Cannula assembly and blood pump

Abstract

Provided are a blood pump (10) and a driving apparatus (20). The blood pump (10) comprises a proximal tube (100), a distal tube (200), a cannula (300), and a support wire (500). The cannula (300) is provided with a liquid flow channel (301) communicating a first port (101) of the proximal tube (100) with a second port (201) of the distal tube (200). The cannula (300) is provided with a first tube section (310) and a second tube section (320) connected to each other, and a main tube section (330) located between the first tube section (310) and the second tube section (320). The first tube section (310) is fixedly connected to the proximal tube (100). The second tube section (320) is fixedly connected to the distal tube (200). The first tube section (310), the main tube section (330), and the second tube section (320) are all provided with a flexible membrane. The main tube section (330) is not provided with an elastic stent, and the main tube section (330) is tubular in a natural state. The support wire (500) is disposed in the liquid flow channel (301) and is configured to connect the proximal tube (100) to the distal tube (200).

Description

Catheter assembly and blood pump

[0001] This application claims priority to Chinese patent application No. CN202410904845.7, filed on July 8, 2024, with the Chinese Patent Office, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of medical device technology, and in particular to a cannulation assembly and a blood pump. Background Technology

[0003] An interventional catheter pump, also known as a blood pump, is typically inserted from a blood vessel into the ventricles of a patient's heart to assist the heart in pumping blood from the ventricles into the arteries, thus supporting the patient's blood circulation. A blood pump generally includes a cannula that forms a flow channel; this cannula is flexible enough to adapt to the convoluted shape of the patient's tissues. However, the cross-sectional area of ​​this cannula (i.e., the flow surface area) cannot change according to variations in blood flow, limiting the pumping capacity to the radial dimensions of the cannula, resulting in relatively low pumping efficiency. Summary of the Invention

[0004] Therefore, it is necessary to provide a cannulation assembly and blood pump whose flow surface area can be changed according to changes in blood flow to address the above problems.

[0005] In one embodiment of this application, the cannulation assembly includes a proximal tube, a distal tube, a cannula, and a support wire; the proximal tube has a first opening; the distal tube has a second opening; the cannula has a fluid flow channel connecting the first opening and the second opening; the cannula has a first tube segment, a second tube segment, and a main tube segment located between the first tube segment and the second tube segment; the first tube segment is fixedly connected to the proximal tube; the second tube segment is fixedly connected to the distal tube; the first tube segment, the main tube segment, and the third tube segment all have flexible membranes, at least the main tube segment does not have an elastic support, and the main tube segment is tubular in its natural state; the support wire is disposed within the fluid flow channel, and the support wire connects the proximal tube and the distal tube.

[0006] In one embodiment of the blood pump provided in this application, the blood pump includes an impeller and a cannulation assembly; the cannulation assembly refers to the above embodiment; the impeller is rotatably disposed within the proximal tube of the cannulation assembly.

[0007] Details of one or more embodiments of the present invention are set forth in the following drawings and description. Other features, objects, and advantages of the invention will become apparent from the specification, drawings, and claims. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 is a schematic diagram of the structure of a blood pump provided in an embodiment of this application.

[0010] Figure 2 is a schematic diagram of the blood pump shown in Figure 1 after the cannulation process is transparent.

[0011] Figure 3 is a schematic diagram of the blood pump shown in Figure 1.

[0012] Figure 4 is a cross-sectional view of the blood pump shown in Figure 1.

[0013] Figure 5 is a magnified view of the blood pump at point A provided in Figure 4.

[0014] Figure 6 is a schematic diagram of the proximal tube, motor and impeller of the blood pump shown in Figure 1.

[0015] Figure 7 is an exploded view of the proximal tube, motor and impeller of the blood pump shown in Figure 1.

[0016] Figure 8 is a schematic diagram of the distal tube and non-invasive flexible component of the blood pump shown in Figure 1.

[0017] Figure 9 is a magnified view of the blood pump at point B provided in Figure 4.

[0018] Figure 10 is a longitudinal cross-sectional view of the blood pump provided in Figure 1 after it has been inserted into the interventional guidewire.

[0019] Figure 11 is a cross-sectional view of the blood pump cannula provided in Figure 10.

[0020] Figure 12 is a schematic diagram of one embodiment of the cannula provided in Figure 4.

[0021] Figure 13 is a structural schematic diagram of another embodiment of the cannula provided in Figure 4.

[0022] Figure 14 is a schematic diagram showing the increased membrane wall thickness at both ends of the cannula provided in Figure 13.

[0023] Figure 15 is a structural schematic diagram of another embodiment of the cannula provided in Figure 4.

[0024] Figure 16 is a schematic diagram of the structure of a traditional cannula.

[0025] Figure 17 is a schematic diagram of the structure of a blood pump provided in another embodiment of this application.

[0026] Figure 18 is a cross-sectional view of the blood pump shown in Figure 17.

[0027] Figure 19 is a magnified view of the blood pump at point C provided in Figure 17.

[0028] Figure 20 is a magnified view of the blood pump at point D provided in Figure 17.

[0029] Figure 21 is a magnified view of the proximal end of the cannula shown in Figure 18.

[0030] Figure 22 is a magnified view of the distal end of the cannula shown in Figure 18.

[0031] Figure 23 is a longitudinal sectional view of a blood pump provided in another embodiment of this application.

[0032] Figure 24 is a cross-sectional view of the blood pump in the middle of the cannula, as shown in Figure 23.

[0033] Figure 25 is a schematic diagram of the structure of a blood pump provided in another embodiment of this application.

[0034] Figure 26 is a magnified view of point E of the blood pump provided in Figure 25.

[0035] Figure 27 is a front view of the blood pump shown in Figure 25.

[0036] Figure 28 is a cross-sectional view of the blood pump along line JJ provided in Figure 27.

[0037] Figure 29 is a magnified view of the blood pump at point F provided in Figure 28.

[0038] Figure 30 is a magnified view of the blood pump at point G provided in Figure 28.

[0039] Figure 31 is a magnified view of the blood pump at point H provided in Figure 28.

[0040] Figure 32 is a cross-sectional view of the blood pump along line KK provided in Figure 27.

[0041] Figure 33 is an enlarged cross-sectional view of the flexible sheath, support wire, and lead wire of the blood pump shown in Figure 32. Detailed Implementation

[0042] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0043] In the description of this application, it should be understood that if the terms "center", "longitudinal", "transverse", "length", "width", "membrane wall thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0044] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0045] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0046] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0047] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0048] 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.

[0049] Referring to Figure 16, the cannulation assembly of a conventional blood pump typically includes a cannula for forming a fluid flow channel. This cannula 300' is usually a multi-layered structure, with at least one layer being an elastic stent 340 and a flexible membrane covering the elastic stent 340; wherein the elastic stent 340 extends from one end of the cannula 300' to the other end and surrounds the entire fluid flow channel 301 of the cannula 300'. The material of this elastic stent 340 is a shape memory material, and it is typically made into a helical stent with a spiral shape, or a mesh stent woven into a grid shape, or a coil stent composed of multiple coils arranged axially at intervals. This elastic stent 340 allows the cannula 300' to be flexible, thereby enabling the cannula 300' to bend to adapt to the curved shape of tissues within the patient's body. However, this elastic stent 340 also increases the rigidity of the cannula 300', making it difficult for the cannula 300' to expand and contract radially. As a result, the cross-sectional area (i.e., the flow surface area) of the cannula 300' cannot change according to the blood flow rate, which limits the blood flow rate to the radial dimension of the cannula 300', resulting in low blood pumping efficiency.

[0050] Based on this, as shown in Figures 1 to 3, one embodiment of this application provides a cannulation assembly that can be applied to a blood pump 10. The cannulation assembly includes a proximal cannula 100, a distal cannula 200, and a cannula 300. The proximal cannula 100 has a first opening 101; the distal cannula 200 has a second opening 201, where one of the second opening 201 and the first opening 101 is a blood inlet, and the other is a blood outlet. The cannula 300 has a fluid flow channel 301 forming inside, connecting the first opening 101 and the second opening 201. The cannula 300 has a first tube segment 310, a second tube segment 320, and a main tube segment 330 located between the first tube segment 310 and the second tube segment 320. The first tube segment 310 is fixedly connected to the proximal tube 100; the second tube segment 320 is fixedly connected to the distal tube 200; the first tube segment 310, the second tube segment 320, and the main tube segment 330 all have flexible membranes, but the main tube segment 330 does not have an elastic support (see Figure 12), and the main tube segment 330 is tubular in its natural state. Specifically, the tubular shape of the main tube segment 330 in its natural state refers to the fact that the flexible membrane of the main tube segment 330 is tubular in its natural state.

