Blood pump and ventricular assist system

Abstract

The utility model relates to a blood pump and a ventricular assist system. The blood pump comprises a cannula assembly, an impeller and a driving unit. The cannula assembly includes a proximal tube having a proximal opening; the impeller is rotatably arranged in the intubation tube assembly; the driving unit comprises a pump shell and a rotating shaft, the rotating shaft is rotatably installed on the pump shell, the rotating shaft penetrates through the pump shell and is provided with a connecting end contained in the near-side pipe, and the connecting end is fixedly connected with the impeller; the proximal tube has a tube outer diameter D1w, the pump housing has a housing outer diameter D2w, and D2w < D1w. According to the blood pump, the minimum inner diameter of the guide sheath is reduced by reducing the outer diameter of the pump shell, the guide sheath with the small inner diameter can be used for assisting in pushing the blood pump, the pushing difficulty of the guide sheath in the body of a patient is reduced, then the difficulty of interventional operation of the blood pump is reduced, and the operation duration is shortened.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a blood pump and ventricular assist system. Background Technology

[0002] An interventional catheter pump, also known as a blood pump, is typically implanted into the ventricles of the heart to assist the heart in pumping blood from the ventricles to the arteries, thus supporting the patient's blood circulation. When inserting the blood pump into the patient, it is usually guided to the target location (such as the heart) using an interventional guidewire. At least a portion of the guidewire is housed between the outer surface of the blood pump and the inner surface of the guiding sheath, thus occupying internal space within the guiding sheath. Therefore, the diameter of the guiding sheath is generally designed to be relatively large, which increases the difficulty of inserting the guiding sheath into the blood vessel, and consequently increases the complexity of the blood pump interventional procedure. Utility Model Content

[0003] Therefore, it is necessary to provide a blood pump and ventricular assist system that reduces the diameter of the guide sheath required for the blood pump, thereby reducing the difficulty of blood pump interventional surgery.

[0004] In one embodiment of the blood pump provided in this application, the blood pump includes a cannulation assembly, an impeller, and a drive unit. The cannulation assembly includes a proximal tube with a proximal opening; the impeller is rotatably disposed within the cannulation assembly; the drive unit includes a pump housing and a rotating shaft; the pump housing is connected to the proximal tube; the rotating shaft is rotatably mounted on the pump housing, extending through the pump housing and having a connecting end housed within the cannulation assembly, the connecting end being fixedly connected to the impeller. The proximal tube has an outer diameter D. 1w The pump casing has an outer diameter D. 2w And D 2w <D 1w .

[0005] In one embodiment, the blood pump further includes at least one of the following features:

[0006] The outer diameter D of the pipe 1w The size is 5.4mm≤D 1w ≤6.5mm;

[0007] The outer diameter D of the shell 2w Size ≤ 5mm D 2w ≤6mm;

[0008] The outer diameter D of the pipe 1w and the outer diameter D of the shell 2w The difference is 0.15mm ≤ △D ≤ 0.4mm;

[0009] The pump housing includes a housing and a distal end cover connected to the distal end of the housing. The distal end cover and the proximal tube are an integral structure.

[0010] In one embodiment, the pump housing has an outer peripheral wall and a distal wall; the proximal tube includes a tube body and a plurality of connecting posts connected to the proximal end of the tube body, with a proximal opening spaced between two adjacent connecting posts; the proximal end of each connecting post has a reduced diameter portion, the reduced diameter portion having an outer reduced diameter surface, the outer reduced diameter surface connecting the outer surface of the connecting post and the outer peripheral wall; the reduced diameter portion also has an inner reduced diameter surface, the inner reduced diameter surface connecting the inner surface of the connecting post and the distal wall.

[0011] In one embodiment, at least one of the outer diameter reduction surface and the inner diameter reduction surface is configured as a slope or an arc surface.

[0012] In one embodiment, the inner diameter reduction surface is an arc surface, and the circle containing the inner diameter reduction surface has a radius R, the radius R being equal to the outer diameter D of the proximal tube. 1w The outer diameter D of the pump casing 2w The three satisfy R > 0.5 × (D) 1w -D 2w ).

