Blood pump

Abstract

This application relates to a blood pump, which includes a shell tube and a drive unit. The shell tube has an inlet at its proximal end and an outlet at its distal end. The drive unit is located inside the shell tube and forms a blood flow channel radially spaced from the inner wall of the shell tube, the blood flow channel connecting the inlet and the outlet. The drive unit includes a motor and an impeller connected to the motor. The proximal end of the shell tube is fixedly connected to the proximal end of the motor or a conduit of the blood pump. This configuration allows for a smaller axial dimension of the pump body, enabling the blood pump to pass through the path from the inferior vena cava (or superior vena cava) to the pulmonary artery, thus assisting the right ventricle in pumping blood into the pulmonary artery and reducing the risk of excessive expansion during right ventricular congestion.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a blood pump. Background Technology

[0002] An interventional blood pump, also known as an intracardiac blood pump or intravascular blood pump, can be inserted into a blood vessel and protruded into the patient's heart to function as a left ventricular assist pump or a right ventricular assist pump.

[0003] In traditional techniques, when a right ventricular assist pump (LVAP) assists the heart in pumping blood, it can easily lead to excessive expansion of the right ventricle, which is detrimental to the patient's health. Summary of the Invention

[0004] Based on this, this application provides a blood pump designed to assist the right ventricle in blood circulation and to solve the problem of excessive expansion of the right ventricle.

[0005] This application provides a blood pump, the blood pump comprising:

[0006] A shell-and-tube assembly, wherein a liquid inlet is provided at the proximal end of the shell-and-tube assembly, and a liquid outlet is provided at the distal end of the shell-and-tube assembly; and

[0007] A driving unit is disposed inside the shell tube and forms a blood flow channel radially spaced from the inner wall surface of the shell tube, the blood flow channel connecting the inlet and the outlet.

[0008] The drive unit includes a motor and an impeller connected to the motor; the proximal end of the shell tube is fixedly connected to the proximal end of the motor or the conduit of the blood pump; the shell tube includes:

[0009] An outlet pipe, the proximal end of which is fixedly connected to the distal end of the motor, a communication port is provided on the side wall of the proximal end of the outlet pipe, and the liquid outlet is provided at the distal end of the outlet pipe; and

[0010] An inlet pipe is sleeved on the outer periphery of the motor. The proximal end of the inlet pipe is provided with the liquid inlet. The proximal end of the inlet pipe is fixedly connected to the motor or the conduit. The distal end of the inlet pipe is fixedly connected to the outer peripheral wall of the outlet pipe so that the communication port is accommodated inside the inlet pipe.

[0011] The impeller is housed within the outlet pipe; a gap is provided between the inner wall of the motor and the inlet pipe, and this gap communicates with the connecting port and the inner cavity of the outlet pipe to form the blood flow channel;

[0012] The distal end of the motor extends into the outlet pipe, and the distal end of the motor has a first variable diameter surface. The first variable diameter surface is located inside the communication port, and the diameter of the first variable diameter surface gradually decreases along the direction from the motor to the impeller.

[0013] In one embodiment, the motor includes a motor body and a shaft support; wherein the motor body is housed within the inlet pipe; the shaft support is connected to the distal end of the motor body and extends into the outlet pipe, and the outer peripheral wall of the shaft support forms the first variable diameter surface.

[0014] In one embodiment, the inlet pipe includes a main body section and a first constricted section connected to the distal end of the main body section, the distal end of the first constricted section being fixedly connected to the outer peripheral surface of the outlet pipe; the first constricted section has an inner diameter changing surface, the inner diameter changing surface being located outside the communication port, and the diameter of the inner diameter changing surface and the diameter of the first diameter changing surface being gradually reduced in the same direction.

[0015] In one embodiment, the distance between the inner diameter-changing surface of the first constriction section and the first diameter-changing surface is gradually increased in the direction from the motor to the impeller.

[0016] In one embodiment, the first constricted segment further has an outer diameter-changing surface opposite to the inner diameter-changing surface, which can be received in the right ventricle for contact and engagement of the pulmonary valve's surface facing the right ventricle.

[0017] In one embodiment, the first constricted segment has a first axial length D1, the main body segment has a second axial length D2, and the ratio of the first axial length D1 to the second axial length D2 is 1 / 4 ≤ D1 / D2 ≤ 1 / 3.

[0018] In one embodiment, the inlet pipe includes a main body section and a second constricted section connected to the proximal end of the main body section. The proximal end of the second constricted section is fixed to the motor or the conduit. The diameter of the second constricted section gradually increases along the direction from the motor to the impeller. The liquid inlet extends axially from the second constricted section to the main body section.

[0019] In one embodiment, the inlet includes a first inlet area located on the second constricted section and a second inlet area located on the main body section; wherein the first inlet area has a first width along the circumference of the inlet pipe, and the second inlet area has a second width along the circumference of the inlet pipe, the second width being greater than the first width; the first width gradually increases along the direction from the conduit to the motor.

[0020] In one embodiment, the motor includes a motor body and a proximal end cover; the proximal end cover is disposed at the proximal end of the motor body and is fixedly connected to the conduit, and the outer peripheral surface of the proximal end cover has a second variable diameter surface, the diameter of the second variable diameter surface gradually increasing along the direction from the conduit to the motor;

[0021] The second variable diameter surface extends from the interior of the main body section to the interior of the second constricted section, such that the proximal portion of the second variable diameter surface is radially opposite to the liquid inlet, and the distal portion of the second variable diameter surface is radially opposite to the inner wall surface of the main body section.

[0022] In one embodiment, the outlet pipe includes a first pipe section and a second pipe section connected to the first pipe section. The first pipe section is provided with the liquid outlet, and the second pipe section extends into the inlet pipe and is provided with the communication port.

[0023] The outer diameter of the first pipe section is larger than the outer diameter of the second pipe section, so that a step is formed between the outer peripheral surface of the second pipe section and the outer peripheral surface of the first pipe section; the distal end of the inlet pipe is provided with a first insertion part, the end face of the first insertion part abuts against the step, and the outer surface of the first insertion part is flush with the outer peripheral surface of the second pipe section.

[0024] And / or, the motor has a shoulder at its distal end, and the second pipe section has a second plug at its proximal end, the end face of the second plug abuts against the shoulder, and the outer peripheral surface of the second plug is flush with the outer peripheral surface of the motor.

[0025] In one embodiment, the thickness of the second connector is greater than the thickness of the second pipe segment; and / or, the connection between the inner wall of the second connector and the inner wall of the second pipe segment is provided with a rounded corner.

[0026] In one embodiment, the outlet includes a plurality of second openings, which are arranged at intervals along the circumference of the shell tube; each of the second openings extends in a strip shape along the axial direction of the shell tube.

[0027] In one embodiment, the inlet pipe is made of a rigid material to make the inlet pipe a non-expandable structure; and / or, the outlet pipe is made of a rigid material to make the outlet pipe a non-expandable structure.

[0028] In one embodiment, the outlet pipe includes a first pipe section and a second pipe section connected to the first pipe section. The first pipe section is provided with the liquid outlet, and the second pipe section extends into the inlet pipe and is provided with the communication port.

