blood pump

Abstract

This application relates to a blood pump, comprising a primary pumping device, a first catheter, a secondary pumping device, and a second catheter connected in sequence. The primary pumping device has a first inlet and a first outlet, and the secondary pumping device has a second inlet and a second outlet. The secondary pumping device includes a secondary cannula, which has a proximal end, a distal end, and an enlarged portion. The proximal end is adjacent to the second catheter and has a second outlet. The distal end is connected to the first catheter and has a second inlet. The two ends of the enlarged portion are smoothly transitioned to the proximal end and the distal end, respectively. This blood pump increases the blood volume pumped by the secondary pumping device, allowing most of the blood in the aorta to be accelerated by the secondary pumping device, thus significantly improving the pumping efficiency of the secondary pumping device.

Description

Technical Field

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

[0002] Blood pumps, as cardiac assist devices, are typically used to partially or completely replace the heart's function to assist in blood circulation. However, traditional blood pumps have the drawback of pumping a small volume of blood, resulting in low pumping efficiency. Summary of the Invention

[0003] Based on this, this application provides a blood pump designed to solve the problem of low pumping efficiency of traditional blood pumps.

[0004] In one embodiment, the blood pump includes a primary pumping device, a first catheter, a secondary pumping device, and a second catheter connected in sequence; the primary pumping device has a first inlet and a first outlet, and the secondary pumping device has a second inlet and a second outlet; wherein, the secondary pumping device includes a secondary cannula, the secondary cannula having a proximal end, a distal end, and an enlarged diameter section; the proximal end is close to the second catheter and has a second outlet; the distal end is connected to the first catheter and has a second inlet; the two ends of the enlarged diameter section are smoothly connected to the proximal end and the distal end, respectively.

[0005] In one embodiment, the circle at the point where the diameter of the expanded section is at its maximum is used as the reference circle; the pipe wall of the expanded section includes a first arc-shaped wall and a second arc-shaped wall; wherein,

[0006] The diameter of the first arc-shaped wall gradually decreases from the reference circle toward the proximal end;

[0007] The diameter of the second arc-shaped wall gradually decreases from the reference circle toward the distal end.

[0008] In one embodiment, the second outlet includes a plurality of outlet holes, which are spaced apart circumferentially along the secondary sleeve; the outlet holes extend from the proximal end of the secondary sleeve to the first arcuate wall of the enlarged diameter portion, and the width of the outlet holes gradually increases in the extending direction.

[0009] In one embodiment, the outlet hole has a first hole edge, a second hole edge, and two third hole edges; wherein the first hole edge is located on the first arc-shaped wall, and the second hole edge is located on the proximal end; and the arc length of the first hole edge extending circumferentially along the secondary sleeve is greater than the arc length of the second hole edge extending in the same direction; the two third hole edges are arranged in a straight line and connect the first hole edge and the second hole edge.

[0010] In one embodiment, the diameter of the proximal end of the secondary sleeve is D1; ​​the diameter of the distal end of the secondary sleeve is D2; and the maximum diameter of the enlarged portion of the secondary sleeve is D3; wherein, 1.2D1≤D3≤1.5D1, and D2≤D1.

[0011] In one embodiment, the secondary pumping device further includes a secondary impeller disposed within the secondary sleeve and capable of rotating relative to the secondary sleeve; the proximal end of the secondary impeller corresponds to the second outlet, and the distal end of the secondary impeller extends into the enlarged diameter section and is close to the second inlet.

[0012] In one embodiment, the primary pumping device includes a sleeve assembly, which includes a primary sleeve, an outlet pipe having the first outlet, and an inlet pipe having the first inlet, the primary sleeve connecting the outlet pipe and the inlet pipe; the secondary pumping device includes a secondary sleeve, which has a second inlet and a second outlet; wherein the primary sleeve is an elastic tube; and the secondary sleeve is a rigid tube.

[0013] In one embodiment, the distal end of the secondary cannula is provided with a connecting end and a fixing cap; wherein the fixing cap is sleeved on the proximal end of the first conduit, and the fixing cap is welded to the connecting end to fix the proximal end of the first conduit to the connecting end.

[0014] In one embodiment, the connecting end includes a tapered portion; the first conduit has a sleeve portion, which is flared to fit into the tapered portion; the fixing cap is sleeved on the outer periphery of the sleeve portion, and the fixing cap has a reduced diameter port and an expanded diameter port, the periphery of the expanded diameter port being fixedly connected to the connecting end; the periphery of the reduced diameter port is wrapped around the first conduit, and the diameter of the reduced diameter port is smaller than the diameter of the sleeve portion.

[0015] In one embodiment, the distal end of the tapered portion is spherical, and the distal end of the tapered portion passes through the sleeve portion and is embedded in the lumen of the first catheter.

[0016] In one embodiment, the secondary pumping device further includes a secondary motor connected to the second conduit and the secondary sleeve; the secondary motor includes a shaft extending from the distal end of the secondary motor into the secondary sleeve to be fixedly connected to an impeller disposed within the secondary sleeve.

