Cannula assembly and blood pump

Abstract

This invention relates to a cannula assembly and a blood pump. The cannula assembly includes a cannula, a delivery tube, and a connecting tube. The cannula has a blood flow channel extending along its length; the delivery tube has a blood inlet or a blood outlet; the connecting tube connects the cannula and the delivery tube to communicate the blood flow channel and the delivery port; the connecting tube includes a first connecting section connected to the cannula and a second connecting section connected to the delivery tube; wherein, one of the first connecting section and the cannula serves as a male and the other as a female, and the female has a fitting groove between its inner and outer peripheral walls that opens toward the male; the male is inserted into the fitting groove. The cannula assembly of this invention connects the cannula and the delivery tube through the connecting tube, making the cannula and the delivery tube less prone to loosening, resulting in a more secure and stable connection.

Description

Technical Field

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

[0002] A blood pump is a device that draws blood from the venous system or heart and pumps it directly into the arterial system. Blood pumps can partially or completely replace the work of the ventricles and are now an effective treatment for heart failure patients. Traditional blood pumps use a socket connection between the cannula and the delivery tubing (inlet or outlet tubing), requiring the diameter of either the cannula or the delivery tubing to be changed to a larger or smaller diameter to allow them to fit together. This socket connection method is prone to loosening and has poor connection stability. Furthermore, changing the diameter of the cannula or delivery tubing may affect the blood pump's transfusion capacity and the difficulty of implantation. Summary of the Invention

[0003] This invention provides a sleeve assembly designed to solve the problem of poor stability in traditional sleeve and delivery pipe connection methods.

[0004] This invention provides a cannula assembly, comprising a cannula, a delivery tube, and a connecting tube. The cannula has a blood flow channel extending along its length; the delivery tube has a blood inlet or a blood outlet; the connecting tube connects the cannula and the delivery tube to communicate the blood flow channel and the blood inlet or blood outlet; the connecting tube includes a first connecting section connected to the cannula and a second connecting section connected to the delivery tube; wherein, one of the first connecting section and the cannula serves as a male connector and the other as a female connector, the female connector having a fitting groove between its inner and outer peripheral walls that opens toward the male connector; the male connector is inserted into the fitting groove.

[0005] In one embodiment, the sleeve includes an elastic support and an inner membrane and an outer membrane disposed on the inner and outer sides of the elastic support; the sleeve has a fixed end facing the connecting tube to serve as the female seat, and the inner membrane and the outer membrane located at the fixed end protrude relative to the elastic support toward the connecting tube to form the fitting groove between the ends of the inner membrane and the outer membrane.

[0006] In one embodiment, the length by which the outer membrane protrudes toward the connecting tube from the end of the elastic support relative to the outer membrane is greater than the length by which the inner membrane protrudes toward the connecting tube from the same end of the elastic support relative to the inner membrane.

[0007] In one embodiment, the first connecting segment serves as the male seat; the first connecting segment includes a tapered segment connected to the second connecting segment and a cylindrical segment connected to the constricted end of the tapered segment; the cylindrical segment is inserted into the fitting groove.

[0008] In one embodiment, a plurality of perforated holes are provided on the side wall of the first connecting segment that is inserted into the fitting groove, and the plurality of perforated holes are arranged at intervals on the first connecting segment.

[0009] In one embodiment, the inner membrane and / or the outer membrane have an inner membrane wall facing the fitting groove, the inner membrane wall being at least partially embedded in the perforation.

[0010] In one embodiment, the delivery pipe has an assembly end facing the connecting pipe, and the outer peripheral wall of one of the assembly end and the second connecting segment is recessed with an outer annular groove for the other to be looped around; and / or, the inner peripheral wall of one of the assembly end and the second connecting segment is recessed with an inner annular groove for the other to be inserted.

[0011] In one embodiment, the outer peripheral surfaces of the sleeve, the connecting pipe, and the delivery pipe are flush with each other; and / or, the inner peripheral surfaces of the sleeve, the connecting pipe, and the delivery pipe are flush with each other.

[0012] In one embodiment, the delivery pipe is an outlet pipe with the blood outlet; or, the delivery pipe is an inlet pipe with the blood inlet; or, there are two delivery pipes, one of which is an outlet pipe with the blood outlet and the other is an inlet pipe with the blood inlet, and there are two connecting pipes, which are respectively referred to as an outlet connecting pipe and an inlet connecting pipe, the outlet connecting pipe connecting the outlet pipe and the sleeve, and the inlet connecting pipe connecting the inlet pipe and the sleeve.