[0029] The proximal portion of the impeller is housed within the second pipe section, such that the side of the proximal portion of the impeller faces the communication port; the distal portion of the impeller is housed within the first pipe section and is adjacent to or close to the liquid outlet.

[0030] In one embodiment, the inner wall surface of the inlet pipe is provided with a plurality of guide fins, the plurality of guide fins are arranged at intervals along the circumference of the inlet pipe, and each guide fin extends along the axial direction of the inlet pipe.

[0031] In one embodiment, the inlet includes a plurality of first openings arranged circumferentially along the inlet pipe, with a partition wall formed between two adjacent first openings; the plurality of guide fins correspond one-to-one with the plurality of partition walls, and the proximal end of the guide fin extends at least partially to the inner wall surface of the partition wall.

[0032] And / or, the first height of the proximal end of the guide fin protruding from the inner wall of the inlet pipe gradually increases along the direction from the conduit to the motor; the second height of the distal end of the guide fin protruding from the inner wall of the inlet pipe gradually decreases along the direction from the conduit to the motor.

[0033] In one embodiment, the shell tube has a first length along the axial direction of the drive unit; the first length enables the blood pump to pass through the right atrium, right ventricle, and pulmonary valve to extend into the pulmonary artery, such that the inlet is located in the right ventricle and the outlet is located in the pulmonary artery.

[0034] In one embodiment, the first length is 20mm-32mm.

[0035] The blood pump provided in this application has an inlet and an outlet on the shell tube, and a drive unit is disposed inside the shell tube. A blood flow channel is formed radially between the inner wall of the shell tube and the drive unit, connecting the inlet and outlet. The drive unit includes a motor and an impeller connected to the motor. The proximal end of the shell tube is fixedly connected to the proximal end of the motor or the conduit of the blood pump. This effectively shortens the axial length of the pump body, making the blood pump suitable for a delivery path from the inferior vena cava (or superior vena cava) to the pulmonary artery. When the blood pump is used in the right ventricle of an interventional patient, it can pass through the tricuspid valve into the right ventricle from the right atrium, and then through the pulmonary valve to partially extend into the pulmonary artery, so that the inlet of the blood pump is located within the right ventricle, and the outlet is located within the pulmonary artery.

[0036] After the blood pump is started, the motor of the drive unit drives the impeller to rotate, thereby driving blood from the right atrium into the right ventricle. Blood in the right ventricle is then drawn into the blood flow channel inside the blood pump through its inlet, and then discharged into the pulmonary artery from the outlet under the drive of the impeller. Therefore, compared to traditional blood pumps where both the inlet and outlet are located in the inferior vena cava, posing a risk of over-expansion of the right ventricle, the blood pump of this application can extend from the right ventricle to the pulmonary artery to assist in right ventricular decompression, thereby reducing the risk of over-expansion during right ventricular congestion and improving the safety of the blood pump during use. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the anatomical structure of the human heart.

[0038] Figure 2 This is a schematic diagram of a blood pump used to assist the right ventricle in pumping blood, according to an embodiment of this application.

[0039] Figure 3 for Figure 2 A schematic diagram of the blood pump shown.

[0040] Figure 4 for Figure 3 The blood pump shown is a cross-sectional view along line AA.

[0041] Figure 5 for Figure 4 The diagram shows a magnified view of the outlet pipe at point B.

[0042] Figure 6 for Figure 4 The image shows a magnified view of the blood pump at point C.

[0043] Figure 7 for Figure 4 The diagram shows the flow of blood through the channels of the blood pump.

[0044] Figure 8 for Figure 3 The diagram shows an explosion of a blood pump.

[0045] Figure 9 for Figure 4 A cross-sectional view of the inlet tube in the blood pump shown.

[0046] Figure 10 This is a cross-sectional view of a blood pump according to another embodiment of this application.

[0047] Figure 11 for Figure 10 The image shows a magnified view of the blood pump at point D.

[0048] Figure 12 for Figure 4A cross-sectional view of the drive unit in the blood pump shown.

[0049] Figure 13 for Figure 4 The image shows a cross-sectional view of the outlet tube in the blood pump.

[0050] Figure 14 for Figure 13 The image shows a magnified view of the blood pump at point E.

[0051] Figure 15 This is a schematic diagram of a blood pump intervening in the right ventricle of the heart, according to yet another embodiment of this application.

[0052] Reference numerals: 10, Blood pump; 11, Pump body; 12, Catheter; 100, Drive unit; 110, Motor; 111, Motor body; 101, Cylindrical housing; 102, Shaft shoulder; 103, First rotor; 104, Stator; 105, Second rotor; 106, Shaft; 112, Shaft support; 112a, First diameter changing surface; 113, Proximal end cap; 113a, Second diameter changing surface; 12 0. Impeller; 200. Shell and tube; 210. Inlet pipe; 211. First constriction section; 211a. Inner diameter change surface; 211b. Outer diameter change surface; 212. Second constriction section; 213. Main body section; 214. Liquid inlet; 214a. First inlet area; 214b. Second inlet area; 214c. First opening; 215. First insertion part; 216. Guide fin; 217. Partition wall; 220. 1. Outlet pipe; 220a. Liquid outlet; 220b. Second opening; 221. First pipe section; 222. Second pipe section; 222a. Connecting port; 222b. Second insertion part; 223. Stepped part; 224. Fixing part; 224a. Glue tank; 400. Blood flow channel; 410. Gap; 411. First guide channel; 412. Second guide channel; 413. First delivery channel; 420. Second delivery channel; 20. Heart; 21. Right atrium; 22. Right ventricle; 23. Tricuspid valve; 24. Pulmonary valve; 31. Superior vena cava; 32. Inferior vena cava; 33. Pulmonary artery; L1. Width of the first guide channel; D1. First axial length; D2. Second axial length; S1. First width; S2. Second width; R. Rounded corner; H1. First height; H2. Second height.

[0053] 20. Inferior vena cava; 21. Superior vena cava; 22. Right atrium; 23. Tricuspid valve; 24. Right ventricle; 25. Pulmonary valve; 25a. Medial surface; 26. Pulmonary artery; 27. Pulmonary vein; 28. Left atrium; 29. ​​Mitral valve; 30. Left ventricle; 31. Aortic valve; 32. Aorta. Detailed Implementation

[0054] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0055] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0056] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0057] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0058] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0059] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0060] In related technologies, interventional assistive devices, also known as blood pumps, are primarily used to insert into a patient's blood vessels to assist blood circulation. To facilitate understanding of the application of blood pumps, a brief explanation of the heart structure and blood flow direction is provided below. Please refer to... Figure 1 , Figure 1 This is an anatomical diagram of the human heart. Human blood circulation includes systemic circulation and pulmonary circulation. In systemic circulation, blood is ejected from the left ventricle (30) through the aortic valve (31) into the aorta (32). From there, it flows through the aorta to the capillaries throughout the body for substance exchange, transforming arterial blood into venous blood. This venous blood then returns to the right atrium (22) via the superior vena cava (21) and inferior vena cava (20). Next, blood from the right atrium (22) enters the right ventricle (24) through the tricuspid valve (23), and is then ejected from the right ventricle (24) through the pulmonary valve (25) into the pulmonary artery (26). From there, it flows through the pulmonary artery (26) to the pulmonary capillaries for gas exchange, transforming venous blood into arterial blood. Finally, this arterial blood returns to the left atrium (28) through the pulmonary veins (27). Blood from the left atrium (28) then enters the left ventricle (30) through the mitral valve (29). This circulation is called pulmonary circulation.