[0017] In one embodiment, the secondary pumping device further includes a fixed tube, one end of which is fixed to the proximal end of the secondary motor, and the other end of which passes through the rotating shaft and the secondary impeller and is fixed to the distal end of the secondary sleeve; the fixed tube is configured as a hollow tube, and a first gap is formed between the outer circumferential surface of the fixed tube and the inner circumferential surface of the rotating shaft, the first gap communicating with the lumen of the secondary sleeve to allow flushing fluid to pass through.

[0018] The blood pump of this application, by providing an enlarged section between the proximal and distal ends of the secondary cannula, reduces the distance between the enlarged section of the secondary cannula and the inner wall of the aorta during the operation of the secondary pumping device, making this distance smaller than the distance between its distal end and the inner wall of the aorta. Thus, when blood in the aorta flows through the space between the enlarged section and the inner wall of the aorta, it is throttled, and the throttled portion of the blood is drawn into the second inlet, thereby effectively increasing the flow rate of blood drawn into the second inlet, and consequently increasing the flow rate of blood pumped by the secondary cannula. Therefore, by providing an enlarged section between the proximal and distal ends of the secondary cannula, this application increases the flow rate of blood pumped from the secondary pumping device, allowing most of the blood in the aorta to be accelerated by the secondary pumping device, greatly improving the pumping efficiency of the secondary pumping device. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the blood pump structure in one embodiment of this application.

[0020] Figure 2 This is a schematic diagram of a blood pump inserted into a portion of the aorta in one embodiment of this application.

[0021] Figure 3 for Figure 2 A cross-sectional view of the blood pump inserted into part of the aorta.

[0022] Figure 4 This is a schematic diagram of another embodiment of the secondary pumping device in one embodiment of this application.

[0023] Figure 5 for Figure 4 An exploded view of the assembly structure of the secondary pumping device and the first and second conduits.

[0024] Figure 6 for Figure 4 Cross-sectional view of the secondary pumping unit along AA.

[0025] Figure 7 for Figure 6 Enlarged schematic diagram at point P1.

[0026] Figure 8 for Figure 6 Enlarged diagram of point P2 in the image.

[0027] Figure 9 for Figure 4 Cross-sectional view of the secondary pumping unit along BB.

[0028] Figure 10 for Figure 4 An assembly diagram of some structures of the intermediate and secondary pumping unit.

[0029] Figure 11 for Figure 10 A schematic diagram of blood flowing through the secondary cannula.

[0030] Figure 12 This is a schematic diagram of the secondary bushing structure in one embodiment of this application.

[0031] Figure 13 for Figure 12 Front view of the secondary bushing.

[0032] Figure 14 This is a schematic diagram showing the connection between the rotating shaft, the fixed tube, and the secondary impeller in position 12.

[0033] Figure 15 for Figure 14 A schematic diagram showing the connection between the transfer shaft and the fixed tube.

[0034] Figure 16 This is a schematic diagram of the main pumping device in one embodiment of this application.

[0035] Figure 17 This is a schematic diagram illustrating the blood flow direction of a traditional straight tubular cannula in the aorta.

[0036] Explanation of reference numerals in the attached figures:

[0037]

[0038] Detailed Implementation

[0039] 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.

[0040] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] This application provides an embodiment of a blood pump, which can be used to assist blood flow in the right ventricle or the left ventricle, without limitation. To avoid redundancy, the following description uses the application of the blood pump to assist blood flow in the right ventricle as an example. For ease of description, "proximal" is defined as the end of the interventional medical device closer to the operator, and "distal" is defined as the end of the interventional medical device farther from the operator, but this is not intended to be limiting.

[0046] Please see Figures 1 to 4 The blood pump 10 includes a primary pumping device 100, a first catheter 200, a secondary pumping device 300, and a second catheter 400 connected in sequence. The primary pumping device 100 is provided with a first inlet 101 and a first outlet 102; the secondary pumping device 300 is provided with a second inlet 301 and a second outlet 302, and the second inlet 301 is disposed on the outer peripheral surface of the secondary pumping device 300.

[0047] Specifically, the distal end of the primary pumping device 100 can be connected to a pig tail tube (not shown in the figure), which is used to support and position the device against the inner wall of the heart. The proximal end of the primary pumping device 100 is connected to the distal end of the first catheter 200, and the proximal end of the first catheter 200 is connected to the distal end of the secondary pumping device 300; the proximal end of the secondary pumping device 300 is connected to the distal end of the second catheter 400.