[0013] The present invention also provides a blood pump, the blood pump comprising a drive device, an impeller, and a cannula assembly as described in any one of the above; the impeller is connected to the drive shaft of the drive device; the impeller is at least partially housed within the cannula assembly.

[0014] One technical advantage of an embodiment of the present invention is that by transitionally connecting the sheath and delivery tube in the cannula assembly via a connecting tube, and using one of the connecting sections of the connecting tube as the male end and the other as the female end, a fitting groove open to the male end is provided between the inner and outer walls of the female end, allowing the male end to be fitted into the fitting groove. This not only allows the sheath and delivery tube to be spliced ​​into a continuous pipeline, but also, compared to the traditional method of directly fitting the sheath and delivery tube together, this connection method is less prone to loosening, more secure, and has higher connection stability. Furthermore, it eliminates the need to change the diameter of the sheath or delivery tube to a larger or smaller diameter, simplifying the assembly operation and reducing the impact of changes in the diameter of the sheath and delivery tube on the blood pump's transfusion volume. Attached Figure Description

[0015] Figure 1 This is a schematic cross-sectional view of the structure under the assumed condition that the delivery pipe is directly inserted into the sleeve cavity;

[0016] Figure 2 A schematic diagram of the planar structure of a blood pump provided in one embodiment;

[0017] Figure 3 for Figure 1 A schematic diagram of the planar cross-sectional structure of the blood pump shown;

[0018] Figure 4 for Figure 1 A three-dimensional exploded view of the blood pump shown.

[0019] Figure 5 for Figure 4 Enlarged structural diagram at point P1;

[0020] Figure 6 for Figure 4 Schematic diagram of the inlet pipe;

[0021] Figure 7 for Figure 5 Schematic diagram of the outlet pipe;

[0022] Figure 8 for Figure 3 A partial structural diagram;

[0023] Figure 9 Figure 8 Enlarged view at P2;

[0024] Figure 10 for Figure 1 A schematic diagram of the planar cross-sectional structure of the cannula in the blood pump shown;

[0025] Figure 11 for Figure 1 A three-dimensional structural diagram of the connecting tubes in the blood pump shown.

[0026] Figure 12 for Figure 11 A three-dimensional structural diagram of the connecting pipe shown from another perspective;

[0027] Figure 13 for Figure 11 The front view of the connecting pipe is shown.

[0028] Figure 14 for Figure 13 The cross-sectional view of the connecting pipe shown along line AA;

[0029] Figure 15 for Figure 14 The enlarged view at point P3 is shown.

[0030] Figure label:

[0031] 10. Blood pump 11. Drive unit 12. Impeller

[0032] 13. Sleeve assembly 100, sleeve 110, fitting groove

[0033] 120, Inner membrane 130, Outer membrane 140, Elastic stent

[0034] 200, Connecting pipe 201, Outlet connecting pipe 202, Inlet connecting pipe

[0035] 210. First connecting segment; 211. Cylindrical segment; 212. Conical segment

[0036] 213, Hollow hole 220, Second connecting section 300, Conveying pipe

[0037] 310, Outlet pipe 320, Inlet pipe 311, 301, Assembly end

[0038] 302. Outer ring groove; 303. Inner ring groove Detailed Implementation

[0039] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0040] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "inner," "outer," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0041] Please see Figures 2 to 4 An embodiment of the present invention provides a blood pump 10 including a drive device 11, an impeller 12, and a cannula assembly 13. The distal end of the drive device 11 is connected to the cannula assembly 13; the impeller 12 is at least partially housed within the cannula assembly 13 and connected to the drive shaft of the drive device 11. The distal end of the cannula assembly 13 has a blood inlet; the proximal end of the cannula assembly 13 has a blood outlet. It should be noted that in the field of interventional medicine, the end of the device closer to the operator is generally defined as the proximal end, and the end farther from the operator is defined as the distal end.

[0042] When the blood pump 10 is working, the drive device 11 drives the impeller 12 to rotate, so that blood enters the cannula assembly 13 from the blood inlet, then passes through the cannula assembly 13, and finally exits from the blood outlet, thereby driving blood circulation.