[0061] A common type of blood pump is the left ventricular assist pump (LVAP). This type of LVAP typically includes a drive unit and a cannula assembly. The cannula assembly has an outlet at its proximal end and an inlet at its distal end. The motor of the drive unit is fixed to the proximal end of the cannula assembly, and the impeller of the drive unit is arranged inside the cannula assembly and connected to the motor shaft. The length of this cannula assembly is usually several times the length of the drive unit, resulting in a relatively long axial length of the pump body. When the LVAP is applied to the left ventricle 30, it is typically passed through the aortic valve 31 from the aorta 32, with the inlet of the LVAP extending into the left ventricle 30, while the outlet remains within the aorta 32; that is, only the distal portion of the LVAP extends into the left ventricle 30. Thus, the LVAP assists the left ventricle 30 in pumping blood from the left ventricle 30 to the aorta 32. The path of the left ventricular assist pump from the ascending portion of the aorta 32 through the aortic valve 31 to enter the left ventricle 30 is relatively close to the same axial direction. Therefore, this left ventricular assist pump with a pump body of relatively long axial length can adapt to the pushing path of the left ventricle 30.

[0062] If a patient has functional impairment in right ventricle 24, a blood pump is also required to assist right ventricle 24 in pumping blood. Therefore, the application of a left ventricular assist pump (LVAP) to assist right ventricle 24 in pumping blood has been considered. However, the typical delivery path for a blood pump implanted in the right ventricle is from the inferior vena cava 20 or superior vena cava 21, through the right atrium, tricuspid valve 23, right ventricle 24, pulmonary valve 25, and finally to the pulmonary artery 26. This path is short, winding, and complex. Because the axial length of a traditional left ventricular assist pump is too long to pass through the right ventricle 24 delivery path, its application in right ventricle 24 is difficult.

[0063] Therefore, a right ventricular assist pump (LVAP) has emerged on the market to assist blood flow in the right ventricle 24. This LVAP is designed to be inserted into the inferior vena cava 20 via an incision in the patient's lower back or thigh, with both the inlet and outlet located within the inferior vena cava 20; that is, the outlet does not extend into the pulmonary artery 26. When the LVAP is activated, it only accelerates the flow of blood from the inferior vena cava 20 to the right atrium, and then into the right ventricle 24. However, it cannot assist the right ventricle 24 in pumping blood to the pulmonary artery 26 for decompression. This results in a significant defect: the right ventricle 24 is prone to over-inflation during congestion, posing a potential safety hazard to the patient.

[0064] Please see Figure 1To address the aforementioned problems, this application provides a blood pump 10, which is primarily used as a right ventricular assist pump. The blood pump 10 extends from the right ventricle 24 into the pulmonary artery 26 to assist the right ventricle 24 in pumping blood into the pulmonary artery 26, thereby relieving pressure in the right ventricle 24. Of course, in other embodiments, the blood pump 10 can also be used as a left ventricular assist pump. It should be noted that in the field of medical device technology, the end of a medical device closer to the physician or operator is typically referred to as the proximal end, and the end farther from the physician or operator is referred to as the distal end.

[0065] Please see Figures 2 to 4 The blood pump 10 provided in one embodiment of this application includes a drive unit 100 and a shell tube 200. The proximal end of the shell tube 200 has an inlet 214, and the distal end of the shell tube 200 has an outlet 220a. The drive unit 100 is disposed inside the shell tube 200, and a blood flow channel 400 is formed radially between the drive unit 100 and the inner wall surface of the shell tube 200, connecting the inlet 214 and the outlet 220a. The radial direction refers to the radial direction of the drive unit 100. The drive unit 100 includes a motor 110 and an impeller 120 connected to the motor 110. The proximal end of the shell tube 200 is fixedly connected to the motor 110 or the conduit 12 of the blood pump 10, so that the drive unit 100 is stably positioned inside the shell tube 200.

[0066] Specifically, the drive unit 100 and the shell tube 200 constitute the pump body 11 of the blood pump 10, and the axial length of the blood pump 10 refers to the length of the pump body 11. Here, by placing both the motor 110 and the impeller 120 of the drive unit 100 inside the shell tube 200, that is, by housing the entire drive unit 100 inside the shell tube 200, instead of arranging the motor 110 and the shell tube 200 axially (as in the arrangement of the motor and cannula assembly of a traditional left ventricular assist pump), the axial length of the pump body 11 of the blood pump 10 can be greatly shortened, so that the pump body 11 of the blood pump 10 can pass through a short and winding push path from the inferior vena cava 20 (or superior vena cava 21) to the pulmonary artery 21, so that the inlet 214 is located in the right ventricle 24, and the outlet 220a is located in the pulmonary artery 26.

[0067] Specifically, such as Figure 2 As shown, the Figure 2 This diagram illustrates the blood pump 10 of this application as a right ventricular auxiliary pump used to assist the right ventricle in pumping blood. Figure 2The dashed arrow F indicates the direction of blood flow. One of the pushing paths of the blood pump 10 is as follows: the pump body 11 of the blood pump 10 passes through the inferior vena cava 20 into the right atrium 22, then passes through the tricuspid valve 23 into the right ventricle 24 from the right atrium 22, and then passes through the pulmonary valve 25 from the right ventricle 24 to partially extend into the pulmonary artery 26, ensuring that the inlet 214 of the blood pump 10 is located in the right ventricle 24, while the outlet 220a of the blood pump 10 is located in the pulmonary artery 26. Another delivery path of the blood pump 10 is that the pump body 11 of the blood pump 10 enters the right atrium 22 from the superior vena cava 21, then passes through the tricuspid valve 23 from the right atrium 22 into the right ventricle 24, and then passes through the pulmonary valve 25 from the right ventricle 24 to partially extend into the pulmonary artery 26, ensuring that the inlet 214 of the blood pump 10 is located in the right ventricle 24, while the outlet 220a of the blood pump 10 is located in the pulmonary artery 26.

[0068] from Figure 1 and Figure 2 It is evident that the delivery path of the blood pump 10 from the inferior vena cava 20 or the superior vena cava 21 to the pulmonary artery 26 is characterized by a short path, numerous bends, and complex internal tissues. Because the pump body 11 of the blood pump 10 of this application has a relatively short axial length, the pump body 11 can pass through each bend of the shorter delivery path and bend upwards (or deflect) into the pulmonary artery 26 within the narrow right ventricle 24, greatly reducing the difficulty of the blood pump 10 entering the right ventricle 24 and improving the smoothness of the blood pump 10 traversing the delivery path.