[0051] Specifically, the blood pump 10 can be a left ventricular interventional pump or a right ventricular interventional pump. When the blood pump 10 is a right ventricular interventional pump, the first opening 101 is the blood inlet and the second opening 201 is the blood outlet. During delivery, the blood pump 10 is pushed from the right ventricle to the pulmonary artery, so that the main tube segment 330 of the cannula 300 crosses the pulmonary valve, the first opening 101 is located in the right ventricle, and the second opening 201 is located in the pulmonary artery. When the blood pump 10 is a left ventricular interventional pump, the first opening 101 is the blood outlet and the second opening 201 is the blood inlet. During delivery, the blood pump 10 is pushed from the aorta to the left ventricle, so that the main tube segment 330 of the cannula 300 crosses the aortic valve, the second opening 201 is located in the left ventricle, and the first opening 101 is located in the aorta.

[0052] Because the main tube segment 330 of the cannula 300 has a flexible membrane but does not contain an elastic support, the rigidity of at least the main tube segment 330 of the cannula 300 is less than that of a conventional cannula 300'. The main tube segment 330 is more flexible, which means that, on the one hand, the main tube segment 330 does not need to be pre-shaped into a curved form, and it is easier to bend to adapt to the curvature of tissues within the patient's body; on the other hand, the main tube segment 330 can also undergo a smaller range of radial deformation. During blood flow through the fluid channel 301 of the cannula 300, if the blood flow increases, the main tube segment 330 can expand slightly radially outward to allow the increased blood flow to pass through the cannula 300, thereby increasing the amount of blood delivered by the cannula 300 and improving the pumping efficiency of the blood pump. Subsequently, if the blood flow decreases, the main tube segment 330 of the cannula 300 can contract radially inward to return to its initial state.

[0053] Taking the blood pump 10 as a right ventricular interventional pump as an example, when the blood pump 10 is working, the motor 12 of the blood pump 10 drives the impeller 400 to rotate. Blood enters the main tube section 330 of the cannula 300 from the proximal tube 100, flows from the main tube section 330 into the distal tube 200, and finally exits from the distal tube 200. The control system of the blood pump 10 controls the frequency of the motor 12 according to the rhythm of the heartbeat and the pumping of blood, so that the frequency of the motor 12 changes in a certain pattern (such as, but not limited to, changing according to a sine and cosine pattern). This causes the blood flow pumped by the blood pump 10 to fluctuate regularly (similar to the flow rate sometimes being large and sometimes small). The main tube section 330 of the cannula 300 can expand and contract slightly according to the changes in blood flow, so that blood can pass smoothly through the main tube section 330. For example, when the frequency of motor 12 increases, the blood flow rate also increases, and the blood pressure increases. Under the pressure of the blood, the main pipe section 330 of the cannula 300 expands adaptively, increasing the radial dimension of the main pipe section 330 and the area of ​​the flow surface, so that a large amount of blood can pass through the main pipe section 330. Then, when the frequency of motor 12 decreases, the blood flow rate also decreases, and the main pipe section 330 of the cannula 300 returns to its initial state, and the cycle continues.

[0054] It should be noted that the flexible membrane of the cannula 300 is typically made of a material with greater hardness than that of medical balloons (silicone rubber), such as TPU (thermoplastic polyurethane elastomer). Therefore, even if the main tube segment 330 does not have an elastic support, it can maintain its tubular shape in its natural state. Of course, by appropriately designing the membrane wall thickness of the main tube segment 330 (e.g., but not limited to 0.5mm–0.12mm), it can be made to maintain its tubular shape well in its natural state. Furthermore, the diameter of the cannula 300 is usually small. Therefore, when the main tube segment 330 of the cannula 300 does not have an elastic support, the expansion and contraction of the main tube segment 330 along its radial direction is a small deformation, and the change in diameter is small, generally not easily observed with the naked eye; that is, it will not experience the large-scale expansion and contraction with a diameter increase as seen in catheter balloons. This ensures that when the main tube segment 330 of the cannula 300 expands and contracts back to its initial state, the main tube segment 330 remains tubular instead of shrinking into a deflated balloon shape. This allows the main tube segment 330 to be stably clamped and fixed by the pulmonary valve or aortic valve, preventing the main tube segment 330 from loosening and falling off the pulmonary valve or aortic valve.

[0055] Therefore, the cannula 300 used in the blood pump 10 of this application has a flexible membrane but no elastic support in its main pipe section 330. This makes the rigidity of the main pipe section 330 of the cannula 300 less than that of a conventional cannula 300', and the main pipe section 330 is more flexible. In addition to being able to bend to adapt to the curved shape of the patient's internal tissues, the main pipe section 330 can also undergo a small range of radial deformation. Thus, when the frequency of the control motor of the blood pump 10 changes in a certain pattern, causing changes in blood flow, the flow surface area of ​​the main pipe section 330 of the cannula 300 can change according to the change in blood flow, so that blood can pass through the main pipe section 330 more smoothly. For example, when the blood flow increases, the main pipe section 330 expands slightly accordingly, increasing the flow surface area of ​​the main pipe section 330, which allows the increased blood flow to pass through the cannula 300 smoothly, increasing the amount of blood delivered by the cannula 300 and improving the pumping efficiency of the blood pump. When blood flow decreases, the main tube segment 330 contracts slightly, returning to its natural or at least near-natural tubular shape, rather than shrinking into a deflated balloon shape. This allows the main tube segment 330 to be stably held and fixed by the pulmonary valve or aortic valve, preventing it from loosening and falling off.

[0056] Furthermore, since the cannula 300 can adapt to radial expansion or contraction of blood flow, its diameter can be designed to be slightly smaller than that of a conventional cannula 300', thus reducing the difficulty of implanting the blood pump 10. Additionally, when the blood pump 10 is used as a right ventricular interventional pump, its interventional path is from the inferior or superior vena cava, right atrium, right ventricle to the pulmonary artery. This interventional path is characterized by its short length, numerous bends, and complex internal structure. Because the main tube segment 330 of the cannula 300 of the blood pump 10 in this application is more flexible than that of a conventional cannula 300', the blood pump 10 can more easily adapt to changes in this interventional path, effectively reducing the difficulty of advancement. Moreover, since the main tube segment 330 of the cannula 300 does not have an elastic stent, it is not necessary to shape the main tube segment 330 of the cannula 300 into a curved shape.

[0057] Referring to Figures 3 and 4, both the proximal tube 100 and the distal tube 200 are metal tubes with high rigidity and are not easily deformed. This allows the proximal tube 100 to support the first segment 310 of the cannula 300, and the distal tube 200 to support the second segment 320 of the cannula 300. Specifically, the first segment 310 is fitted onto the proximal tube 100 and can be fixed to it using methods such as bonding or interference fit. The second segment 320 is fitted onto the distal tube 200 and can be fixed to it using methods such as bonding or interference fit. Considering that bonding can ensure a strong connection and reduce the manufacturing difficulty of the blood pump 10, it can be given priority.

[0058] Optionally, as shown in Figure 3, the outer peripheral surface of the proximal end of the proximal tube 100 may be provided with multiple first adhesive grooves 102 along the axial direction of the blood pump 10. The first adhesive grooves 102 are used to hold adhesive to bond the proximal tube 100 to the first tube segment 310 of the cannula 300. As shown in Figure 3, the outer peripheral surface of the proximal end of the distal tube 200 may be provided with multiple second adhesive grooves 202 along the axial direction of the blood pump 10. The second adhesive grooves 202 are used to hold adhesive to bond the distal tube 200 to the second tube segment 320 of the cannula 300.

[0059] Referring to Figure 12, for the cannula 300, the flexible membrane (denoted as the main flexible membrane 331) of the main pipe section 330 of the cannula 300 can be a single-layer flexible membrane. Theoretically, the main flexible membrane of the main pipe section 330 of the cannula 300 can also be multi-layered flexible membranes. However, the more layers there are, the weaker the radial expansion and contraction ability of the cannula 300 will be. Therefore, the number of layers of the cannula 300 can be set according to the material characteristics of the cannula 300 and the magnitude of the blood flow pressure to ensure that the cannula 300 can perform corresponding radial expansion and contraction with changes in blood flow.

[0060] The cannula 300 is cylindrical, and its inner circumferential surface smoothly transitions with the inner circumferential surfaces of the proximal cannula 100 and the distal cannula 200 to form a cylindrical surface; the outer circumferential surface of the cannula 300 smoothly transitions with the outer and inner circumferential surfaces of the proximal cannula 100 and the distal cannula 200 to form a cylindrical surface, which can reduce the chance of thrombosis.