[0043] In one embodiment of the cannula assembly 100 provided by the present invention, the cannula assembly 13 includes a cannula 100 and a delivery tube 300; wherein, the cannula 100 is provided with a blood flow channel 101 extending along its length direction; the delivery tube 300 is provided with a blood inlet 102 or a blood outlet 103, and the delivery tube 300 is connected to the cannula 100 so that the delivery tube 300 and the blood flow channel 101 are in communication. The delivery tube 300 may also be an outlet tube 310, in which case the delivery tube 300 is provided with a corresponding blood outlet 103, and the delivery tube 300 is connected to the proximal end of the cannula 100. Of course, in another embodiment, the delivery tube 300 may be an inlet tube 320, in which case the delivery tube 300 is provided with a corresponding blood inlet 102, and the delivery tube 300 is connected to the distal end of the cannula 100. In another embodiment, there are two delivery tubes 300, one of which serves as an inlet tube 320 and has a blood inlet 102 and is connected to the distal end of the cannula 100; the other delivery tube 300 serves as an outlet tube 320 and has a blood outlet 103 and is connected to the distal end of the cannula 100.

[0044] Please see Figure 1 The traditional connection method between the cannula 100 and the delivery tube 300 typically involves directly fitting the cannula 100 and the delivery tube 300 together. Since the cannula 100 is a flexible tube and the delivery tube 300 is a rigid tube, there is no matching fitting point between them. Therefore, the diameter of one of the cannula 100 or the delivery tube 300 needs to be changed to a larger or smaller diameter to allow them to fit together. This direct fitting method is prone to loosening and has poor connection stability. Furthermore, changing the diameter of the cannula 100 or the delivery tube 300 may also affect the blood pump's transfusion capacity and the difficulty of implantation.

[0045] Please see Figure 4 and Figure 5In one embodiment of the present invention, the cannula assembly 13 further includes a connecting pipe 200, which connects the delivery pipe 300 and the cannula 100 to communicate the blood flow channel 101 and the blood inlet 102 or the blood outlet 103. The connecting pipe 200 includes a first connecting section 210 and a second connecting section 220. The first connecting section 210 is connected to the cannula 100, and the second connecting section 220 is connected to the delivery pipe 300. One of the first connecting section 210 and the cannula 100 serves as a male connector, and the other serves as a female connector. The female connector has a fitting groove 110 that opens towards the male connector between its inner and outer peripheral walls. The male connector is fitted into the fitting groove 110. The connecting pipe 200 can be a metal pipe, so that the second connecting section 220 can be integrally formed with the delivery pipe 300; or, the second connecting section 220 and the delivery pipe 300 can be spliced ​​and fixed into one piece.

[0046] Please see Figure 8 and Figure 9 It is understandable that when the sleeve 100 can be used as a female connector, the first connecting segment 210 is used as a male connector. When the sleeve 100 can be used as a male connector, the first connecting segment 210 is used as a female connector. The sleeve 100 and the delivery pipe 300 in the sleeve assembly 13 are connected by a connecting pipe 200, with one of the first connecting segments 210 of the connecting pipe 200 and the sleeve 100 serving as the male connector and the other as the female connector. A fitting groove 110 is provided between the inner and outer walls of the female connector, opening towards the male connector, so that the male connector is fitted into the fitting groove 110. This not only allows the sleeve 100 and the delivery pipe 300 to be spliced ​​into a continuous pipeline, but also, compared to the traditional method of directly connecting the sleeve 100 and the delivery pipe 300, this connection method is less prone to loosening, more secure, and has higher connection stability. In addition, it is not necessary to change the diameter of the cannula 100 or the delivery tube 300 to a larger or smaller diameter, which simplifies the assembly operation and reduces the impact of changes in the diameter of the cannula 100 and the delivery tube 300 on the blood pump's transfusion volume.

[0047] like Figure 4 and Figure 6 As shown, optionally, the delivery pipe 300 is an inlet pipe 320 with a blood inlet 102, and the connecting pipe 200 connects the inlet pipe 320 and the sleeve 100. Figure 4 and Figure 7 As shown, in another embodiment, the delivery tube 300 may be an outlet tube 310 having a blood outlet 103, and the connecting tube 200 connects the outlet tube 310 and the cannula 100. Figure 4 and Figure 5As shown, in another embodiment, there can be two delivery pipes 300. One delivery pipe 300 is an inlet pipe 320 with a blood inlet 102, and the other delivery pipe 300 is an outlet pipe 310 with a blood outlet 103. There are also two connecting pipes 200, referred to as outlet connecting pipe 201 and inlet connecting pipe 202, respectively. Outlet connecting pipe 201 connects the proximal end of sleeve 100 to outlet pipe 310, and inlet connecting pipe 202 connects the distal end of sleeve 100 to inlet pipe 320. Impeller 12 is at least partially housed within outlet pipe 310. When the driving device 11 drives impeller 12 to rotate within outlet pipe 310, impeller 12 generates suction force, causing blood to flow in from inlet pipe 320, pass through sleeve 100 into inlet pipe 320, and finally flow out from inlet pipe 320, thus realizing the blood pumping function of blood pump 10.

