Cannula assembly and blood pump

Abstract

The invention relates to a cannula assembly and a blood pump. The cannula assembly comprises a cannula, a circulation pipe core wire and a fastener. The cannula is provided with a blood flow channel; the circulation pipe is connected to one end of the cannula, and the circulation pipe is provided with a first blood flow hole communicated with the blood flow channel; the runner pipe is also provided with a fixing frame; the core wire is fixed to the blood flow channel and extends in the axial direction of the cannula. The fastener comprises a fastening sleeve, and the fastening sleeve is arranged at the end, close to the fixing frame, of the core wire in a sleeving mode. The fastening sleeve is connected with the core wire and the fixing frame so that the core wire and the fixing frame can be connected and fixed. According to the cannula assembly, the installation firmness of the core wire in the cannula can be enhanced, and the surgical risk is reduced.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to cannulation components and blood pumps. Background Technology

[0002] Percutaneous interventional mechanical circulatory support systems, often referred to as blood pumps, are typically inserted from a blood vessel into the ventricles of the heart to assist the heart in pumping blood from the ventricles into the arteries, thus supporting the patient's blood circulation. Blood pumps usually include a cannula for creating a blood flow path. This cannula is flexible enough to adapt to the tortuous deformation of the blood vessel, allowing it to pass through the vessel and be pushed to the target location within the body. However, in some related techniques, the core wire within the cannula is prone to loosening and dislodgement, increasing surgical risks. Summary of the Invention

[0003] Therefore, it is necessary to provide a cannulation assembly and blood pump to address the above problems, which can enhance the stability of the core wire installation inside the cannula and reduce surgical risks.

[0004] In a first aspect, the present invention provides an intubation assembly, the intubation assembly comprising an intubation cannula, a flow tube mandrel, and fasteners. The intubation cannula has a blood flow channel; the flow tube is connected to one end of the intubation cannula and has a first blood flow hole communicating with the blood flow channel; the flow tube also has a fixing bracket; the mandrel is fixed to the blood flow channel and extends axially along the intubation cannula; the fastener includes a fastening sleeve, the fastening sleeve being sleeved on the end of the mandrel near the fixing bracket; the fastening sleeve is connected to both the mandrel and the fixing bracket to connect and fix the mandrel and the fixing bracket.

[0005] In some embodiments, the core wire includes a core body and a fixed end connected to the core body; at least one of the fixing frame and the fastener is provided with a receiving cavity; the fastener further includes a stop portion provided on the inner wall of the fastening sleeve, the stop portion being opposite to the receiving cavity along the axial direction of the insertion tube; wherein the core body passes through the stop portion; the fixed end is accommodated in the receiving cavity and is able to abut against the stop portion.

[0006] In some embodiments, the stop portion is configured as annular; the stop portion has a wire-passing hole through which the core passes; wherein...

[0007] The diameter of the through hole is smaller than the maximum radial dimension of the fixed end; and / or,

[0008] The wall of the wire hole is interference-fitted with the circumferential surface of the core.

[0009] In some embodiments, the fixed end includes a large-diameter section, the maximum radial dimension of which is greater than the diameter of the core;

[0010] The fixed end also includes a variable diameter section, which connects the large diameter section and the core, and the radial dimension of the variable diameter section gradually increases from the core to the large diameter section.

[0011] In some embodiments, the stop portion has a first stop surface facing the receiving cavity; a space is formed between the circumferential surface of the variable diameter section, the first stop surface, and the circumferential cavity wall of the receiving cavity.

[0012] In some embodiments, the stop portion is provided with a wire-passing hole for the core to pass through. The wire-passing hole includes a connected straight hole section and a variable diameter hole section. The hole wall of the straight hole section fits with the circumferential surface of the core. The diameter of the variable diameter hole section gradually increases along the direction from the core to the large diameter section, so that the hole wall of the variable diameter hole section forms a second stop surface, and the second stop surface fits with the circumferential surface of the variable diameter section.

[0013] In some embodiments, the variable diameter section is provided with a spiral groove, which is spirally wound around the circumference of the variable diameter section along the direction from the core to the large diameter section.

[0014] In some embodiments, the fastening sleeve has a fixing cavity, the stop portion is located between the fixing cavity and the receiving cavity, and the stop portion has a third stop surface facing the fixing cavity; the insertion assembly also includes a flexible sheath that wraps around the core wire, one end of the flexible sheath being installed in the fixing cavity and abutting against the third stop surface.

[0015] In some embodiments, the fastening sleeve includes a first sleeve portion; the fixing frame includes a base and a fixing ring disposed on the base, the fixing ring forming a portion of the receiving cavity, and the first sleeve portion is fixedly sleeved around the outer periphery of the fixing ring;

[0016] And / or, the fastening sleeve further includes a second sleeve portion, which is fixedly sleeved on the outer periphery of the core, and the outer periphery surface of the second sleeve portion is configured as a conical surface, the diameter of which gradually decreases along the direction from the fixed end to the core.

[0017] In some embodiments, the cannulation assembly also has at least one of the following features:

[0018] The core wire is a solid nickel-titanium wire;

[0019] The diameter of the core wire ranges from 0.45 mm to 0.55 mm;

[0020] The core wire includes a core body and a fixed end connected to the core body. The fixed end is fixedly connected to the fixing frame, and the maximum radial dimension of the fixed end is greater than the diameter of the core body.

[0021] The cannula has a wall that surrounds the blood flow channel, and the wall does not have an elastic support.

[0022] In some embodiments, the cannula includes a main tube section and a first connecting section connected to the main tube section, the first connecting section being sleeved around the periphery of the flow tube; the cannula assembly further includes a first locking ring, the first locking ring being sleeved around the periphery of the first connecting section, the first locking ring being interference-fitted with the first connecting section.

[0023] In some embodiments, the flow tube is connected to the proximal end of the cannula, and the cannula assembly further includes a delivery tube connected to the distal end of the cannula; the delivery tube is provided with a second blood flow hole communicating with the blood flow channel, and both the delivery tube and the flow tube are rigid tubes; the two ends of the core wire are respectively fixed to the flow tube and the delivery tube, so that the core wire can transmit axial pushing force between the flow tube and the delivery tube.

[0024] In some embodiments, the core wire has a connecting end located away from the flow tube; the delivery tube includes a plurality of supports and a guide portion connected to the supports, the guide portion having an insertion hole, and the connecting end fixed to the insertion hole; wherein...

[0025] The insertion hole has a first section near the blood flow channel, and the guide portion has a glue-filled groove on its wall facing away from the blood flow channel, the glue-filled groove communicating with the first section; and / or,

[0026] The insertion hole has a second hole section away from the blood flow channel. The guide portion has a molten material groove on its wall surface away from the blood flow channel. The molten material groove is connected to the second hole section and is used to collect the molten material after the connection end is heated.

[0027] In some embodiments, the cannula includes a main tube section and a second connecting section connected to the main tube section, the second connecting section being sleeved around the outer periphery of the delivery tube; the cannula assembly further includes a second locking ring, the second locking ring being sleeved around the outer periphery of the second connecting section, the second locking ring being interference-fitted with the second connecting section.

[0028] In a second aspect, the present invention also provides a blood pump, the blood pump including an impeller and a cannulation assembly as described in any of the foregoing embodiments; wherein the impeller is rotatably disposed within the cannulation assembly.

[0029] In one embodiment, the blood pump further includes a motor fixedly connected to the flow tube, the motor having a shaft connected to the impeller to drive the impeller to rotate.