[0069] When the blood pump 10 is turned on, the motor 110 of the drive unit 100 drives the impeller 120 to rotate, thereby driving blood through the right atrium into the right ventricle 24. The blood in the right ventricle 24 is then drawn into its blood flow channel 400 by the inlet 214 of the blood pump 10. The blood in the blood flow channel 40 continues to be driven by the impeller 120 to flow towards the outlet 220a, and finally the blood is discharged from the outlet 220a into the pulmonary artery 26. Thus, the blood pump 10 of this application can extend from the right ventricle 24 to the pulmonary artery 26 to assist in depressurization of the right ventricle 24, thereby reducing the risk of excessive expansion during the congestion of the right ventricle 24 and improving the safety of the blood pump 10 during use. Figures 4 to 5 M1 and M2 are two points on the axis (i.e., axial direction) of the blood pump 10. The dashed line M1M2 can represent the axis of the blood pump 10. The direction from M1 to M2 is along the axis of the blood pump 10 and from the proximal end to the distal end. Conversely, the direction from M2 to M1 is along the axis of the blood pump 10 and from the distal end to the proximal end.

[0070] It is understandable that, since the drive unit 100 is housed inside the shell tube 200 and the blood flow channel 400 is formed between the inner peripheral wall of the shell tube 200 and the drive unit 100, the length of the shell tube 200 is equivalent to the axial length of the pump body 11. The length of the shell tube 200 can be designed to be only slightly longer than the drive unit 100 (to accommodate the drive unit and enable it to work properly), instead of being designed to be several times longer than the drive unit 100 as in traditional cannula assemblies.

[0071] Please see Figure 3 and Figure 4 The blood pump 10 also includes a catheter 12, the distal end of which is fixedly connected to the proximal end of the motor 110. The catheter 12 contains supply lines such as wires and flushing tubing (not shown in the figure). The proximal end of the shell tube 200 can be directly fixed to the catheter 12, or the proximal end of the shell tube 200 can be fixed to the proximal end of the motor 110. Since the catheter 12 is typically deformable to fit into blood vessels, its axial size usually has little impact on the difficulty of implanting the blood pump 10 within the heart 20. That is, the ability to design a smaller axial size for the blood pump 10 mainly refers to the axial size of the pump body 11 of the blood pump 10. The portion of the blood pump 10 located within the heart 20 mainly refers to the pump body 11. This application is configured such that the axial length of the pump body 11 of the blood pump 10 can be designed to be smaller, so that after the pump body 11 of the blood pump 10 enters the right ventricle 24, it can bend (or deflect) upward in the right ventricle 24 to pass through the pulmonary valve 25, so that the inlet 214 of the blood pump 10 is located in the right ventricle 24, while the outlet 220a of the blood pump 10 can pass through the pulmonary valve 25 into the pulmonary artery 26.

[0072] Please see Figures 4 to 8 In one embodiment, the shell tube 200 includes an inlet tube 210 and an outlet tube 220, with the inlet tube 210 connected to the outlet tube 220. The proximal end of the outlet tube 220 is fixedly connected to the distal end of the motor 110, and a communication port 222a is also provided on the side wall of the proximal end of the outlet tube 220; the distal end of the outlet tube 220 is provided with a liquid outlet 220a; the inlet tube 210 is sleeved on the outer periphery of the motor 110, and a liquid inlet 214 is provided on the proximal end of the inlet tube 210. The proximal end of the inlet tube 210 is fixedly connected to the motor 110 or the conduit 12, and the distal end of the inlet tube 210 is fixedly connected to the outer peripheral wall of the outlet tube 220, so that the communication port 222a is accommodated inside the inlet tube 210. The impeller 120 is housed within the outlet pipe 220; the inner walls of the motor 110 and the inlet pipe 210 are separated by a gap 410, which communicates with the connecting port 222a and the inner cavity of the outlet pipe 220 to form a blood flow channel 400.

[0073] Specifically, the catheter 12, motor 110, and outlet tube 220 are arranged and connected sequentially along the axial direction of the blood pump 10 from proximal to distal (i.e., from M1 to M2). The proximal end of the inlet tube 210 is fixed to the distal end of the catheter 12 or the proximal end of the motor 110 to support the proximal end of the motor 110; the distal end of the inlet tube 210 is connected to the outer peripheral wall of the outlet tube 220, and the connection point between the two is located on the outer peripheral wall between the outlet port 220a and the connecting port 222a of the outlet tube 220, so that the proximal end of the outlet tube 220 extends into the interior of the inlet tube 210 and is fixed to the distal end of the motor 110 to support the distal end of the motor 110. That is to say, the inlet pipe 210 and the outlet pipe 220 support the near end and far end of the motor 110 respectively, thereby stably supporting the motor 110 inside the shell tube 200, and thus stably defining the gap 410 between the outer peripheral surface of the motor 110 and the inner wall surface of the inlet pipe 210.

[0074] Both the inlet pipe 210 and the outlet pipe 220 are hollow tubular structures; the connecting port 222a at the proximal end of the outlet pipe 220 connects the gap 410 located on the outer periphery of the motor 110 with the inner cavity of the outlet pipe 220 to form the blood flow channel 400. Blood first enters the gap 410 from the inlet port 214 (see...). Figure 7 The blood flows from the gap 410 to the connecting port 222a, and then enters the inner cavity of the outlet pipe 220 from the connecting port 222a, finally exiting from the outlet port 220a of the outlet pipe 220. Thus, the shell tube 200 can cooperate with the drive unit 100 to form a blood flow channel 400 for smooth blood flow, providing a basis for shortening the axial dimension of the pump body 11 of the blood pump 10, thereby improving the ability of the blood pump 10 to traverse complex paths and facilitating the smooth insertion of the distal end of the blood pump 10 with the outlet port 220a into the pulmonary artery 26. (The dashed arrow F indicates the direction of blood flow.)

[0075] Please see Figures 4 to 8 In one embodiment, the distal end of the motor 110 extends into the outlet pipe 220, and the distal end of the motor 110 has a first variable diameter surface 112a. The first variable diameter surface 112a is located inside the connecting port 222a, and the diameter of the first variable diameter surface 112a gradually decreases along the direction from the motor 110 to the impeller 120. With this configuration, after blood enters the proximal end of the outlet pipe 220 from the connecting port 222a, the blood first contacts the first variable diameter surface 112a of the motor 110, so that at least part of the blood flows along the wall of the first variable diameter surface 112a and is guided by the first variable diameter surface 112a towards the outlet port 220a of the outlet pipe 220, thereby improving the smoothness of blood flowing from the inlet pipe 210 through the connecting port 222a into the outlet pipe 220 and accelerating blood flow.

[0076] It is understood that the first variable diameter surface 112a is the outer peripheral surface of the distal end of the motor 110. Optionally, the motor 110 includes a motor body 111 and a shaft support 112. The shaft support 112 is connected to the distal end of the motor body 110. The motor body 111 has a rotating shaft 106, which axially passes through the shaft support 112 and is fixedly connected to the impeller 120. The shaft support 112 can support the rotating shaft 106 so that the rotating shaft 106 stably drives the impeller 120 to rotate. The outer diameter of the shaft support 112 gradually decreases along the direction from the motor 110 to the impeller 120, so that the shaft support 112 is approximately frustoconical in shape.

