Outflow tube, cannula assembly and blood pump
By designing a smooth cross-section for the outlet pipe support, the problem of hemolysis caused by blood contact with the support was solved, improving the safety and efficiency of the blood pump and simplifying the processing.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SHENZHEN CORE MEDICAL TECH CO LTD
- Filing Date
- 2025-11-10
- Publication Date
- 2026-06-04
AI Technical Summary
The outlet tube support of existing blood pumps has sharp angles or edges, which can easily cause hemolysis when blood comes into contact with it, and the polishing process is complicated.
The cross-section of the support column is designed to be circular or elliptical to ensure a smooth perimeter, reduce sharp angles and edges, avoid blood damage, and simplify the manufacturing process.
It reduces the risk of hemolysis, improves blood flow and pumping efficiency, and reduces processing complexity.
Smart Images
Figure CN2025133744_04062026_PF_FP_ABST
Abstract
Description
Outlet tube, cannulation assembly and blood pump
[0001] This application claims priority to Chinese patent application No. 202411713668.0, filed on November 27, 2024, with the Chinese Patent Office, the entire contents of which are incorporated herein by reference. Technical Field
[0002] This application relates to the field of medical device technology, and in particular to an outlet tube, an insertion assembly, and a blood pump. Background Technology
[0003] A blood pump is a percutaneous blood pump inserted into a patient's heart, primarily used to assist in blood circulation. The blood pump has an outlet tube with multiple blood outlets. When the blood pump is working, it draws the patient's blood into the pump, where it is accelerated by an impeller and finally exits through the outlet tube. However, there are supports between adjacent blood outlets in the outlet tube, and these supports have many sharp angles or edges. During the blood's exit from the outlet, the blood collides with these sharp angles or edges, which can easily lead to hemolysis. Summary of the Invention
[0004] Therefore, it is necessary to provide an outlet tube that can reduce hemolysis, a cannulation assembly with said outlet tube, and a blood pump to address the above problems, aiming to reduce the occurrence of hemolysis and lower the risk of blood hemolysis.
[0005] In one embodiment of the outlet tube provided in this application, the outlet tube includes a tube body and a plurality of supports; the tube body has an inner circumferential surface and an outer circumferential surface, the inner circumferential surface enclosing a lumen; the plurality of supports are connected to the proximal end of the tube body, the plurality of supports extend along the axial direction of the tube body and are arranged at intervals along the circumference of the tube body, with a blood outlet spaced between adjacent two supports, the blood outlet communicating with the lumen. The supports have a cross-section perpendicular to the central axis of the outlet tube, and at least one support has a cross-section that is at least one of a circular cross-section and an elliptical cross-section, such that the circumferential surface of the support is a smooth surface.
[0006] This application also provides a cannulation assembly, which includes an inlet tube, an insertion tube, and an outlet tube as described above; the inlet tube is provided with a blood inlet; the proximal end of the insertion tube is fixedly connected to the tube body of the outlet tube; and the distal end of the insertion tube is connected to the inlet tube.
[0007] This application also provides a blood pump, which includes an impeller and the aforementioned outlet pipe, wherein the impeller is rotatably disposed in the cavity of the outlet pipe.
[0008] The aforementioned outlet pipe, by setting the cross-section of the support column to at least one of a circular or elliptical cross-section, allows the circumferential surface of the support column to be smooth. Therefore, when blood exits from the lumen through the blood outlet, regardless of the angle or direction of the blood discharge, the circumferential surface of the support column is less likely to damage or destroy blood cells, thereby reducing hemolysis, effectively lowering the risk of hemolysis, and improving the safety performance of the outlet pipe. Furthermore, the smooth circumference of the support column provides less resistance to blood flow, allowing blood to exit more smoothly and quickly from the blood outlet, which is beneficial for improving pumping efficiency. In addition, after the outlet pipe is formed, because the circumferential surface of the support column is smooth and has no sharp corners or edges, polishing or deburring of the support column can be reduced or eliminated, thus reducing processing steps.
[0009] Details of one or more embodiments of the present invention are set forth in the following drawings and description. Other features, objects, and advantages of the invention will become apparent from the specification, drawings, and claims. Attached Figure Description
[0010] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0011] Figure 1 is a schematic diagram of the structure of a blood pump according to an embodiment of this application.
[0012] Figure 2 is a schematic diagram of the longitudinal section of the blood pump in Figure 1.
[0013] Figure 3 is a schematic diagram of the structure of the outlet pipe of the first embodiment provided in this application.
[0014] Figure 4 is a cross-sectional view along line A1-A1 in Figure 3.
[0015] Figure 5 is a cross-sectional view along line A2-A2 in Figure 3.
[0016] Figure 6 is an enlarged view of point P1 in Figure 5.
[0017] Figure 7 is a schematic diagram of the outlet pipe of the second embodiment provided in this application.
[0018] Figure 8 is a cross-sectional view along line B1-B1 in Figure 3.
[0019] Figure 9 is a schematic diagram of the outlet pipe of the third embodiment provided in this application.
[0020] Figure 10 is a cross-sectional view along line C1-C1 in Figure 3.
[0021] Figure 11 is a schematic diagram of the outlet pipe of the fourth embodiment provided in this application.
[0022] Figure 12 is a front view of the outlet pipe in Figure 11.
[0023] Figure 13 is a cross-sectional view along line D1-D1 in Figure 12.
[0024] Figure 14 is a cross-sectional view along line D2-D2 in Figure 12.
[0025] Figure 15 is an enlarged view of point P2 in Figure 14.
[0026] Figure 16 is a schematic diagram of the outlet pipe of the fifth embodiment provided in this application.
[0027] Figure 17 is a cross-sectional view along line E1-E1 in Figure 16.
[0028] Figure 18 is a cross-sectional view along line E2-E2 in Figure 16.
[0029] Figure 19 is an enlarged view of point P3 in Figure 18.
[0030] Figure 20 is a schematic diagram of the outlet pipe of the sixth embodiment provided in this application.
[0031] Figure 21 is a cross-sectional view along line F1-F1 in Figure 20.
[0032] Figure 22 is a cross-sectional view along line F2-F2 in Figure 16.
[0033] Figure 23 is a cross-sectional view along line F3-F3 in Figure 16.
[0034] Figure 24 is an enlarged view of point P4 in Figure 23. Detailed Implementation
[0035] 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.
[0036] In the description of this application, it should be understood that if the terms "center", "longitudinal", "transverse", "length", "width", "membrane wall thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. 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.
