represented as liquid feed cavity 130-communication hole 232-storage cavity 234-flow gap 240-outlet 121. The dashed arrows in FIGS. 6 and 7 indicate the flow trajectories of the blood. Because the impeller 200 includes the second blades 220 , the suction force generated by the second blades 220 can increase the velocity and flow rate of blood flowing through the receiving cavity 234 .

[0023] 3, 6, and 7, in some embodiments, the rotating shaft 300 is fixedly connected to the impeller 200. The rotating shaft 300 is drilled into the rotating body 230, and the central axis of the rotating shaft 300 overlaps the central axis of the impeller 200. The rotating shaft 300 may be fixed to the rotating body 230 by adhesive. The end of the rotating shaft 300 remote from the base 400 is a cone-shaped body 310, which extends into the first cannula 110 and is engaged with the mounting cavity 113 within the first cannula 110. When the rotating shaft 300 rotates following the rotation of the impeller 200, the cone-shaped body 310 rotates within the mounting cavity 113.

[0024] The mounting cavity 113 is adapted to the shape and size of the cone-shaped body 310, and on the one hand, when the rotating shaft 300 is engaged with the mounting cavity 113, it can act as an axial position limiter for the rotating shaft 300, and on the other hand, it provides a fulcrum for the end of the rotating shaft 300, improving the stability during the rotation of the rotating shaft 300 and the impeller 200. A diamond coating may be applied to the free end of the inner fin 112, and the rotating shaft 300 may be made of a ceramic material, and when the rotating shaft 300 comes into contact with the diamond coating, it can reduce frictional resistance during the rotation of the rotating shaft 300 and improve the smoothness during the rotation of the rotating shaft 300 and the impeller 200.

[0025] The rotating shaft 300 further includes a protrusion 320, which is located at an end of the rotating shaft 300 closer to the base 400. The protrusion 320 may be spherical or semi-spherical, or may be cylindrical, for example. The protrusion 320 is accommodated in the accommodation cavity 234. The protrusion 320 has a convex surface 321, which protrudes along the axial direction of the rotating shaft 300 and abuts against the base 400.

[0026] 3, 6, and 7, in some embodiments, the base 400 includes a carrier 410, a support shaft 420, and a stator 430. The stator 430 is disposed within the carrier 410. When power is supplied to the stator 430, the stator 430 generates a rotating magnetic field to rotate the rotor 233, thereby rotating the entire impeller 200. The second cannula 120 is fitted and fixed to the carrier 410. The carrier 410 has a support surface 411. The support surface 411 is spaced apart from the mounting surface 231 of the rotor 230, so that the flow gap 240 is located between the support surface 411 and the mounting surface 231. The support shaft 420 is connected to the support surface 411 and protrudes from the support surface 411 by a certain length along the axial direction of the carrier 410. The support shaft 420 is accommodated in the accommodation cavity 234, and there is a gap between the support shaft 420 and the cavity wall of the accommodation cavity 234, i.e., the support shaft 420 does not contact the cavity wall of the accommodation cavity 234, in other words, the support shaft 420 does not fill the entire accommodation cavity 234, thus ensuring that there is still space for blood to flow through the accommodation cavity 234. The support shaft 420 overlaps with the central axis of the rotating shaft 300, and the end of the support shaft 420 abuts against the rotating shaft 300, i.e., the support shaft 420 supports the rotating shaft 300 and the impeller 200, and ensures that the flow gap 240 exists between the mounting surface 231 and the support surface 411.

[0027] 7, 8, and 9, the end of the support shaft 420 far from the support surface 411 has an end surface 421, which surrounds a recess 421a, and the end surface 421 is recessed to a certain depth along the axial direction of the support shaft 420. Because the shape of the recess 421a matches the shape of the protrusion 320, the protrusion 320 can engage with the recess 421a, the protrusion 320 can rotate within the recess 421a, and the recess 421a can provide excellent radial positioning for the rotation of the protrusion 320 and the entire rotating shaft 300. Because the protrusion 320 and the recess 421a engage with each other, the convex surface 321 of the protrusion 320 and the end surface 421 a abut against each other. At least a portion of convex surface 321 is accommodated within recess 421a. For example, the entire convex surface 321 may be located within recess 421a. Alternatively, for example, a portion of convex surface 321 may be located within recess 421a and another portion may be located outside recess 421a. The small-diameter opening of communicating hole 232 is farther from flow gap 240 than end face 421 of support shaft 420. Generally speaking, the small-diameter opening of communicating hole 232 is located diagonally above end face 421. When blood in fluid feed cavity 130 flows into storage cavity 234 via communicating hole 232, the blood flowing out from the small-diameter opening of communicating hole 232 flows smoothly toward convex portion 320 and end face 421.