[0013] In one embodiment, the inner diameter surface has a first connection point that engages with the inner surface of the connecting column. The first connection point is located on the far side of the distal end wall of the pump housing. There is an axial distance L between the first connection point and the distal end wall of the pump housing, and 0 < L ≤ 0.3 mm.

[0014] And / or, the outer diameter-reducing surface has a second connection point that engages with the outer surface of the connecting post, the second connection point being located near the inner diameter-reducing surface.

[0015] In one embodiment, the proximal tube also has an inner diameter D. 1n The inner diameter surface has a connecting line that connects to the pump housing and is closest to the central axis of the proximal tube; the connecting lines of the plurality of inner diameter surfaces are located on a first circle, the center of which is located on the central axis and has a diameter φ, where φ < D. 1n .

[0016] In one embodiment, the blood pump also has at least one of the following features:

[0017] The inner diameter surface has a first width along the circumference of the proximal tube, and the first width gradually increases along the direction from the inner surface of the connecting post to the central axis of the proximal tube.

[0018] The outer diameter reduction surface has a second width along the circumference of the proximal tube, and the second width gradually increases along the direction from the proximal tube to the pump housing;

[0019] A rounded surface is provided at the junction of the distal wall and the outer peripheral wall, and the inner diameter surface is connected to the rounded surface.

[0020] In one embodiment, the cannulation assembly further includes a cannula with a distal opening at its distal end and a proximal end of the cannula fixedly connected to the proximal tube; or, the cannulation assembly further includes a cannula and a distal tube, with the proximal end of the cannula fixedly connected to the proximal tube and the distal tube fixedly connected to the distal end of the cannula, and the distal tube having a distal opening.

[0021] This application also provides a ventricular assist system, comprising an interventional guidewire, a guiding sheath, and a blood pump as described in any of the above embodiments. The interventional guidewire includes a first portion and a second portion connected together. The first portion is capable of passing through the cannulation assembly of the blood pump, and the second portion is capable of passing through the outer surface of the drive unit and the inner surface of the guiding sheath. The second portion of the interventional guidewire has a guidewire diameter D. S The guide sleeve has an inner diameter D. h The inner diameter D of the sheath h The outer diameter D of the proximal tube 1w The outer diameter D of the pump casing 2w and the diameter D of the guide wire S The relationship between the four satisfies D. 2w +D S ≤D h <D 1w +D S .

[0022] The aforementioned blood pump and ventricular assist system, by adjusting the outer diameter D of the pump casing... 2w Set to a diameter D smaller than that of the proximal tube. 1w This allows for a corresponding reduction in the minimum inner diameter of the guide sheath required for the blood pump. Consequently, a guide sheath with a smaller inner diameter than the traditional guide sheath can be used to assist in pushing the blood pump, thereby reducing the difficulty of pushing the guide sheath into the patient's body, and thus reducing the difficulty of blood pump intervention surgery and shortening the operation time. Attached Figure Description

[0023] Figure 1 A schematic diagram of an interventional guidewire inserted into a blood pump in one embodiment of the ventricular assist system provided in this application.

[0024] Figure 2 A schematic diagram of the drive unit, proximal tube, and impeller in one embodiment of the blood pump provided in this application.

[0025] Figure 3 for Figure 2 A cross-sectional view of the blood pump drive unit, proximal tube, and impeller along the AA direction.

[0026] Figure 4 for Figure 2 An exploded schematic diagram of the blood pump's drive unit, proximal tube, and impeller.

[0027] Figure 5 for Figure 2 The provided axonometric view of the proximal tubing of the blood pump and the distal end cap of the pump housing.

[0028] Figure 6 A partial longitudinal cross-sectional view of the interventional guidewire and blood pump passing through the guide sheath in one embodiment of the ventricular assist system provided in this application.

[0029] Figure 7 for Figure 2 A front view of the proximal tubing of the blood pump and the distal end cap of the pump housing.

[0030] Figure 8 for Figure 7 The provided cross-sectional view of the proximal pipe and the distal cover of the pump casing in the CC direction.

[0031] Figure 9 for Figure 8 Enlarged diagram at point D.