[0061] It is understandable that the cannula 300, except for the main tube section 330, may or may not have elastic supports. As an example, the flexible membranes of the first tube section 310 and the second tube section 320 are integrated with the flexible membrane of the main tube section 330, and neither has an elastic support. Specifically, the flexible membrane of the first tube section 310 is designated as the first end flexible membrane 311; the flexible membrane of the second tube section 320 is designated as the second end flexible membrane 321, and the first end flexible membrane 311 is integrated with the main body flexible membrane 331 and the second end flexible membrane 321. In other words, the entire cannula 300 has no elastic supports. Thus, the cannula 300 does not need multiple layers of flexible membranes to cover the elastic supports, allowing the cannula 300 to be a single-layer structure. In other words, the entire cannula 300 has only a single layer of flexible membrane and is formed in one piece, thereby reducing the manufacturing steps of the cannula 300 and improving production efficiency.

[0062] Referring to Figure 13, further, the flexible membrane of the main tube segment 330 (i.e., the main flexible membrane 331) has a first membrane wall thickness H1; the flexible membranes of the first tube segment 310 and the second tube segment 320 (i.e., the first end flexible membrane 311 and the second end flexible membrane 321) have a second membrane wall thickness H2, and the second membrane wall thickness H2 is greater than the first membrane wall thickness H1, i.e., H2 > H1. This arrangement can also increase the strength of the first tube segment 310 and the second tube segment 320, making the first tube segment 310 and the second tube segment 320 less prone to deformation, thus less likely to be washed away by blood, increasing the strength of the connection between the first tube segment 310 and the proximal tube 100, and the strength of the connection between the second tube segment 320 and the distal tube 200, preventing the first tube segment 310 and the second tube segment 320 from loosening and falling off. In addition, the flexibility of the main tube segment 330 of the cannula 300 is better than that of the first tube segment 310 and the second tube segment 320 of the cannula 300, so that the main tube segment 330 of the cannula 300 can better adapt to the shape of the blood vessel and facilitate the push of the blood pump 10.

[0063] It is worth noting that if the first membrane wall thickness H1 of the main tube segment 330 is constant along the length of the cannula 300, then the second membrane wall thickness H2 is greater than the first membrane wall thickness H1 at any position of the main tube segment 330. If the first membrane wall thickness H1 of the main tube segment 330 varies along the length of the cannula 300, then the second membrane wall thickness H2 is greater than the maximum first membrane wall thickness H1 of the main tube segment 330.

[0064] Referring to Figures 13 and 14, in one embodiment, the main tube segment 330 of the cannula 300 includes a proximal end portion 332, a distal end portion 333, and a body portion 334 located between the proximal end portion 332 and the distal end portion 333. The proximal end portion 332 is connected to a first tube segment 310, and the distal end portion 333 is connected to a second tube segment 320. The body portion 334 of the main tube segment 330 has a body membrane wall thickness H.1a Both the proximal end 332 and the distal end 333 of the main pipe section 330 have an end membrane wall thickness H. 1b The end membrane wall thickness H of at least one of the proximal end 332 and the distal end 333 1b Greater than the thickness H of the main membrane wall 1a H 1b >H 1a In other words, the inner or outer diameter of the main tube section 330 varies along the axial direction, causing the first membrane wall thickness H1 to vary along the length of the insertion tube 300. In this case, the second membrane wall thickness H2 of the first tube section 310 and the second tube section 320 can be greater than or equal to the end membrane wall thickness H. 1b .

[0065] For the proximal end 332 of the main tube segment 330, since the entire main tube segment 330 lacks an elastic support, the stiffness of the proximal end 332 differs significantly from that of the proximal tube 100, potentially leading to bending at the proximal end 332. Taking a right ventricular interventional blood pump as an example, during operation, the impeller 400 of the blood pump 10 is a high-pressure zone. If the proximal end 332 of the tube segment 330 bends, blood will have difficulty flowing from the impeller 400 into the cannula 300, and the blood trapped within the proximal tube 100 is prone to thrombosis. Therefore, by adjusting the end membrane wall thickness H of the proximal end 332... 1b Set to be greater than the thickness H of the main membrane wall 1a This can increase the strength of the proximal end 332, making it less prone to bending and preventing blood from congesting and forming a thrombus.

[0066] For the distal end 333 of the main tube segment 330, since the entire main tube segment 330 lacks an elastic support, the distal end 333 is more prone to expansion. When blood flows into the distal tube 200 along the Y+ direction (see Figure 4), the distal end 333 easily expands and stretches the connected second tube segment 200, increasing the inner diameter of the second tube segment 200. This, in turn, makes the second tube segment 320 more likely to loosen and detach from the distal tube 200. Therefore, by increasing the end membrane wall thickness H of the distal end 333... 1b Set to be greater than the thickness H of the main membrane wall 1a This can increase the strength of the distal end 333, making it less prone to excessive expansion and deformation, and preventing the distal end 333 from expanding and opening up the second pipe section 200, causing the inner diameter of the second pipe section 200 to increase, thereby preventing the second pipe section 200 from loosening and falling off.

[0067] It is understood that in the above embodiments, the axial lengths of the proximal end 332 and the distal end 333 only account for a small portion of the axial length of the main pipe section 330. Therefore, the increased thickness of the proximal end 332 and the distal end 333 will not have a significant impact on the overall expansion of the main pipe section 330, and will not affect the large flow of blood passing through the main pipe section 330 when the blood volume increases. The specific axial lengths of the proximal end 332 and the distal end 333 can be reasonably configured according to the actual axial length of the main pipe section 330.

[0068] Referring to Figure 15, in another embodiment, unlike the above embodiment, at least one of the first segment 310 and the second segment 320 of the cannula 300 has an elastic support, which is embedded in the flexible membrane of the corresponding segment. For example, the elastic support of the first segment 310 is a first elastic support 312, which is embedded in the first end flexible membrane 311. The elastic support of the second segment 320 is a second elastic support 322, which is embedded in the second end flexible membrane 321.

[0069] By configuring the first tube segment 310 and / or the second tube segment 320 as a multi-layer structure consisting of at least a flexible membrane and an elastic stent, the strength of the first tube segment 310 and the second tube segment 320 can be increased, making the first tube segment 310 and the second tube segment 320 less prone to deformation and thus less likely to be flushed away by blood. This increases the strength of the connection between the first tube segment 310 and the proximal tube 100, as well as the strength of the connection between the second tube segment 320 and the distal tube 200, preventing the first tube segment 310 and the second tube segment 320 from loosening and falling off.

[0070] As shown in Figures 2 and 4, in some embodiments, the cannulation assembly further includes a support wire 500 disposed within the fluid flow channel 301. The support wire 500 has a first end 510 and a second end 520 opposite to each other. The first end 510 is fixed to the proximal tube 100, and the second end 520 is fixed to the distal tube 200. Because the main tube segment 310 of the cannulation 300 does not have an elastic support, the main tube segment 310 is more flexible than a conventional cannulation 300', thus making it less likely for the main tube segment 310 to transmit thrust between the proximal tube 100 and the distal tube 200 during the process of pushing the blood pump 10 into the patient's body. Therefore, by providing a support wire 500 in the fluid flow channel 301 of the cannula 300, which connects the proximal tube 100 and the distal tube 200, the support wire 500 can transmit the pushing force between the proximal tube 100 and the distal tube 200 when the blood pump 10 is pushed from outside the body along the interventional path to the target position inside the body, thus providing support and facilitating the pushing of the blood pump 10. This ensures that the cannula 300 itself can expand and contract without affecting the pushing of the blood pump 10.

[0071] The support wire 500 can be a nickel-titanium wire or other metal wire with a certain degree of flexibility, which can be bent to adapt to the shape of the blood vessel. Of course, the support wire 500 may not be provided. In other embodiments, the fluid flow channel 301 of the cannula 300 may not have a support wire 500; when implanting the blood pump 10 into the patient's body, a flexible auxiliary tube can be first fitted over the cannula 300, with its two ends fitted onto the proximal tube 100 and the distal tube 200, respectively. Then, the blood pump 10 is pushed into the body, and after reaching the target position, the auxiliary cannula can be withdrawn.