[0037] 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.
[0038] 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.
[0039] 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.
[0040] 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.
[0041] It should be noted that the terms "distal" and "proximal" throughout the text are only used to indicate relative positional relationships. The "distal" end of a component refers to the end that enters the patient's body first and / or is farther from the operator during normal operation, while the "proximal" end refers to the end that enters the patient's body later and / or is closer to the operator. As shown in Figures 1, 3, 7, 9, 12, and 16, Y+ indicates the direction from "proximal" to "distal," and Y- indicates the direction from "distal" to "proximal."
[0042] Referring to Figure 1, the blood pump 10 mentioned in this application is designed as a percutaneous interventional vessel to assist the heart in pumping blood. The blood pump 10 is mainly used to push blood to the left ventricle via the aorta to assist the left ventricle in pumping blood.
[0043] Referring to Figures 1 and 2, the blood pump 10 includes an outlet tube 100 having multiple blood outlets 102. The term "multiple" as used in this application refers to two or more. When the blood pump 10 is in operation, blood passes through the lumen 101 of the outlet tube 100 and then exits outward from the blood outlets 102 to the outside of the blood pump 10.
[0044] Referring to Figures 1 and 2, the blood pump 10 also includes an impeller 300, which is rotatably disposed in a cavity 101 inside the outlet pipe 100. The impeller 300 includes a hub 310 and blades 320 disposed on the hub 310. When the impeller 300 rotates, it can drive blood to flow through the outlet pipe 100.
[0045] Referring to Figures 1 and 2, the blood pump 10 also includes a cannula (not shown in the figures), the proximal end of which is connected to and communicates with the outlet tube 100. The distal end of the cannula has a blood inlet, allowing blood to enter the cannula from the blood inlet and then be transported through the cannula to the outlet tube 100.
[0046] Referring to Figures 1 and 2, the blood pump 10 also includes an inlet tube (not shown in the figures), which is connected to the proximal end of the cannula and has a blood inlet. When the blood pump 10 is operating, blood Q in the left ventricle can enter through the blood inlet of the inlet tube, flow through the lumen of the cannula, and finally exit through the blood outlet 102 of the outlet tube 100. The inlet tube, the cannula, and the outlet tube 100 together form a cannula assembly. Alternatively, the cannula assembly may not have the inlet tube; for example, the blood inlet can be directly provided at the distal end of the cannula.
[0047] Referring to Figures 1 and 2, the blood pump 10 also includes a motor 200, which is connected to the impeller 300, allowing the motor 200 to drive the impeller 300 to rotate. The motor 200 is an in-vivo motor, meaning it can be pushed into the patient's body along with the cannulation assembly.
[0048] Referring to Figures 1 and 2, the motor 200 may include a housing 210, a stator 220, a rotor 230, and a shaft 240. The shaft 240 is rotatably mounted on the housing 210; the shaft 240 has a connecting end located outside the housing 210, which is fixedly connected to the impeller 300. The rotor 230 is housed inside the housing 210 and is fixedly connected to the shaft 240. The stator 220 is housed inside the housing 210. The stator 220 is fixedly connected to the housing 210 and is capable of driving the rotor 230 to rotate.
[0049] The housing 210 is cylindrical. The distal end of the housing 210 is fixedly connected to the proximal end of the outlet pipe 100; the proximal end of the housing 210 is fixedly connected to the distal end of the conduit 400. The stator 220 and the rotor 230 are both housed inside the housing 210 and are arranged at intervals along the axial direction of the housing 210.
[0050] The number of rotors 230 can be one, two, or more. Specifically, in this embodiment, there are two rotors 230, which are located on opposite sides of the stator 220 along its axial direction. Each rotor 230 may include multiple magnets, which are arranged in a ring along the outer periphery of the shaft 240. For example, the multiple magnets are arranged in a Hellbeck array magnetic ring.
[0051] The number of stators 220 can be one, two, or more. One stator 220 can drive at least one rotor 230 to rotate. Specifically, in this embodiment, the number of stators 220 is two. Each stator 220 can drive at least one rotor 230 to rotate.
[0052] Referring to Figures 1 and 2, the blood pump 10 also includes a catheter 400, which is fixedly connected to the proximal end of the motor 200. The catheter 400 is used to accommodate the wires, flushing lines, and other components of the motor 200.
[0053] In other embodiments, the motor 200 is an external motor connected to a flexible shaft that passes through a conduit 400 such that the distal end of the flexible shaft is connected to an impeller 300, thereby driving the motor 200 to rotate by driving the flexible shaft to twist.
[0054] Referring to Figures 1 and 2, the outlet tube 100 includes a tube body 110. The tube body 110 has an inner circumferential surface 111 and an outer circumferential surface 112, the inner circumferential surface 111 enclosing a lumen 101. The tube body 110 has a proximal end and a distal end, through which blood can flow from the distal end through the lumen 101 to the proximal end.
[0055] The outlet tube 100 also includes multiple supports 120, which are connected to the proximal end of the tube body 110. The supports 120 extend axially along the tube body 110 and are arranged at intervals circumferentially along the tube body 110. A blood outlet 102 is spaced between adjacent supports 120 and communicates with the lumen 101. Blood can be discharged from the proximal end of the tube body 110 through the blood outlet 102 to the outside of the blood pump.
[0056] In some related technologies, the support column 120 is generally a prism, meaning that the cross-section of the support column 120 perpendicular to the central axis O1 of the outlet pipe 100 is polygonal, resulting in numerous sharp angles or edges on the peripheral surface of the support column 120. When blood is discharged from the blood outlet 102, the blood comes into contact with and collides with the sharp angles or edges of the support column 120, which can easily lead to hemolysis. To reduce the sharp angles or edges on the peripheral surface of the support column 120, the commonly used method in related technologies prior to this application is to polish and deburr the sharp angles or edges on the peripheral surfaces of the multiple support columns 120 of the outlet pipe 100 after the outlet pipe 100 is formed, so as to round or chamfer the sharp angles or edges. However, this method cannot completely remove the sharp angles or edges on the peripheral surface of the support column 120, and the processing is also relatively cumbersome.
[0057] Referring to Figures 3 to 5, in this application, to reduce hemolysis problems, the support 120 has a cross-section perpendicular to the central axis O1 of the outlet pipe 100. At least one support 120 has a cross-section that is at least one of a circular cross-section S1 and an elliptical cross-section S2, so that the circumferential surface of the support 120 is a smooth surface. It is understood that the outline of the cross-section of the support 120 is a smooth, rounded annular curve without sharp edges, thereby making the circumferential surface of the support 120 a smooth surface, such as a circular cross-section S1 or an elliptical cross-section S2.