[0032] Figure 10 for Figure 5 Enlarged diagram at point B.

[0033] Figure 11 for Figure 2 A schematic diagram of the cross-section of the proximal tube of the blood pump is provided.

[0034] The labels in the attached diagram are explained as follows:

[0035] 1. Ventricular Assist System; 10. Blood Pump; 100. Cannulation Assembly; 110. Proximal Cannula; 110a. Central Axis; 110b. Proximal Opening; 110c. Distal Opening; 111. Cannula Body; 112. Connecting Post; 112a. Inner Surface; 112b. Outer Surface; 113. Reduced Diameter Section; 113a. Inner Reduced Diameter Surface; 113b. Outer Reduced Diameter Surface; 120. Cannula; 130. Distal Cannula; 101. First Connection; 102. Second Connection; 103. Wire Connection; 104. First Circle; 200. Drive Unit; 210 1. Pump casing; 210a. Outer peripheral wall; 210b. Distal end wall; 210c. Shaft sleeve mounting hole; 211. Housing; 212. Proximal end cover; 213. Distal end cover; 220. Rotary shaft; 221. Connecting end; 230. Rotor; 240. Stator; 250. First shaft sleeve; 250a. Groove; 260. Second shaft sleeve; 270. Fixed seat; 300. Impeller; 310. Hub; 320. Blade; 400. Guide tube; 20. Intervention guide wire; 20a. First part; 20b. Second part; 30. Guide sleeve; S. Rounded surface. Detailed Implementation

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] See Figure 1and Figure 6 This application provides a blood pump 10 and a ventricular assist system 1. The ventricular assist system 1 can be a left ventricular assist system or a right ventricular assist system. The ventricular assist system 1 includes an interventional guidewire 20, a guiding sheath 30, and the blood pump 10. The blood pump 10 can be inserted percutaneously into a patient's blood vessel as an interventional catheter pump to assist the patient's heart in achieving blood circulation. The interventional guidewire 20 and the guiding sheath 30 are used to assist the operator in pushing the blood pump 10 through the patient's blood vessel to the patient's target location (such as the heart). The guiding sheath 30 is generally tubular. The guiding sheath 30 has an inner lumen through which the interventional guidewire 20 and the blood pump 10 pass; wherein at least a portion of the interventional guidewire 20 passes between the outer surface of the blood pump 10 and the inner surface of the guiding sheath 30.

[0044] The structure of the blood pump 10 and its ventricular assist system 1 will be described in detail below.

[0045] like Figure 1 As shown, arrow Y+ indicates the direction of the blood pump 10 from proximal to distal; arrow Y- indicates the direction of the blood pump 10 from distal to proximal. The blood pump 10 includes a cannulation assembly 100 and an impeller 300. The cannulation assembly 100 has a distal opening 110c at its distal end and a proximal opening 110b at its proximal end; the cannulation assembly 100 has a blood flow channel inside, which connects the distal opening 110c and the proximal opening 110b. The impeller 300 is rotatably disposed within the cannulation assembly 100. The impeller 300 has a hub 310 and two to three blades 320 disposed on the hub 310. One of the proximal opening 110b and the distal opening 110c serves as a blood inlet, and the other as a blood outlet.

[0046] When the blood pump 10 is used as a left ventricular interventional pump, the proximal opening 110b is the blood outlet and the distal opening 110c is the blood inlet. The blood pump 10 is pushed into the left ventricle via the aorta, with the distal opening 110c of the blood pump 10 located within the left ventricle and the proximal opening 110b located within the aorta. Blood from the left ventricle flows from the distal opening 110c of the blood pump 10 into the blood passage within the cannulation assembly 100 and flows out from the proximal opening 110b into the aorta, thus assisting the left ventricle in pumping blood.

[0047] When the blood pump 10 is used as a right ventricular interventional pump, the proximal opening 110b is the blood inlet and the distal opening 110c is the blood outlet. The blood pump 10 is propelled through the right ventricle to the pulmonary artery, with the proximal opening 110b of the blood pump 10 located within the right ventricle and the distal opening 110c located within the pulmonary artery. Blood from the right ventricle flows from the proximal opening 110b of the blood pump 10 into the blood passage within the cannulation assembly 100 and flows out from the distal opening 110c into the pulmonary artery, thus assisting the right ventricular pumping function.