[0030] The cannulation assembly of the present invention, by adding a fastener, including a fastening sleeve, is fitted onto the end of the mandrel near the fixing frame. The fastener is fixed to the fixing frame, thereby securing the fixed end of the mandrel to the fixing frame. This fastener enhances the strength of the connection between the mandrel and the flow tube, reducing the possibility of the mandrel loosening or falling off. Furthermore, when the cannulation assembly bends near the connection between the mandrel and the fixing frame, the fastener bears part of the bending force, thereby reducing the force acting on the connection between the mandrel and the fixing frame, and further reducing the risk of breakage at the connection, effectively enhancing the stability of the mandrel installation. Therefore, the cannulation assembly of the present invention can effectively reduce surgical risks. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the blood pump provided by the present invention.

[0032] Figure 2 for Figure 1 A schematic diagram of the disassembled blood pump.

[0033] Figure 3 for Figure 1 A cross-sectional view of the blood pump.

[0034] Figure 4 for Figure 3 A magnified view of a portion of point A in the middle.

[0035] Figure 5 for Figure 3 A magnified view of a section at point B.

[0036] Figure 6 for Figure 3 A magnified view of a section at point C.

[0037] Figure 7 for Figure 2 A magnified view of a section at point D.

[0038] Figure 8 for Figure 2 A schematic diagram of the core wire of a blood pump.

[0039] Figure 9 for Figure 2 A three-dimensional structural diagram of the fasteners of the blood pump.

[0040] Figure 10 for Figure 9 Longitudinal sectional view of the fastener.

[0041] Figure 11 for Figure 2 A three-dimensional structural diagram of the flow tube in a blood pump.

[0042] Figure 12 for Figure 11 Longitudinal sectional view of the central flow duct.

[0043] Figure 13 for Figure 2 A three-dimensional structural diagram of the delivery tubes of a blood pump.

[0044] Figure 14 for Figure 13 Longitudinal sectional view of the central conveying pipe.

[0045] Figure 15 A schematic diagram of another embodiment of the core wire provided by the present invention.

[0046] Figure 16 This is a schematic diagram of another embodiment of the core wire provided by the present invention.

[0047] Figure 17 This is a schematic diagram of another embodiment of the core wire provided by the present invention.

[0048] Figure 18 A schematic diagram of another embodiment of the fastener provided by the present invention.

[0049] Explanation of reference numerals in the attached figures:

[0050] 10. Blood pump;

[0051] 100. Intubation; 101. Blood flow path; 110. Main tube section; 120. First connecting section; 130. Second connecting section;

[0052] 200. Flow tube; 210. Fixing bracket; 211. Fixing ring; 211a. First annular portion; 211b. Second annular portion; 212. Base; 201. First cavity; 201a. Inner wall; 202. Hole; 203. First blood flow hole; 220. Opening tube; 221. Mounting groove; 230. Adapter tube; 231. First tube segment; 232. Second tube segment;

[0053] 300, Core wire; 310, Fixed end; 311, Large diameter section; 312, Variable diameter section; 320, Connecting end; 330, Core body; 301, Limiting surface; 302, Spiral groove;

[0054] 400. Fastener; 410. Fastening sleeve; 411. First opening; 412. Second opening; 413. First sleeve portion; 414. Second sleeve portion; 420. Stop portion; 421. Wire through hole; 421a. Straight hole section; 421b. Variable diameter hole section; 422. First stop surface; 423. Second stop surface; 424. Third stop surface; 401. Second cavity; 402. Fixed cavity;

[0055] 500, delivery pipe; 510, support column; 520, connecting pipe; 530, guide section; 531, insertion hole; 531a, first hole section; 531b, second hole section; 532, settling tank; 533, melting tank; 501, second blood flow hole;

[0056] 600, Flexible sheath;

[0057] 710. First locking ring; 720. Second locking ring;

[0058] 810. Impeller; 820. Motor; 830. Guide tube;

[0059] Q1, receiving cavity; Q2, spacer space. Detailed Implementation

[0060] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be 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 the present invention. However, the present invention can be practiced 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 the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0061] In the description of this invention, it should be understood that if terms such as "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 invention 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 invention.

[0062] 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 as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0063] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," 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 explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0064] In this invention, unless otherwise explicitly 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.

[0065] 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. Where applicable, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this invention are for illustrative purposes only and do not represent the only possible implementation.

[0066] It should be noted that the terms "distal" and "proximal" in 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 away 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.

[0067] This application provides a cannulation assembly that enhances the stability of the mandrel installation within the cannula and reduces surgical risks. It should be noted that the cannulation assembly can be used in blood pumps, but is not limited to blood pumps. The cannulation assembly can also be used in medical devices that require insertion into the patient's body, such as thrombus aspiration catheters, mechanical thrombectomy systems, and interventional catheters.

[0068] The following is combined with Figures 1 to 18 The cannulation assembly according to an embodiment of the present invention will be described.

[0069] See Figures 1 to 3 In one embodiment of the present invention, the cannulation assembly includes a cannula 100. The cannula 100 has a blood flow channel 101. The blood flow channel 101 extends along the length direction of the cannula 100. Generally, the length direction of the cannula 100 is also referred to as the axial direction of the cannula 100.

[0070] See Figures 1 to 3 The cannula 100 has a wall surrounding a blood flow channel 101, said wall being a flexible membrane without an elastic support. Some conventional cannulas typically have walls with elastic supports made of shape memory materials, often in the form of helical supports, mesh supports, or coil supports composed of multiple coils spaced axially. This elastic support allows the conventional cannula to bend and adapt to the curvature of the patient's tissues. However, this elastic support also increases the rigidity of the conventional cannula, making it difficult for it to expand and contract radially. Consequently, the cross-sectional area (i.e., the flow surface area) of the conventional cannula cannot change according to blood flow, limiting blood flow to the radial dimension of the cannula and resulting in lower blood pumping efficiency.

[0071] Because the wall of the cannula 100 lacks an elastic support, its rigidity is lower than that of traditional cannulas, making it more flexible. This means that, on the one hand, the cannula 100 does not need to be pre-shaped into a curved form, allowing it to bend more easily to adapt to the curvature of tissues within the patient's body; on the other hand, the cannula 100 can also undergo a smaller range of radial deformation. As blood flows through the blood flow channel 101 of the cannula 100, if the blood flow increases, the cannula 100 can expand slightly radially outward to allow the increased blood flow to pass through, thereby increasing the amount of blood delivered and improving the pumping efficiency of the blood pump 10. Subsequently, if the blood flow decreases, the cannula 100 can contract radially inward to return to its initial state.

[0072] It should be noted that the flexible membrane of the cannula 100 is typically made of a material with greater hardness than that of medical balloons (silicone rubber), such as TPU (thermoplastic polyurethane elastomer). Therefore, even without an elastic support, the cannula 100 can maintain its tubular shape in its natural state. Of course, by appropriately designing the membrane wall thickness of the cannula 100 (e.g., but not limited to 0.5mm–1.2mm), it is possible to maintain its tubular shape well in its natural state. Furthermore, the diameter of the cannula 100 is usually small. Therefore, when the cannula 100 does not have an elastic support, the expansion and contraction along its radial direction are relatively small deformations, and the change in diameter is minimal, generally not easily observed with the naked eye. This prevents the large-scale expansion and contraction seen in catheter balloons, where the diameter changes exponentially. This ensures that when the cannula 100 expands and contracts back to its initial state, it retains its tubular shape, rather than shrinking into a deflated balloon shape.