[0077] Optionally, the shaft support 112 extends into the outlet pipe 220. The outer peripheral wall of the shaft support 112 forms a first variable diameter surface 112a, which is located inside the connecting port 222a. The diameter of the first variable diameter surface 112a gradually decreases along the direction from the motor 110 to the impeller 120 (i.e., from M1 to M2). After blood enters the proximal end of the outlet pipe 220 from the connecting port 222a, the blood first contacts the first variable diameter surface 112a of the shaft support 112, so that at least part of the blood flows along the wall of the first variable diameter surface 112a and is guided by the first variable diameter surface 112a towards the outlet port 220a of the outlet pipe 220. This improves the smoothness of blood flowing from the inlet pipe 210 through the connecting port 222a into the outlet pipe 220 and accelerates blood flow.

[0078] Please see Figure 3 and Figure 9 In one embodiment, the inlet pipe 210 includes a main body segment 213 and a first constricted segment 211; the first constricted segment 211 is connected to the distal end of the main body segment 213 and is fixedly connected to the outer peripheral wall of the outlet pipe 220. The inlet pipe 210 may also include a second constricted segment 212, which is connected to the proximal end of the main body segment 213 and is fixedly connected to the motor 110 or the conduit 12. That is, the inlet pipe 210 may include the main body segment 213 and at least one of the first constricted segment 211 and the second constricted segment 212.

[0079] Please see Figure 4 , Figure 5 and Figure 9 In one embodiment, the inlet pipe 210 includes a main body section 213 and a first constriction section 211. The distal end of the first constriction section 211 is fixed to the outer peripheral wall of the outlet pipe 220. The first constriction section 211 has an inner diameter changing surface 211a located outside the connecting port 222a. The diameter of the inner diameter changing surface 211a and the diameter of the first diameter changing surface 112a gradually decrease in the same direction. That is, the diameter of the inner diameter changing surface 211a also gradually decreases in the direction from the motor 110 to the impeller 120 (i.e., from M1 to M2), so that the inner diameter changing surface 211a is inclined relative to the connecting port 222a from the proximal end to the distal end.

[0080] Understandably, the first constricted section 211 serves as the distal portion of the inlet pipe 210. Since the inner diameter-changing surface 211a of the first constricted section 211 is located outside the connecting port 222a, the gap 410 is formed by the area between the inner diameter-changing surface 211a of the first constricted section 211 and the outer peripheral wall of the proximal end of the outlet pipe 220. Therefore, when blood flows within the gap 410 to its distal end, at least a portion of the blood adheres to the inner diameter-changing surface 211a of the first constricted section 211, and is obliquely guided by the inner diameter-changing surface 211a to the connecting port 222a of the outlet pipe 220, allowing the blood within the gap 410 to pass more smoothly through the connecting port 222a and enter the proximal end of the outlet pipe 220.

[0081] Clearly, the blood entering the proximal end of the outlet pipe 220 from the connecting port 222a is further guided by the first variable diameter surface 112a of the shaft support 112 to flow towards the distal end of the outlet pipe 220. In other words, the inner variable diameter surface 211a of the first constricted section 211 and the first variable diameter surface 112a of the shaft support 112 respectively cooperate on the inner and outer sides of the connecting port 222a to guide the blood flow, so that the blood can flow smoothly from the connecting port 222a into the outlet pipe 220 through the gap 410, which can both accelerate the blood flow and reduce blood collision damage.

[0082] Please see Figure 4 , Figure 5 and Figure 7 The flow channel formed by the gap between the first variable diameter surface 112a and the inner variable diameter surface 211a of the first constriction section 211 is denoted as the first guide flow channel 411, which is part of the gap 410. In one embodiment, the distance L1 between the first variable diameter surface 112a and the inner variable diameter surface 211a gradually increases in the direction from the outlet pipe 220 to the motor 110 to the impeller 120 (i.e., from M1 to M2). The distance L1 is also equivalent to the width of the first guide flow channel 411. Thus, the cross-section of the first guide flow channel 411 is approximately a gradually expanding trumpet shape, which facilitates the guidance of blood from the inlet pipe 210 through the connecting port 222a to the outlet pipe 220.

[0083] Please see Figure 4 , Figure 5 and Figure 15The first constricted section 211 also has an outer diameter-changing surface 211b facing away from the inner diameter-changing surface 211a. The diameter of the outer diameter-changing surface 211b of the first constricted section 211 decreases in the same direction as the inner diameter-changing surface 211a. The outer diameter-changing surface 211b can be accommodated within the right ventricle 24 to allow the surface of the pulmonary valve 25 facing the right ventricle 24 to contact and engage. That is, when the blood pump 10 intervenes in the right ventricle 24, the first constricted section 211 of the inlet tube 210 of the blood pump 10 is located within the right ventricle 24. The pulmonary valve 25 has a valve side surface 25a facing the right ventricle 24; the outer diameter-changing surface 211b of the first constricted section 211 has a similar shape to the valve side surface 25a of the pulmonary valve 25, thereby being able to be adhered and clamped by the valve side surface 25a, improving the stability of the blood pump 10 on the pulmonary valve 25. Furthermore, the diameter of the distal end of the first constriction section 211 or the position of the outlet tube 220 adjacent to the first constriction section 211 is smaller, and the force on the pulmonary valve 25 clamping at this position is also smaller, thereby reducing the force on the pulmonary valve 25 and reducing damage to the pulmonary valve 25.

[0084] Please continue reading. Figure 7 The flow channel formed by the radially spaced arrangement of the motor body 111 and the inlet pipe 210 is designated as the first conveying flow channel 413, which is also a component of the gap 410. In one embodiment, the first constriction section 211 has a first axial length D1, and the main body section 213 has a second axial length D2, where 1 / 4D2≤D1≤1 / 3D2. That is, the axial length of the first guiding flow channel 411 is between 1 / 4 and 1 / 3 of the axial length of the first conveying flow channel 413. This ensures that the first guiding flow channel 411 has sufficient length to drain blood, allowing effective drainage of blood on both the inner and outer sides of the connecting port 222a, thus improving the smoothness of blood flow from the first conveying flow channel 413 through the first guiding flow channel 411 into the outlet pipe 220.

[0085] Please see Figure 4 and Figure 9In one embodiment, the inlet pipe 210 includes a main body section 2133 and a second constricted section 212 connected to the proximal end of the main body section 2133. The proximal end of the second constricted section 212 is fixed to the motor 110 or the conduit 12, and the diameter of the second constricted section 212 gradually increases along the direction from the motor 110 to the impeller 120 (i.e., from M1 to M2). The inlet port 214 extends axially from the second constricted section 212 onto the main body section 213. This provides, on the one hand, a larger axial size for the inlet port 214 to facilitate blood flow. On the other hand, since the gap 410 is approximately located on the outer periphery of the blood pump 10, the diameter of the second constricted section 212 is designed to gradually increase from the proximal end to the distal end, allowing the inner wall surface of the second constricted section 212 to guide radially inner blood into the gap 410 near the outer periphery, thereby improving blood flow at the inlet port 214.