[0048] See Figures 4 to 7 In some embodiments, for example, the outlet connecting pipe 201 and the outlet pipe 310 can be integrally formed; or the outlet connecting pipe 201, the outlet pipe 310, and the sleeve 100 are three independently formed components, assembled by a separate connection method. The inlet connecting pipe 202 and the outlet pipe 310 can be integrally formed, while the inlet connecting pipe 202 and the sleeve 100 are separately connected. This can improve the assembly accuracy and efficiency of the sleeve assembly 13. In other embodiments, the inlet connecting pipe 202 can also be separately connected to the inlet pipe 320.

[0049] See Figure 4 , Figure 8 and Figure 9 In some embodiments, the connecting pipe 200 may be made of metal. One of the first connecting section 210 of the connecting pipe 200 and the sleeve 100 serves as the male connector and the other as the female connector. The end of the female connector has a fitting groove 110 opening towards the male connector. The fitting groove 110 extends a certain length along the axial direction of the female connector to allow the male connector to be fitted. The fitting groove 110 is formed between the inner and outer circumferential walls of the female connector. Regarding the shape and structure of the fitting groove 110 on the female connector, the fitting groove 110 may extend circumferentially around the female connector and be arranged in a ring shape. In this case, the diameter of the fitting groove 110 is smaller than the outer diameter of the female connector and larger than the inner diameter of the female connector; correspondingly, the male connector may be arranged in a ring shape to be fitted into the annular fitting groove 110.

[0050] Of course, in other embodiments, the fitting groove 110 can also be configured as a strip-shaped groove extending along the length direction of the sleeve assembly 13, and there are multiple such strip-shaped grooves, which are arranged at intervals around the circumference of the female seat; correspondingly, the male head can be provided with multiple strip-shaped insertion ribs, which are respectively embedded in the multiple fitting grooves 110. Specifically, in this embodiment, the fitting groove 110 extends around the circumference of the female seat and is arranged in a ring shape.

[0051] Please see Figures 8 to 10 In one embodiment, the cannula 100 includes an inner membrane 120, an outer membrane 130, and an elastic stent 140. The elastic stent 140 is cylindrical; the inner membrane 120 is attached to the inner surface of the elastic stent 140, forming the inner peripheral wall of the cannula 100; the outer membrane 130 is attached to the outer surface of the elastic stent 140, forming the outer peripheral wall of the cannula 100. The inner membrane 120, the outer membrane 130, and the elastic stent 140 all have a certain degree of flexibility, making the entire cannula 100 flexible and capable of bending and deforming. Thus, during the implantation of the cannula assembly 13 into the body, the cannula 100 can bend to adapt to the shape of the blood vessel, reducing the difficulty of implanting the cannula assembly 13 and the blood pump 10.

[0052] Based on this, the sleeve 100 serves as the female connector; the first connecting section 210 of the connecting tube 200 serves as the male connector. The sleeve 100 has a fixed end facing the connecting tube 200 to serve as the female connector, and the inner membrane 120 and the outer membrane 130 located at the fixed end protrude toward the connecting tube 200 relative to the elastic support 140 to form a fitting groove 110 between the ends of both the inner membrane 120 and the outer membrane 130.

[0053] Specifically, the lengths of both the inner membrane 120 and the outer membrane 130 are greater than the length of the elastic support 140, causing the portions of the inner membrane 120 and the outer membrane 130 located at the fixed ends to protrude relative to the elastic support 140 toward the connecting pipe 200. This means that the ends of the elastic support 140 maintain a certain distance from the ends of the inner membrane 120 and the outer membrane 130, thus forming a fitting groove 110 between the ends of the inner membrane 120 and the outer membrane 130. When there are two delivery pipes 300 and two connecting pipes 200, fitting grooves 110 are provided at both ends of the sleeve 100, and the fitting grooves 110 at both ends of the sleeve 100 are respectively connected and engaged with the two connecting pipes 200.