[0048] After the blood pump 10 is inserted into the patient's body, the primary pumping device 100 extends from the aorta 20 through the valve 21 and partially into the ventricle, such that the first inlet 101 of the primary pumping device 100 is located in the ventricle, and the first outlet 102 of the primary pumping device 100 is located in the aorta 20; while the secondary pumping device 300 and the first catheter 200 are located in the aorta 20; the second catheter 400 extends from the secondary pumping device 300 to the patient's body. When the blood pump 10 is started, blood in the ventricles flows into the primary pumping device 100 from the first inlet 101, is accelerated by the primary pumping device 100, and then flows out from the first outlet 102 to the ascending portion 22 of the aorta 20. It then flows along the ascending portion 22 of the aorta 20 towards the aortic arch 22. Subsequently, the blood meets the secondary pumping device 300 and is drawn into it by the second inlet 301 of the secondary pumping device 300. The secondary pumping device 300 accelerates the drawn-in blood again and discharges it from the second outlet 302 into the descending portion 23 of the aorta 20. This accelerates blood flow, allowing blood to flow smoothly through the aortic arch 22 and speeding up blood circulation.

[0049] Therefore, the blood pump 10 of this application, by configuring a primary pumping device 100, a first conduit 200, a secondary pumping device 300, and a second conduit 400, and sequentially connecting these components, accelerates the blood flow at least twice using both the primary and secondary pumping devices 100 and 300. This gives the blood pump 10 a dual-stage drive function, effectively enhancing its driving force and increasing the blood flow rate. Due to the presence of the secondary pumping device 300, a negative pressure is generated at the aortic arch 22, causing the blood in the ascending portion 22 of the aorta 20 to flow more rapidly towards the descending portion 23, thereby increasing the blood flow rate.

[0050] It is understandable that, since the blood pump 10 of this application has a primary pumping device 100 and a secondary pumping device 300, while ensuring that the total pumping power of the blood pump 10 is not less than that of a conventional blood pump 10, the pumping power of a single pumping device (such as the primary pumping device 100 or the secondary pumping device 300) can be appropriately reduced to decrease the axial dimension of the single pumping device, thereby reducing the length of the primary pumping device 100, which facilitates implantation into the patient. In particular, reducing the length of the primary pumping device 100 can greatly reduce the difficulty of the primary pumping device 100 passing through the aortic arch 22.

[0051] Please see Figures 5 to 6In some embodiments, the secondary pumping device 300 includes a secondary sleeve 320; a second inlet 301 and a second outlet 302 are both disposed on the outer peripheral wall of the secondary sleeve 320, and the distal end of the secondary sleeve 320 is connected to the first conduit 200.

[0052] Since the secondary pumping device 300 is entirely located within the aorta 20, and blood flows along the length of the aorta 20, that is, along the axial direction of the secondary pumping device 300, when blood passes the outer periphery of the second inlet 301 of the secondary sleeve 320, a portion of the blood F1 will be drawn into the secondary sleeve 320 by the suction force of the secondary pumping device 300 through the second inlet 301 (e.g., Figure 17 As shown), after being accelerated within the secondary sleeve 320, the blood flows along the secondary sleeve 320 to the second outlet 302 and is finally discharged from the second outlet 302. Due to the high flow rate of the blood, inevitably some blood F2 will not be drawn into the secondary sleeve 320 by the second inlet 301, and will not be accelerated by the secondary pumping device 300. Instead, it will flow directly through the outer periphery of the secondary sleeve 320, which will reduce the blood flow rate pumped by the secondary pumping device 300.

[0053] Please see Figure 6 , Figure 10 and Figure 12 In view of the above problems, in order to improve the blood flow rate pumped by the secondary pumping device 300, in some embodiments, the secondary cannula 320 includes a proximal end 321, a distal end 322, and an enlarged diameter portion 323; wherein, the proximal end 321 is close to the second conduit 400 and is provided with a second outlet 302; the distal end 322 is connected to the first conduit 200 and is provided with a second inlet 301; the enlarged diameter portion 323 is located between the proximal end 321 and the distal end 322, and the two ends of the enlarged diameter portion 323 are smoothly connected to the proximal end 321 and the distal end 322, respectively.

[0054] Specifically, the second inlet 301 is located at the distal end 322; the second outlet 302 is located at the proximal end 321. The two ends of the enlarged diameter portion 323 are smoothly connected to the proximal end 321 and the distal end 322, respectively. That is, the two ends of the inner wall surface of the enlarged diameter portion 323 are smoothly connected to the inner wall surfaces of the proximal end 321 and the distal end 322, and the two ends of the outer wall surface of the enlarged diameter portion 323 are also smoothly connected to the inner wall surfaces of the proximal end 321 and the distal end 322. Optionally, the proximal end 321, the distal end 322, and the enlarged diameter portion 323 of the secondary sleeve 320 can be integrally formed.

[0055] Because the secondary cannula 320 has an enlarged diameter section 323, when the secondary pumping device 300 is operating, the distance D4 between the enlarged diameter section 323 of the secondary cannula 320 and the inner wall surface of the aorta 20 is smaller than the distance D5 between its distal end 322 and the inner wall surface of the aorta 20 (i.e., D4 is smaller than D5). Thus, the blood F2 flowing through the periphery of the secondary cannula 320 will be throttled at the distance D4, and the throttled portion of the blood will be drawn into the second inlet 301, thereby effectively increasing the flow rate of blood F1 drawn into the second inlet 301, and thus increasing the blood flow rate pumped by the secondary cannula 320. In other words, the enlarged diameter section 323 of the secondary cannula 320 reduces the flow rate F2 of blood flowing directly through the periphery of the secondary cannula 320, and increases the flow rate F1 of blood entering through the second inlet 301. Therefore, by providing an enlarged diameter portion 323 between the proximal end 321 and the distal end 322 of the secondary cannula, this application can increase the blood flow rate pumped from the secondary pumping device 300, so that most of the blood in the aorta 20 can be accelerated by the secondary pumping device 300, greatly improving the pumping efficiency of the secondary pumping device 300.