[0086] Please see Figure 4 , Figure 7 and Figure 9 In one embodiment, the inlet 214 includes a first inlet area 214a and a second inlet area 214b. The first inlet area 214a is located on the second constriction section 212, and the second inlet area 214b is located on the main body section 213. The first inlet area 214a has a first width S1 along the circumference of the inlet pipe 210, and the second inlet area 214b has a second width S2 along the circumference of the inlet pipe 210. The second width S2 is greater than the first width S1, and the first width S1 gradually increases along the direction from the conduit 12 to the motor 110 (i.e., from M1 to M2). This arrangement is equivalent to gradually increasing the inlet area of ​​the inlet 214 along the blood flow direction, which not only facilitates guiding blood to gradually flow into the inlet 214 from near to far, but also increases the inlet area of ​​the inlet 214.

[0087] Please see Figure 4 , Figure 7 and Figure 8 In one embodiment, the motor 110 further includes a proximal end cap 113, which is disposed at the proximal end of the motor body 111 and connects the motor body 111 and the conduit 12 to accommodate the connection between the motor body 111 and the conduit 12. The proximal end cap 113 is located inside the inlet 214 and has the function of guiding blood entering from the inlet 214 into the gap 410.

[0088] Specifically, the motor body 111 can be housed within the main body section 213. The proximal end cap 113 is fixedly connected to the conduit 12, and the proximal end cap 113 can be connected to the proximal end of the inlet pipe 210 through the conduit 12. The outer peripheral surface of the proximal end cap 113 is provided with a second diameter-changing surface 113a, the diameter of which gradually increases along the direction from the conduit 12 to the motor 110 (i.e., from M1 to M2). The second diameter-changing surface 113a is located inside the liquid inlet 214, and the second diameter-changing surface 113a and the second constriction section 212 are radially opposite each other, forming a second guide channel 412 between them, which is the front end of the gap 410.

[0089] When blood enters the second guide channel 412 of the gap 410 from the inlet 214, at least part of the blood comes into contact with the second variable diameter surface 113a. Under the suction of the impeller 120, this part of the blood is driven to flow along the wall of the second variable diameter surface 113a to the first delivery channel 413 of the gap 410, so as to effectively guide the blood that has just flowed into the blood pump 10 to the distal end, improve the blood flow at the inlet 214, and reduce the risk of blockage at the inlet 214.

[0090] Furthermore, the second variable diameter surface 113a extends from the interior of the main body section 213 to the interior of the second constricted section 212, such that the proximal portion of the second variable diameter surface 113a is radially opposite to the inlet 214, and the distal portion of the second variable diameter surface 113a is radially opposite to the inner wall surface of the main body section 213. That is, the inner wall surface of the main body section 213 radially blocks the distal portion of the second variable diameter surface 113a. The purpose of this arrangement is that the blood just discharged from the distal portion of the second variable diameter surface 113a has a tendency to flow obliquely in the radial direction; by making the distal portion of the second variable diameter surface 113a radially opposite to the inner wall surface of the main body section 213, when the blood discharged from the distal portion of the second variable diameter surface 113a flows obliquely in the radial direction and comes into contact with the inner wall surface of the main body section 213, it can be blocked by the inner wall surface of the main body section 213 and guided to flow axially into the first delivery channel 413, thereby reducing the resistance of blood entering the first delivery channel 413.

[0091] Please see Figure 10 and Figure 11 In one embodiment, the inner wall surface of the inlet pipe 210 is provided with a plurality of guide fins 216. The plurality of guide fins 216 are arranged at intervals along the circumference of the inlet pipe 210. Each guide fin 216 extends along the axial direction of the inlet pipe 210. The guide fins 216 can guide the blood at various points around the gap 410 to flow axially to the distal end.

[0092] Please continue reading. Figure 10 and Figure 11In one embodiment, the inlet 214 includes a plurality of first openings 214c arranged circumferentially along the inlet pipe 210, with a partition wall 217 formed between adjacent first openings 214c. A plurality of guide fins 216 correspond one-to-one with the plurality of partition walls 217, and the proximal end of each guide fin 216 extends at least partially to the inner wall surface of the partition wall 217. Because the proximal end of each guide fin 216 extends at least partially to the inner wall surface of the partition wall 217, blood entering the blood pump 10 from the first openings 214c can first contact the guide fins 216. Therefore, the guide fins 216 can guide and restrict the blood flowing into the blood pump 10 from the first openings 214c to flow axially to the distal end, reducing the occurrence of circumferential interference between the blood flows entering the blood pump 10 from each opening, thus improving the blood flow smoothness at the inlet 214. Simultaneously, the one-to-one correspondence between the guide fins 216 and the partition walls 217 also increases the structural strength of the partition walls 217.

[0093] Please also see Figure 10 and Figure 11 In one embodiment, the first height H1 of the proximal end of the guide fin 216 protruding from the inner wall of the inlet pipe 210 gradually increases along the direction from the conduit 12 to the motor 110. Thus, as blood flows from the proximal end to the distal end into the inlet 214, the guide fin 216 gradually provides a separating effect on the blood, gradually guiding and separating it, reducing the occurrence of abrupt obstruction that could impede blood flow. The second height H2 of the distal end of the guide fin 216 protruding from the inner wall of the inlet pipe 210 gradually decreases along the direction from the conduit 12 to the motor 110, thereby relatively increasing the space available for blood flow within the gap 410 and facilitating blood convergence.

[0094] Please see Figure 12 In one embodiment, the motor body 111 includes a cylindrical shell 101, a first rotor 103, a second rotor 105, a stator 104, and a rotating shaft 106. The first rotor 103, the second rotor 105, and the stator 104 are disposed within the cylindrical shell 101, and the rotating shaft 106 passes through the cylindrical shell 101. The distal end of the cylindrical shell 101 is connected to a shaft support 112, and the proximal ends of the cylindrical shell 101 are connected to each other. The rotating shaft 106 passes through the shaft support 112 and is connected to an impeller 120. The motor 110 drives the impeller 120 to rotate, thereby promoting blood flow. The first rotor 103, the second rotor 105, the stator 104, and the rotating shaft 106 are all disposed within the motor body 111. The first rotor 103, the stator 104, and the second rotor 105 are sequentially fitted onto the rotating shaft 106, and the first rotor 103 and the second rotor 105 are fixedly connected to the rotating shaft 106. The stator 104 generates a rotating magnetic field that drives the first rotor 103 and the second rotor 105 to rotate. When the first rotor 103 and the second rotor 105 rotate, they drive the shaft 106 to rotate. The shaft 106 is connected to the impeller 120 to drive the impeller 120 to rotate.

[0095] Please see Figure 11 In one embodiment, the cylindrical shell 101 and the main body section 213 of the inlet pipe 210 form a first delivery channel 413. Along the axial direction of the blood pump 10, the radial dimensions of the cylindrical shell 101 and the main body section 213 are approximately the same. Therefore, the width of the first delivery channel 413, formed by the cylindrical shell 101 and the main body section 213, remains approximately constant along the axial direction of the blood pump 10, thereby enabling stable blood delivery.