[0073] The cannulation assembly also includes a flow tube 200. The flow tube 200 is used to house the impeller 810. The flow tube 200 is connected to one end of the cannula 100 and has a first blood flow orifice 203 communicating with the blood flow channel 101. The first blood flow orifice 203 can serve as a blood inlet or a blood outlet. Optionally, the flow tube 200 is a rigid tube, such as a metal tube. The flow tube 200 can be connected to the proximal end of the cannula 100 to serve as a proximal tube located near the cannula 100. The flow tube 200 can also be connected to the distal end of the cannula to serve as a distal tube located near the cannula 100. Specifically, in this embodiment, the flow tube 200 is connected to the proximal end of the cannula 100.

[0074] See Figures 1 to 4 The cannulation assembly further includes a mandrel 300, which is fixed to the blood flow channel 101 of the cannula 100. The mandrel 300 extends axially along the cannula 100. One end of the mandrel 300 is fixed to the proximal end of the cannula assembly, and the other end is fixed to the distal end of the cannula assembly. The mandrel 300 is used to transmit a pushing force between the proximal end and the distal end of the cannula assembly.

[0075] Because the wall of the cannula 100 lacks an elastic support, it is more flexible than traditional cannulas. Consequently, during the insertion of the blood pump 10 into the patient's body, the cannula 100 does not easily transmit thrust between the proximal and distal ends of the cannula assembly. However, this application addresses this by incorporating a mandrel 300 in the blood flow channel 101 of the cannula 100. When the blood pump 10 is pushed from outside the body along the interventional path to the target location inside the body, the mandrel 300 can transmit thrust between the proximal and distal ends of the cannula assembly, providing support and facilitating the insertion of the blood pump 10. This ensures that the cannula 100 itself can expand and contract without affecting the insertion of the blood pump 10.

[0076] It is worth mentioning that the cannulation assembly may include two flow tubes 200, one flow tube 200 connected to the proximal end of the cannula 100 and the other flow tube 200 connected to the distal end of the cannula 100; the two ends of the core wire 300 are respectively fixed to the two flow tubes 200, so that the core wire 300 transmits pushing force between the two flow tubes 200. Of course, in its embodiment, the cannulation assembly may include a delivery tube 500 (see the description below), the delivery tube 500 and the flow tube 200 are respectively connected to the two ends of the cannula 100, and the two ends of the core wire 300 are respectively fixed to the flow tube 200 and the delivery tube 500, so that the core wire 300 transmits pushing force between the flow tube 200 and the delivery tube 500.

[0077] Understandably, the mandrel 300 is located distal to the impeller 810 and spaced axially from the impeller 810 along the cannula 100. In other words, the mandrel 300 is positioned between the impeller 810 and the distal end of the cannula assembly (such as the delivery tube 500). This prevents the mandrel 300 from passing through the impeller 810. On one hand, during the insertion process, when the mandrel 300 bends to adapt to the shape of the blood vessel, it is less likely to come into contact with the impeller 810, avoiding friction and wear. On the other hand, the mandrel 300 does not interfere with the rotation of the impeller 810.

[0078] Alternatively, the core wire 300 is a metal wire. To ensure that the bending performance of the cannula 100 is not affected, the core wire 300 generally has a small diameter, making it relatively flexible. In this way, the core wire 300 can not only transmit pushing force, but also adapt to the shape and bending deformation of the blood vessel.

[0079] See Figures 1 to 4 The core wire 300 includes a core body 330 and a fixed end 310 connected to the core body 330. The fixed end 310 is fixed to the flow tube 200. It is understood that when the flow tube 200 is connected to the proximal end of the cannula 100, the fixed end 310 of the core wire 300 is correspondingly the proximal end of the core wire 300; when the flow tube 200 is connected to the distal end of the cannula 100, the fixed end 310 of the core wire 300 is correspondingly the distal end of the core wire 300. The core wire 300 may also include a connecting end 320 connected to the core body 330. The connecting end 320 is located away from the fixed end 310, that is, away from the flow tube 200 fixed to the fixed end 310. The connecting end 320 is used to connect to the end of the cannula assembly away from the flow tube 200, such as being fixed to another flow tube 200, or being fixed to the delivery tube 500. It should be noted that the fixed end 310 and the connecting end 320 may be the same or different.

[0080] See Figure 3 and Figure 4The flow tube 200 is provided with a fixing frame 210. The fixing end 310 of the core wire 300 can be connected and fixed to the fixing frame 210. In some related technologies, the connection between the core wire 300 and the fixing frame 210 is not secure enough, and there is a risk of detachment. In view of this, the cannula assembly also includes a fastener 400, which includes a fastening sleeve 410. The fastening sleeve 410 is sleeved on the end of the core wire 300 near the fixing frame 210. The fastener 400 is connected to both the core wire 300 and the fixing frame 210 to connect and fix the core wire 300 and the fixing frame 210.

[0081] Understandably, fastener 400 is a single, small component. Fastener 400 can be fitted onto the fixed end 310, or onto the connection between the fixed end 310 and the core 330, or onto the end of the core 330 closest to the fixed end 310. After the fastening sleeve 410 is fitted onto the core wire 300, the fastening sleeve 410 and the core wire 300 can be connected and fixed by any one or more methods, such as adhesive bonding, interference fit, or interlocking with a concave-convex structure. Both fastener 400 and the fixing bracket 210 are made of metal, such as 316L stainless steel.

[0082] The cannulation assembly of the present invention, by adding a fastener 400, which includes a fastening sleeve 410, is fitted onto the end of the core wire 300 near the fixing bracket 210. The fastener 400 is connected to both the core wire 300 and the fixing bracket 210 to securely connect and fix the core wire 300 and the fixing bracket 210. This fastener 400 enhances the connection between the core wire 300 and the flow tube 200, reducing the possibility of the core wire 300 loosening or falling off. Furthermore, when the cannulation assembly bends near the connection between the core wire 300 and the fixing bracket 210, the fastener 400 can share some of the bending force, thereby reducing the force acting on the fixing end 310 of the core wire 300 when the cannulation assembly bends, further reducing the risk of the core wire 300 loosening or falling off, and effectively enhancing the secure installation of the core wire 300.

[0083] Furthermore, since the fastener 400 is located at the end of the core wire 300 near the fixing frame 210, the fastener 400 occupies less space in the cannula assembly, and the fastener 400 is less likely to interfere with the bending of the cannula 100. Therefore, the limitations on the size and material of the fastener 400 are less than those on the core wire 300. Thus, depending on actual needs, the size of the fastener 400 can be designed to be slightly larger than that of the core wire 300, or the fastener 400 can be made of a material with a higher hardness than the core wire 300, so that the fastener 400 is harder than the core wire 300, thereby making the connection between the fastener 400 and the fixing frame 210 more secure and effectively reducing the risk of the core wire 300 loosening.

[0084] See Figure 3 and Figure 4 and combined Figures 7 to 10 The fastening sleeve 410 is sleeve-shaped. The fastening sleeve 410 has an inner cavity extending axially along the insertion tube 100, the inner cavity having a first opening 411 and a second opening 412. The first opening 411 is located at the end of the fastening sleeve 410 near the fixing frame 210, and the second opening 412 is located at the end of the fastening sleeve 410 away from the fixing frame 210. The core wire 300 passes through the first opening 411 and the second opening 412. The end of the core 330 near the fixing end 310 passes through the inner cavity of the fastening sleeve 410; a portion of the fixing end 310 may be located within the inner cavity of the fastening sleeve 410, and another portion extends through the first opening 411 to the outside of the fastening sleeve 410. Of course, in other embodiments, the entire fixing end 310 may be located on the outside of the fastening sleeve 410. That is, at least a portion of the fixing end 310 is located on the outside of the fastening sleeve 410 to facilitate connection between the fixing end 310 and the fixing frame 210.