[0028] In some embodiments, the rotating shaft 300 is made of a ceramic material, and a diamond layer is provided on the end surface 421 of the support shaft 420. This reduces frictional resistance during the rotation of the rotating shaft 300 and improves the smoothness of the rotation of the rotating shaft 300 and the impeller 200.

[0029] When blood flows into the accommodating cavity 234, the rotating shaft 300 engages with the recessed portion 421a of the support shaft 420 via the convex portion 320, and the relative position and specific shape of the convex surface 321 and the end surface 421 provide an excellent flow guide for the blood, increasing the opportunity for the blood to come into contact with the contact point between the support shaft 420 and the rotating shaft 300, and facilitating the blood flow between the support shaft 420 and the rotating shaft 300. This increases the opportunity for the blood to effectively wash away the contact point between the support shaft 420 and the rotating shaft 300, preventing viscous matter or coagulated matter in the blood from concentrating at the contact point for a long period of time and forming a blood clot. At the same time, the speed and flow rate of the blood flowing through the contact point are increased, improving the fluidity of the blood and the washing power at the contact point, further preventing viscous matter or coagulated matter from concentrating at the contact point and forming a blood clot. Therefore, the engagement between the convex portion 320 and the concave portion 421a can effectively reduce the probability of thrombus formation.

[0030] The presence of the second blade 220 increases the velocity and volume of blood flowing through the accommodating cavity 234, further increasing the fluidity and washing force of blood in the accommodating cavity 234 and effectively reducing the likelihood of blood clots forming within the accommodating cavity 234. The diamond layer attached to the end face 421 also reduces the flow resistance of blood within the recess 421a, increasing the fluidity and washing force of blood and reducing the likelihood of blood clots forming. It also reduces heat generated by friction between the rotating shaft 300 and the support shaft 420, thereby improving the service life of the blood pump 10. Naturally, the blood flowing between the rotating shaft 300 and the support shaft 420 also absorbs frictional heat, further improving the service life of the blood pump 10. When the blood flow rate within the accommodating cavity 234 is high, more frictional heat can be absorbed.

[0031] In some embodiments, the support shaft 420 further includes an outer peripheral surface 422 and a flow guide surface 423. The outer peripheral surface 422 is an annular surface and is connected to the periphery of the end surface 421 so as to surround the end surface 421. One end of the support shaft 420 remote from the support surface 421 is recessed to form a flow guide groove 424. The flow guide groove 424 passes through the end surface 421 and the outer peripheral surface 422 and communicates with the recess 421a, and therefore, the flow guide groove 424 also communicates with the accommodating cavity 234. The number of flow guide grooves 424 may be multiple, for example, two, three, four, or more, and the multiple flow guide grooves 424 may be arranged at equal intervals along the circumferential direction of the support shaft 420. The flow guide surface 423 is connected between the outer peripheral surface 422 and the end surface 421 and defines a boundary of a portion of the flow guide groove 424. The flow guiding surface 423 is provided at an incline with respect to the central axis of the support shaft 420. The flow guiding surface 423 intersects with the central axis of the support shaft 420 at an acute angle. The distance from the flow guiding surface 423 to the central axis of the support shaft 420 gradually increases along the direction from one end farther from the support surface 411 to the other end closer to the support surface 411. In other words, the flow guiding surface 423 gradually moves away from the central axis of the support shaft 420 in the direction away from the rotation shaft 300. Generally speaking, the flow guiding surface 423 is provided obliquely downward so that the recess depth of the flow guiding groove 424 near the end face 421 is relatively large and the recess depth of the flow guiding groove 424 farther from the end face 421 is relatively small.