[0056] Furthermore, because the secondary cannula 320 has an enlarged diameter section 323, the secondary cannula 320 can gradually widen from the distal end 322 to the enlarged diameter section 323, conforming to the streamlined shape of blood. This facilitates the secondary cannula 320 drawing blood from the second inlet into its interior, where the drawn blood quickly flows towards the enlarged diameter section 323. Conversely, the secondary cannula 320 gradually narrows from the enlarged diameter section 323 to the proximal end 321, which facilitates the enlarged diameter section 323 gradually squeezing blood towards the proximal end 321, causing a rise in blood pressure within the proximal end 321, which then quickly drains the blood outward from the second outlet of the proximal end 321. Therefore, the shape of the secondary cannula 320 in this application can also guide blood inflow and outflow, greatly reducing blood flow resistance, effectively increasing pumping volume, and improving pumping efficiency.

[0057] It is worth mentioning that the maximum diameter of the enlarged portion 323 should preferably be smaller than the inner diameter of the aorta 20, so that the distance between the enlarged portion 323 and the inner wall surface of the aorta 20 is not zero, avoiding the enlarged portion 323 and the aorta 20 from adhering to each other. This prevents the secondary cannula 320 from being inside the aorta 20 for a prolonged period of time and thus avoids dilating the aorta 20, reducing the impact of the secondary pumping device 300 on the contractile performance of the aorta 20. Furthermore, this design can also reduce the radial dimension of the secondary pumping device 300, reducing the difficulty of implantation.

[0058] Please see Figures 10 to 13In some embodiments, the circle at the point where the diameter of the expanded portion 323 is at its maximum is taken as the reference circle 323a; the tube wall of the expanded portion 323 includes a first arc-shaped wall 323b and a second arc-shaped wall 323c; wherein, the diameter of the first arc-shaped wall 323b gradually decreases from the reference circle 323a toward the proximal end 321; and the diameter of the second arc-shaped wall 323c gradually decreases from the reference circle 323a toward the distal end 322.

[0059] Specifically, the reference circle 323a is a virtual circle used to divide the first arcuate wall 323b and the second arcuate wall 323c. The enlarged diameter portion 323 has one and only one reference circle 323a. The first arcuate wall 323b extends from the reference circle 323a to the proximal end portion 321, so that the enlarged diameter portion 323 and the proximal end portion 321 transition smoothly; the second arcuate wall 323c extends from the reference circle 323a to the distal end portion 322, so that the enlarged diameter portion 323 and the distal end portion 322 transition smoothly. This makes the wall of the secondary cannula 320 smoother and more conforms to the fluid profile, resulting in less resistance to blood flow within the secondary cannula 320, reducing the likelihood of blood collisions and blood damage, and also increasing the pumping volume.

[0060] Furthermore, the second outlet includes a plurality of outlet holes, which are distributed circumferentially along the secondary sleeve 320; the outlet holes extend from the proximal end 321 of the secondary sleeve 320 to the first arcuate wall 323b of the enlarged diameter portion 323; and the width of the outlet holes gradually increases in its extending direction.

[0061] When blood flows within the secondary cannula 320 and into the first arc-shaped wall 323b of the enlarged portion 323, at least a portion of the blood will flow along the first arc-shaped wall 323b. Since the diameter of the first arc-shaped wall 323b gradually decreases from the reference circle 323a towards the proximal end 321, the blood flowing along the first arc-shaped wall 323b is gradually guided into the outlet hole by the first arc-shaped wall 323b, thereby quickly draining the blood. Furthermore, because the width of the outlet hole gradually increases in its extending direction—that is, the widest end of the outlet hole is located at the first arc-shaped wall 323b, and the narrowest end is located at the proximal end 321—the outlet hole can obtain a larger outlet area, reducing damage from blood contact with the periphery of the outlet hole.

[0062] Please see Figures 10 to 13Furthermore, each outlet hole of the second outlet 302 has a first hole edge 302a, a second hole edge 302b, and two third hole edges 302c; wherein, the first hole edge 302a is located on the first arc-shaped wall 323b, and the second hole edge 302b is located on the proximal end 321; and the arc length of the first hole edge 302a extending circumferentially along the secondary sleeve 320 is greater than the arc length of the second hole edge 302b extending in the same direction; the two third hole edges 302c are arranged in a straight line and connect the first hole edge and the second hole edge.