[0072] As shown in Figures 4 to 6, in one embodiment, the proximal tube 100 has a proximal section for accommodating the impeller 400 and a distal section located at one end of the proximal section. The distal section has an internally provided hollow mounting bracket 130. The mounting bracket 130 has a first insertion hole 130a, and the first end 510 of the support wire 500 is inserted into the first insertion hole 130a. Inserting the first end 510 of the support wire 500 into the first insertion hole 130a of the mounting bracket 130 facilitates the fixation of the support wire 500 to the mounting bracket 130.

[0073] Regarding the structure of the mounting bracket 130, the mounting bracket 130 can be hollow, with holes formed in the hollow portion of the mounting bracket 130, allowing blood to pass through the holes. It should be noted that, as shown in Figure 5, the mounting bracket 130 is located on the side of the impeller 400 near the liquid flow channel 301. The mounting bracket 130 and the impeller 400 are spaced apart along the axial direction of the proximal tube 100 by a first axial distance P. The first axial distance P prevents interference between the impeller 400 and the mounting bracket 130 during rotation. It is understood that the size of the first axial distance P should be reasonably configured according to the axial length of the proximal tube 100 and the impeller 400, and no specific limitation is set here.

[0074] The specific shape and structure of the mounting bracket 130 can be customized according to requirements. As an example, as shown in Figures 5 to 7, the mounting bracket 130 includes a base 131 and a plurality of support arms 132 circumferentially along the base 131; the support arms 132 are fixedly connected to the base 131 and the proximal tube 100; after the impeller 400 is installed to the proximal section of the proximal tube 100, the impeller 400 and the base 131 of the mounting bracket 130 are axially opposite and spaced apart. The base 131 is provided with a first insertion hole 130a. At least one hole is formed between two adjacent support arms 132. The mounting bracket 130 with this structure is simple and can also ensure that blood can flow smoothly into the cannula 300 or the proximal tube 100 through the mounting bracket 130.

[0075] Both the base 131 and the support arm 132 can be edgeless structures, and the transition between the support arm 132 and the base 131, as well as between the support arm 132 and the inner circumferential surface of the proximal tube 100, is smooth (e.g., with rounded corners). This can reduce the probability of thrombosis. It should be noted that an edgeless structure means that there are no sharp corners at the connection between the two surfaces.

[0076] The number of support arms 132 can be set to 2 to 5 (e.g., 2, 3, 4, or 5). If there are fewer than 2, the connection strength between the mounting bracket 130 and the proximal tube 100 may not be guaranteed; if there are more than 5, it may obstruct blood flow, making it difficult for blood in the proximal tube 100 to flow smoothly into the cannula 300 or the proximal tube 100 through the mounting bracket 130. In addition, the support arms 132 can be connected to the base 131 and the proximal tube 100 by means of integral molding, bonding, etc. Considering that the integral molding method has the characteristic of high connection strength, it can be given priority.

[0077] Referring again to Figure 5, the base 131 of the mounting bracket 130 has a first surface 1311 facing the distal tube 200. The first insertion hole 130a has an inlet 130b penetrating the first surface 1311 and a support surface 130c opposite to the inlet 130b for supporting the support wire 500. The support wire 500 can be interference-fitted with the circumferential inner wall of the inlet 130b to facilitate the installation of the support wire 500 on the mounting bracket 130. The support surface 130c of the first insertion hole 130a can support the support wire 500. During the pushing process of the blood pump 10, the first end 510 of the support wire 500 abuts against the support surface 130c, so that the proximal tube 100 transmits the pushing force to the distal tube 200 through the support wire 500.

[0078] Of course, in some other embodiments, the support wire 500 is a metal wire, and a magnet is provided in the first insertion hole 130a, which can be magnetically attracted and fixed to the support wire 500. That is to say, the support wire 500 is a metal wire made of a magnetically conductive metal that can be attracted by a magnet. By limiting the support wire 500 with the first insertion hole 130a and magnetically attracting the support wire 500 with the magnet, the firmness of the first end 510 of the support wire 500 is ensured to be mounted on the mounting bracket 130.

[0079] Referring to Figure 4, the base 131 of the mounting bracket 130 further has a second surface 1312 facing away from the distal tube 200. The second surface 1312 is axially spaced from the distal end of the impeller 400 and is an arcuate surface protruding in the direction away from the distal tube 200. In this way, the second surface 1312 can guide the flow of blood.

[0080] Specifically, when blood flows from the impeller 400 to the cannula 300, the blood comes into contact with the second surface 1312 and is guided by the second surface 1312 to flow into the holes around the mounting bracket 130, allowing the blood to flow smoothly into the cannula 300 from the holes. Conversely, when blood flows from the cannula 300 to the impeller 400, after passing through the holes around the mounting bracket 130, some of the blood adheres to the wall of the second surface 1312 and flows towards the central axis of the impeller 100, thus allowing this portion of the blood to flow into the impeller 100. Therefore, the second surface 1312 can guide blood flow and reduce the resistance of the mounting bracket 130 to blood flow.

[0081] It is understandable that the support wire 500 may also be adjacent to the inner wall of the cannula 300; the mounting bracket 130 may also be a protrusion on the inside of the proximal tube 100, and the first end 510 of the support wire 500 may be fixed to the protrusion.

[0082] As shown in Figures 6 and 7, in some embodiments, the proximal tube 100 may include an open tube 110 and an adapter tube 120. The adapter tube 120 connects the open tube 110 and the first section 310 of the insertion tube 300. The open tube 110 has a first opening 101, a mounting bracket 130 is disposed within the adapter tube 120, and an impeller 400 is disposed at least within the open tube 110. The open tube 110 forms the proximal section of the proximal tube 100, and the adapter tube 120 forms the distal section of the proximal tube 100. The outer circumferential surface of the adapter tube 120 has a first adhesive groove 102. The adapter tube 120 is a reducing tube, which can smoothly connect the insertion tube 300 and the open tube 110 with different diameters.

[0083] The adapter tube 120 can be fixed to the open tube 110 by means of bonding, integral molding, etc. The adapter tube 120 is not necessary. The proximal tube 100 can only have the open tube 110. The open tube 110 is directly connected to the first tube segment 310 of the insertion tube 300. It is only necessary that the length of the open tube 110 is long enough to accommodate the impeller 400 and the mounting bracket 130.

[0084] In some embodiments, as shown in Figures 8 and 9, the distal tube 200 includes a tube body 220 and an installation end 210; wherein the tube body 220 is connected to the second tube segment 320 and the tube body 220 is provided with a second opening 201; the installation end 210 is connected to the end of the tube body 220 that is away from the insertion tube 300.

[0085] Furthermore, the mounting end 210 includes a flow guide cone 211 located within the tube body 220, the diameter of which gradually decreases in the direction from the mounting end 210 to the tube body 220. The flow guide cone 211 can guide the flow of blood, facilitating the discharge of blood from the second opening 201 or its flow into the distal tube 200.

[0086] Referring again to Figures 8 and 9, the guide cone 211 at the mounting end 210 is provided with a second insertion hole 210a, and the second end 520 of the support wire 500 is inserted into the second insertion hole 210a. Inserting the second end 520 of the support wire 500 into the second insertion hole 210a of the guide cone 211 facilitates the fixing of the support wire 500 to the distal tube 200.

[0087] In some embodiments, as shown in Figures 1 to 4 and Figure 8, the blood pump 10 further includes a non-invasive flexible element 900, which is fixedly connected to the mounting end 210. The non-invasive flexible element 900 is used to abut against tissues within the patient's body (such as the ventricular wall or arterial wall) to position the blood pump 10. Specifically, referring to Figures 8 and 9, the mounting end 210 also includes a connecting seat 212, which is connected to the distal end of the guide cone 211. The connecting seat 212 is located outside the tube body portion 220 and is fixedly connected to the non-invasive flexible element 900. It is understood that the non-invasive flexible element 900 can be configured as a pigtail tube with a pigtail shape (as shown in Figure 1). Alternatively, the non-invasive flexible element 900 has a flexible long axis portion 910 and a ball head 920 connected to the flexible long axis portion 910 (as shown in Figure 25).

[0088] As shown in Figure 10, when pushing the blood pump 10, the interventional guidewire 20 is first inserted into the patient's body, with the proximal end of the interventional guidewire 20 remaining outside the body. Then, as shown in Figure 10, the proximal end of the interventional guidewire 20 is inserted through the non-invasive flexible part 900 of the blood pump 10, and then through the distal tube 200, the fluid flow channel 301 of the cannula 300, and the proximal tube 100, and finally out through the first opening 101 of the proximal tube 100, so that the blood pump 10 is fitted on the interventional guidewire 20. Then, the blood pump 10 is pushed into the patient's body along the interventional guidewire 20.