[0032] 8, 9, and 10, the flow directing surface 423 includes an intermediate flow directing portion 423a and two edge flow directing portions 423b, which are arranged along the circumferential direction of the support shaft 420, and the intermediate flow directing portion 423a is connected between the two edge flow directing portions 423b. Specifically, it should be understood that the intermediate flow directing portion 423a protrudes in a direction away from the central axis of the support shaft 420, and therefore the intermediate flow directing portion 423a is a raised surface, and the edge flow directing portions 423b are recessed in a direction approaching the central axis of the support shaft 420, and therefore the edge flow directing portions 423b are recessed surfaces, and the flow directing groove 424 is high in the center and low at the edges. It should be understood that the length A that the intermediate flow guide section 423a occupies in the circumferential direction of the support shaft 420 gradually increases along the direction away from the rotation axis 300, and that the intermediate flow guide section 423a is an isosceles trapezoid that is approximately convex arc-shaped.

[0033] Because flow guiding groove 424 is provided, flow guiding groove 424 penetrates end face 421 of support shaft 420, thereby reducing the contact area between convex surface 321 of convex portion 320 and support shaft 420. Furthermore, because flow guiding surface 423 is provided at an angle, the recess depth of flow guiding groove 424 near end face 421 is relatively large, thereby relatively increasing the area removed by end face 421 being penetrated by flow guiding groove 424, further reducing the contact area between convex surface 321 and support shaft 420 and ultimately reducing the probability of thrombus formation. Furthermore, as blood in accommodating cavity 234 flows through flow guiding groove 424, there is an increased chance of contact between the blood in flow guiding groove 424 and the contact point between support shaft 420 and rotating shaft 300, further reducing the probability of thrombus formation.

[0034] Because the intermediate flow guiding portion 423a is a raised surface and the edge flow guiding portion 423b is a recessed surface, when blood flows through the flow guiding groove 424, the blood flows from the higher middle position to the lower edge position, i.e., from the intermediate flow guiding portion 423a to the edge flow guiding portion 423b. In other words, as the blood flows from top to bottom along the axial direction of the support shaft 420, it also flows left and right along the circumferential direction of the support shaft 420, increasing the turbulence of the blood flow and generating vortices in the blood, which reasonably extends the time for blood to be washed away from the contact point between the support shaft 420 and the rotating shaft 300, increasing the washing force, preventing blood blockage in the joint space, and reducing the likelihood of blood clot formation. When the intermediate flow guide section 423a is an isosceles trapezoid with a roughly convex arc shape, the blood in the edge flow guide section 423b flows diagonally downward along a direction that forms an included angle with the axial direction of the support shaft 420, so that the blood flow in the edge flow guide section 423b has a branching direction along the axial direction of the support shaft 420 and also along the circumferential direction of the support shaft 420, thereby increasing the vortex flow strength of the blood and reducing the probability of thrombus formation.

[0035] The above embodiments are only for illustrating the technical solutions of the present invention, and are not intended to be limiting. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art may modify the technical solutions described in the above embodiments or make equivalent substitutions for some technical features thereof, and such modifications and substitutions shall not deviate from the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and shall all fall within the protection scope of the present invention.

Claims

1. a cannula assembly having a fluid delivery cavity; an impeller rotatably provided in the liquid feed cavity, the impeller having a receiving cavity and a communication hole communicating between the liquid feed cavity and the receiving cavity; a rotating shaft fixedly connected to the impeller and having a protrusion at one end positioned within the receiving cavity; a base connected to the cannula assembly and including a support shaft, wherein an end surface of the support shaft surrounds a recess that engages with the protrusion, forming a flow gap between the impeller and the base, the flow gap communicating with the accommodating cavity; the support shaft further has an outer circumferential surface and a flow guide surface, the outer circumferential surface is located within the accommodating cavity and surrounds the end face, the support shaft further has a flow guide groove that penetrates the outer circumferential surface and the end face and communicates with the recess, and the flow guide surface connects the outer circumferential surface and the end face and defines a boundary of a portion of the flow guide groove.

2. 2. The blood pump according to claim 1, wherein the convex portion is spherical or devoid of spherical shape.