[0058] It is understood that the statement that the cross-section of at least one support 120 is at least one of a circular cross-section and an elliptical cross-section means that the cross-section of the support 120 is either a circular cross-section or an elliptical cross-section from its distal end to its proximal end; or, the support 120 is divided into different segments along its length, wherein one segment has a circular cross-section and another segment has an elliptical cross-section. Further details will be provided later.
[0059] Furthermore, the shapes of the multiple supports 120 of the outlet pipe 100 may be the same or different. In some embodiments, all supports 120 have a circular cross-section S1, that is, all supports 120 are cylinders. In other embodiments, all supports 120 have an elliptical cross-section S2, that is, all supports 120 are elliptical cylinders. In still some embodiments, some supports 120 are cylinders; the remaining supports 120 are elliptical cylinders.
[0060] The aforementioned outlet pipe 100, by setting the cross-section of the support column 120 to at least one of a circular cross-section S1 and an elliptical cross-section S2, allows the peripheral surface of the support column 120 to be a smooth surface. Therefore, when blood flows out from the lumen 101 through the blood outlet 102, regardless of the angle or direction of the blood flow, the peripheral surface of the support column 120 is less likely to damage or destroy blood cells, thereby reducing the occurrence of hemolysis, effectively lowering the risk of hemolysis, and improving the safety performance of the outlet pipe 100. Furthermore, the smooth peripheral surface of the support column 120 provides less resistance to blood flow, allowing blood to flow out of the blood outlet 102 more smoothly and quickly, which is beneficial for improving pumping efficiency. In addition, after the outlet pipe 100 is formed, because the peripheral surface of the support column 120 is smooth and has no sharp corners or edges, polishing and deburring of the support column 120 can be performed with little or no effort, thus reducing processing steps.
[0061] In this application, the number of pillars 120 can be 2 to 4, for example, 2, 3 or 4.
[0062] The following provides a detailed description of specific embodiments of the outlet pipe 100 in this application.
[0063] Figures 3 to 6 illustrate the outlet pipe 100A according to the first embodiment of this application. Referring to Figures 3 to 5, in the first embodiment, the cross-section of the support 120 is specifically a circular cross-section S1. The outline of the circular cross-section S1 is a circular curve. From the far end to the near end of the support 120, the cross-section of the support 120 is a circular cross-section S1. This makes the circumferential surface of the support 120 a circular circumferential surface, and the circumferential surface of the support 120 is smoother.
[0064] Specifically, the pipe body 110 of the outlet pipe 100A also has a proximal end face 113, and the distal ends of the plurality of supports 120 can be directly connected to the proximal end face 113 of the pipe body 110. The outlet pipe 100A has a central axis O1; the supports 120 have a central axis O2, and the central axis O2 of the supports 120 is parallel to the central axis O1 of the outlet pipe 100A. Thus, the supports 120 become long, straight cylinders extending along the axial direction of the outlet pipe 100A.
[0065] Under essentially the same conditions (e.g., similar length and cross-sectional area), compared to traditional prisms, the support column 120 in this embodiment is a cylinder, eliminating sharp edges and corners. This allows pressure to be evenly distributed across the entire column, enabling it to withstand greater weight. The force characteristics of the support column 120 ensure that the force is highly uniform and symmetrical throughout, reducing the risk of damage to the contact surfaces. Consequently, the support column 120 has a strong load-bearing capacity, thus improving its pushing ability. During the insertion of the blood pump 10 into the patient's body, the support column 120 effectively transmits the pushing force to the cannula of the blood pump 10, reducing the difficulty of insertion and improving its pushing performance.
[0066] Because the support column 120 of this application has a strong load-bearing capacity, the number of support columns 120 on one outlet pipe 100A can be relatively reduced. For example, when the support column of a conventional outlet pipe is a prism, at least 5 to 6 support columns are required; while the number of support columns 120 required for the outlet pipe 100A of this application can be reduced to 2 to 4, with 3 being preferred. Thus, the number of support columns 120 in the outlet pipe 100A of this application is smaller, resulting in a larger outlet area of the blood outlet 102 of the outlet pipe 100A, thereby increasing the amount of blood transported by the outlet pipe 100A.
[0067] Referring to Figures 4 to 6, the circumferential surface of the support column 120 includes an inner portion 123 facing the central axis O1 of the outlet pipe 100A and an outer portion 124 facing away from the central axis O1 of the outlet pipe 100A. The outer portion 124 and the inner portion 123 together form the circumferential surface of the support column 120.
[0068] It is understandable that the diameter Φ1 of the support 120 can be equal to the wall thickness H of the pipe body 110, i.e., Φ1 = H. In this way, the radial thickness of the support 120 is exactly equal to the wall thickness of the pipe body 110, and the distal end of the support 120 can be fitted and connected to the proximal end face 113 of the pipe body 110. The inner portion 123 of the support 120 will not protrude radially inward relative to the inner circumferential surface 111 of the pipe body 110 along the radial direction of the outlet pipe 100A; the outer portion 124 of the support 120 will not protrude radially outward relative to the outer circumferential surface 112 of the pipe body 110 along the radial direction of the outlet pipe 100A.
[0069] In other words, the support 120 is located between the inner circumferential surface 111 of the tube 110 and the outer circumferential surface 112 of the tube 110. The outer portion 124 of the support 120 is tangent to the outer circumferential surface 112 of the tube 110, and the inner portion 123 of the support 120 is tangent to the inner circumferential surface 111 of the tube 110.
[0070] Specifically, the outer portion 124 of the support 120 does not protrude radially outward relative to the outer peripheral surface 112 of the tube body 110 along the outlet pipe 100A, which reduces the contact friction between the support 120 and the inner wall of the blood vessel during the pushing of the blood pump 10. The inner portion 123 of the support 120 does not protrude radially inward relative to the inner peripheral surface 111 of the tube body 110 along the outlet pipe 100A, which makes it less likely for the inner portion 123 of the support 120 to interfere with the impeller 300 arranged in the outlet pipe 100A.