[0085] See Figure 4 and combined Figures 10 to 12 At least one of the fastener 400 and the fixing frame 210 is provided with a receiving cavity Q1, and the fixing end 310 of the core wire 300 is installed in the receiving cavity Q1. The receiving cavity Q1 can be configured in various ways. For example, the fixing frame 210 is provided with a first cavity 201, which constitutes the receiving cavity Q1. Alternatively, the fastener 400 is provided with a second cavity 401, which constitutes the receiving cavity Q1. Or, the fixing frame 210 is provided with a first cavity 201, the fastener 400 is provided with a second cavity 401, and the first cavity 201 and the second cavity 401 are joined together to form the receiving cavity Q1. Specifically, in this embodiment, the receiving cavity Q1 is formed by joining the first cavity 201 and the second cavity 401.

[0086] See Figure 4 and Figure 10 As shown, the fastener 400 also includes a stop portion 420, which is disposed on the inner wall of the fastening sleeve 410. The stop portion 420 is opposite to the receiving cavity Q1 along the axial direction of the core wire 300. The core body 330 of the core wire 300 passes through the stop portion 420, so that the fixing end 310 is installed in the receiving cavity Q1. The fixing end 310 can abut against the stop portion 420 along the axial direction. On the one hand, when the fixing end 310 has a tendency to move and fall off along the direction from the receiving cavity Q1 to the stop portion, the fixing end 310 abuts against the stop portion 420, thereby the stop portion 420 prevents the fixing end 310 from falling out of the receiving cavity Q1. On the other hand, the stop portion 420 of the fastener 400 encapsulates the fixed end 310 of the core wire 300 in the receiving cavity Q1. When the section of the insertion assembly near the flow tube 200 bends, the fastener 400 bears the bending force, and the fixed end 310 is not easily subjected to bending force, so the fixed end 310 is not easily broken or detached.

[0087] See Figure 4 and combined Figures 7 to 10 The core 330 of the core wire 300 has a diameter D1, and the fixed end 310 of the core wire 300 has a maximum radial dimension D2. The maximum radial dimension D2 is set to be greater than the diameter D1 of the core 330, i.e., D2 > D1. In this way, it can not only ensure that the core 330 can pass through the stop part 420 and that the fixed end 310 can abut against the stop part 420, but also increase the area of ​​the circumferential surface of the fixed end 310, thereby increasing the bonding area between the fixed end 310 and the inner wall of the receiving cavity Q1 and improving the firmness of the connection between the two.

[0088] It is understood that the fixed end 310 has a cross-section perpendicular to the length direction of the core wire 300. The cross-section of the fixed end 310 can be circular, elliptical, polygonal, etc. When the cross-section of the fixed end 310 is circular, the maximum radial dimension D2 of the fixed end 310 is the diameter of the fixed end 310. When the cross-section of the fixed end 310 is elliptical, the maximum radial dimension D2 of the fixed end 310 is the length of the major axis of the cross-section of the fixed end 310. When the cross-section of the fixed end 310 is square, the maximum radial dimension D2 of the fixed end 310 is the length of the longest side of the fixed end 310. When the cross-section of the fixed end 310 is rhomboid, the maximum radial dimension D2 of the fixed end 310 is the length of the diagonal of the cross-section of the fixed end 310. In addition to the above shapes, the cross-section of the fixed end 310 may also be other shapes.

[0089] See Figure 4 , Figure 11 and Figure 12 The fixed end 310 can be welded and fixed within the receiving cavity Q1. Since the fixed end 310 is confined within the receiving cavity Q1 by the stop part 420, even if the weld of the fixed end 310 breaks, the fixed end 310 will still be stopped by the stop part 420 and cannot fall out of the receiving cavity Q1, thus preventing the core wire 300 from loosening and falling off. However, considering that the connection between the core body 330 of the core wire 300 and the fixed end 310 is relatively thin and soft, if welding is used for fixation, there is a risk of melting at the connection between the core body 330 and the fixed end 310. Therefore, in this embodiment, the fixed end 310 is fixed within the receiving cavity Q1 by adhesive bonding.

[0090] Specifically, the first cavity 201 on the fixing frame 210 forms part of the receiving cavity Q1, and the fixing end 310 is bonded to the inner sidewall 201a of the first cavity 201 (e.g., Figure 12(As shown). Compared with high-temperature welding, on the one hand, using adhesive bonding can prevent the connection between the core 330 of the core wire 300 and the fixed end 310 from melting; on the other hand, the stress at the bonding point of the fixed end 310 will not be too concentrated, which can prevent the connection between the fixed end 310 and the fixing frame 210 from being too stressed and breaking.

[0091] During installation, first, the fixed end 310 of the core wire 300 is glued and fixed inside the first cavity 201 of the fixing frame 210; then, the fastener 400 is sleeved on the core wire 300, and finally the fastener 400 is fixed to the fixing frame 210.

[0092] See Figure 4 and combined Figures 8 to 10 The stop portion 420 is annular, extending circumferentially around the inner wall of the fastening sleeve 410. The stop portion 420 has a wire-passing hole 421 through which the core 330 of the core wire 300 passes. Optionally, the wire-passing hole 421 has a diameter D3, which is set to be smaller than the maximum radial dimension D2 of the fixed end 310, i.e., D3 < D2. Thus, the fixed end 310 is difficult to pass through the wire-passing hole 421, thereby confining the fixed end 310 within the receiving cavity Q1. Therefore, even if the connection between the core wire 300 and the fixing bracket 210 accidentally detaches, the fixed end 310 can still be blocked by the stop portion 420 and the wire-passing hole 421, thereby confining the fixed end 310 within the receiving cavity Q1 and effectively preventing the core wire 300 from detaching from the receiving cavity Q1.

[0093] See Figure 4 , Figure 9 and Figure 10 The wall of the wire through hole 421 is interference-fitted with the circumferential surface of the core 330. That is, the diameter D1 of the core 330 is equal to or slightly larger than the diameter D3 of the wire through hole 421, so that the wall of the wire through hole 421 and the core 330 are interference-fitted. After the core 330 passes through the wire through hole 421, the stop part 420 clamps the core 330 in a clamping position, so that the stop part 420 can clamp and fix the core 330, making it difficult for the core 330 to loosen from the fastening sleeve 410.

[0094] See Figure 4 , Figure 9 and Figure 10 The stop portion 420 has a first stop surface 422, which is used to prevent the fixed end 310 from moving out along the direction from the receiving cavity Q1 to the stop portion 420. In one embodiment, the first stop surface 422 is perpendicular to the central axis of the insertion tube 100, and the first stop surface 422 is opposite to the receiving cavity Q1 along the axial direction of the insertion tube 100. The stop portion 420 abuts against the fixed end 310 through the first stop surface 422. Correspondingly, the fixed end 310 has a limiting surface 301, which can cooperate with the first stop surface 422 to abut.