[0054] like Figure 8 and Figure 9As shown, since the first connecting segment 210 of the connecting tube 200 is embedded in the fitting groove 110 between the inner membrane 120 and the outer membrane 130, the first connecting segment 210 is essentially wrapped within the inner membrane 120 and the outer membrane 130. The inner membrane 120 and the outer membrane 130 cover the metal ends of the elastic stent 140 and the first connecting segment 210, preventing the relatively sharp metal ends from being exposed, thereby effectively reducing the difficulty of implanting the blood pump 10. Furthermore, both the inner diaphragm 120 and the outer diaphragm 130 are relatively thin. The outer diaphragm 130 is attached to the outer peripheral surface of the first connecting segment 210, resulting in a nearly smooth transition between the outer diaphragm 130 and the outer peripheral surface of the first connecting segment 210. This avoids abrupt changes in the outer diameter of the sleeve assembly 13. Similarly, the inner diaphragm 120 is attached to the inner peripheral surface of the first connecting segment 210, resulting in a nearly smooth transition between the inner diaphragm 120 and the inner peripheral surface of the first connecting segment 210. This also avoids abrupt changes in the inner diameter of the sleeve assembly 13. Therefore, this connection method allows sleeves 100 and connecting tubes 200 with the same diameter to be connected together.

[0055] Furthermore, during the process of embedding the first connecting segment 210 of the connecting tube 200 into the fitting groove 110 of the sleeve 100, the connecting tube 200 and the sleeve 100 can be further fixed by heat fusion connection. Specifically, firstly, the first connecting segment 210 of the connecting tube 200 is inserted into the fitting groove 110 of the sleeve 100, and the first connecting segment 210 is sandwiched between the inner membrane 120 and the outer membrane 130, thereby achieving radial positioning of the connecting tube 200 along the sleeve 100; at this time, the end of the first connecting segment 210 can abut against the end of the elastic support 140 to achieve axial positioning of the connecting tube 200 along the sleeve 100. Then, the inner membrane 120 and the outer membrane 130 are heated, so that the parts of the inner membrane 120 and the outer membrane 130 that are in contact with the first connecting segment 210 are melted by heat and adhere to the first connecting segment 210. After cooling for a certain period of time, the inner membrane 120 and the outer membrane 130 are connected together with the first connecting section 210, thus achieving a heat-fusion connection between the entire sleeve 100 and the connecting pipe 200.

[0056] In one embodiment, a plurality of perforated holes 213 are provided on the sidewall of the first connecting segment 210 inserted into the fitting groove 110, and the plurality of perforated holes 213 are arranged at intervals on the first connecting segment 210. This design can reduce the rigidity of the first connecting segment 210, allowing the first connecting segment 210 to bend and deform. After the first connecting segment 210 is embedded into the fitting groove 110 of the sheath 100, the first connecting segment 210 and the elastic support 140 of the sheath 100 are connected to form a support structure supporting the intima 120 and the adventitia 130. During the intervention of the blood pump 10 into the patient's body, when the sheath 100 of the sheath assembly 13 bends, the first connecting segment 210 of the connecting tube 200 can also bend to a certain extent in the same direction to adapt to the shape of the blood vessel, thereby preventing the first connecting segment 210 from breaking off radially outward from the restraint of the adventitia 130.

[0057] Given the presence of the perforated hole, optionally, the inner membrane 120 and / or the outer membrane 130 have an inner wall facing the fitting groove 110, the inner wall being at least partially embedded in the perforated hole 213. During the aforementioned process of heat-fusion connection between the connecting tube 200 and the sleeve 100, the portions of the inner membrane 120 and / or the outer membrane 130 that contact the first connecting segment 210 are heated and melted. A portion of the resulting heat melt penetrates into the perforated hole 213, which can enhance the connection strength between the connecting tube 200 and the sleeve 100; another portion of the heat melt adheres to the surface of the first connecting segment 210 to cover the first connecting segment 210.

[0058] Furthermore, due to the thinness of the inner lining 120, when the inner lining 120 is thermally fused with the first connecting segment 210, the portion of the inner lining 120 at the fixed end, when heated, forms a molten body that partially penetrates into the perforated hole 213. This reduces the thickness of the inner lining 120 at the fixed end, resulting in a smoother transition with the first connecting segment 210. Consequently, the inner diameter of the sheath 100 is approximately close to the inner diameter of the first connecting segment 210, and the inner diameters of the sheath 100 and the first connecting segment 210 are approximately equal, making their inner circumferential surfaces flush. This prevents blood flow disturbance caused by a large abrupt change in the inner diameter of the entire sheath assembly 13, increases the amount of blood transported per unit time, and further ensures the required transfusion volume.