[0048] See Figure 1 The cannulation assembly 100 includes a proximal cannula 110 with a proximal opening 110b. The cannulation assembly 100 also includes a cannula 120, the proximal end of which is fixedly connected to the distal end of the proximal cannula 110. The lumen of the cannula 120 forms a blood flow channel. The cannulation assembly 100 also includes a distal cannula 130 with a distal opening 110c. The cannula 120 is a flexible tube, capable of bending and deforming to adapt to the shape of a blood vessel. In its natural state, the cannula 120 can be a straight tube or pre-shaped into a curved tube with a certain bending angle. The proximal cannula 110 and the distal cannula 130 are rigid tubes, such as metal tubes, with a stable shape and not easily deformed.

[0049] It is understood that the distal cannula 130 is not necessary. In other embodiments, the distal opening 110c can be directly formed at the distal end of the cannula 120.

[0050] See Figures 1 to 3 The blood pump 10 also includes a drive unit 200 connected to an impeller 300. The drive unit 200 drives the impeller 300 to rotate, thereby driving blood to flow through the blood flow channel. The drive unit 200 is fixed to the proximal end of the cannulation assembly 100 and can be inserted into the patient's blood vessel together with the cannulation assembly 100.

[0051] See Figures 2 to 4 The drive unit 200 includes a pump housing 210 and a rotating shaft 220. The pump housing 210 is connected to a proximal tube 110. The rotating shaft 220 is rotatably mounted on the pump housing 210 and extends out of the pump housing 210, having a connecting end 221 housed within the cannulation assembly 100. The connecting end 221 is fixedly connected to the impeller 300. Specifically, the connecting end 221 is fixedly connected to the hub 310 of the impeller 300. The proximal opening 110b of the proximal tube 110 is typically located adjacent to the distal end of the pump housing 210.

[0052] The drive unit 200 may further include a rotor 230 and a stator 240. The rotor 230 and stator 240 are housed in the pump casing 210 and are arranged axially at intervals. A rotating shaft 220 rotatably passes through the stator 240 and is fixedly connected to the rotor 230. The number of stators 240 can be one, two, or more; the number of rotors 230 can also be one, two, or more. When the stator 240 is operating, it generates a rotating magnetic field that causes at least one rotor 230 to rotate. Under this rotating magnetic field, the rotor 230 drives the rotating shaft 220 to rotate, and the impeller 300 also rotates accordingly.

[0053] Of course, the drive unit 200 may also exclude the rotor and stator. In other embodiments, the drive unit 200 may include a coupling and a flexible shaft (not shown); the coupling is housed within the pump housing 210; the proximal end of the flexible shaft is connected to an external motor, and the distal end of the flexible shaft is connected to the coupling, which connects to the proximal end of the rotating shaft 220. Thus, the external motor drives the flexible shaft to rotate, causing the flexible shaft to drive the rotating shaft 220 to rotate together via the coupling. The coupling may be a magnetic coupling or a conventional coupling. For example, the coupling is a magnetic coupling, specifically including a driving magnet and a driven magnet; the driving magnet and the flexible shaft are fixedly connected; the driven magnet is fixedly connected to the proximal end of the rotating shaft 220, and there is a mutual magnetic attraction between the driving magnet and the driven magnet.

[0054] See Figure 3 and Figure 4 The pump housing 210 may include a housing 211 and a distal end cap 213; the distal end cap 213 is connected to the distal end of the housing 211. A pivot 220 passes through the distal end cap 213, such that the pivot 220 has a connection end 221 received into the cannulation assembly 100. The pump housing 210 may also include a proximal end cap 212, which is connected to the proximal end of the housing 211. It is understood that either the proximal end cap 212 or the distal end cap 213 is not necessary. That is, the pump housing 210 may not have a proximal end cap 212; or, the pump housing 210 may not have a distal end cap 213.