[0095] join Figure 4 and Figure 7 The fixed end 310 includes a large-diameter section 311, which has a maximum radial dimension D2, greater than the diameter D1 of the core 330. The circumferential surface of the large-diameter section 311 can be adapted to fit the inner wall surface of the receiving cavity Q1. The fixed end 310 also includes a variable-diameter section 312, which connects the large-diameter section 311 and the core 330. The radial dimension of the variable-diameter section 312 gradually increases from the core 330 to the large-diameter section 311. The circumferential surface of the variable-diameter section 312 forms the limiting surface 301 of the fixed end 310. The end of the circumferential surface of the variable-diameter section 312 (i.e., the limiting surface 301) near the wire hole 421 abuts against the edge of the first stop surface 422 near the wire hole 421.

[0096] The variable diameter section 312 can avoid the formation of a right-angle transition step between the large diameter section 311 and the core 330 due to a sudden change in diameter, thereby avoiding stress concentration at the position between the large diameter section 311 and the core 330, and improving the structural strength and fatigue resistance of the core wire 300 itself.

[0097] A large gap space Q2 is formed between the circumferential surface of the variable diameter section 312 (i.e., the limiting surface 301), the first stop surface 422, and the circumferential cavity wall of the receiving cavity Q1. The gap space Q2 can serve as a tolerance clearance when assembling the fixed end 310 and the receiving cavity Q1, thereby reducing the dimensional accuracy requirements for the assembly of the fixed end 310 and the receiving cavity Q1. Furthermore, the gap space Q2 can be used to accommodate the adhesive used to bond the fixed end 310 and the fixing bracket 210, increasing the amount of adhesive on the inner wall surfaces of the fixed end 310 and the receiving cavity Q1, and enhancing the firmness of the connection between the two.

[0098] Furthermore, during the adhesive injection process, the circumferential surface (i.e., the limiting surface 301) of the variable diameter section 312 can effectively guide the adhesive flow, promoting better penetration and filling of the tiny gaps between the large diameter section 311 and the inner wall 201a of the first cavity 201, ensuring sufficient adhesion. In this way, the variable diameter section 312 can maintain abutment against the first stop surface 422, increase the adhesive capacity of the receiving cavity Q1, and ensure sufficient adhesion.

[0099] Figure 4 and Figure 7 Optionally, the circumferential surface of the variable diameter section 312 can be either an arc surface or an inclined surface. Specifically, the variable diameter section 312 has a generatrix that rotates around the central axis of the core wire 300 to form the outline of the circumferential surface of the variable diameter section 312. When the generatrix of the variable diameter section 312 is an arc, the circumferential surface of the variable diameter section 312 is an arc surface. When the generatrix of the variable diameter section 312 is a straight line, the circumferential surface of the variable diameter section 312 is an inclined surface.

[0100] See Figure 15The variable diameter section 312 may also be provided with a spiral groove 302, which is spirally wound around the circumference of the variable diameter section 312 along the direction from the core 330 to the large diameter section 311. By providing a spiral groove 302 on the circumference of the variable diameter section 312, on the one hand, the stress on the circumference of the variable diameter section 312 can be dispersed and weakened, avoiding stress concentration and reducing the risk of bending and breaking of the variable diameter section 312; on the other hand, the spiral groove 302 can accommodate adhesive, which can increase the amount of adhesive and enhance the bonding strength between the fixed end 310 and the fixed frame 210.

[0101] See Figure 16 In some other embodiments, the fixed end 310 does not have a variable diameter section 312. That is, the fixed end 310 only has a large diameter section 311. The end face of the large diameter section 311 that is opposite to the first stop surface 422 along the axial direction of the insertion tube 100 is a limiting surface 301. The limiting surface 301 is perpendicular to the central axis of the insertion tube 100. The limiting surface 301 and the first stop surface 422 cooperate to abut against each other to restrict the movement of the fixed end 310 along the direction from the receiving cavity Q1 to the stop portion 420.

[0102] See Figure 17 and Figure 18 In other embodiments, the stop portion 420 of the fastener 400 may also have a second stop surface 423. Specifically, the stop portion 420 has a wire passage hole 421 through which the core 330 passes. The wire passage hole 421 includes a straight hole section 421a and a variable diameter hole section 421b connected axially. The hole wall of the straight hole section 421a mates with the circumferential surface of the core 330. The diameter of the variable diameter hole section 421b gradually increases from the core 330 to the large diameter section 311, so that the hole wall of the variable diameter hole section 421b mates with the circumferential surface of the variable diameter section 312. The hole wall of the variable diameter hole section 421b constitutes the second stop surface 423. The hole wall of the straight hole section 421a can restrict the radial movement of the core 330; the hole wall of the variable diameter hole section 421b can restrict the radial movement of the core 330 and its axial movement along the direction from the receiving cavity Q1 to the stop portion 420. It is understandable that the first stop 422 and the second stop 423 can coexist, or only one of them can exist.

[0103] The variable-diameter section 312 of the fixed end 310 has a first length L1 along the central axis of the insertion tube 100, and the variable-diameter hole section 421b of the wire hole 421 has a second length L2 along the central axis of the insertion tube 100. The second length L2 can also be set to be less than the first length L1, i.e., L2 < L1. With this configuration, a portion of the circumferential surface (i.e., the limiting surface 301) of the variable-diameter section 312 contacts and engages with the second stop surface 423; another portion is located within the receiving cavity Q1, and this portion, together with the first stop surface 422 and the circumferential cavity wall of the receiving cavity Q1, forms a space Q2 (see [reference]). Figure 4 ).

[0104] like Figure 4 and Figure 5 As shown, the cannulation assembly also includes a flexible sheath 600 that encloses the core wire 300. The flexible sheath 600 extends a considerable length along the axial direction of the cannulation 100, such that it covers most of the core 330 of the core wire 300, reducing the surface area of ​​the core wire 300 exposed in the blood flow channel 101. By enclosing the core wire 300 with the flexible sheath 600, contact between the core wire 300 and the blood can be avoided. The material of the flexible sheath 600 may be, but is not limited to, TPU (thermoplastic polyurethane elastomer).

[0105] Furthermore, the fastening sleeve 410 also has a fixing cavity 402, and one end of the flexible sheath 600 is installed in the fixing cavity 402. The core wire 300 passes through the flexible sheath 600 and the fixing cavity 402 so that the fixed end 310 of the core wire 300 can be connected to the fixing frame 210. The stop portion 420 is located between the receiving cavity Q1 (specifically the second cavity 401) and the fixing cavity 402. In other words, the stop portion 420 divides the inner cavity of the fastening sleeve 410 into the fixing cavity 402 and the second cavity 401. The core 330 passes through the stop portion 420 so that the fixed end 310 is installed in the receiving cavity Q1, and the fixed end 310 can be stopped by the stop portion 420.

[0106] The stop portion 420 also has a third stop surface 424 facing the fixed cavity 402. The third stop surface 424 is part of the cavity wall of the fixed cavity 402. The third stop surface 424 abuts against the flexible sheath 600 and is positioned by the flexible sheath 600.

[0107] like Figure 4 , Figure 11 and Figure 12 As shown, the fixing bracket 210 may include a base 212 and a fixing ring 211 disposed on the base 212, the fixing ring 211 forming a part of the receiving cavity Q1. The fixing ring 211 is annular in shape. The outer peripheral surface of the fixing ring 211 is cylindrical. The fixing ring 211 is used for fixing to the fastening sleeve 410.