[0059] Please see Figures 11 to 13The shape of the perforated hole 213 is not limited. The shape of the perforated hole 213 can be, but is not limited to, circular, square, strip-shaped, arc-shaped, or other irregular shapes. Specifically, in this embodiment, the perforated hole 213 is arc-shaped and extends circumferentially along the connecting pipe 200. Optionally, the perforated holes 213 are arranged along the axial direction of the first connecting segment 210 to form multiple rows of hole units, that is, the perforated holes 213 are divided into multiple rows of hole units. Each row of hole units may include multiple perforated holes 213, and the multiple perforated holes 213 are arranged at intervals along the circumferential direction of the first connecting segment 210. For example, the same row of hole units may have two perforated holes 213. Two perforated holes 213 in any two adjacent rows of hole units are spaced a certain distance apart along the circumferential direction of the first connecting segment 210, so that the two perforated holes 213 are misaligned rather than aligned in the circumferential direction.

[0060] This design of the perforated hole 213 allows the first connecting segment 210 to undergo greater bending deformation due to its high flexibility, adapting to the shape of the blood vessel and reducing the difficulty of implanting the cannula assembly 13 and the blood pump 10. In other embodiments, the perforated hole 213 can also be circular, elongated, or square, which also allows the first connecting segment 210 to have high flexibility. Furthermore, in other embodiments, the perforated hole 213 can also be strip-shaped, thus penetrating one end of the distal second connecting segment 220 of the first connecting segment 210. Multiple perforated holes 213 are arranged along the axial direction of the first connecting segment 210, thereby forming multiple strip-shaped insertion ribs between two adjacent perforated holes 213. These multiple strip-shaped insertion ribs can also be embedded in the fitting groove 110 of the cannula 100.

[0061] In the aforementioned process of embedding the first connecting segment 210 of the connecting tube 200 into the fitting groove 110 of the sleeve 100, in addition to using a heat-fusion connection to reinforce the first connecting segment 210 and the sleeve 100, in another embodiment, the connecting tube 200 and the sleeve 100 can be further fixed by adhesive bonding. After the adhesive is poured into the fitting groove 110, similar to the heat-fusion connection described above, a first portion of the adhesive will be located between the inner membrane 120 and the first connecting segment 210, and between the outer membrane 130 and the first connecting segment 210. After cooling, the first portion of the adhesive will solidify to form a cylindrical adhesive layer. The adhesive extends along the axial direction of the sleeve 100. Through the action of the adhesive layer, the connection between the connecting tube 200 and the inner membrane 120 and the outer membrane 130 can be achieved. At the same time, given the existence of the perforated hole 213, a second portion of the adhesive will penetrate into the perforated hole 213, thereby enhancing the connection strength between the connecting tube 200 and the sleeve 100. In another embodiment, the connecting pipe 200 and the sleeve 100 can be further fixed by welding.

[0062] Please see Figures 8 to 10 , Figure 10In this context, L1 represents the length of the outer membrane 130 protruding towards the delivery pipe 300 from the end of the elastic support 140 relative to the sleeve 100, and L2 represents the length of the inner membrane 120 protruding towards the delivery pipe 300 from the same end of the elastic support 140 relative to the sleeve 100. Optionally, the length L1 of the outer membrane 130 protruding towards the connecting pipe 200 from the end of the elastic support 140 relative to the sleeve 100 is greater than the length L2 of the inner membrane 120 protruding towards the connecting pipe 200 from the same end of the elastic support 140 relative to the sleeve 100, i.e., L1 > L2. In this way, on the one hand, during the assembly process of the connecting tube 200 by inserting the first connecting segment 210 into the fitting groove 110, the protruding part of the outer membrane 130 relative to the inner membrane 120 will play a certain guiding role for the first connecting segment 210, thereby improving the assembly efficiency of the connecting tube 200; on the other hand, the coverage area of ​​the first connecting segment 210 by the outer membrane 130 can be reasonably increased, enhancing the connection strength between the connecting tube 200 and the sheath 100, so that when the sheath 100 and the connecting tube 200 of the sheath assembly 13 bend during the intervention of the blood pump 10 into the patient's body, the outer membrane 130 can tighten the first connecting segment 210, preventing the first connecting segment 210 from breaking off radially outward from the restraint of the outer membrane 130.

[0063] Please see Figure 4 , Figure 9 and Figure 11 The connecting pipe 200 can be a pipe with a constant diameter. In one embodiment, the first connecting segment 210 of the connecting pipe 200 includes a cylindrical segment 211 and a tapered segment 212, which are concentrically arranged. The tapered segment 212 is connected to the second connecting segment 220; the cylindrical segment 211 is connected to the end of the tapered segment 212 away from the second connecting segment 220, and the cylindrical segment 211 is inserted into the fitting groove 110. A perforated hole 213 is provided on the cylindrical segment 211.