[0096] Please see Figure 13 In one embodiment, the outlet pipe 220 includes a first pipe section 221 and a second pipe section 222 connected to the first pipe section 221. The first pipe section 221 is provided with the liquid outlet 220a. The second pipe section 222 extends into the inlet pipe 210 and is provided with a connecting port 222a. The second pipe section 222 is used to connect to the motor 110. The inner cavity of the outlet pipe 220 is designated as the second delivery channel 420. The connecting port 222a communicates with the second delivery channel 420, and the second delivery channel 420 communicates with the gap 410 through the connecting port 222a. Thus, the inlet 214 communicates with the outlet 220a through the gap 410 and the second delivery channel 420, thereby forming a blood flow channel 400 within the blood pump 10.

[0097] Please see Figure 4 and Figure 6 In one embodiment, the outer diameter of the first pipe segment 221 is larger than the outer diameter of the second pipe segment 222, so that a step portion 223 is formed between the outer peripheral surface of the second pipe segment 222 and the outer peripheral surface of the first pipe segment 221. A first insertion portion 215 is provided at the distal end of the inlet pipe 210. The end face of the first insertion portion 215 abuts against the step portion 223. The positioning effect of the step portion 223 allows the first insertion portion 215 to be quickly inserted into place, improving the efficiency and accuracy of the connection between the inlet pipe 210 and the outlet pipe 220. The outer surface of the first insertion portion 215 is flush with the outer peripheral surface of the second pipe segment 222, so that the overall outer peripheral surface of the shell tube 200 is smooth and regular, facilitating movement within the blood vessels and heart 20. Please refer to [link to relevant documentation]. Figure 9 and Figure 6 In one embodiment, the first insertion portion 215 may be located at the distal end of the first narrowed section 211.

[0098] Please see Figure 5 , Figure 13 and Figure 14In one embodiment, the distal end of the motor 110 is provided with a shoulder 102. The proximal end of the second tube segment 222 is provided with a second insertion portion 222b, the end face of which abuts against the shoulder 102. The positioning effect of the shoulder 102 allows the second tube segment 222 to be quickly inserted into the motor 110, improving the efficiency and accuracy of the assembly of the outlet tube 220 and the motor 110. The outer peripheral surface of the second insertion portion 222b is flush with the outer peripheral surface of the motor 110. Since the outer peripheral surface of the motor 110 is part of the enclosing blood flow channel 400, it will be in contact with blood; and since the second insertion portion 222b is inserted into the motor 110, its outer peripheral surface can also contact blood. Therefore, by setting the outer peripheral surface of the second insertion portion 222b to be flush with the outer peripheral surface of the motor 110, blood flow resistance can be reduced and blood flow smoothness improved.

[0099] Furthermore, the thickness of the second insertion portion 222b is greater than the thickness of the second pipe segment 222. This improves the stability of the connection between the second pipe segment 222 and the drive unit 100, and also balances the weakening of the structural strength near the end of the outlet pipe 220 caused by the opening of the communication port 222a, so as to provide a larger communication port 222a.

[0100] Optionally, in one embodiment, a rounded corner R is provided at the connection between the inner wall surface of the second insertion part 222b and the inner wall surface of the second tube segment 222, so that the outer surface of the second insertion part 222b is smooth and facilitates the flow of blood at the communication port 222a.

[0101] Please see Figure 13 In one embodiment, the outlet 220a includes a plurality of second openings 220b, which are arranged at intervals along the circumference of the shell tube 200 to allow blood to flow from the shell tube 200 to various parts of the blood pump 10, thereby improving the outflow efficiency of the blood pump 10. Each second opening 220b extends in a strip shape along the axial direction of the shell tube 200 to ensure that the axially flowing blood flows fully into the blood pump 10, reducing the risk of blockage.

[0102] In one embodiment, the inlet pipe 210 is made of a rigid material, making it a non-expandable structure. This provides the inlet pipe 210 with strong resistance to blood flow impact, thus stably assisting blood delivery. Furthermore, it stabilizes the shape of the blood flow channel 400 formed by the inlet pipe 210 and the drive unit 100, ensuring stable blood delivery. The rigid material can be metal.

[0103] Similarly, in one embodiment, the outlet pipe 220 can also be made of a rigid material to make it a non-expandable structure. This gives the outlet pipe 220 a stronger ability to resist blood flow impact, thus stably assisting in blood delivery. Furthermore, it stabilizes the shape of the partial blood flow channel 400 formed by the outlet pipe 220, ensuring stable blood delivery. The rigid material can be metal.

[0104] In one embodiment, the proximal portion of the impeller 120 is housed within the second pipe section 222, such that the side of the proximal portion of the impeller 120 faces the connecting port 222a. Therefore, when the impeller 120 rotates, it can more effectively guide blood from the inlet pipe 210 through the connecting port 222a into the outlet pipe 220. Further, the distal portion of the impeller 120 is housed within the first pipe section 221 and is adjacent to or near the outlet 220a. That is, the impeller 120 extends from the second pipe section 222 into the first pipe section 221. Therefore, when the impeller 120 rotates, it can more effectively guide blood from the outlet 220a into the blood pump 10, thereby improving the blood outflow efficiency.

[0105] Please see Figure 13 In one embodiment, the blood pump 10 further includes a pig tail tube (not shown in the figure), and a fixing part 224 is provided at the distal end of the outlet tube 220. The pig tail tube is connected to the fixing part 224 to facilitate the fixing of the distal end of the blood pump 10. The fixing part 224 can be glued to the pig tail tube. The pig tail tube facilitates the fixing of the distal end of the blood pump 10 in the pulmonary artery 26.

[0106] In one embodiment, a glue-containing groove 224a is provided on the outer periphery of the fixing part 224 to hold glue. The pig tail tube is sleeved around the outer periphery of the fixing part 224 and covers the glue-containing groove 224a. The glue-containing groove 224a can increase the glue content between the fixing part 224 and the pig tail tube, thereby improving the stability of the adhesive connection between the fixing part 224 and the pig tail tube.

[0107] Please see Figure 3In one embodiment, the shell tube 200 has a first length L along the axial direction of the drive unit 100. This first length L allows the blood pump 10 to pass through the right atrium 22, right ventricle 24, and pulmonary valve 25 to extend into the pulmonary artery 26, such that the inlet 214 is located within the right ventricle 24, while the outlet 220A is located within the pulmonary artery 26. Since the drive unit 100 and the shell tube 200 constitute the pump body 11 of the blood pump 10, and the drive unit 100 is located inside the shell tube 200, the first length L of the shell tube 200 corresponds to the axial length of the pump body 11 of the blood pump 10. It is understood that the size or anatomical shape of the tissues within the push path of the right ventricle 24 varies slightly among different patients; for example, the size or distance of the tissues within the push path of the right ventricle differs between young and elderly patients, and the requirements for the first length L also differ. Therefore, in practical applications, the length of the first length L should be set according to the patient's actual condition.