[0089] The guide cone 211 at the mounting end 210 is provided with a guide wire hole 210b for the interventional guide wire 20 to pass through, and the guide wire hole 210b communicates with the non-invasive flexible element 900. The proximal end of the interventional guide wire 20 passes through the non-invasive flexible element 900 of the blood pump 10 and can enter the distal tube 200 through the guide wire hole 210b of the guide cone 211.

[0090] To enable the support wire 500 to better direct and transmit the pushing force, the support wire 500 is positioned as close as possible to the central axis 11 of the blood pump 10. This means that the first insertion hole 130a and the second insertion hole 210a for inserting the support wire 500 are also positioned as close as possible to the central axis 11 of the blood pump 10. However, considering that the proximal end of the non-invasive flexible element 900 and the distal tube 200 are coaxially arranged, both of which are located on the central axis 11 of the blood pump 10, the interventional guide wire 20 should also be positioned as close as possible to the central axis 11 in order to allow the interventional guide wire 20 to pass smoothly from the non-invasive flexible element 900 into the guide wire hole 210b of the guide cone 211.

[0091] As shown in Figures 4, 5, and 9, in one embodiment, the guidewire hole 210b and the first insertion hole 130a are opposite each other along the central axis 11 of the blood pump 10, and the second insertion hole 210a is adjacent to the central axis 11 of the blood pump 10. The alignment of the guidewire hole 210b and the first insertion hole 130a along the central axis 11 of the blood pump 10 allows the interventional guidewire 20 (see Figure 10) to smoothly pass through the non-invasive flexible member 900 into the guidewire hole 210b of the guide cone 211. The second insertion hole 210a is slightly offset to one side of the central axis 11 of the blood pump 10, making the second insertion hole 210a as close as possible to the central axis 11 of the blood pump 10, which helps maintain good axial transmission of the pushing force by the support wire 500.

[0092] Of course, in another embodiment, the first insertion hole 130a can be opposite to the second insertion hole 210a along the central axis 11 of the blood pump 10, and the guide wire hole 210b is adjacent to the central axis 11 of the blood pump 10. The first insertion hole 130a and the second insertion hole 210a being opposite each other along the central axis 11 of the blood pump 10 facilitates the insertion and installation of the support wire 500; while the guide wire hole 210b is slightly offset to one side of the central axis 11 of the blood pump 10, making the guide wire hole 210b as close as possible to the central axis 11 of the blood pump 10, thus minimizing its impact on the passage of the interventional guide wire 20.

[0093] As shown in Figure 10, in some embodiments, considering that the proximal end of the interventional guidewire 20 may become entangled with the support wire 500 in the fluid flow channel 301 after being inserted into the cannula 300, the cannula 300 can also be made of a transparent flexible material to reduce the occurrence of this situation, thereby allowing the interior of the cannula 300 to be seen. Therefore, when the blood pump 10 is implanted, the position of the interventional guidewire 20 inside the cannula 300 can be observed, allowing for timely adjustment of the position of the interventional guidewire 20 within the fluid flow channel 301 to avoid entanglement between the interventional guidewire 20 and the support wire 500; simultaneously, it also facilitates the calibration of the interventional guidewire 20 passing through the hole in the mounting bracket 130.

[0094] As shown in Figure 11, in some embodiments, the support wire 500 has a first diameter D1, and the interventional guide wire 20 has a second diameter D2, wherein the first diameter D1 is greater than or equal to the second diameter D2, i.e., D1 ≥ D2. This configuration ensures that the support wire 500 has sufficient strength to transmit the pushing force between the proximal tube 100 and the distal tube 200. It is understood that the first diameter D1 should not be too large. If the first diameter D1 is too large, it will increase the stiffness of the support wire 500, thereby increasing the difficulty of bending the cannula 300. Therefore, the first diameter D1 should not be too large, and can be reasonably configured according to the actual bending degree required by the cannula 300.

[0095] Optionally, the first diameter D1 is less than or equal to 1.5 times the second diameter D2, i.e., D1 ≤ 1.5D2. The value of D1 can be, but is not limited to, 1.1D2, 1.2D2, 1.3D2, 1.4D2, etc. This setting ensures that the stiffness of the support wire 500 is not too high, ensuring that the support wire 500 has sufficient strength, while also making it less difficult for the insertion tube 300 to bend.

[0096] As shown in Figures 1 and 4, and as previously explained, since the cannula 300 lacks an elastic support, it may bend at its proximal end. Taking a right ventricular interventional blood pump as an example, during operation, the impeller 400 of the blood pump 10 is a high-pressure area. If the proximal end of the cannula 300 bends, blood will have difficulty flowing from the impeller 400 into the cannula 300, and the blood may become trapped in the proximal tube 100, easily forming a thrombus. In addition to increasing the membrane wall thickness at both ends of the cannula 300 as described above, another embodiment to solve this problem is provided below.

[0097] As shown in Figures 17 and 18, in this embodiment, the blood pump 10 further includes a first rectifier tube 610; the first rectifier tube 610 is disposed at the proximal end of the cannula 300 to increase the strength of the proximal end of the cannula 300. Therefore, by adding the first rectifier tube 610 at the proximal end of the cannula 300 to strengthen the proximal end of the cannula 300, bending of the proximal end of the cannula 300 can be avoided, thereby preventing the formation of thrombi at this location.

[0098] As shown in Figures 18, 19, and 21, specifically, the first rectifier tube 610 includes a first rectifier section 612, which is fixedly sleeved on the outer periphery of the proximal end 332 of the main pipe section 330. This can strengthen the proximal end 332 of the main pipe section 330 to a certain extent, preventing bending at the proximal end 332 and thus preventing thrombus formation there.

[0099] Furthermore, the first rectifier tube 610 also includes a first fixing section 611 connected to the first rectifier segment 612, the first fixing section 611 being fixedly fitted onto the outer periphery of the first pipe segment 310. The first rectifier segment 612 can clamp the first pipe segment 310 and the proximal pipe 100 to strengthen the connection between the first pipe segment 310 and the proximal pipe 100 and prevent the first pipe segment 310 from loosening and falling off. The first fixing section 311 and the first rectifier segment 612 are integrally formed.

[0100] As shown in Figures 17 and 18, in some embodiments, the blood pump 10 further includes a second rectifier tube 620, which is disposed at the distal end of the cannula 300 to improve the strength of the distal end of the cannula 300. Taking a right ventricular interventional blood pump as an example, blood flows along the Y+ direction shown in Figure 18 to the distal end of the cannula 300, which may cause the distal end of the cannula 300 to over-expand, increasing the diameter of the distal end of the cannula 300 and making it prone to loosening. Therefore, by adding a second rectifier tube 620 at the distal end of the cannula 300, the strength of the distal end of the cannula 300 is increased, making the distal end of the cannula 300 less prone to radial expansion, thereby preventing the distal end of the cannula 300 from loosening and falling off the distal tube 200.

[0101] As shown in Figures 18, 20, and 22, specifically, the second rectifier tube 620 includes a second rectifier section 621, which is fixedly sleeved on the outer periphery of the distal end 333 of the main pipe section 330. This can strengthen the distal end 333 of the main pipe section 330 to a certain extent, preventing the distal end 333 from excessively expanding and stretching the second pipe section 320, thereby preventing the second pipe section 320 from loosening and falling off.

[0102] Furthermore, the second rectifier tube 620 also includes a second fixing section 622 connected to the second rectifier section 621, the second fixing section 622 being fixedly fitted onto the outer periphery of the second tube section 320. The second fixing section 622 can tighten the second tube section 320 and the distal tube 200 to enhance the firmness of the connection between the second tube section 320 and the distal tube 200, preventing the second tube section 320 from loosening and falling off. The second fixing section 622 and the second rectifier section 621 are integrally formed.

[0103] It is understandable that both the first rectifier tube 610 and the second rectifier tube 620 are individually manufactured components and are both flexible. During assembly, the first rectifier tube 610 and the second rectifier tube 620 are first fitted onto both ends of the insertion tube 300 and fixedly connected to it. Then, both ends of the insertion tube 300 are connected and fixed to the proximal tube 100 and the distal tube 200, respectively. Both the first rectifier tube 610 and the second rectifier tube 620 can be connected and fixed to the insertion tube 300 by adhesive bonding or heat fusion welding.