[0064] Specifically, in the direction from the second connecting section 220 to the first connecting section 210, the outer and inner diameters of the cylindrical section 211 remain unchanged, while the outer diameter of the tapered section 212 gradually decreases, and the inner diameter of the tapered section 212 remains unchanged. By setting the tapered section 212, on the one hand, the tapered section 212 can play a guiding role, thereby reducing the assembly difficulty of the connecting pipe 200; on the other hand, the tapered section 212 can play a good sealing role for the fitting groove 110, thereby improving the sealing performance of the connection between the connecting pipe 200 and the sleeve 100.

[0065] See Figures 13 to 15 Based on any of the above embodiments, the conveying pipe 300 includes an assembly end 301, which is disposed toward the second connecting section 220 of the connecting pipe 200, and the assembly end 301 and the second connecting section 220 are connected and fixed. Optionally, the outer peripheral wall of one of the assembly end 301 and the second connecting section 220 is recessed with an outer annular groove 302 for the other to be looped around. Figure 7 (As shown). Alternatively, the inner peripheral wall of one of the assembly end 301 and the second connecting section 220 is recessed with an inner ring groove 303 for the other to be inserted.

[0066] Specifically, the delivery tube 300 has an outer ring groove 302 recessed on the outer peripheral wall of the assembly end 301. The second connecting section 220 is fitted around the outer ring groove 302 of the assembly end 301, so that the second connecting section 220 is essentially accommodated in the outer ring groove 302. The end of the second connecting section 220 is less likely to form a sharp edge protruding from the outer peripheral surface of the delivery tube 300, which can reduce collision damage to the inner wall of the blood vessel. Furthermore, the inner peripheral wall of the second connecting section 220 is also recessed with an inner ring groove 303. After the second connecting section 220 is fitted around the outer ring groove 302 of the assembly end 301, the assembly end 301 is correspondingly inserted into the inner ring groove 303 of the second connecting section 220, so that the assembly end 301 is essentially accommodated in the inner ring groove 303, thereby reducing collision damage to the blood cells in the cannula 100 by the end of the assembly end 301. This connection method allows the diameters of the second connecting section 220 of the connecting pipe 200 and the conveying pipe 300 to be designed to be the same.

[0067] Therefore, by combining the aforementioned connection of the first connecting segment 210 of the connecting tube 200 as a male end to the fitting groove 110 on the sleeve 100, and the connection of the second connecting segment 220 of the connecting tube 200 to the delivery tube 300 via the outer ring groove 302 provided on both, the connecting tube 200 can connect the sleeve 100 and the delivery tube 300 with the same diameter together, thereby ensuring that the diameter of the sleeve assembly 13 remains consistent at any position. Compared to the traditional method of directly connecting the sleeve 100 and the delivery tube 300, the method of connecting the tube 100 and the delivery tube 300 of the present invention through the aforementioned connecting tube 200 allows the sleeve 100 and the delivery tube 300 to maintain their original diameters without increasing the diameter of the sleeve 100 or the delivery tube 300, thus not increasing the difficulty of blood pump implantation, nor decreasing the diameter of the sleeve 100 or the delivery tube 300, thus not reducing the blood pump's transfusion capacity. Furthermore, the inner circumferential surface of the cannula assembly 13 of the present invention is less prone to radial dimension abrupt changes, which can reduce collision damage to blood cells and is less likely to interfere with the installation of the impeller 12, ensuring that the impeller 12 can maintain its original diameter or slightly increase its diameter. The outer circumferential surface of the cannula assembly 13 is also less prone to radial dimension abrupt changes, thus reducing collision damage to the inner wall of the blood vessel.

[0068] Therefore, optionally, the outer peripheral surfaces of the cannula 100, connector 200, and delivery tube 300 are flush with each other; and / or, the inner peripheral surfaces of the cannula 100, connector 200, and delivery tube 300 are flush with each other. In other words, the diameters of the cannula 100, connector 200, and delivery tube 300 are equal. This configuration improves the smoothness of the outer peripheral wall of the entire cannula assembly 13, and there are no radial dimensional abrupt changes on either the inner or outer peripheral surfaces of the cannula assembly 13. This reduces the likelihood of jamming and impact during implantation into the patient, lowers the difficulty of implanting the cannula assembly 13, and reduces collision damage to the vascular wall and blood cells.