3. 2. The blood pump according to claim 1, wherein the protrusion has a convex surface that abuts against the end surface, and at least a portion of the convex surface is housed in the recess.

4. 2. The blood pump according to claim 1, wherein the distance from the flow guide surface to the central axis of the support shaft gradually increases along a direction away from the rotation shaft.

5. 2. The blood pump according to claim 1, wherein the flow guide surface includes an intermediate flow guide portion and two edge flow guide portions arranged along the circumferential direction of the support shaft, the intermediate flow guide portion being connected between the two edge flow guide portions, the intermediate flow guide portion protruding in a direction away from the central axis of the support shaft, and the edge flow guide portions being recessed in a direction approaching the central axis of the support shaft.

6. 6. The blood pump according to claim 5, wherein the length of the intermediate flow guide portion in the circumferential direction of the support shaft gradually increases along a direction away from the rotation shaft.

7. 2. The blood pump according to claim 1, wherein the number of the flow guide grooves is plural, and the plural flow guide grooves are arranged at intervals along the circumferential direction of the support shaft.

8. 2. The blood pump of claim 1, wherein the base has a support surface, the support shaft is connected to the support surface and protrudes from the support surface, the impeller further includes a rotating body and first and second blades provided on the rotating body, the accommodating cavity is formed in the rotating body, the flow gap is located between the rotating body and the support surface, the first blade is located in the liquid supply cavity, and at least a portion of the second blade is located in the flow gap.

9. 9. The blood pump according to claim 8, wherein the rotating body further has a mounting surface, the mounting surface facing the support surface, the mounting surface and the support surface being spaced apart in the axial direction of the rotating body, and at least a portion of the flow gap being located between the mounting surface and the support surface.

10. 10. The blood pump according to claim 9, wherein the mounting surface is perpendicular to a central axis of the impeller, the second blades are provided on the mounting surface and extend along a radial direction of the rotor, the number of the second blades is plural, and the second blades are arranged at intervals along a circumferential direction of the rotor.

11. 9. The blood pump according to claim 8, wherein the base includes a carrier, the support shaft, and a stator, the stator being disposed within the carrier, the stator being capable of generating a rotating magnetic field when energized to rotate the impeller, the cannula assembly being fitted into and fixed to the carrier, and the carrier having the support surface.

12. 2. The blood pump according to claim 1, wherein the communication hole has two openings, the two openings communicating with the storage cavity and the fluid supply cavity, respectively, the opening communicating with the storage cavity faces the recess, and the opening communicating with the storage cavity is farther from the flow gap than the end face of the support shaft.

13. 2. The blood pump according to claim 1, wherein the communication hole has a small-diameter opening and a large-diameter opening, the small-diameter opening communicating with the storage cavity, and the large-diameter opening communicating with the fluid-feeding cavity.

14. 2. The blood pump according to claim 1, wherein a plurality of inner fins are provided within the fluid feed cavity, the inner fins protruding from a cavity wall surface of the fluid feed cavity, and the plurality of inner fins surround an attachment cavity that rotatably engages with the rotating shaft.

15. 15. The blood pump of claim 14, wherein the end of the axle distal to the base is a cone, the cone fitting into the mounting cavity.

16. 16. The blood pump of claim 15, wherein the cannula assembly includes a first cannula and a second cannula, the first cannula including a cannula body and the inner fin, the cannula body and the second cannula being coaxially arranged and detachably connected, the second cannula being arranged on the base, and the diameter of the mounting cavity gradually decreases along a direction from the second cannula to the first cannula.

17. 2. The blood pump of claim 1, wherein the cannula assembly further includes an outlet communicating with the fluid delivery cavity, the outlet being located at an end of the cannula assembly closer to the base, and the position of the flow gap corresponds to the position of the outlet.

18. 2. The blood pump according to claim 1, wherein a central axis of the communicating hole is a first central axis, a central axis of the impeller is a second central axis that forms an acute angle with the first central axis, and a diameter of the communicating hole gradually decreases along a direction of fluid flowing through the communicating hole, and a distance from the first central axis to the second central axis gradually decreases along the direction of fluid flowing through the communicating hole.