[0104] Optionally, the hardness of the first rectifier tube 610 is greater than the hardness of the insertion tube 300; and / or, the hardness of the second rectifier tube 620 is greater than the hardness of the insertion tube 300, which can effectively improve the deformation resistance of the proximal and distal ends of the insertion tube 300. Of course, in other embodiments, the first rectifier tube 610 and the second rectifier tube 620 can be made of the same material as the insertion tube 300, that is, the deformation resistance of the proximal and distal ends of the insertion tube 300 can be increased by increasing the membrane wall thickness at both ends of the insertion tube 300.

[0105] As an example, as shown in Figure 19, the first rectifier tube 610 includes a metal spring layer 601 and a flexible membrane layer 602 disposed outside the metal spring layer 601. This structure gives the first rectifier tube 610 a certain degree of flexibility, allowing it to bend to adapt to the shape of the blood vessel. The flexible membrane layer 602 can be made of a flexible material such as TPU.

[0106] The structure of the second rectifier tube 620 can be the same as that of the first rectifier tube 610. For example, as shown in FIG20, the second rectifier tube 620 also includes a metal spring layer 601 and a flexible film layer 602 disposed outside the metal spring layer 601. Of course, in some other embodiments, the structure of the second rectifier tube 620 may also be different from that of the first rectifier tube 610.

[0107] As shown in Figure 18, in some embodiments, the first tube segment 310 and the second tube segment 320 both have a first length L1 along the axial direction of the cannula 300, the first rectifier section 612 has a second length L2 along the axial direction of the cannula 300, and the main tube segment 330 has a third length L3 along the axial direction of the cannula 300; then L1≤L2≤3L1; and / or, 3%<L2 / L3<10%. This configuration avoids the second length L2 of the first rectifier section 612 being too short, thus ensuring sufficient strength at both the proximal and distal ends of the cannula 300, preventing the proximal end of the cannula 300 from "folding" and the distal end of the cannula 300 from detaching from the distal tube 200; it also avoids the second length L2 of the first rectifier section 612 being too long, reducing the impact of the first rectifier section 612 on the radial expansion and contraction of the main tube segment 330, thereby reducing the limitation of the radial dimensions of the cannula 300 on blood flow and improving blood pumping efficiency.

[0108] It is understandable that the second length L2 of the first rectifier section 612 is the same as the axial length of the proximal end 332 of the main pipe section 330 of the cannula 300, and the second length L2 of the second rectifier section 622 is the same as the axial length of the distal end 333 of the main pipe section 330 of the cannula 300. The proportional relationship between the first length L1, the second length L2, and the third length L3 can be set according to specific needs, such as L2=L1, L2=2L1, L2=3L1, etc., and L2 / L3=3.1%, 4%, 5%, 6%, 7%, 8%, 9%, 9.9%, etc.

[0109] Referring to Figures 23 and 24, in some embodiments, a support frame 510 is provided on the outer peripheral surface of the support wire 500. The support frame 510 is located in the middle of the support wire 500, and the outer peripheral surface of the support frame 510 is radially spaced from the inner wall surface of the main tube section 330 by a first radial distance D3. Because the outer peripheral surface of the support frame 510 and the inner wall surface of the main tube section 330 have the first radial distance D3, the support frame 510 allows the cannula 300 to bend within a certain range without excessive bending. During the process of the blood pump 10 pushing the cannula 300 into the patient's body, if the cannula 300 bends excessively to adapt to the shape of the blood vessel, the support frame 510 can support the main body 334 of the main tube section 330 from the middle of the support wire 500, thereby preventing the main body 334 from bending and thus preventing the main tube section 330 from collapsing and blocking the fluid flow channel 301.

[0110] Understandably, the support frame 510 should be hollow, with holes forming in the hollow areas to allow blood to flow smoothly through the fluid channel 301. There are various design options for the shape and structure of the support frame 510. For example, the support frame 510 can be a support ring 511, which has an annular support portion 511a surrounding the support wire 500, and a support rib 511b connecting the annular support portion 511 and the support wire 500. The annular support portion 511a is spaced apart from the inner wall surface of the main pipe section 330. Another example is that the support frame 510 can be a support mesh 512, which is a grid shape and loops around the outer periphery of the middle part of the support wire 500. Only the outer peripheral surface of the support frame 510 needs to be spaced apart from the inner wall surface of the main pipe section 330. Either the support mesh 512 or the support ring 511 can be used.

[0111] It is worth noting that the middle part of the support wire 500 refers to the position that roughly bisects the axial length of the support wire 500. The support frame 510 can also be placed at other locations on the main pipe section 330 that are prone to significant bending. The support frame 510 can be elastic or inelastic. When the support frame 510 is inelastic, its axial dimension should be designed to be shorter to avoid affecting the bending deformation of the cannula 300. There can be one or more support frames 510. If there are multiple support frames 510, they should be spaced apart along the length of the support wire 500. Support frames 510 are not mandatory. The number of support frames 510 and their total axial length can be rationally designed based on the axial length of the main pipe section 330 to avoid affecting the proper bending and radial deformation of the main pipe section 330.

[0112] Because there is a first radial distance D3 between the outer peripheral surface of the support frame 510 and the inner wall surface of the main pipe section 330, the support frame 510 is less likely to affect the small-amplitude expansion and contraction of the main pipe section 330 along its radial direction. The size of the first radial distance D3 can be reasonably designed according to the actual size of the inner diameter of the insertion tube 300. Optionally, the first radial distance D3 is less than or equal to 1 / 4 times the inner diameter D4 of the main pipe section 330, i.e., D3 ≥ 1 / 4 D4. Optionally, D3 ≤ 1 / 2 D4. Since D3 ≥ 1 / 4 D4, it can be ensured that when the main pipe section 330 undergoes normal small-amplitude expansion and contraction along its radial direction, the support frame 510 will not abut against the inner wall surface of the main pipe section 330, avoiding the support frame 510 affecting the radial deformation of the main pipe section 330; while when the main pipe section 330 undergoes excessive bending and the inner wall surface of the main pipe section 330 touches the support frame 510, the support frame 510 can support the main pipe section 330, thereby preventing the main pipe section 330 from collapsing.

[0113] When the blood pump 10 is a right ventricular interventional pump, if the blood pressure in the pulmonary artery is too high, and the blood pump 10 continues to pump blood into the pulmonary artery at a high flow rate, it can easily lead to pulmonary edema, pulmonary congestion, and other conditions in the patient. Therefore, in the embodiments shown in Figures 25 to 28, the cannulation assembly further includes a pressure sensor 800. The pressure sensor 800 includes a probe 810 and a wire 820 connected to the probe 810. The probe 810 is mounted on the mounting end 210 of the distal tube 200, and the wire 820 at least partially passes through the fluid flow channel 301 of the cannulation assembly, allowing the wire 820 to be connected to the controller of the blood pump 10 (not shown in the figures). The pressure sensor 800 can be used to detect blood pressure. After the blood pump 10 enters the pulmonary artery through the right ventricle, the distal tube 200 of the cannulation assembly is located in the pulmonary artery, so that the probe 810 on the distal tube 200 can detect the blood pressure in the pulmonary artery. Therefore, the pressure sensor 800 detects the blood pressure in the pulmonary artery and feeds back the detected blood pressure to the controller of the blood pump 10. When the blood pressure is high, the controller can control the blood pump 10 to reduce the blood flow to avoid excessively high blood pressure in the pulmonary artery, thereby preventing the patient from developing pulmonary edema, pulmonary congestion and other diseases.

[0114] Referring to Figures 28 and 29, it can be understood that the probe 810 has a sensing surface 811. The connector 212 of the mounting end 210 has a distal surface 212a and an annular side surface 212b, with the distal surface 212a facing the non-invasive flexible component 900. The sensing surface 811 of the probe 810 can be disposed on either the distal surface 212a or the annular side surface 212b. If the sensing surface 811 of the probe 810 is disposed on the annular side surface 212b, it may come into contact with the inner wall of the pulmonary artery, causing the sensing surface 811 to inaccurately sense blood pressure. Therefore, in this embodiment, the sensing surface 811 of the pressure sensor 800 can be disposed on the distal surface 212a. Since the distal surface 212a is less likely to come into contact with the inner wall of the pulmonary artery, the sensing surface 811 located on the distal surface 212a can more accurately sense blood pressure. Optionally, the sensing surface 811 of the probe 810 is flush with the distal surface 212a.

[0115] Alternatively, the probe 810 of the pressure sensor 800 is located on the central axis 11 of the cannulation assembly, such that the sensing surface 811 of the probe 810 is located in the central region of the distal surface 212a, thus making it less likely to contact the inner wall of the pulmonary artery. Correspondingly, the non-invasive flexible member 900 is positioned on one side of the central axis 11 to avoid contact with the probe 810 of the pressure sensor 800. When the non-invasive flexible member 900 is positioned against the inner wall of the pulmonary artery, the sensing surface 811 of the probe 810 of the pressure sensor 800 is located on the side of the non-invasive flexible member 900 away from the inner wall of the pulmonary artery, making it even less likely to contact the inner wall of the pulmonary artery.