[0071] Specifically, there is a first radial distance L1 between the inner circumferential surface 111 of the tube body 110 and the blades 320 of the impeller 300, and a second radial distance L2 between the circumferential surface (specifically the inner portion 123) of the support column 120 and the blades 320 of the impeller 300. Since the inner portion 123 of the support column 120 is tangent to the cylindrical surface of the inner circumferential surface 111 of the tube body 110, the second radial distance L2 is equal to the first radial distance L1, i.e., L2 = L1. This avoids interference when the impeller 300 rotates and contacts the support column 120.
[0072] In this embodiment, the diameter Φ1 of the support column 120 is set to be greater than the wall thickness H of the tube body 110, i.e., Φ1 > H. This increases the strength of the support column 120, making it less prone to bending and deformation, and improving its pushing capacity. At this time, the inner portion 123 of the support column 120 protrudes inward relative to the inner circumferential surface 111 of the tube body 110 along the radial direction of the outlet pipe 100A; or, the outer portion 124 of the support column 120 protrudes outward relative to the outer circumferential surface 112 of the tube body 110 along the radial direction of the outlet pipe 100A.
[0073] However, since the support 120 is a cylinder, even if the inner part 123 of the support 120 protrudes slightly inward along the radial direction of the outlet pipe 100A relative to the inner circumferential surface 111 of the pipe body 110, the inner part 123 of the support 120 does not have any sharp edges or corners, so the inner part 123 of the support 120 is not likely to damage the blood inside the outlet pipe 100A.
[0074] Similarly, even if the outer portion 124 of the support 120 protrudes slightly outward along the radial direction of the outlet pipe 100A relative to the outer peripheral surface 112 of the tube body 110, the outer portion 124 of the support 120 is not prone to scraping and damaging the inner wall of the blood vessel because it has no sharp edges or corners.
[0075] It is understood that the diameter Φ1 of the support 120 should be slightly larger than the wall thickness H of the tube body 110, i.e., the difference between the two should not be too large. Optionally, the ratio of the diameter Φ1 of the support 120 to the wall thickness H of the tube body 110 can be 1.15 to 1.35, i.e., the ratio of Φ1 / H is 1.15 to 1.35. Within this range, the difference between the diameter Φ1 of the support 120 and the wall thickness H of the tube body 110 will not be too large, so that the inner part 123 of the support 120 will not excessively protrude from the inner circumferential surface 111 of the tube body 110, avoiding interference of the support 120 with the impeller 300; the outer part 124 of the support 120 will also not excessively protrude from the outer circumferential surface 111 of the tube body 110, reducing the scraping of the inner wall of the blood vessel by the support 120. The ratio can be, but is not limited to, 1.18, 1.2, 1.22, 1.25, 1.28, 1.30, 1.33, etc.
[0076] Since the diameter Φ1 of the support column 120 is greater than the wall thickness H of the pipe body 110, when the inner portion 123 of the support column 120 protrudes slightly inward relative to the inner circumferential surface 111 of the pipe body 110 along the radial direction of the outlet pipe 100A, the second radial distance L2 between the circumferential surface of the support column 120 (specifically the inner portion 123) and the blade 320 of the impeller 300 will be less than the first radial distance L1 between the inner circumferential surface 111 of the pipe body 110 and the blade 320 of the impeller 300, i.e., L2 < L1. To avoid interference between the inner portion 123 of the support column 120 and the blade 320 of the impeller 300, optionally, the second radial distance L2 is not less than 0.8 times the first radial distance L1, i.e., L2 ≥ 0.8L1. The value of L1 can be, but is not limited to, 0.82L1, 0.85L1, 0.9L1, 0.95L1, etc. For example, the first radial distance L1 is typically in the range of 0.1mm to 0.12mm; therefore, the first radial distance L1 is at least 0.08mm. Since L2 ≥ 0.8L1, it can be ensured that the second radial distance L2 is not too small, thus avoiding interference between the inner portion 123 of the support 120 and the blade 320 of the impeller 300.
[0077] Referring to Figures 4 to 6, since the inner portion 123 protrudes radially inward relative to the inner circumferential surface 111 of the tube body 110 along the outlet pipe 100A, if a radially protruding step surface is formed at the connection between the distal end of the support 120 and the inner portion 123 of the tube body 110, then when blood flows from the lumen 101 to the blood outlet 102 between the two supports 120, the step surface may generate a certain resistance to blood flow.
[0078] In view of the above, in this embodiment, the inner circumferential surface 111 of the tube body 110 is provided with a connecting portion 114. The connecting portion 114 is sloped, so that the connecting portion 114 has a transition slope 114a. The transition slope 114a smoothly connects the inner circumferential surface 111 of the tube body 110 and the inner side portion 123 of the circumferential surface of the support 120. This allows the inner side portion 123 of the support 120 to smoothly transition to the inner circumferential surface 111 of the tube body 110 along the transition slope 114a. A portion of the blood in the lumen 101 can flow along the transition slope 114a into the inner side of the support 120, thereby preventing the blood from directly impacting the distal end of the support 120.
[0079] Optionally, the transition slope 114a can be any one of a sloped plane, a concave arc surface, or a convex arc surface. The connecting part 114 can be made of materials such as solder or solid adhesive. The connecting part 114 can also be a protrusion integrally formed with the tube body 110.
[0080] Furthermore, the support 120 is located entirely inside the cylindrical surface of the outer peripheral surface 112 of the tube body 110, with the outer portion 124 of the support 120 being tangent to the cylindrical surface of the outer peripheral surface 112 of the tube body 110. This prevents the outer portion 124 of the support 120 from protruding radially outward relative to the outer peripheral surface 112 of the tube body 110. During the process of pushing the blood pump 10 into the patient's blood vessel, the outer portion 124 of the support 120 is less likely to scrape against the inner wall of the blood vessel.
[0081] For the proximal end face 113 of the tube body 110, the proximal end face 113 of the tube body 110 is divided into multiple sub-end faces by multiple supports 120, and the multiple sub-end faces are arranged along the circumferential direction of the tube body 110; the connection between the sub-end faces and the far ends of the supports 120 is provided with a rounded portion 115.
[0082] Regarding the connection between the proximal end of the outlet pipe 100A and the motor 200 of the blood pump 10, generally speaking, the proximal end of the support 120 of the outlet pipe 100A is directly welded to the distal end of the motor 200. However, when welding each support 120 to the motor 200 one by one, operational errors are often prone to occur, making it difficult to ensure that each support 120 maintains a uniform second radial distance L2 with the impeller 300.