[0108] Optionally, the first length L is 20mm-32mm. The first length L can be, but is not limited to, 22mm, 25mm, 28mm, 30mm, 31mm, etc. Specific designs can be tailored to patients of different ages, body types, or conditions, and will not be elaborated upon here.

[0109] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0110] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A blood pump, characterized in that, The blood pump includes: A shell-and-tube assembly, wherein a liquid inlet is provided at the proximal end of the shell-and-tube assembly, and a liquid outlet is provided at the distal end of the shell-and-tube assembly; and A driving unit is disposed inside the shell tube and forms a blood flow channel radially spaced from the inner wall surface of the shell tube, the blood flow channel connecting the inlet and the outlet. The drive unit includes a motor and an impeller connected to the motor; the shell tube includes: An outlet pipe, the proximal end of which is fixedly connected to the distal end of the motor, a communication port is provided on the side wall of the proximal end of the outlet pipe, and the liquid outlet is provided at the distal end of the outlet pipe; and An inlet pipe is sleeved on the outer periphery of the motor. The inlet port is located at the proximal end of the inlet pipe and is fixedly connected to the motor or a conduit. The distal end of the inlet pipe is fixedly connected to the outer peripheral wall of the outlet pipe so that the communication port is accommodated inside the inlet pipe. The inlet pipe includes a main body section and a second constricted section connected to the proximal end of the main body section. The proximal end of the second constricted section is fixedly connected to the proximal end of the motor. The diameter of the second constricted section gradually increases along the direction from the motor to the impeller. The inlet port extends axially from the second constricted section to the main body section. The impeller is housed within the outlet pipe; a gap is provided between the inner wall of the motor and the inlet pipe, and this gap communicates with the connecting port and the inner cavity of the outlet pipe to form the blood flow channel; The distal end of the motor extends into the outlet pipe, and the distal end of the motor has a first variable diameter surface. The first variable diameter surface is located inside the communication port, and the diameter of the first variable diameter surface gradually decreases along the direction from the motor to the impeller.

2. The blood pump of claim 1, wherein, The motor includes a motor body and a shaft support; the shaft support is connected to the far end of the motor body so that the rotating shaft of the motor body can pass through; the shaft support extends into the outlet pipe, and the outer peripheral wall of the shaft support forms the first variable diameter surface.

3. The blood pump of claim 1, wherein, The inlet pipe includes a main body section and a first constricted section connected to the distal end of the main body section. The distal end of the first constricted section is fixed to the outer peripheral wall of the outlet pipe. The first constricted section has an inner diameter-changing surface located outside the communication port. The diameter of the inner diameter-changing surface and the diameter of the first diameter-changing surface are gradually decreasing in the same direction.

4. The blood pump of claim 3, wherein, The distance between the inner diameter-changing surface and the first diameter-changing surface of the first constricted section gradually increases in the direction from the motor to the impeller; and / or, the first constricted section also has an outer diameter-changing surface facing away from the inner diameter-changing surface, the outer diameter-changing surface being accommodating within the right ventricle for contact and engagement of the pulmonary valve's valve side facing the right ventricle; and / or, the first constricted section has a first axial length D1, the main body section has a second axial length D2, and the ratio of the first axial length D1 to the second axial length D2 is 1 / 4 ≤ D1 / D2 ≤ 1 / 3.

5. The blood pump according to claim 1, characterized in that, The inlet includes a first inlet area located on the second constricted section and a second inlet area located on the main body section; wherein, the first inlet area has a first width along the circumference of the inlet pipe, and the second inlet area has a second width along the circumference of the inlet pipe, the second width being greater than the first width; the first width gradually increases along the direction from the conduit to the motor.

6. The blood pump according to claim 5, characterized in that, The motor includes a motor body and a proximal end cover; the proximal end cover is disposed at the proximal end of the motor body and is fixedly connected to the conduit; the outer peripheral surface of the proximal end cover has a second variable diameter surface, and the diameter of the second variable diameter surface gradually increases along the direction from the conduit to the motor. The second variable diameter surface extends from the interior of the main body section to the interior of the second constricted section, such that the proximal portion of the second variable diameter surface is radially opposite to the liquid inlet, and the distal portion of the second variable diameter surface is radially opposite to the inner wall surface of the main body section.

7. The blood pump according to any one of claims 1 to 6, characterized in that, The inlet pipe is made of a rigid material to make it a non-expandable structure; and / or, the outlet pipe is made of a rigid material to make it a non-expandable structure.

8. The blood pump according to any one of claims 1 to 6, characterized in that, The outlet pipe includes a first pipe section and a second pipe section connected to the first pipe section. The first pipe section is provided with the liquid outlet, and the second pipe section extends into the inlet pipe and is provided with the communication port. The proximal portion of the impeller is housed within the second pipe section, such that the side of the proximal portion of the impeller faces the communication port; the distal portion of the impeller is housed within the first pipe section and is adjacent to or close to the liquid outlet.

9. The blood pump according to any one of claims 1 to 6, characterized in that, The inner wall of the inlet pipe is provided with a plurality of guide fins, which are arranged at intervals along the circumference of the inlet pipe, and each guide fin extends along the axial direction of the inlet pipe; wherein, The liquid inlet includes a plurality of first openings arranged circumferentially along the inlet pipe, and a partition wall is formed between two adjacent first openings; the plurality of guide fins correspond one-to-one with the plurality of partition walls, and the proximal end of the guide fin extends at least partially to the inner wall surface of the partition wall. And / or, the first height of the proximal end of the guide fin protruding from the inner wall of the inlet pipe gradually increases along the direction from the conduit to the motor; the second height of the distal end of the guide fin protruding from the inner wall of the inlet pipe gradually decreases along the direction from the conduit to the motor.

10. The blood pump according to any one of claims 1 to 6, characterized in that, The outlet pipe includes a first pipe section and a second pipe section connected to the first pipe section. The first pipe section is provided with the liquid outlet, and the second pipe section extends into the inlet pipe and is provided with the communication port. The outer diameter of the first pipe section is larger than the outer diameter of the second pipe section, so that a step is formed between the outer peripheral surface of the second pipe section and the outer peripheral surface of the first pipe section; the distal end of the inlet pipe is provided with a first insertion part, the end face of the first insertion part abuts against the step, and the outer surface of the first insertion part is flush with the outer peripheral surface of the second pipe section. And / or, the motor has a shoulder at its distal end, and the second pipe section has a second plug at its proximal end, the end face of the second plug abuts against the shoulder, and the outer peripheral surface of the second plug is flush with the outer peripheral surface of the motor; And / or, the thickness of the second connector is greater than the thickness of the second pipe segment; and / or, the connection between the inner wall of the second connector and the inner wall of the second pipe segment is provided with a rounded corner.

11. The blood pump according to any one of claims 1 to 6, characterized in that, The shell tube has a first length along the axial direction of the drive unit; the first length enables the blood pump to pass through the right atrium, right ventricle, and pulmonary valve to extend into the pulmonary artery, such that the inlet is located in the right ventricle and the outlet is located in the pulmonary artery.

12. The blood pump according to claim 11, characterized in that, The first length is 20mm-32mm.

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