[0116] Referring to Figures 28, 32, and 33, in some embodiments, the cannulation assembly further includes a flexible sheath 700, which is fixed within the fluid flow channel 301 and has a first inner cavity 710 through which a support wire 500 passes. The flexible sheath 700 protects the support wire 500 from contact with blood. Specifically, the flexible sheath 700 is elongated, and the first inner cavity 710 extends along its length, penetrating at least one end of the flexible sheath 700 to allow the support wire 500 to be inserted. The proximal end of the flexible sheath 700 is fixed to the mounting end 210 of the distal tube 200, and the distal end of the flexible sheath 700 extends to and is fixed to the mounting bracket 130. Optionally, the proximal end of the flexible sheath 700 can also be fixed in the first insertion hole 130a of the mounting bracket 130; the distal end of the flexible sheath 700 can also be fixed in the second insertion hole 210a of the mounting end 210. Of course, in other embodiments, corresponding slots can also be provided on the outer periphery of the first insertion hole 130a and the second insertion hole 210a for insertion of the flexible sheath 700. The material of the flexible sheath 700 can be, but is not limited to, TPU material (i.e., thermoplastic polyurethane elastomer).

[0117] Referring again to Figures 28, 31 to 33, in some embodiments, the flexible sheath 700 further has a second inner cavity 720. The mounting bracket 130 inside the proximal tube 100 is provided with a radial channel 132a, and the tube wall of the proximal tube 100 is provided with a wire passage hole 103, which communicates with the radial channel 132a and the second inner cavity 720 to allow the wire 820 of the pressure sensor 800 to pass through. Specifically, the proximal tube 100 has a mounting bracket 130 for mounting the support wire 500, and the support arm 132 of the mounting bracket 130 is provided with a radial channel 132a.

[0118] The wire 820 of the pressure sensor 800 includes a first segment 821, a second segment 822, and a third segment 823 connected together. The first segment 821 passes through the second inner cavity 720 of the flexible sheath 700, and the end of the first segment 821 away from the second segment 822 is connected to the probe 810. The second segment 822 is housed in the radial channel 132a. The third segment 823 passes through the wire hole 103 and is fixed to the outer wall of the proximal tube 100 and the motor 12. The wire 820 also includes a fourth segment 824 connected to the third segment 823, which is housed in the conduit 13.

[0119] Referring to Figure 33, for a flexible sheath 700 having a first inner cavity 710 and a second inner cavity 720, the flexible sheath 700 has a maximum width L4 extending along the arrangement direction of the first inner cavity 710 and the second inner cavity 720 (as shown in the X direction in Figure 33). If the outer peripheral surface of the flexible sheath 700 is set as a cylindrical surface 704, then the diameter of the cylindrical surface 704 is the maximum width L4, that is, the radial dimension of the flexible sheath 700 is large at all points, which makes the volume of the flexible sheath 700 large. The flexible sheath 700 occupies a large space in the fluid flow channel 301, which affects the blood flow rate.

[0120] In view of the above, in this embodiment, the outer peripheral surface of the flexible sheath 700 is set as a non-cylindrical surface. The outer peripheral surface of the flexible sheath 700 includes a first arc surface 701, a second arc surface 702, and two side planes 703 connecting the first arc surface 701 and the second arc surface 702. The first arc surface 701 surrounds the side of the first inner cavity 710 away from the second inner cavity 720; the second arc surface 702 surrounds the side of the second inner cavity 720 away from the first inner cavity 710. This allows the dimension of the flexible sheath 700 in the X direction to be the maximum width L4, while the radial dimension of the flexible sheath 700 in other directions (such as the Z direction) is smaller than the maximum width L4. This results in a smaller volume of the flexible sheath 700 and a smaller space occupied by the flexible sheath 700 in the fluid flow channel 301, thereby increasing the blood flow rate through the fluid flow channel 301.

[0121] Optionally, both the first arc surface 701 and the second arc surface 702 are circular arc surfaces. The diameter of the conductor 820 is smaller than the diameter of the support wire 500, therefore the diameter of the second inner cavity 720 is smaller than the diameter of the first inner cavity 710. Correspondingly, the diameter of the circle containing the second arc surface 702 is also smaller than the diameter of the circle containing the first arc surface 701, thus the two side planes 703 connecting the first arc surface 701 and the second arc surface 702 are inclined planes facing each other, i.e., the two side planes 703 are not parallel. This further reduces the volume of the flexible sheath 700.

[0122] Of course, in other embodiments, an axial channel may be provided in the wall of the cannula 300, and the wire 820 of the pressure sensor 800 may pass through the axial channel.

[0123] Referring to Figures 1 to 4, this application also provides a blood pump 10, which includes an impeller 400 and a cannulation assembly; the specific structure of the cannulation assembly is as described in the above embodiments; the impeller 400 is rotatably disposed on the proximal tube 100 of the cannulation assembly. Since the blood pump 10 of this application adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.

[0124] The blood pump 10 can be a left ventricular interventional pump or a right ventricular interventional pump. When the blood pump 10 is a right ventricular interventional pump, the first opening 101 is the blood inlet and the second opening 201 is the blood outlet. During delivery, the blood pump 10 is pushed from the right ventricle to the pulmonary artery, so that the main tube segment 330 of the cannula 300 crosses the pulmonary valve, the first opening 101 is located in the right ventricle, and the second opening 201 is located in the pulmonary artery. When the blood pump 10 is a left ventricular interventional pump, the first opening 101 is the blood outlet and the second opening 201 is the blood inlet. During delivery, the blood pump 10 is pushed from the aorta to the left ventricle, so that the main tube segment 330 of the cannula 300 crosses the aortic valve, the second opening 201 is located in the left ventricle, and the first opening 101 is located in the aorta.

[0125] Referring to Figures 1 to 4, in some embodiments, the blood pump 10 further includes a motor 12. The distal end of the motor 12 is fixedly connected to the proximal tube 100, and the shaft of the motor 12 is fixedly connected to the impeller 400, enabling the motor 12 to drive the impeller 400 to rotate. The blood pump 10 also includes a conduit 13, the distal end of which is fixedly connected to the proximal end of the motor 12. The inner cavity of the conduit 13 can accommodate flushing lines of the blood pump 10, wires 820 of the sensor 800, and other wires.

[0126] 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.

[0127] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A cannulation assembly, characterized in that, The cannulation assembly includes: A proximal tube, wherein the proximal tube is provided with a first opening; The distal tube has a second opening, one of which, along with the first opening, is a blood inlet and the other is a blood outlet. An intubation cannula has a fluid flow channel connecting a first opening and a second opening; the cannula has a first tube segment, a second tube segment, and a main tube segment located between the first tube segment and the second tube segment; wherein the first tube segment is fixedly connected to the proximal tube; the second tube segment is fixedly connected to the distal tube; the first tube segment, the main tube segment, and the second tube segment all have flexible membranes, the main tube segment does not have an elastic support, and the main tube segment is tubular in its natural state; and A support wire is disposed within the fluid flow channel and connects the proximal tube and the distal tube.

2. The cannulation assembly according to claim 1, characterized in that, The support wire is inserted into the fluid flow channel. The support wire has a first end and a second end, the first end of which is fixed to the proximal tube and the second end of which is fixed to the distal tube.

3. The cannulation assembly according to claim 2, characterized in that, The proximal tube has a proximal section for accommodating the impeller and a distal section near the distal tube. The interior of the distal section is provided with a hollow mounting bracket, and the mounting bracket is provided with a first insertion hole. The first end of the support wire is inserted into the first insertion hole.

4. The cannulation assembly according to claim 3, characterized in that, The cannulation assembly further includes at least one of the following features: The mounting bracket has a first surface facing the distal tube, the first insertion hole has an inlet through the first surface, and a support surface opposite the inlet for supporting the support wire; The mounting bracket has a second surface facing away from the distal tube, the second surface being axially spaced from the distal end of the impeller, and the second surface being an arcuate surface protruding in the direction away from the distal tube. The proximal pipe includes an open pipe and a transfer pipe. The transfer pipe connects the second pipe segment and the open pipe. The open pipe has the first opening and can accommodate the impeller. The mounting bracket is disposed inside the transfer pipe.