[0083] This application takes into account that the housing 210 of the motor 200 generally has a distal opening, and is connected to the housing 210 via a motor cover 130 to cover the distal opening of the housing 210. The motor cover 130 has a mounting opening 131 for accommodating a bushing or bearing 250 that supports the rotation of the rotating shaft 240. Therefore, the proximal end of the support column 120 can be connected to the motor cover 130, making the support column 120 and the motor cover 130 integrally formed. After forming, the distance from each support column 120 to the central axis of the motor cover 130 remains consistent. Thus, when the motor cover 130 and the housing 210 of the motor 200 are connected, it is only necessary to align the central axis of the motor cover 130 with the central axis of the rotating shaft 240 (i.e., the central axis of the impeller 300), thereby ensuring that the second radial distance L2 between each support column 120 and the impeller 300 remains substantially consistent.
[0084] Of course, the motor cover 130 is not essential. In other embodiments, the outlet pipe 100A also includes a connecting ring 150 as shown in FIG. 11, which is connected to the proximal end of the support column 120 and can be fixed to the distal end of the motor 200 of the blood pump 10. The connecting ring 150 can be integrally formed with the support column 120. After aligning the central axis of the connecting ring 150 with the central axis of the motor 200, the second radial distance L2 between each support column 120 and the impeller 300 can also be substantially consistent.
[0085] Figures 7 and 8 illustrate the outlet pipe 100B according to a second embodiment of this application. In this second embodiment, the outlet pipe 100B differs from the outlet pipe 100A of the previous embodiment in that a transition slope 12a is provided at the distal end of the support column 120. The distal end of the transition slope 12a is smoothly connected to the inner circumferential surface 111 of the pipe body 110, and extends obliquely from the position of the smooth connection along the direction from the pipe body 110 to the support column 120 (i.e., the Y-direction) to the inner side portion 123 of the support column 120; the distance between the transition slope 114a and the central axis O1 of the outlet pipe 100B gradually decreases in this extension direction.
[0086] Specifically, the distal end face of the support 120 connects to the proximal end face 113 of the tube body 110; the distal end of the transition slope 12a intersects with the distal end face of the support 120 and smoothly connects to the inner circumferential surface 111 of the tube body 110. The transition slope 12a extends obliquely along the Y-direction and gradually approaches the central axis O1 of the outlet tube 100B, intersecting with the inner portion 123. Since the support 120 is a cylinder, the intersection line M of the inner portion 123 of the support 120 and the transition slope 12a is a smooth teardrop shape, resulting in less resistance to blood flowing along the transition slope 12a towards the inner side of the support 120. The stress around the periphery of the transition slope 12a is also less, making it less likely to damage blood cells.
[0087] Of course, the intersection of the inner part 123 of the support column 120 and the transition slope 12a can also be rounded to make the connection between the inner part 123 and the transition slope 12a smooth and without sharp corners.
[0088] Alternatively, the transition slope 12a can also be any one of a sloped plane, a concave arc surface, or a convex arc surface.
[0089] Figures 9 and 10 illustrate the outlet pipe 100C according to the third embodiment of this application. In this third embodiment, the outlet pipe 100C differs from the outlet pipe 100B of the second embodiment in that the proximal end face 113 of the pipe body 110 is provided with a plurality of extension arms 140 arranged circumferentially at intervals along the pipe body 110, and the plurality of extension arms 140 are respectively connected to the distal ends of a plurality of support columns 120. The radial thickness of the extension arm 140 is the same as the pipe wall thickness H of the pipe body 110. The outer arm surface 142 of the extension arm 140 is coplanar with the outer peripheral surface 112 of the pipe body 110; the inner arm surface 141 of the extension arm 140 is coplanar with the inner peripheral surface 111 of the pipe body 110.
[0090] Because the circumferential surface (specifically the inner portion 123) of the support 120 protrudes relative to the inner circumferential surface 111 of the tube body 110, the distal end of the support 120 may obstruct a small portion of the axially flowing blood. However, due to the presence of the extension arm 140, there is an axial distance between the connection between the extension arm 140 and the support 120 and the inner circumferential surface 111 of the tube body 110. When blood flows from the lumen 101 into the space between two adjacent extension arms 140, some blood can be discharged from the blood outlet 102 between the two adjacent extension arms 140, reducing the blood flow rate. Consequently, the flow rate of blood rushing to the connection between the extension arm 140 and the support 120 will be relatively reduced. Even if some blood rushes to the connection between the extension arm 140 and the support 120, the blood, obstructed by this connection, will be diverted to the blood outlets 102 on both sides of the extension arm 140, and will then be discharged from the blood outlets 102 on both sides of the extension arm 140.
[0091] Furthermore, the distal end of the support column 120 is provided with a transition slope 12a, which smoothly connects to the inner arm surface 141 of the extension arm 140. The transition slope 12a extends obliquely from the smooth connection position along the direction from the tube body 110 to the support column 120 to the inner side portion 123 of the circumference of the support column 120. This avoids the formation of a stepped surface at the connection between the support column 120 and the extension arm 140. Blood can flow along the inner arm surface 141 of the extension arm 140 to the transition slope 12a, and then slowly pass through the transition slope 12a, resulting in low blood flow resistance.
[0092] Figures 11 to 15 illustrate the outlet pipe 100D according to the fourth embodiment of this application. Referring to Figures 11 to 14, in this fourth embodiment, the outlet pipe 100D differs from the outlet pipe 100A of the first embodiment in that the cross-section of the support 120 of the outlet pipe 100D is an elliptical cross-section S2. The outline of the elliptical cross-section S2 is an elliptical curve. In this embodiment, from the distal end to the proximal end of the support 120, the cross-section of the support 120 is an elliptical cross-section S2. Thus, the support 120 is an elliptical cylinder, and the circumferential surface of the support 120 is an elliptical circumferential surface, which is also relatively smooth.
[0093] Referring to Figures 13 to 15, specifically, the elliptical cross-section S2 has a minor axis Φ 2x and major axis Φ 2z minor axis Φ 2x It is the radial dimension of the elliptical cross-section S2 along the tube body 110; the major axis Φ 2z It is the elliptical cross section S2 perpendicular to the minor axis Φ 2x The dimension in the direction. Clearly, Φ 2z >Φ 2x The radial thickness of support 120 (i.e., the minor axis Φ) 2x The smaller size of the support column 120 reduces the space occupied by the support column 120 along the radial direction, preventing the support column 120 from interfering with the impeller 300 inside the outlet pipe 100D; while the circumferential width of the support column 120 along the outlet pipe 100D (i.e., the major axis Φ) 2z The larger size can increase the strength of the support column 120 and improve its pushing ability.