[0063] Specifically, because the circumference of the first arc-shaped wall 323b is relatively large, it has a large outer circumferential surface area. Setting the arc length of the first hole edge to be greater than the arc length of the second hole edge extending in the same direction allows the distal end of the outlet hole to have a larger outlet area, which is beneficial for guiding blood outflow. Furthermore, the two third hole edges are arranged in a straight line, which guides the blood discharged from the distal end of the outlet hole to flow outwards towards the proximal end 321, thereby increasing the velocity of the blood flowing towards the second conduit 400 and improving pumping efficiency.

[0064] In some embodiments, the secondary pumping device 300 further includes a secondary impeller 330 disposed within the secondary sleeve 320 and rotatable relative to the secondary sleeve 320; the proximal end of the secondary impeller 330 corresponds to the second outlet 302, and the distal end of the secondary impeller 330 extends into the enlarged diameter portion 323 and is close to the second inlet 301.

[0065] Specifically, the proximal side of the secondary impeller 330 is positioned opposite to the second outlet 302; the distal end of the secondary impeller 330 passes through the expansion section 323 and is close to the second outlet 302, meaning the distal end of the secondary impeller 330 and the second outlet 302 are axially spaced by a small distance. This design allows the secondary impeller 330 to have a longer axial length, enabling the distal end of the secondary impeller 330 to drive the second inlet 301 to rapidly draw in external blood, which then rotates axially along the secondary impeller 330 towards its proximal end, and is finally centrifugally guided to the second outlet 302. This significantly increases the working power of the secondary impeller 330, thereby improving the pumping efficiency of the blood pump.

[0066] Please see Figure 12In some embodiments, the diameter of the proximal end 321 is D1, the diameter of the distal end 322 is D2, and the maximum diameter of the expanded portion 323 is D3; wherein 1.2D1≤D3≤1.5D1, and D2≤D1. Specifically, the reference circle 323a of the expanded portion 323 has a maximum diameter D3. If the difference between the maximum diameter D3 of the expanded portion 323 and the diameter D1 of the proximal end 321 is too large, the transition between the expanded portion 323 and the proximal end 321 will be steep, easily colliding with the blood pump and generating eddies; if the difference between the maximum diameter D3 of the expanded portion 323 and the diameter of the proximal end 321 is too small, the guiding effect of the expanded portion 323 will be insignificant. Similarly, the difference between the maximum diameter D3 of the expanded portion 323 and the diameter D2 of the distal end 322 is also similar. Therefore, 1.2D1≤D3≤1.5D1 is preferred.

[0067] Please see Figures 6 to 8 In some embodiments, the secondary pumping device 300 further includes a secondary motor 310; the secondary motor 310 connects the second conduit 400 and the secondary sleeve 320; the secondary motor 310 includes a rotating shaft 314 extending from the distal end of the secondary motor 310 into the secondary sleeve 320 to be fixedly connected to a secondary impeller 330 disposed within the secondary sleeve 320. Of course, the secondary motor 310 is not essential; the secondary impeller 330 can be connected to an external motor via a flexible shaft passing through the second conduit 400.

[0068] Specifically, in this embodiment, the secondary motor 310 includes a housing 311 and a stator 312, a rotor 313, and a shaft 314 installed within the housing 311; wherein, the distal end of the shaft 314 extends out of the housing 311 to be connected and fixed to the secondary impeller 330; the rotor 313 is connected and fixed to the outer peripheral surface of the shaft 314; the stator 312 is capable of generating a magnetic field that drives the rotor 313 to rotate.

[0069] The rotor 313, stator 312, sensor 360, and secondary impeller 330 are all connected to the outer periphery of the rotating shaft 314, and the rotor 313, sensor 360, and stator 312 are all located inside the housing 311. There are two rotors 313, which are located at opposite ends of the stator 312 and are fixedly connected to the rotating shaft 314. The housing 311 includes a cylindrical shell 311a, a proximal end cover 311b, and a distal end cover 311c; wherein, the proximal end cover 311b is connected to the proximal end of the cylindrical shell 311a, and the distal end cover 311c is connected to the distal end of the housing, so as to protect the rotor 313, sensor 360, and stator 312 and prevent blood from entering the interior of the housing.

[0070] Please see Figure 6 , Figure 7 and Figure 12In some embodiments, to enhance the robustness of the connection between the secondary sheath and the first conduit, a connecting end and a fixing cap are provided at the distal end of the secondary sheath; wherein, the fixing cap is fitted onto the proximal end of the first conduit, and the fixing cap is welded to the connecting end to fix the proximal end of the first conduit to the connecting end.

[0071] Specifically, the secondary sheath is a rigid tube, meaning it is made of metal. A fixing cap, also made of metal, covers the proximal end of the first conduit, allowing it to be welded to the connecting end. This welding method significantly improves the strength of the connection between the secondary sheath and the first conduit.

[0072] Furthermore, to facilitate the connection between the first conduit 200 and the distal end of the secondary pumping device 300, the connection end 324 includes a tapered portion 3241 and a ball head 3242; wherein, the ball head 3242 is configured as a hemisphere to guide the flow to the second inlet 301; the tapered portion 3241 is located on the side of the ball head 3242 opposite to the second inlet 301; the first conduit 200 is provided with a sleeve portion 210, which is sleeved with the tapered portion 3241.