[0108] Specifically, the fixing frame 210 has a first cavity 201, which forms part of the receiving cavity Q1. A portion of the first cavity 201 is located inside the base 212, and another portion of the first cavity 201 is located inside the fixing ring 211, so that the first cavity 201 has a large longitudinal depth in the axial direction. This can effectively increase the bonding area between the inner sidewall 201a of the first cavity 201 and the fixed end 310 of the core wire 300, thereby enhancing the connection strength between the first cavity 201 and the fixed end 310.

[0109] See Figure 4 , Figure 9 and Figure 10As shown, the fastening sleeve 410 includes a first sleeve portion 413, which is sleeved on the outer periphery of the fixing ring 211. A second cavity 401 of the fastening sleeve 410 is formed on the inner side of the first sleeve portion 413, and a first opening 411 of the fastening sleeve 410 is located at one end of the first sleeve portion 413.

[0110] Optionally, the outer peripheral surface of the first socket 413 is set as a cylindrical surface, so that the outer peripheral surface of the first socket 413 and the outer peripheral surface of the fixing ring 211 are joined together to form a cylindrical surface, that is, the outer peripheral surface of the first socket 413 and the outer peripheral surface of the fixing ring 211 are coplanar.

[0111] The fixing ring 211 includes a first annular portion 211a and a second annular portion 211b connected axially along the insertion tube 100; the first annular portion 211a is connected to the base 212. The inner diameters of the first annular portion 211a and the second annular portion 211b are the same and coplanar, and the outer diameter of the first annular portion 211a is larger than the outer diameter of the second annular portion 211b, thereby forming a transition step surface between the outer peripheral surfaces of the first annular portion 211a and the second annular portion 211b. The first sleeve portion 413 of the fastening sleeve 410 is fixedly fitted onto the outer peripheral surface of the second annular portion 211b and abuts against the transition step surface; the outer peripheral surface of the first sleeve portion 413 is coplanar with the outer peripheral surface of the first annular portion 211a. The first sleeve portion 413 is connected to the second annular portion 211b of the fixing ring 211. Specifically, the first sleeve portion 413 and the second annular portion 211b are connected by welding.

[0112] See Figure 4 , Figure 9 and Figure 10 The fastening sleeve 410 also includes a second fitting portion 414. The second fitting portion 414 and the first fitting portion 413 are arranged along the axial direction of the fastening sleeve 410. The second fitting portion 414 is fitted onto the outer periphery of the core 330. Specifically, a fixing cavity 402 of the fastening sleeve 410 is formed on the inner side of the second fitting portion 414. The second opening 412 of the fastening sleeve 410 is located at one end of the second fitting portion 414. A stop portion 420 is located on the inner wall at the connection between the first fitting portion 413 and the second fitting portion 414.

[0113] Optionally, the outer peripheral surface of the second socket 414 is configured as a conical surface, the diameter of which gradually decreases along the direction from the fixed end 310 to the core 330. The outer peripheral surface of the second socket 414 can guide the flow of blood and reduce the resistance of the fastener 400 to the flow of blood.

[0114] When blood flows from the flow tube 200 to the insertion tube 100, some blood flows along the outer peripheral surface of the second socket 414, converging and flowing towards the core wire 300 (i.e., the central region of the insertion tube 100), reducing the resistance to blood flow towards the distal end of the insertion tube assembly. Conversely, when blood flows from the insertion tube 100 to the flow tube 200, after contacting the outer peripheral surface of the second socket 414, the blood is guided by the second socket 414 to the holes 202 around the fixing frame 210, allowing the blood to flow smoothly through the holes 202 of the fixing frame 210, reducing the resistance of the blood as it flows from the insertion tube 100 to the flow tube 200 through the fixing frame 210. Therefore, the outer peripheral surface of the second socket 414 can guide blood flow and reduce the resistance of the fastener 400 to blood flow.

[0115] In an embodiment of the present invention, the core wire 300 is a solid metal wire. The metal wire can be made of nickel-titanium material. The unique superelastic properties of the nickel-titanium material allow it to recover its original shape after undergoing significant deformation, and its fatigue life far exceeds that of conventional metals.

[0116] Regarding the base 212 of the fixation frame 210, the base 212 is designed to be hollow. Holes 202 are formed in the hollow portion of the base 212, allowing blood to pass through the holes 202 in the hollow portion of the fixation frame 210. Multiple holes 202 can be provided and are located around the periphery of the fixing ring 211. Specifically, the base 212 has a central portion and multiple extension arms connected circumferentially to the central portion. The end of each extension arm away from the central portion is fixedly connected to the inner wall of the flow tube 200. A hole 202 is spaced between every two adjacent extension arms.

[0117] In an exemplary embodiment, the diameter of the core wire 300 ranges from 0.45 mm to 0.55 mm (e.g., 0.45 mm, 0.47 mm, 0.48 mm, 0.50 mm, 0.51 mm, 0.53 mm, 0.55 mm) to ensure that the core wire 300 has sufficient structural rigidity to maintain pushing stability during cannulation while retaining the high toughness and fatigue resistance provided by the nickel-titanium material. If the diameter of the core wire 300 is less than 0.45 mm, the rigidity of the core wire 300 will decrease significantly, making it prone to buckling instability during pushing, thus affecting positioning accuracy and operational feel. If the diameter of the core wire 300 is greater than 0.55 mm, the rigidity of the core wire 300 is excessively enhanced, and its flexibility decreases. This not only weakens its fatigue resistance to repeated bending but may also exacerbate wear on the cannula body or affect its ability to pass through narrow cavities when mated with the cannula 100 due to the mismatch between rigidity and flexibility.

[0118] See Figure 1 and Figure 2In one embodiment, the cannulation assembly further includes a delivery tube 500 connected to the end of the cannula 100 away from the flow tube 200. The delivery tube 500 is provided with a second blood flow orifice 501 communicating with the blood flow channel 101; one of the second blood flow orifice 501 and the first blood flow orifice 203 is a blood outlet, and the other is a blood inlet. Both the delivery tube 500 and the flow tube 200 are rigid tubes (e.g., metal tubes).

[0119] The end of the core wire 300 furthest from the flow tube 200 is fixedly connected to the delivery tube 500, and the core wire 300 can transmit axial pushing force between the flow tube 200 and the delivery tube 500. The core wire 300 has a connecting end 320 furthest from the fixed end 310, and the connecting end 320 is fixedly connected to the delivery tube 500.

[0120] Specifically, the flow tube 200 is connected to the proximal end of the cannula 100, serving as a proximal tube located near the cannula 100. The delivery tube 500 is connected to the distal end of the cannula 100, serving as a distal tube located far from the cannula 100. Correspondingly, the fixed end 310 is the proximal end of the core wire 300, and the connecting end 320 is the distal end of the core wire 300.

[0121] When the cannulation assembly is applied to a right ventricular interventional blood pump, the first blood flow orifice 203 of the flow tube 200 serves as the blood inlet, and the second blood flow orifice 501 of the delivery tube 500 serves as the blood outlet. During insertion, the blood pump 10 is pushed from the right ventricle to the pulmonary artery, causing the cannula 100 to cross the pulmonary valve. The first blood flow orifice 203 of the flow tube 200 is located within the right ventricle, while the second blood flow orifice 501 of the delivery tube 500 is located within the pulmonary artery.

[0122] When the cannulation assembly is applied to the left ventricular interventional blood pump, the first blood flow orifice 203 of the flow tube 200 is the blood outlet, and the second blood flow orifice 501 of the delivery tube 500 is the blood inlet. During push-in, the blood pump 10 pushes from the aorta to the left ventricle, so that the cannula 100 crosses the aortic valve, the second blood flow orifice 501 of the delivery tube 500 is located in the left ventricle, and the first blood flow orifice 203 of the flow tube 200 is located in the aorta.