[0094] In this embodiment, the minor axis Φ of the elliptical cross section S2 2x and major axis Φ 2z The size remains constant along the direction from the support 120 to the tube body 110 (i.e., the Y+ direction). The minor axis Φ... 2x It can be equal to the wall thickness H of the tube body 110. In this way, the radial thickness of the support 120 is exactly equal to the wall thickness H of the tube body 110, and the distal end of the support 120 can be fitted and connected to the proximal end face 113 of the tube body 110. The inner part 123 of the support 120 will not protrude radially inward relative to the inner circumferential surface 111 of the tube body 110, and the outer part 124 of the support 120 will not protrude radially outward relative to the outer circumferential surface 112 of the tube body 110.
[0095] In other words, the support 120 is located between the inner circumferential surface 111 of the tube 110 and the outer circumferential surface 112 of the tube 110. The outer portion 124 of the support 120 is tangent to the outer circumferential surface 112 of the tube 110, and the inner portion 123 of the support 120 is tangent to the inner circumferential surface 111 of the tube 110.
[0096] The inner portion 123 of the support column 120 does not protrude radially inward relative to the inner circumferential surface 111 of the tube body 110, which makes it less likely for the inner portion 123 of the support column 120 to interfere with the impeller 300 (see Figure 2) inside the outlet pipe 100D. Specifically, there is a first radial distance L1 between the inner circumferential surface 111 of the tube body 110 and the blades 320 of the impeller 300, and a second radial distance L2 between the circumferential surface of the support column 120 and the blades 320 of the impeller 300. Since the inner portion 123 of the support column 120 is tangent to the cylindrical surface of the inner circumferential surface 111 of the tube body 110, the second radial distance L2 is equal to the first radial distance L1, i.e., L2 = L1. This avoids interference between the impeller 300 and the support column 120 when the impeller 300 rotates.
[0097] It is understandable that if the major axis Φ 2z With minor axis Φ 2x The difference is too large; the support column 120 is at the long axis Φ 2z The two ends may form sharp points. Therefore, optionally, the major axis Φ 2z With minor axis Φ 2x The ratio is 1.5 to 3. Within this range, the major axis Φ of the support column 120 can be... 2z With minor axis Φ 2x The difference will not be too large, which can effectively prevent the support column 120 from being too large along its long axis Φ. 2z The two ends form sharp points. The ratio can be, but is not limited to, 1.6, 1.8, 2.0, 2.2, 2.5, 2.8, 2.9, etc.
[0098] In this embodiment, the minor axis Φ of the support column 120 2x Set the pipe wall thickness H to be greater than 110mm, i.e., Φ. 2x >H. This increases the strength of the support column 120, making it less prone to bending and deformation, and improving its pushing capacity. At this time, the inner portion 123 of the support column 120 will protrude inward relative to the inner circumferential surface 111 of the tube body 110 along the radial direction of the outlet pipe 100A; or, the outer portion 124 of the support column 120 will protrude outward relative to the outer circumferential surface 112 of the tube body 110 along the radial direction of the outlet pipe 100A.
[0099] However, since the support 120 is an elliptical cylinder, even if the inner part 123 of the support 120 protrudes slightly inward along the radial direction of the outlet pipe 100A relative to the inner circumferential surface 111 of the pipe body 110, the inner part 123 of the support 120 does not have any sharp edges or corners, so the inner part 123 of the support 120 is not likely to damage the blood inside the outlet pipe 100A.
[0100] Of course, the minor axis Φ 2xThe difference between the pipe wall thickness H of pipe body 110 and the pipe wall thickness H should not be too large. Optionally, the minor axis Φ 2x The ratio of Φ to the wall thickness H of pipe body 110 can be 1.15 to 1.35. That is, Φ 2x The ratio of / H is 1.15 to 1.35. Within this range, the minor axis Φ of the support column 120 can be... 2x The difference between the wall thickness H of the tube body 110 and the inner portion 123 of the support 120 and the inner circumferential surface 111 of the tube body 110 will not be too large, thus preventing the support 120 from interfering with the impeller 300; the outer portion 124 of the support 120 will also not protrude excessively from the outer circumferential surface 111 of the tube body 110, reducing the scraping of the inner wall of the blood vessel by the support 120. The ratio can be, but is not limited to, 1.18, 1.2, 1.22, 1.25, 1.28, 1.30, 1.33, etc.
[0101] Similar to the first embodiment shown in Figures 3 to 6 above, the outlet pipe 100D of this embodiment may also have a connecting part 114 provided on the inner circumferential surface 111 of the pipe body 110 so as to be connected to the support column 120 through the connecting part 114. The transition slope 114a of the connecting part 114 smoothly connects the inner side portion 123 of the pipe body 110 and the circumferential surface of the support column 120.
[0102] Similar to the second embodiment shown in Figures 7 and 8, the outlet pipe 100D in this embodiment may also have a transition slope 12a at the far end of the support column 120, so that the transition slope 12a smoothly connects to the inner part 123 of the pipe body 110. As for the shape and structure of the transition slope 12a, it can be implemented with reference to the second embodiment described above, and will not be repeated here.
[0103] Of course, similar to the third embodiment shown in Figures 9 and 10, the outlet pipe 100D of this embodiment can also have an extension arm 140 provided on the near end face 113 of the pipe body 110, and be connected to the support column 120 through the extension arm 140. The shape and structure of the extension arm 140 and its connection method with the support column 120 are specifically implemented with reference to the third embodiment described above, and will not be repeated here.
[0104] In this embodiment, the outlet pipe 100D further includes a connecting ring 150, which is connected to the proximal end of the support column 120, making the support column 120 and the connecting ring 150 integrally formed. After forming, the distance from the central axis of each support column 120 to the connecting ring 150 remains consistent. Thus, when the connecting ring 150 is connected to the distal end of the motor 200, as long as the central axis of the connecting ring 150 is aligned with the central axis of the impeller 300, the central axes of multiple support columns 120 to the impeller 300 can all be aligned, thereby ensuring that the second radial distance L2 between each support column 120 and the impeller 300 remains consistent.
[0105] Of course, the connecting ring 150 is not essential. In other embodiments (such as the first to third embodiments described above), the outlet pipe 100D also includes a motor cover 130, which is connected to the proximal end of the support column 120 and can cover the distal opening of the housing 210 of the motor 200 of the blood pump 10. The motor cover 130 and the support column 120 are integrally formed. That is, the motor cover 130 can be used instead of the connecting ring 150.