[0055] See Figure 3 and Figure 4 The drive unit 200 may further include a first bushing 250 and a second bushing 260. The first bushing 250 is disposed at the near end of the pump housing 210, and the second bushing 260 is disposed at the far end of the pump housing 210. The first bushing 250 is used for rotatably mounting the rotating shaft 220, and the second bushing 260 is used for the rotating shaft 220 to pass through. Both the first bushing 250 and the second bushing 260 are used to support the rotating shaft 220 to ensure that the rotating shaft 220 rotates smoothly.

[0056] like Figure 3 As shown, the first bushing 250 has a groove 250a, and the proximal end of the rotating shaft 220 is rotatably installed in the groove 250a and abuts against the bottom of the groove 250a; the second bushing 260 has a shaft hole, and the rotating shaft 220 passes through the shaft hole of the second bushing 260. The shaft hole of the second bushing 260 and the groove 250a of the first bushing 250 are on the same central axis 110a.

[0057] To facilitate the installation of the first bushing 250, such as Figure 3As shown, the blood pump 10 may further include a mounting base 270, which is disposed within the proximal end cover 212. The mounting base 270 may be a fixing pin, and may be fixed to the proximal end of the housing 211 by means of threads, adhesive bonding, etc. The first bushing 250 may be disposed within the mounting base 270 by means of adhesive bonding, snap-fit ​​bonding, etc. In addition, the distal end of the pump housing 210, i.e., the distal end cover 213, has a bushing mounting hole 210c, and the second bushing 260 is installed in the bushing mounting hole 210c (see...). Figure 5 ).

[0058] See Figure 1 The blood pump 10 also includes a catheter 400, the distal end of which is connected to the proximal end of the drive unit 200. The inner lumen of the catheter 400 can receive cables such as flushing tubing, sensor optical fibers, and conductors of the stator 240. The outer diameter of the catheter 400 is typically smaller than the outer diameter of the cannulation assembly 100 and the drive unit 200.

[0059] See Figure 1 and Figure 6 When the blood pump 10 is inserted into the patient's body, the guiding sheath 30 is first inserted into the patient's blood vessel, or a suture graft anastomosed to the blood vessel is placed. Then, the interventional guidewire 20 is inserted into the guiding sheath 30 and pushed along the Y+ direction, so that the distal end of the interventional guidewire 20 is pushed along the blood vessel to the target location in the patient's body, such as the left ventricle of the heart. Next, the cannulation assembly 100 of the blood pump 10 is inserted onto the interventional guidewire 20. Specifically, the proximal end of the interventional guidewire 20 is inserted into the cannulation assembly 100 of the blood pump 10 through an opening at the distal end of the blood pump 10 (such as the distal opening 110c or the guidewire channel of the distal flexible support), and the blood pump 10 is pushed along the Y+ direction until the proximal end of the interventional guidewire 20 exits from the proximal opening 110b of the blood pump 10, thereby enabling the distal part of the blood pump 10 to be inserted onto the interventional guidewire 20. Following this, the blood pump 10 is advanced along the Y+ direction along the interventional guidewire 20 until the distal end of the blood pump 10 passes through the guide sheath 30 and reaches the target location inside the patient's body. Finally, the interventional guidewire 20 and the guide sheath 30 are withdrawn from the body.

[0060] Since the proximal opening 110b of the proximal cannula 110 is typically located near the distal end of the pump housing 210, during the insertion of the blood pump 10 into the patient's body, the portion of the interventional guidewire 20 that protrudes from the proximal opening 110b of the blood pump 10 will be housed between the outer surface of the drive unit 200 of the blood pump 10 and the inner surface of the guide sheath 30. That is, the interventional guidewire 20 has a connected first portion 20a and a second portion 20b; the first portion 20a passes through the cannula assembly 100 of the blood pump 10, and the second portion 20b, after protruding from the proximal opening 110b of the proximal cannula 110, passes between the outer surface of the drive unit 200 and the inner surface of the guide sheath 30. Therefore, the second portion 20b of the interventional guidewire 20 occupies a portion of the space inside the guide sheath 30.