[0123] See Figure 1 , Figure 13 and Figure 14 The delivery tube 500 has a plurality of supports 510 and guide portions 530 connected to the distal ends of the supports 510. A second blood flow orifice 501 is formed between adjacent supports 510. The guide portion 530 is typically tapered or tapered to facilitate the advancement of the distal end of the cannulation assembly within the body.

[0124] The guide portion 530 and the blood flow channel 101 of the cannula 100 are axially opposite each other. The guide portion 530 is provided with an insertion hole 531, and the connecting end 320 of the core wire 300 is fixed in the insertion hole 531. The end of the flexible sheath 600 away from the fixing bracket 210 is also fixed in the insertion hole 531.

[0125] Furthermore, the insertion port 531 has a first section 531a near the blood flow channel 101 and a second section 531b away from the blood flow channel 101. The end of the flexible sheath 600 away from the fixing bracket 210 is fixed to the first section 531a; the core wire 300 passes through the flexible sheath 600 in the first section 531a, so that the connecting end 320 is fixed to the second section 531b.

[0126] See Figure 3 , Figure 5 and Figure 14 Optionally, a glue-filled groove 532 is provided on the wall surface of the guide portion 530 near the blood flow channel 101, and the glue-filled groove 532 communicates with the first hole section 531a. The glue-filled groove 532 is used to hold the glue for bonding the flexible sheath 600, the core wire 300 and the guide portion 530, thereby increasing the glue capacity and strengthening the firmness of the flexible sheath 600 and the core wire 300 to the guide portion 530.

[0127] See Figure 3 , Figure 5 and Figure 14 Optionally, a molten material groove 533 is provided on the wall of the guide portion 530 opposite to the blood flow channel 101. The molten material groove 533 communicates with the second hole section 531b and is used to collect the molten material after the connecting end 320 has been melted. When welding the connecting end 320 and the guide portion 530, a high-energy beam (such as a laser) is applied to the connecting end 320 of the core wire 300, causing the end of the nickel-titanium wire to melt. The molten metal droplets fill the cavity of the entire molten material groove 533. After it cools and solidifies, the connecting end 320 of the core wire 300 forms a firm connection with the delivery pipe 500 through a metallurgical bonding method.

[0128] Specifically, the molten metal bath 533 provides a guarantee for welding at this location: on the one hand, as a pre-formed cavity, the molten metal bath 533 can effectively constrain and contain the molten nickel-titanium metal, preventing it from flowing randomly and ensuring the regularity and controllability of the weld shape; on the other hand, the sidewalls and bottom of the molten metal bath 533 increase the contact and bonding area between the molten metal and the conveying pipe 500. When the molten metal fills the bath and solidifies, it not only forms an anchor in the axial direction but also generates a strong mechanical interlocking force in the radial direction. Therefore, compared to simple surface spot welding, the molten metal bath 533 implementation creates a more reliable connection strength, fully utilizing the fluidity of the nickel-titanium material in the molten state to achieve a large-area metallurgical bond with the conveying pipe 500. This effectively resists axial pull-out force and circumferential torsional force, significantly improving the connection stability of the core wire 300 at the far end and the safety of the entire assembly under long-term use.

[0129] Because the wall of the cannula 100 is a flexible membrane, it is difficult to form a strong bond between the flexible membrane and the metal parts. Experiments have shown that even when using various types of specialized adhesives, or combinations of treatment with surfactants before application, the achieved bond strength fails to meet the pull-out force requirements (e.g., greater than or equal to 15N) necessary for safe use of the component. Therefore, the following describes a method of fixing the cannula 100 to the flow tube 200 or the delivery tube 500 using a locking ring.

[0130] See Figure 3 and Figure 4 In one embodiment, the cannula 100 includes a main pipe section 110 and a first connecting section 120 connected to the main pipe section 110, the first connecting section 120 being sleeved around the outer periphery of the flow tube 200; the cannula assembly further includes a first locking ring 710, the first locking ring 710 being sleeved around the outer periphery of the first connecting section 120. The first locking ring 710 and the first connecting section 120 are interference-fitted.

[0131] The first locking ring 710 is typically a metal ring. During assembly, the first connecting segment 120 of the cannula 100 is first fitted onto the flow tube 200 and pre-fixed with adhesive. Then, the first locking ring 710 is slid to the periphery of the first connecting segment 120 of the cannula 100. The inner diameter of the first locking ring 710 is smaller than the outer diameter of the first connecting segment 120 of the cannula 100. Utilizing the extensibility of the cannula 100, the first locking ring 710 and the first connecting segment 120 of the cannula 100 are press-fitted, locking the first connecting segment 120 of the cannula 100 onto the flow tube 200. After repeated testing, the pull-out force of this structure exceeds 15N.

[0132] See Figure 3 and Figure 4Optionally, the flow tube 200 includes an open tube 220 and an adapter tube 230 connected to the open tube 220. The open tube 220 is provided with the first blood flow hole 203. The adapter tube 230 is provided with a fixing bracket 210.

[0133] The outer peripheral surface of the open tube 220 near the end of the insertion tube 100 is provided with a mounting groove 221. The adapter tube 230 includes a first tube segment 231 and a second tube segment 232. After the first tube segment 231 is installed into the mounting groove 221, the inner surface of the second tube segment 232 is flush with the inner surface of the open tube 220, and the outer surface of the second tube segment 232 is closer to the central axis of the open tube 220 than the outer surface of the open tube 220. The first connecting section 120 of the insertion tube 100 is located between the first locking ring 710 and the second tube segment 232 of the flow tube 200, so as to be clamped by the first locking ring 710 and the second tube segment 232 of the flow tube 200.

[0134] It is understood that in this embodiment, the open tube 220 and the adapter tube 230 are independent parts, and are fixed together by means of bonding or welding. In other embodiments, the open tube 220 and the adapter tube 230 can be integrally formed.

[0135] See Figure 3 and Figure 6 In one embodiment, the cannula 100 further includes a second connecting section 130 connected to the main tube section 110, the second connecting section 130 being sleeved around the outer periphery of the delivery tube 500; the cannula assembly further includes a second locking ring 720, the second locking ring 720 being sleeved around the outer periphery of the second connecting section 130. The second locking ring 720 is interference-fitted with the second connecting section 130. The second locking ring 720 is typically a metal ring.

[0136] Specifically, the delivery tube 500 also includes a connecting tube 520 connected to the support column 510, with the connecting tube 520 and the guide portion 530 located at opposite ends of the support column 510. The inner surface of the connecting tube 520 is flush with the inner surface of the support column 510, and the outer surface of the connecting tube 520 is closer to the central axis of the support column 510 than the outer surface of the support column 510. The second connecting section 130 of the insertion tube 100 is located between the second locking ring 720 and the connecting tube 520 of the delivery tube 500, and is clamped by the second locking ring 720 and the connecting tube 520 of the delivery tube 500.

[0137] Although the flow tube 200 and delivery tube 500 have different specific structures when connected to the insertion tube 100 as described above, the principle is the same, and their specific structures can be interchanged or similarly adjusted.

[0138] See Figures 1 to 3 The present invention also provides a blood pump 10. The blood pump 10 can be a left ventricular interventional blood pump or a right ventricular interventional blood pump. The blood pump 10 includes an impeller 810 (see attached diagram). Figures 1 to 3 The blood pump 10 of the present invention employs all the technical solutions of all the above embodiments, and therefore possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here.