[0106] Figures 16 to 19 illustrate the outlet pipe 100E according to the fifth embodiment of this application. Referring to Figures 16 to 19, in the fifth embodiment, the outlet pipe 100E differs from the outlet pipe 100D of the fourth embodiment described above in that the minor axis Φ of the support 120... 2x and major axis Φ 2z At least one of them gradually changes in the direction along the pipe body 110 to the support 120 (i.e., the Y-direction). Specifically, the minor axis Φ of the support 120 2x From the connection point between the support 120 and the tube body 100 (i.e., the proximal end face 113), the diameter gradually increases along the direction from the tube body 110 to the support 120. This allows the inner portion 111 of the support 120 to form an arcuate surface 12b curved in the Y-direction, and the distance between the arcuate surface 12b and the central axis O1 of the outlet tube 100E gradually decreases in the Y-direction. Thus, the arcuate surface 12b can reduce the occurrence of contact interference with the blades 320 of the impeller 300, and also guide the blood to flow in the Y-direction to the blood outlet 102.
[0107] Obviously, due to the minor axis Φ of the support 120 2x It gradually increases along the Y-direction, thus having a minor axis Φ at the distal end of the support 120. 2x The minimum value of the minor axis Φ. 2x The minimum value is equal to the wall thickness H of the pipe body 110, so the radial thickness of the far end of the support 120 is exactly equal to the wall thickness H of the pipe body 110, and the far circumferential surface of the arc surface 12b can smoothly connect with the inner circumferential surface 111 of the pipe body 110.
[0108] In this embodiment, the major axis Φ of the support column 120 2z It can remain unchanged along the direction from the pipe body 110 to the support 120 (i.e., the Y-direction). This is in conjunction with the aforementioned minor axis Φ of the support 120. 2x The tube gradually increases in size from the tube body 110 to the support 120, resulting in a larger cross-sectional area at the proximal end of the support 120. This provides greater strength to the proximal end of the support 120, making the connection between the proximal end of the support 120 and the motor 200 more secure. However, the flow rate at the proximal end of the support 120 is relatively low. Even with a slightly larger cross-sectional area at the proximal end of the support 120, its impact on blood flow is small and almost negligible.
[0109] Of course, in other embodiments, the major axis Φ of the support column 120 2z It can also gradually decrease in the direction from the pipe body 110 to the support 120.
[0110] Figures 20 and 24 illustrate the outlet pipe 100F according to a sixth embodiment of this application. Referring to Figures 20 to 23, in this sixth embodiment, the support 120 of the outlet pipe 100F includes a proximal section 121 and a distal section 122 connected together; the proximal section 121 is located away from the pipe body 110; the distal end of the distal section 122 is connected to the proximal end of the pipe body 110. The cross-section of the proximal section 121 is a circular cross-section S1; the cross-section of the distal section 122 is an elliptical cross-section S2. In other words, the proximal section 121 of the support 120 is a cylinder, and the distal section 122 of the support 120 is an elliptical cylinder.
[0111] Referring to Figures 21 to 24, specifically, the cross-section (circular section S1) of the proximal segment 121 has a diameter Φ1. The size of the diameter Φ1 can be referenced to the first embodiment described above, achieving essentially the same effect, and will not be elaborated further here. The cross-section (elliptical section S2) of the distal segment 122 has a minor axis Φ 2x and major axis Φ 2z minor axis Φ 2x It is the radial dimension of the elliptical cross-section S2 along the tube body 110; the major axis Φ 2z It is the elliptical cross section S2 perpendicular to the minor axis Φ 2x The dimension in the direction. Clearly, Φ 2z >Φ 2x Minor axis Φ 2x and major axis Φ 2z The size can be referred to in the fourth embodiment described above, and the same effect can be achieved, so it will not be described in detail here. In addition, the proximal segment 121 can make the support 120 have a stronger pushing ability; while the distal segment 122 can reduce the resistance of the support 120 to the flow of blood along the lumen 101 to the blood outlet 102.
[0112] Specifically, in this embodiment, the minor axis Φ of the distal segment 122 2x The proximal end face 113 of the tube body 100 gradually increases in the direction (i.e., the Y-direction) from the tube body 110 to the support column 120. This allows the inner portion 111 of the distal section 122 to form an arcuate surface 12b curved in the Y-direction, and the distance between the arcuate surface 12b and the central axis O1 of the outlet tube 100F gradually decreases in the Y-direction. Thus, the arcuate surface 12b can reduce the occurrence of contact interference with the blades 320 of the impeller 300, and also guide the blood to flow in the Y-direction to the blood outlet 102.
[0113] Obviously, due to the minor axis Φ of the distal segment 122 2xFrom the connection point between the support 120 and the tube body 100 (i.e., the proximal end face 113), the diameter gradually increases along the direction from the tube body 110 to the support 120, thus having a short axis Φ at the distal end of the distal segment 122. 2x The minimum value of the minor axis Φ. 2x The minimum value is equal to the wall thickness H of the tube body 110, so the radial thickness of the distal end of the distal segment 122 is exactly equal to the wall thickness H of the tube body 110, and thus the distal end of the arc surface 12b can be smoothly connected to the inner circumferential surface 111 of the tube body 110.
[0114] The major axis Φ of the distal segment 122 2z The length can remain constant or gradually decrease along the direction from the pipe body 110 to the support 120 (i.e., the Y-direction). At the junction of the distal section 122 and the proximal section 121, the minor axis Φ of the distal section 122... 2x Major axis Φ 2z The diameter Φ1 of the proximal segment 121 is equal to that of the distal segment 122, allowing for a smooth connection between the circumferential surfaces of the distal segment 122 and the proximal segment 121. Relatively speaking, the proximal segment 121 is cylindrical, which allows it to better transmit pushing force along the Y+ direction; while the distal segment 122 is an elliptical cylinder, which reduces the resistance of the support 120 to the flow of blood along the lumen 101 to the blood outlet 102.
[0115] It is understandable that the distal segment 122 can be integrally formed with the proximal segment 121.
[0116] 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.