[0073] Specifically, the distal end 322 of the secondary cannula 320 is provided with the connecting end 324. The second inlet 301 is adjacent to the connecting end 324 and includes multiple outlet holes. Multiple connecting posts 325 are formed between adjacent outlet holes, and the end of each connecting post 325 is fixedly connected to the connecting end 324. The sleeve portion 210 is fitted onto the outer peripheral surface of the connecting end 324, with both surfaces in close contact, effectively sealing the proximal end of the first catheter 200 and preventing blood from seeping into the first catheter 200.

[0074] Please see Figure 4 and Figure 6 The sleeve portion 210 is flared, and its inner diameter gradually increases along the direction from the first conduit 200 to the secondary pumping device 300. The connecting end 324 includes a first variable-diameter circumferential surface 324a, which is contoured to the inner circumferential surface of the sleeve portion 210 for a suitable fit. In this embodiment, the sleeve portion 210 is glued to the first variable-diameter circumferential surface 324a. The tighter the fit along the direction from the secondary pumping device 300 to the first conduit 200, the better the sealing performance of the proximal end of the first conduit 200.

[0075] Please see Figure 6 and Figure 7In some embodiments, the fixing cover 350 of the secondary pumping device 300 has an annular structure and is fitted around the outer periphery of the sleeve portion 210. The fixing cover 350 has a reduced diameter port 351 and an expanded diameter port 352. The periphery of the expanded diameter port 352 is fixedly connected to the connecting end 324, and the periphery of the reduced diameter port 351 is fitted around the first conduit 200. The diameter of the reduced diameter port 351 is smaller than the diameter of the sleeve portion 210. When the fixing cover 350 connects the secondary pumping device 300 and the first conduit 200, the fixing cover 350 is fitted around the outer periphery of the sleeve portion 210, the sleeve portion 210 is fitted around the outside of the first variable diameter circumferential surface 324a, and the fixing cover 350 is fixedly connected to the first variable diameter circumferential surface 324a, thereby reinforcing the connection between the first conduit 200 and the secondary pumping device 300. In this embodiment, the fixing cover 350 is made of metal material. The periphery of the enlarged diameter port 352 of the fixing cover 350 is welded to the connecting end 324, and the outer peripheral surface of the fixing cover 350 and the outer peripheral surface of the connecting end 324 are smoothly connected.

[0076] Please see Figure 6 and Figure 7 Furthermore, the distal end of the tapered portion 3241 is configured as a spherical surface 324b, and the distal end of the tapered portion 3241 passes through the sleeve portion 210 and is embedded in the inner cavity of the first conduit 200. By configuring the distal end of the tapered portion 3241 as a spherical surface 324b, when the tapered portion 3241 is inserted into the sleeve portion 210, an external force can be used to drive the spherical surface 324b of the distal end of the tapered portion 3241 to abut against the inner wall surface of the sleeve portion 210, thereby expanding the sleeve portion 210 without damaging it; and then the distal end of the tapered portion 3241 passes through the sleeve portion 210 to be embedded in the inner cavity of the first conduit 200, so that the distal end of the tapered portion 3241 is in an interference fit with the inner wall of the first conduit 200, thereby improving the tightness of the connection between the sleeve portion 210 and the connecting end 324.

[0077] Please see Figure 6 and Figure 14In some embodiments, the secondary pumping device 300 further includes a fixing tube 340. One end of the fixing tube 340 is fixed to the proximal end of the secondary motor 310, and the other end of the fixing tube 340 passes through the rotating shaft 314 and the secondary impeller 330 and is fixed to the distal end 322 of the secondary sleeve 320. By configuring the fixing tube 340 inside the secondary pumping device 300, the fixing tube 340 can support the secondary impeller 330 of the secondary pumping device 300, allowing the secondary impeller 330 to rotate stably and enhancing the stability of the secondary pumping device 300 during operation. Even if the second catheter 400 and the first catheter 200 are swayed by blood flow, the secondary impeller 330 is supported by the fixing tube 340 and will not easily sway radially. Optionally, the fixing tube 340 is made of metal or ceramic material to give it better strength, prevent it from bending, and stably support the secondary pumping device 300.

[0078] Please see Figure 4 , Figure 6 and Figure 8 In some embodiments, the primary pumping device 100 is provided with a first flushing channel for injecting flushing fluid (such as physiological saline) to prevent blood from entering the primary pumping device 100 and causing thrombosis, and also for heat dissipation of the primary pumping device 100. The secondary pumping device 300 is provided with a second flushing channel for injecting flushing fluid (such as physiological saline) to prevent blood from entering the secondary pumping device 300 and causing thrombosis, and also for heat dissipation of the secondary pumping device 300. Accordingly, the first conduit 200 is internally provided with a first flushing tube 220 for supplying flushing fluid to the primary pumping device 100; the second conduit 400 is internally provided with a second flushing tube 420 for supplying flushing fluid to the secondary pumping device 300.