19. 2. The blood pump according to claim 1, wherein the accommodating cavity extends along a central axis of the impeller, and the communication hole extends in a direction inclined with respect to the central axis of the impeller.

20. A cannula assembly having a fluid delivery cavity; an impeller rotatably provided in the liquid feed cavity, the impeller having a receiving cavity and a communication hole communicating between the liquid feed cavity and the receiving cavity; a rotating shaft fixedly connected to the impeller and having a protrusion at one end positioned within the receiving cavity; a base connected to the cannula assembly and including a support shaft, wherein an end surface of the support shaft surrounds a recess that engages with the protrusion, forming a flow gap between the impeller and the base, the flow gap communicating with the accommodating cavity; a blood pump, characterized in that the base has a support surface, the support shaft is connected to the support surface and protrudes from the support surface, the impeller further includes a rotating body and a first blade and a second blade provided on the rotating body, the accommodating cavity is formed in the rotating body, the flow gap is located between the rotating body and the support surface, the first blade is located in the fluid supply cavity, and at least a portion of the second blade is located in the flow gap.

21. A cannula assembly having a fluid delivery cavity; an impeller rotatably provided in the liquid feed cavity, the impeller having a receiving cavity and a communication hole communicating between the liquid feed cavity and the receiving cavity; a rotating shaft fixedly connected to the impeller and having a protrusion at one end positioned within the receiving cavity; a base connected to the cannula assembly and including a support shaft, wherein an end surface of the support shaft surrounds a recess that engages with the protrusion, forming a flow gap between the impeller and the base, the flow gap communicating with the accommodating cavity; The blood pump is characterized in that the communication hole has two openings, which are connected to the storage cavity and the fluid supply cavity, respectively, the opening connected to the storage cavity faces the recess, and the opening connected to the storage cavity is farther from the flow gap than the end face of the support shaft.

22. A cannula assembly having a fluid delivery cavity; an impeller rotatably provided in the liquid feed cavity, the impeller having a receiving cavity and a communication hole communicating between the liquid feed cavity and the receiving cavity; a rotating shaft fixedly connected to the impeller and having a protrusion at one end positioned within the receiving cavity; a base connected to the cannula assembly and including a support shaft, wherein an end surface of the support shaft surrounds a recess that engages with the protrusion, forming a flow gap between the impeller and the base, the flow gap communicating with the accommodating cavity; The blood pump according to claim 1, wherein the communication hole has a small-diameter opening and a large-diameter opening, the small-diameter opening communicating with the storage cavity, and the large-diameter opening communicating with the fluid-feeding cavity.

23. A cannula assembly having a fluid delivery cavity; an impeller rotatably provided in the liquid feed cavity, the impeller having a receiving cavity and a communication hole communicating between the liquid feed cavity and the receiving cavity; a rotating shaft fixedly connected to the impeller and having a protrusion at one end positioned within the receiving cavity; a base connected to the cannula assembly and including a support shaft, wherein an end surface of the support shaft surrounds a recess that engages with the protrusion, forming a flow gap between the impeller and the base, the flow gap communicating with the accommodating cavity; A blood pump characterized in that a plurality of inner fins are provided within the fluid supply cavity, the inner fins protruding from the cavity wall surface of the fluid supply cavity, and the plurality of inner fins surround an attachment cavity that rotatably engages with the rotating shaft.

24. A cannula assembly having a fluid delivery cavity; an impeller rotatably provided in the liquid feed cavity, the impeller having a receiving cavity and a communication hole communicating between the liquid feed cavity and the receiving cavity; a rotating shaft fixedly connected to the impeller and having a protrusion at one end positioned within the receiving cavity; a base connected to the cannula assembly and including a support shaft, wherein an end surface of the support shaft surrounds a recess that engages with the protrusion, forming a flow gap between the impeller and the base, the flow gap communicating with the accommodating cavity; a central axis of the communicating hole is a first central axis, a central axis of the impeller is a second central axis that forms an acute angle with the first central axis, and a diameter of the communicating hole gradually decreases along a direction of a fluid flowing through the communicating hole, and a distance from the first central axis to the second central axis gradually decreases.

Images