[0117] 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. An outlet tube characterized in that, The outlet pipe includes: A tube body having an inner circumferential surface and an outer circumferential surface, the inner circumferential surface enclosing a cavity; and Multiple supports are connected to the proximal end of the tube body. The multiple supports extend along the axial direction of the tube body and are arranged at intervals along the circumference of the tube body. A blood outlet is spaced between two adjacent supports and the blood outlet communicates with the lumen. The support column has a cross-section perpendicular to the central axis of the outlet pipe, and at least one of the cross-sections of the support column is at least one of a circular cross-section and an elliptical cross-section, such that the circumferential surface of the support column is a smooth surface.
2. The outlet tube of claim 1, wherein The cross-section of the support column is circular; the diameter of the support column is greater than or equal to the wall thickness of the pipe body.
3. The outlet pipe according to claim 2, characterized in that, The ratio of the diameter of the support column to the wall thickness of the pipe body is 1.15 to 1.
35.
4. The outlet pipe according to claim 1, characterized in that, The cross-section of the support is circular, and the diameter of the support is equal to the wall thickness of the tube. The support is located between the inner circumferential surface of the tube and the outer circumferential surface of the tube, and is tangent to the inner circumferential surface of the tube.
5. The outlet tube of claim 1, wherein The cross-section of the support is elliptical; the elliptical cross-section has a minor axis along the radial direction of the outlet pipe and a major axis perpendicular to the minor axis, the major axis being larger than the minor axis.
6. The outlet tube of claim 5, wherein, The minor axis is greater than or equal to the wall thickness of the tube; and / or the ratio of the major axis to the minor axis is 1.5 to 3.
7. The outlet tube of claim 5, wherein, The circumferential surface of the support includes an inner portion facing the central axis of the outlet pipe; the short axis gradually increases from the connection between the support and the pipe body along the direction from the pipe body to the support, so that the inner portion of the support forms an arcuate surface that gradually approaches the central axis of the outlet pipe along the direction from the pipe body to the support, and the distal end of the arcuate surface is smoothly connected to the inner circumferential surface of the pipe body.
8. The outlet tube of claim 5, wherein, The long axis remains constant or gradually decreases along the direction from the tube body to the support.
9. The outlet tube of claim 5, wherein, The size of the short axis and the long axis remains constant in the direction from the support to the tube body, and the thickness of the short axis is equal to that of the tube wall.
10. The outlet pipe according to claim 1, characterized in that, The support includes a proximal section and a distal section connected together; the distal end of the distal section is connected to the proximal end of the tube body; The distal section has an elliptical cross-section and has a minor axis along the radial direction of the outlet pipe and a major axis perpendicular to the minor axis; the minor axis gradually increases from the proximal end face of the pipe body along the direction from the pipe body to the support, so that the inner part of the distal section forms an arc-shaped surface that bends along the direction from the pipe body to the support, and the distal end of the arc-shaped surface is smoothly connected to the inner circumferential surface of the pipe body. The cross-section of the proximal segment is circular.
11. The outlet tube of claim 10, wherein, The distal end of the distal segment has the minimum value of the short axis, which is equal to the wall thickness of the tube body.
12. The outlet tube of claim 10, wherein, The major axis of the distal segment remains constant or gradually decreases in the direction from the tube body to the support. At the connection between the distal segment and the proximal segment, the minor axis and major axis of the distal segment are equal to the diameter of the proximal segment, so that the circumferential surfaces of the distal segment and the proximal segment are smoothly connected.
13. The outlet pipe according to claim 1, characterized in that, The circumferential surface of the support includes an inner portion facing the central axis of the outlet pipe, the inner portion protruding radially inward relative to the inner circumferential surface of the pipe body along the outlet pipe. The inner circumferential surface of the tube is provided with a connecting part, the connecting part having a transition slope, the transition slope smoothly connecting the inner circumferential surface of the tube and the inner side of the support column; Alternatively, the distal end of the support column is provided with a transition slope, the distal end of which is smoothly connected to the inner circumferential surface of the tube body, and extends obliquely from the position of the smooth connection along the direction from the tube body to the support column to the inner portion, wherein the distance between the transition slope and the central axis of the outlet tube gradually decreases in the direction of extension.
14. The outlet pipe according to claim 13, characterized in that, The transition slope can be any one of a plane, a concave arc surface, or a convex arc surface.
15. The outlet tube of claim 1, wherein, The circumferential surface of the support includes an inner portion facing the central axis of the outlet pipe; the inner portion protrudes radially inward relative to the inner circumferential surface of the pipe body; the proximal end face of the pipe body is provided with a plurality of spaced-apart extension arms, each of the plurality of extension arms being connected to the distal end of a plurality of the supports; wherein, The outer surface of the extension arm is coplanar with the outer peripheral surface of the tube body; The inner arm surface of the extension arm is coplanar with the inner circumferential surface of the tube body; The distal end of the support column is provided with a transition slope, which is smoothly connected to the inner arm surface of the extension arm, and extends obliquely from the position of the smooth connection along the direction from the tube to the support column to the inner part.
16. The outlet tube of claim 1, wherein The support also has at least one of the following characteristics: The number of the support pillars is 2 to 4; The central axis of the support is parallel to the central axis of the outlet pipe; The support is located inside the cylindrical surface of the outer circumference of the tube and is tangent to the cylindrical surface of the outer circumference of the tube.
17. The outlet pipe according to claim 1, characterized in that, The outlet pipe also includes a motor cover, which is connected to the proximal end of the support column. The motor cover can cover the distal opening of the motor housing of the blood pump. The motor cover, the support column, and the pipe body are integrally formed. Alternatively, the outlet pipe may further include a connecting ring connected to the proximal end of the support column, the connecting ring being able to be fixedly connected to the distal end of the blood pump motor, and the connecting ring being integrally formed with the support column and the pipe body.
18. A cannula assembly, characterized by The cannulation assembly is used in a blood pump, and the cannulation assembly includes: The inlet tube is equipped with a blood inlet. The outlet pipe as described in any one of claims 1 to 17; and The cannula is inserted, with its proximal end fixedly connected to the proximal end of the outlet tube; the distal end of the cannula is connected to the inlet tube.
19. A blood pump, characterized in that, The blood pump includes an impeller and an outlet pipe as described in any one of claims 1 to 17, wherein the impeller is rotatably disposed within the lumen of the outlet pipe.
20. The blood pump as claimed in claim 19, characterized in that, The impeller includes a hub and blades disposed on the hub; there is a first radial distance between the inner circumferential surface of the tube and the blades; there is a second radial distance between the support of the outlet pipe and the blades, the second radial distance being not less than 0.8 times the first radial distance.