[0079] Optionally, the fixing tube 340 is configured as a hollow tube, and a first gap 304 is formed between the outer peripheral surface of the fixing tube 340 and the inner peripheral surface of the rotating shaft 314. The first gap 304 communicates with the lumen of the secondary sleeve 320 to allow flushing fluid to pass through. The proximal end of the first gap 304 communicates with the second flushing tube 420, allowing some of the flushing fluid from the second flushing tube 420 to enter the first gap 304 and then be discharged into the lumen of the secondary sleeve 320 through the second gap. This prevents blood in the secondary sleeve 320 from flowing back to the secondary motor 310 through the first gap 304, reducing the risk of thrombosis.

[0080] Combination Figure 10 and Figure 15As shown, since the fixed tube 340 is set as a hollow tube, an intermediate channel 303 can be formed inside the fixed tube 340. The intermediate channel 303 is connected to the first flushing tube 220 and the second flushing tube 420, so that part of the flushing liquid supplied by the second flushing tube 420 can be supplied to the first flushing tube 220 through the intermediate channel 303. Specifically, the fixed tube 340 has a first end 341 and a second end 342, with the second end 342 being away from the first end 341. The first end 341 extends into the interior of the secondary motor 310 and is fixed to the proximal end of the secondary motor 310, thereby communicating with the second flushing tube 420 fixed to the proximal end of the secondary motor 310. The second end 342 extends out from the distal end of the secondary motor 310, passes through the secondary impeller 330, passes through the cavity of the secondary sleeve 320, and is fixed to the distal end of the secondary sleeve 320, thereby communicating with the first flushing tube 220 fixed to the distal end of the secondary motor 310.

[0081] Furthermore, a first drain hole 34a can be provided on the side wall of the fixed tube 340. The first drain hole 34a is used to connect the fluid in the fixed tube 340 with the first gap 304, so that the fluid in the intermediate channel 303 can be partially drained into the first gap 304 through the first drain hole 34a, thereby increasing the flow rate and velocity of the fluid in the first gap 304. This increases the resistance of the blood in the lumen of the secondary sleeve 320 to enter the secondary motor 310 from the first gap 304, thereby effectively preventing the formation of thrombi.

[0082] In some embodiments, the inner circumferential surface of the rotating shaft 314 is provided with a first ceramic material layer, and the outer circumferential surface of the fixed tube 340 is provided with a second ceramic material layer, so as to reduce the coefficient of friction between the rotating shaft 314 and the fixed tube 340 and reduce the frictional force when the rotating shaft 314 and the fixed tube 340 rotate relative to each other.

[0083] Please see Figure 16 The main stage pumping device 100 includes a main stage motor 110, a bushing assembly, and a main stage impeller 130. The bushing assembly includes a main stage bushing 120, an outlet pipe 150 with the first outlet 102, and an inlet pipe 140 with the first inlet 101 (e.g., ...). Figure 16 As shown, the outlet pipe 150 connects the main stage motor 110 and the near end of the main stage sleeve 120; the inlet pipe 140 connects the far end of the main stage sleeve 120 and the first conduit 200. The main stage impeller 130 is disposed inside the outlet pipe 150 and connected to the shaft of the main stage motor 110.

[0084] For the primary cannula 120, it needs to be able to pass through the aorta 20 and its valve 21 and be held by the valve 21. Therefore, the primary cannula 120 needs to be designed as an elastic tube to give it good elasticity and allow it to fully adapt to the shape of the blood vessel, thus facilitating its entry into the ventricle. Furthermore, since the primary pumping device 100 passes through the valve of the aorta 20 and enters the ventricle, the primary cannula 120 is held within the valve. The elasticity of the primary cannula 120 can buffer the force between the valve and the primary cannula 120, reducing the reaction force on the valve and preventing valve damage.

[0085] Regarding the secondary pumping device 300, since it is entirely located within the artery, its secondary cannula 320 does not contact the valve 21 and may therefore lack elasticity. Furthermore, considering that the second catheter 400 and the first catheter 200 are typically quite flexible, they may not be sufficient to stably support the secondary pumping device 300. If the secondary cannula 320 were designed as an elastic tube, the blood pump 10 might bend at the secondary cannula 320 during implantation, increasing the difficulty of manipulating the blood pump 10 through the curved blood vessel.

[0086] Therefore, in this embodiment, the secondary cannula 320 is set as a rigid tube, that is, the secondary cannula 320 is made of metal material, so that the secondary cannula 320 is not easily compressed and deformed. This not only ensures that blood can pass through smoothly, but also that the secondary cannula 320 can support the first catheter 200 and the second catheter 400 during the implantation procedure. Furthermore, the secondary cannula 320 is not easily bent, reducing the difficulty of manipulating the blood pump 10 through curved blood vessels.

[0087] 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.