[0061] In some traditional related technologies, the outer diameter of the proximal tube 110 and the outer diameter of the drive unit 200 are the same, both being D. 1w Therefore, the inner diameter D of the traditional guide sleeve h The minimum value (denoted as D) h1 At least a 20mm diameter guidewire (D) should be used. s The outer diameter D of the proximal tube 110 1w The sum of (i.e., the outer diameter of the drive unit 200) is D. h1 =D 1w +D s This ensures that the conventional guiding sheath can accommodate the blood pump 10 and the interventional guidewire 20. However, this results in a larger diameter conventional guiding sheath, making it more difficult to insert into blood vessels, and consequently increasing the difficulty of the blood pump 10 interventional procedure.

[0062] like Figure 6 As shown, in view of this, in order to solve the above problems, in some embodiments of this application, the proximal tube 110 of the cannulation assembly 100 has an outer diameter D. 1w The pump housing 210 of the drive unit 200 has an outer diameter D. 2w Shell outer diameter D 2w Set to be smaller than the outer diameter D of the pipe 1w D 2w <D 1w Among them, the outer diameter D of the pipe 1w The maximum outer diameter of the near-side tube 110; the outer diameter of the shell D. 2w This is the maximum outer diameter of the pump housing 210. At this point, the required inner diameter D of the guide sleeve 30 for the blood pump 10 is... h The minimum value (denoted as D) h2 The diameter D of the interventional guidewire 20 is changed. S The outer diameter D of the housing of the drive unit 200 2w The sum, which is D h2 =D S +D 2wBecause of D 2w <D 1w Therefore, D h2 <D h1 This means that a guide sheath 30 with a smaller inner diameter can be used to assist in pushing the blood pump 10.

[0063] Therefore, it can be seen that this application improves upon the outer diameter D of the pump casing 210. 2w The outer diameter D of the tube is set to be smaller than that of the proximal tube 110. 1w This allows for a corresponding reduction in the minimum inner diameter of the guide sheath 30 required for the blood pump 10. Consequently, a guide sheath 30 with a smaller inner diameter than the traditional guide sheath can be used to assist in pushing the blood pump 10, thereby reducing the difficulty of pushing the guide sheath 30 into the patient's body, and thus reducing the difficulty of the blood pump 10 interventional surgery and shortening the operation time.

[0064] The second part 20b of the interventional guidewire 20 has a guidewire diameter D s The guide sleeve 30 has an inner diameter D. h Through the above design, the inner diameter D of the sheath can be made... h With guide wire diameter D s The outer diameter D of the proximal tube 110 1w and the outer diameter D of the pump casing 210 2w The size relationship among the four reaches D. 2w +D S ≤D h <D 1w +D S This means that a guide sheath 30 with a smaller inner diameter than a traditional guide sheath can be used to assist in pushing the blood pump 10.

[0065] In some embodiments, the outer diameter D of the proximal tube 110 1w The size can be selected as 5.4mm≤D 1w ≤6.5mm, outer diameter D of the pipe 1w It can be, but is not limited to, 5.4mm, 5.5mm, 5.6mm, 5.7mm, 5.8mm, 6mm, 6.2mm, 6.5mm, etc. The outer diameter D of the pump casing 210... 2w Size can be selected as 5mm≤D 2w ≤6mm, shell outer diameter D 2w It can be, but is not limited to, 5.1mm, 5.3mm, 5.4mm, 5.5mm, 5.6mm, 5.7mm, 5.8mm, 5.9mm, etc.

[0066] In some other embodiments, the outer diameter D of the proximal tube 110 is... 1w The outer diameter D of the pump casing 210 2w The difference is denoted as △D, and △D = D 1w -D 2wThe size of △D can also be selected as 0.15mm≤△D≤0.4mm. The difference △D can be, but is not limited to, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.38mm, 0.39mm, etc.

[0067] Considering this, due to the outer diameter D of the pump casing 210 2w The outer diameter D of the tube is smaller than that of the proximal tube 110. 1w Since these two components have radial dimensional deviations, the proximal end of the proximal tube 110 needs to be made with a reduced diameter, that is, it needs to be recessed towards the central axis 110a of the proximal tube 110, so that it can be smoothly connected to the distal end cover 213 of the pump housing 210. Specifically, the proximal end of the proximal tube 110 is provided with a reduced diameter portion 113, which is deflected inward relative to the outer peripheral surface of the proximal tube 110 and connected to the pump housing 210. Here, the reduced diameter portion 113 is specifically connected to the distal end cover 213 of the pump housing 210.