[0069] 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.

[0070] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A sleeve assembly, characterized in that, The sleeve assembly includes: A cannula having a blood flow channel extending along its length; A delivery tube, wherein the delivery tube is provided with a blood inlet or a blood outlet; and A connecting tube connects the sheath and the delivery tube to communicate the blood flow channel and the blood inlet or the blood outlet; the connecting tube includes a first connecting section connected to the sheath and a second connecting section connected to the delivery tube. In this configuration, one of the first connecting segment and the sleeve serves as the male connector and the other as the female connector. The female connector has a fitting groove between its inner and outer peripheral walls that opens toward the male connector. The male connector is fitted into the fitting groove. The sleeve includes an elastic support and an inner membrane and an outer membrane disposed on the inner and outer sides of the elastic support; the sleeve has a fixed end facing the connecting tube to serve as the female seat, and the inner membrane and the outer membrane located at the fixed end protrude relative to the elastic support toward the connecting tube to form the fitting groove between the ends of the inner membrane and the outer membrane; the first connecting segment is inserted into the fitting groove, and the end of the first connecting segment abuts against the end of the elastic support, so that the first connecting segment and the elastic support are joined to form a support structure supporting the inner membrane and the outer membrane; The length by which the outer membrane protrudes toward the connecting tube from the end of the elastic support relative to the outer membrane is greater than the length by which the inner membrane protrudes toward the connecting tube from the same end of the elastic support relative to the inner membrane.

2. The sleeve assembly according to claim 1, characterized in that, The connecting pipe is a metal pipe; the side wall of the first connecting segment inserted into the fitting groove is provided with multiple hollow holes, so that the first connecting segment made of metal material is flexible and can be bent and deformed.

3. The sleeve assembly according to claim 2, characterized in that, The perforated holes are arc-shaped and extend circumferentially along the connecting pipe; the perforated holes are arranged along the axial direction of the first connecting section to form multiple rows of hole units; each row of hole units includes multiple perforated holes, and the multiple perforated holes are arranged at intervals along the circumferential direction of the first connecting section. The two hollow holes in any two adjacent rows of hole units are staggered in the circumferential direction.

4. The sleeve assembly according to claim 1, characterized in that, The first connecting segment serves as the male connector; the first connecting segment includes a tapered segment and a cylindrical segment; wherein the tapered segment is connected to the second connecting segment; the cylindrical segment is connected to the end of the tapered segment away from the second connecting segment, and the cylindrical segment is inserted into the fitting groove.

5. The sleeve assembly according to any one of claims 2 to 4, characterized in that, The first connecting segment has multiple hollow holes on its side wall that is inserted into the fitting groove, and the multiple hollow holes are arranged at intervals on the first connecting segment.

6. The sleeve assembly according to claim 5, characterized in that, The inner membrane and / or the outer membrane have an inner wall facing the fitting groove, the inner wall being at least partially embedded in the perforated hole.

7. The sleeve assembly according to any one of claims 1 to 4, characterized in that, The conveying pipe is provided with an assembly end facing the connecting pipe, and the outer peripheral wall of one of the assembly end and the second connecting section is recessed with an outer ring groove for the other to be looped around; and / or, the inner peripheral wall of one of the assembly end and the second connecting section is recessed with an inner ring groove for the other to be inserted.

8. The sleeve assembly according to any one of claims 1 to 4, characterized in that, The outer circumferential surfaces of the sleeve, the connecting pipe, and the conveying pipe are flush with each other; and / or, the inner circumferential surfaces of the sleeve, the connecting pipe, and the conveying pipe are flush with each other.

9. The sleeve assembly according to any one of claims 1 to 4, characterized in that, The delivery pipe is an outlet pipe with the blood outlet; or, the delivery pipe is an inlet pipe with the blood inlet; or, there are two delivery pipes, one of which is an outlet pipe with the blood outlet and the other is an inlet pipe with the blood inlet, and there are two connecting pipes, which are respectively referred to as an outlet connecting pipe and an inlet connecting pipe, the outlet connecting pipe connecting the outlet pipe and the sleeve, and the inlet connecting pipe connecting the inlet pipe and the sleeve.

10. A blood pump, characterized in that, The blood pump includes: Drive unit; Impeller, the impeller being connected to the drive shaft of the drive device; and The sleeve assembly as claimed in any one of claims 1 to 9, wherein the sleeve assembly is connected to the distal end of the drive device, and the impeller is at least partially housed within the sleeve assembly.

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