[0088] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A blood pump, characterized in that, The blood pump comprises a primary pumping device, a first conduit, a secondary pumping device and a second conduit connected in sequence; the primary pumping device is provided with a first inlet and a first outlet, and the secondary pumping device is provided with a second inlet and a second outlet; wherein, The secondary pumping device comprises a secondary sleeve, the secondary sleeve comprises a proximal end, a distal end and a diameter expansion part; the proximal end is close to the second conduit and is provided with the second outlet; the distal end is connected with the first conduit and is provided with the second inlet; the diameter expansion part is connected with the proximal end and the distal end in a smooth transition manner at two ends thereof; The diameter expansion part is arranged in the aorta; the tube wall of the diameter expansion part comprises a first arc-shaped wall and a second arc-shaped wall, the diameter expansion part is connected with the proximal end in a smooth transition manner through the first arc-shaped wall, and the diameter expansion part is connected with the distal end in a smooth transition manner through the second arc-shaped wall; the diameter of the first arc-shaped wall gradually decreases in a direction from the distal end to the proximal end; the diameter of the second arc-shaped wall gradually decreases in a direction from the proximal end to the distal end; The second outlet comprises a plurality of outlet holes, and the plurality of outlet holes are distributed in a circumferential direction of the secondary sleeve; the outlet holes extend from the proximal end to the first arc-shaped wall, and the width of the outlet holes gradually increases in the extending direction.

2. The blood pump of claim 1, wherein, A circle with the largest diameter of the diameter expansion part as a reference circle; wherein the diameter of the first arc-shaped wall gradually decreases from the reference circle to the proximal end; The diameter of the second arc-shaped wall gradually decreases from the reference circle to the distal end.

3. The blood pump of claim 1, wherein, The secondary sleeve is a rigid tube, and the secondary sleeve has no elasticity.

4. The blood pump of claim 3, wherein, The outlet hole has a first hole edge, a second hole edge and two third hole edges; wherein the first hole edge is located on the first arc-shaped wall, the second hole edge is located on the proximal end, and the arc length of the first hole edge extending in the circumferential direction of the secondary sleeve is greater than that of the second hole edge extending in the same direction; the two third hole edges are arranged in a straight line and connect the first hole edge and the second hole edge.

5. The blood pump of any one of claims 1 to 4, characterized in that The diameter of the proximal end of the secondary sleeve is D1, the diameter of the distal end of the secondary sleeve is D2, and the largest diameter of the diameter expansion part of the secondary sleeve is D3; wherein 1.2D1≤D3≤1.5D1, and D2≤D1.

6. The blood pump of any one of claims 1 to 4, characterized in that The secondary pumping device further comprises a secondary impeller, the secondary impeller is arranged in the secondary sleeve and can rotate relative to the secondary sleeve; the proximal end of the secondary impeller corresponds to the second outlet, and the distal end of the secondary impeller extends into the diameter expansion part and is close to the second inlet.

7. The blood pump of any one of claims 1 to 4, wherein, The primary pumping device comprises a sleeve assembly, the sleeve assembly comprises a primary sleeve, an outlet tube provided with the first outlet and an inlet tube provided with the first inlet, and the primary sleeve connects the outlet tube and the inlet tube; the secondary pumping device comprises a secondary sleeve provided with the second inlet and the second outlet; wherein the primary sleeve is an elastic tube; and the secondary sleeve is a rigid tube.

8. The blood pump of any one of claims 1 to 4, wherein, The distal end of the secondary sleeve is provided with a connecting end and a fixing cover; wherein the fixing cover is sleeved on the proximal end of the first conduit, and the fixing cover is welded with the connecting end to fix the proximal end of the first conduit to the connecting end.

9. The blood pump of claim 8, wherein, The connecting end comprises a tapered portion; the first conduit is provided with a sleeving portion, which is arranged in a trumpet shape to be adapted to the sleeving of the tapered portion; the fixing cover is sleeved on the outer periphery of the sleeving portion, and the fixing cover is provided with a reduced diameter opening and an enlarged diameter opening, the periphery of the enlarged diameter opening is fixed to the connecting end; the periphery of the reduced diameter opening is sleeved on the first conduit, and the diameter of the reduced diameter opening is smaller than the maximum diameter of the sleeving portion.

10. The blood pump of claim 9, wherein, The distal end surface of the tapered portion is arranged as a spherical surface, and the distal end of the tapered portion passes through the sleeving portion and is embedded into the inner cavity of the first conduit.

11. The blood pump of any one of claims 1 to 4, characterized in that The secondary pumping device further comprises a secondary motor connected with the second conduit and the secondary sleeve; the secondary motor comprises a rotating shaft, which passes out from the distal end of the secondary motor into the secondary sleeve to be fixed with an impeller arranged in the secondary sleeve.

12. The blood pump of claim 11, wherein, The secondary pumping device further comprises a fixing tube, one end of which is fixed to the proximal end of the secondary motor, and the other end of which is fixed to the distal end of the secondary sleeve by passing through the rotating shaft and the impeller in the secondary sleeve; the fixing tube is arranged as a hollow tube, and a first gap is formed between the outer peripheral surface of the fixing tube and the inner peripheral surface of the rotating shaft, which is communicated with the lumen of the secondary sleeve to pass the flushing liquid.

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