[0068] In some embodiments, the proximal tube 110 includes a tube body 111 and a plurality of connecting posts 112. The plurality of connecting posts 112 are arranged circumferentially along the proximal end of the tube body 111, and a proximal opening 110b is formed between every two adjacent connecting posts 112. The proximal end of each connecting post 112 is provided with a reduced diameter portion 113, which is deflected relative to the outer peripheral surface of the proximal tube 110 and connected to the distal end cover 213 of the pump housing 210. The proximal opening 110b extends through the proximal end of the proximal tube 110 along the central axis 110a of the proximal tube 110 to facilitate the processing and production of the proximal tube 110. In addition, only the reduced diameter portion 113 at the proximal end of the connecting column 112 is deflected relative to the outer peripheral surface of the proximal tube 110. That is, the position of the connecting pump housing 210 in the connecting column 112 is reduced inward, which does not affect the inner diameter of the proximal tube 110, thereby keeping the blood flow channel size of the proximal tube 110 unchanged and ensuring the maximum blood flow.

[0069] Of course, in other embodiments, the reduced diameter portion 113 may also be a ring with a shorter axial length.

[0070] See Figure 5 , Figure 7 and Figure 8 The proximal tube 110 has a cylindrical body 111, with both its inner and outer surfaces being cylindrical. The connecting columns 112 are evenly distributed along the circumference of the body 111, thus ensuring that the proximal openings 110b are also evenly distributed along the circumference of the proximal tube 110. This guarantees that blood flows into or out of the proximal tube 110 evenly along its circumference.

[0071] The number of connecting posts 112 can be set to 2, 3, 4, 5, 6, 7, 8 or more. The inner surface of the connecting post 112 and the inner surface of the tube body 111 are on the same cylindrical surface. The outer surface of the connecting post 112 and the outer surface of the tube body 111 are also on the same cylindrical surface.

[0072] See also Figure 5 , Figure 7 and Figure 8 Considering that during the manufacturing of the blood pump 10, the impeller 300 is generally fixed to the shaft 220 of the drive unit 200, and then the proximal end of the proximal tube 110 is welded to the distal end cover 213 of the pump housing 210. However, welding at the reduced diameter section 113 of the proximal tube 110 is prone to dead angles, making welding inconvenient and resulting in poor fixing effect.

[0073] Based on this, in this embodiment, the distal end cap 213 of the pump housing 210 is integrally formed with the proximal tube 110, making the distal end cap 213 and the proximal tube 110 a single structure. That is, the reduced diameter portion 113 of the proximal tube 110 and the distal end cap 213 are a single structure. In other words, the distal end cap 213 and the proximal tube 110 are cast together in a mold as a single component, eliminating the need to cast the proximal tube 110 and the pump housing 210 as two separate components and then weld them together. In other words, the connection between the reduced diameter portion 113 and the distal end cap 213 does not require welding, avoiding machining dead angles and improving robustness.

[0074] During assembly, before connecting the insertion tube 120 to the proximal tube 110, the impeller 300 is first inserted into the proximal tube 110 from the far end opening and placed on the rotating shaft 220 to be fixedly connected to the rotating shaft 220.

[0075] In summary, the blood pump 10 provided in this application, by adjusting the outer diameter D of the pump housing 210... 2w The outer diameter D of the tube is set to be smaller than that of the proximal tube 110. 1w This allows for a corresponding reduction in the minimum inner diameter of the guide sheath 30 required for the blood pump 10. Consequently, a guide sheath 30 with a smaller inner diameter than traditional guide sheaths can be used to assist in pushing the blood pump 10, reducing the difficulty of pushing the guide sheath 30 into the patient's body, thereby reducing the difficulty of the blood pump 10 interventional procedure and shortening the operation time. Furthermore, based on the outer diameter D of the pump housing 210... 2w The outer diameter D of the proximal tube 110 1w The inconsistencies between the two components lead to machining dead angles at the welded joint. To address this, the connection method between the pump housing 210 and the proximal tube 110 is improved by integrally molding the distal end cap 213 of the pump housing 210 with the proximal tube 110. This eliminates the need for separate welding operations between the proximal tube 110 and the pump housing 210, avoiding machining dead angles and improving the robustness of the blood pump 10.