[0139] Specifically, the flow tube 200 is connected to the proximal end of the cannula 100. The flow tube 200 has a proximal section and a distal section connected to the proximal section; an impeller 810 is rotatably mounted on the proximal section. A core wire 300 is located between the distal section and the distal end of the cannula assembly. Alternatively, the core wire 300 extends from the distal section to the distal end of the cannula assembly.

[0140] See Figures 1 to 3 The blood pump 10 also includes a motor 820, the distal end of which is fixedly connected to the flow tube 200. The motor 820 has a rotating shaft, which is connected to an impeller 810 to drive the impeller 810 to rotate. That is, the motor 820 in this embodiment is an in-body motor. The blood pump 10 also includes a conduit 830, the distal end of which is fixedly connected to the proximal end of the motor 820. The inner cavity of the conduit 830 can accommodate flushing lines or other components of the blood pump 10. In other embodiments, the blood pump 10 may not include the motor 820. Alternatively, the blood pump 10 may include an external motor, which is located outside the body and connected to the impeller 810 via a flexible shaft that passes through the conduit 830.

[0141] 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.

[0142] 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 cannula assembly, characterized in that, The cannula assembly comprises: a cannula having a blood flow channel; a flow tube connected to one end of the cannula, the flow tube being provided with a first blood flow hole in communication with the blood flow channel; the flow tube is further provided with a fixing frame; a core wire fixed to the blood flow channel and extending along the axial direction of the cannula; and a fastener comprising a fastening sleeve, the fastening sleeve being sleeved on one end of the core wire close to the fixing frame; the fastening sleeve is connected with the core wire and the fixing frame to connect and fix the core wire and the fixing frame.

2. The cannula assembly of claim 1, wherein, The core wire comprises a core body and a fixed end connected with the core body; at least one of the fixing frame and the fastener is provided with a receiving cavity; the fastener further comprises a stop portion provided on the inner wall of the fastening sleeve, the stop portion being opposite to the receiving cavity in the axial direction of the cannula; wherein the core body passes through the stop portion; the fixed end is accommodated in the receiving cavity and can abut against the stop portion.

3. The cannula assembly of claim 2, wherein, The stop portion is annular; the stop portion has a wire passing hole through which the core body passes; wherein, the hole diameter of the wire passing hole is smaller than the maximum radial dimension of the fixed end; and / or, the hole wall of the wire passing hole is in interference fit with the peripheral surface of the core body.

4. The cannula assembly of claim 2, wherein, The fixed end comprises a large-diameter section, the maximum radial dimension of the large-diameter section being greater than the diameter of the core body; The fixed end further comprises a variable-diameter section connecting the large-diameter section and the core body, the radial dimension of the variable-diameter section gradually increasing from the core body to the large-diameter section.

5. The cannula assembly of claim 4, wherein, The stop portion has a first stop surface facing the receiving cavity; the peripheral surface of the variable-diameter section and the first stop surface and the peripheral cavity wall of the receiving cavity form a spacing space therebetween.

6. The cannula assembly of claim 4, wherein, The stop portion is provided with a wire passing hole through which the core body passes, the wire passing hole comprising a straight hole section and a variable-diameter hole section connected in sequence, the hole wall of the straight hole section being in fit with the peripheral surface of the core body; the hole diameter of the variable-diameter hole section gradually increases in the direction from the core body to the large-diameter section, so that the hole wall of the variable-diameter hole section forms a second stop surface, the second stop surface being in fit with the peripheral surface of the variable-diameter section.

7. The cannula assembly of claim 4, wherein, The variable-diameter section is provided with a helical groove spirally wound on the peripheral surface of the variable-diameter section in the direction from the core body to the large-diameter section.

8. The cannula assembly of claim 2, wherein, The fastening sleeve is provided with a fixing cavity, the stop portion being located between the fixing cavity and the receiving cavity, the stop portion having a third stop surface facing the fixing cavity; the cannula assembly further comprises a flexible sheath, the flexible sheath wrapping the core wire, one end of the flexible sheath being mounted in the fixing cavity and abutting against the third stop surface.

9. The cannula assembly of claim 2, wherein, The fastening sleeve comprises a first sleeve portion; the fixing frame comprises a base and a fixing ring provided on the base, the fixing ring surrounding a part of the receiving cavity, the first sleeve portion fixedly sleeving the outer periphery of the fixing ring; and / or, the fastening sleeve further comprises a second sleeve portion, the second sleeve portion fixedly sleeving the outer periphery of the core body, the outer peripheral surface of the second sleeve portion being provided as a tapered surface, the diameter of the tapered surface gradually decreasing in the direction from the fixed end to the core body.

10. The cannula assembly of claim 1, wherein, The cannula assembly further has at least one of the following features: The core wire is a solid nickel-titanium wire; The core wire has a diameter ranging from 0.45 mm to 0.55 mm; The core wire comprises a core body and a fixed end connected to the core body, the fixed end is fixedly connected to the fixed frame, and the maximum radial dimension of the fixed end is greater than the diameter of the core body; The cannula has a tube wall surrounding the blood flow channel, and the tube wall does not have an elastic stent.

11. The cannula assembly of any one of claims 1 to 9, wherein, The cannula comprises a main tube segment and a first connecting segment connected to the main tube segment, the first connecting segment is sleeved on the outer periphery of the flow-through tube; the cannula assembly further comprises a first locking ring sleeved on the outer periphery of the first connecting segment, and the first locking ring is in interference fit with the first connecting segment.

12. The cannula assembly of any one of claims 1 to 9, wherein, The flow-through tube is connected to the proximal end of the cannula, the cannula assembly further comprises a delivery tube connected to the distal end of the cannula; the delivery tube is provided with a second blood flow hole in communication with the blood flow channel, the delivery tube and the flow-through tube are both hard tubes; the two ends of the core wire are fixedly connected to the flow-through tube and the delivery tube respectively, so that the core wire can transmit axial pushing force between the flow-through tube and the delivery tube.

13. The cannula assembly of claim 12, wherein, The core wire has a connecting end away from the flow-through tube; the delivery tube comprises a plurality of struts and a guide portion connected to the struts, the guide portion is provided with a insertion hole, and the connecting end is fixed in the insertion hole; wherein, The insertion hole has a first hole segment close to the blood flow channel, the guide portion is provided with a sink groove on the wall surface close to the blood flow channel, and the sink groove is in communication with the first hole segment; and / or, The insertion hole has a second hole segment away from the blood flow channel, the guide portion is provided with a melt groove on the wall surface away from the blood flow channel, the melt groove is in communication with the second hole segment, and the melt groove is used for accommodating the melt of the connecting end after heat melting.

14. The cannula assembly of claim 12, wherein, The cannula comprises a main tube segment and a second connecting segment connected to the main tube segment, the second connecting segment is sleeved on the outer periphery of the delivery tube; the cannula assembly further comprises a second locking ring sleeved on the outer periphery of the second connecting segment, and the second locking ring is in interference fit with the second connecting segment.

15. A blood pump, characterized by It comprises an impeller and the cannula assembly as claimed in any one of claims 1-14; wherein the impeller is rotatably arranged in the cannula assembly.

16. The blood pump of claim 15, wherein, The blood pump further comprises a motor fixedly connected to the flow-through tube, the motor has a rotating shaft connected to the impeller to drive the impeller to rotate.

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