5. The cannulation assembly according to claim 2, characterized in that, The distal tube includes a tube body and an installation end; wherein, the tube body is connected to the second section of the insertion tube, and the tube body is provided with the second opening; the installation end is connected to the end of the tube body away from the insertion tube, and the installation end is provided with a second insertion hole, and the second end of the support wire is inserted into the second insertion hole.

6. The cannulation assembly according to claim 5, characterized in that, The mounting end is also provided with a guide wire hole for the interventional guide wire to pass through; wherein, the first insertion hole and the second insertion hole are both located on the central axis of the cannulation assembly, and the guide wire hole is adjacent to the central axis of the cannulation assembly; Alternatively, both the guide wire hole and the first insertion hole are located on the central axis of the cannulation assembly, while the second insertion hole is adjacent to the central axis of the cannulation assembly.

7. The cannulation assembly according to claim 2, characterized in that, The cannulation assembly further includes at least one of the following features: The support wire is a metal wire, and a magnet is provided in the first insertion hole. The magnet can be magnetically attracted and fixed to the metal wire. The outer peripheral surface of the support wire is provided with a support frame, which is located in the middle of the support wire. The outer peripheral surface of the support frame is radially spaced from the inner wall surface of the main pipe section, and there is a first radial distance between them. The first radial distance is greater than or equal to 1 / 4 times the inner diameter of the main pipe section. The cannulation assembly further includes a flexible sheath disposed within the fluid flow channel, and the flexible sheath has a first inner cavity through which the support wire passes.

8. The cannulation assembly according to claim 1, characterized in that, The main tube section of the cannula includes a proximal end, a distal end, and a body portion located between the proximal end and the distal end. The proximal end is adjacent to the first tube section, and the distal end is adjacent to the second tube section. The cannula assembly further includes at least one of a first rectifier tube and a second rectifier tube. The first rectifier tube includes a first rectifier section, which is fixedly sleeved on the outer periphery of the proximal end. The second rectifier tube includes a second rectifier section, which is fixedly sleeved on the outer periphery of the distal end.

9. The cannulation assembly according to claim 8, characterized in that, The cannulation assembly further includes at least one of the following features: The first rectifier tube further includes a first fixed section connected to the first rectifier section, and the first fixed section is fixedly sleeved on the outer periphery of the first tube section; The second rectifier tube also includes a second fixed section connected to the second rectifier section, the second fixed section being sleeved on the outer periphery of the second tube section; Both the first rectifier tube and the second rectifier tube include a metal spring layer and a flexible film layer covering the metal spring layer.

10. The cannulation assembly according to claim 8, characterized in that, Both the first pipe segment and the second pipe segment have a first length L1 along the axial direction of the insertion tube, the first rectifier segment or the second rectifier segment has a second length L2 along the axial direction of the insertion tube, and the main pipe segment has a third length L3 along the axial direction of the insertion tube; wherein, L1≤L2≤3L1; and / or, 0.03<L2 / L3<0.

1.

11. The cannulation assembly according to claim 1, characterized in that, The cannulation assembly further includes at least one of the following features: The flexible membrane of the main pipe section has a first membrane wall thickness, and the flexible membranes of the first pipe section and the second pipe section have a second membrane wall thickness, wherein the second membrane wall thickness is greater than the first membrane wall thickness. The main tube section includes a proximal end, a distal end, and a main body portion located between the proximal end and the distal end. The main body portion has a main membrane wall thickness. At least one of the proximal end and the distal end has an end membrane wall thickness, and the end membrane wall thickness is greater than the main membrane wall thickness. The flexible membrane is made of TPU material; The first pipe segment has an elastic support, which is embedded in the flexible membrane of the first pipe segment; The second pipe segment has an elastic support, which is embedded in the flexible membrane of the second pipe segment.

12. The cannulation assembly according to claim 1, characterized in that, The distal tube has an mounting end for connection to a non-invasive flexible component; the cannulation assembly also includes a pressure sensor, the pressure sensor including a probe and a wire connected to the probe, the probe being mounted on the mounting end, and the wire at least partially passing through the fluid flow channel of the cannula.

13. The cannulation assembly according to claim 12, characterized in that, The cannulation assembly further includes at least one of the following features: The cannulation assembly also includes a flexible sheath, which is fixed inside the fluid flow channel. The flexible sheath also has a second inner cavity. The mounting bracket inside the proximal tube has a radial channel, and the tube wall of the proximal tube has a wire passage hole. The wire passage hole communicates with the radial channel and the second inner cavity to allow the wire of the pressure sensor to pass through. The mounting end has a distal surface, and the sensing surface of the probe is located on the distal surface; The probe is located on the central axis of the cannulation assembly.

14. A blood pump, characterized in that, The blood pump includes an impeller and a cannulation assembly; the cannulation assembly includes: A proximal tube, wherein the proximal tube has a first opening, and the impeller is rotatably disposed within the proximal tube; The distal tube has a second opening, one of which, along with the first opening, is a blood inlet and the other is a blood outlet. An intubation cannula has a fluid flow channel connecting a first opening and a second opening; the cannula has a first tube segment, a second tube segment, and a main tube segment located between the first tube segment and the second tube segment; wherein the first tube segment is fixedly connected to the proximal tube; the second tube segment is fixedly connected to the distal tube; the first tube segment, the main tube segment, and the second tube segment all have flexible membranes, the main tube segment does not have an elastic support, and the main tube segment is tubular in its natural state; and A support wire is disposed within the fluid flow channel and connects the proximal tube and the distal tube.

15. The blood pump according to claim 14, characterized in that, The support wire has a first end and a second end opposite to each other, the first end being fixedly connected to the proximal tube, and the second end being fixedly connected to the distal tube; wherein... The proximal tube has a proximal section for accommodating the impeller and a distal section near the distal tube. The interior of the distal section is provided with a hollow mounting bracket. The mounting bracket is provided with a first insertion hole, and the first end is inserted into the first insertion hole. The distal tube includes a tube body and an installation end; the tube body is connected to the second section of the insertion tube, and the tube body is provided with the second opening; the installation end is connected to the end of the tube body away from the insertion tube, and the installation end is provided with a second insertion hole, and the second end of the support wire is inserted into the second insertion hole.

16. The blood pump according to claim 14, characterized in that, The main tube section of the cannula includes a proximal end, a distal end, and a body portion located between the proximal end and the distal end. The proximal end is adjacent to the first tube section, and the distal end is adjacent to the second tube section. The cannula assembly further includes at least one of a first rectifier tube and a second rectifier tube. The first rectifier tube includes a first rectifier section and a first fixed section connected to the first rectifier section. The first rectifier section is fixedly sleeved on the outer periphery of the proximal end, and the first fixed section is fixedly sleeved on the outer periphery of the first tube section. The second rectifier tube includes a second rectifier section and a second fixed section connected to the second rectifier section. The second fixed section is sleeved on the outer periphery of the second tube section, and the second rectifier section is fixedly sleeved on the outer periphery of the distal end.

17. The blood pump according to claim 14, characterized in that, The distal tube has an mounting end for connection to a non-invasive flexible component; the cannulation assembly also includes a pressure sensor, the pressure sensor including a probe and a wire connected to the probe, the probe being mounted on the mounting end, and the wire at least partially passing through the fluid flow channel of the cannula.

18. The blood pump according to claim 17, characterized in that, The cannulation assembly also includes a flexible sheath, which is fixed inside the fluid flow channel. The flexible sheath also has a first inner cavity and a second inner cavity. The support wire passes through the first inner cavity. The mounting bracket inside the proximal tube has a radial channel. The tube wall of the proximal tube has a wire passage hole, which communicates with the radial channel and the second inner cavity to allow the wire of the pressure sensor to pass through.

19. The blood pump according to claim 18, characterized in that, The outer peripheral surface of the flexible sheath is a non-cylindrical surface; the outer peripheral surface of the flexible sheath includes a first arc surface, a second arc surface, and two side planes connecting the first arc surface and the second arc surface; the first arc surface surrounds the side of the first inner cavity away from the second inner cavity; the second arc surface surrounds the side of the second inner cavity away from the first inner cavity; the diameter of the circle containing the second arc surface is smaller than the diameter of the circle containing the first arc surface.

20. The blood pump according to claim 14, characterized in that, The blood pump also includes an interventional guidewire that can pass through the fluid flow channel of the cannulation assembly, the support wire having a first diameter and the interventional guidewire having a second diameter, the first diameter being greater than or equal to the second diameter; and / or, the blood pump also includes a motor, the distal end of which is fixed to the proximal tube, and the motor shaft being connected to the impeller to drive the impeller to rotate.

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