[0076] like Figure 5 As shown, the pump housing 210 has an outer peripheral wall 210a and a distal wall 210b located at the distal end of the outer peripheral wall 210a. The outer peripheral wall 210a is a cylindrical wall surface. At least a portion of the distal wall 210b is a flat wall surface perpendicular to the central axis of the proximal tube 110. Optionally, the connection between the distal wall 210b and the outer peripheral wall 210a is provided as a rounded surface S. The inner diameter reduction surface 113a of the diameter reduction portion 113 is connected to the rounded surface S of the distal wall 210b. In this way, sharp corners are less likely to form at the connection between the distal wall 210b and the outer peripheral wall 210a. When the interventional guidewire 20 passes through the proximal opening 110b, the curved portion of the interventional guidewire 20 contacts the rounded surface S of the distal wall 210b, making it less likely to scratch and wear the interventional guidewire 20.

[0077] See Figure 8 and Figure 9 The connecting column 112 has an inner surface 112a facing its central axis 110a and an outer surface 112b facing away from the inner surface 112a. The reduced diameter portion 113 has an outer reduced diameter surface 113b, which connects the outer surface 112b of the connecting column 112 and the outer peripheral wall 210a of the pump housing 210. The reduced diameter portion 113 also has an inner reduced diameter surface 113a, which connects the inner surface 112a of the connecting column 112 and the distal wall 210b of the pump housing 210.

[0078] See Figure 8 and Figure 9 For the outer diameter reduction surface 113b, it can be configured as a slope or an arc surface. Preferably, the outer diameter reduction surface 113b is configured as an arc surface so that it smoothly connects the outer surface 112b of the connecting column 112 and the outer peripheral wall 210a of the pump housing 210. This allows for a more uniform stress distribution at the connection between the outer diameter reduction surface 113b and the outer surface 112b of the connecting column 112 and the outer peripheral wall 210a of the pump housing 210, avoiding stress concentration and reducing the likelihood of fracture.

[0079] See Figure 8 and Figure 9 For the inner diameter reduction surface 113a, it can be configured as a slope or an arc surface. Preferably, the inner diameter reduction surface 113a is configured as an arc surface so that it smoothly connects the inner surface 112a of the connecting column 112 and the distal wall 210b of the pump housing 210. On the one hand, this makes the stress distribution at the connection between the inner diameter reduction surface 113a and the inner surface 112a of the connecting column 112 and the distal wall 210b of the pump housing 210 more uniform, avoiding stress concentration and reducing the occurrence of fracture. On the other hand, it avoids sharp edges at the connection between the inner diameter reduction surface 113a and the outer surface 112b of the connecting column 112 and the outer peripheral wall 210a of the pump housing 210, thereby reducing the probability of hemolysis.

[0080] Furthermore, the inner diameter reduction surface 113a is a circular arc surface, and the radius R of the circle containing the inner diameter reduction surface 113a is greater than the outer diameter D of the near-side pipe 110. 1w The outer diameter D of the pump casing 210 2w The difference is 0.5 times, that is, R > 0.5 × (D). 1w -D 2w This configuration allows the inner diameter reduction surface 113a to transition more smoothly to the distal end wall 210b of the pump casing 210, resulting in a smoother connection between the two.

[0081] See Figure 10 The inner diameter reduction surface 113a has a first width W1 along the circumference of the proximal tube 110, and the first width W1 gradually increases along the direction from the inner surface 112a of the connecting post 112 to the central axis 110a of the proximal tube 110. This increases the connection area between the reduced diameter portion 113 and the distal end cover 213 of the pump housing 210, and increases the connection strength between the proximal tube 110 of the pump housing and the distal end cover 213 of the pump housing 210. Optionally, the minimum value of the first width W1 of the inner diameter reduction surface 113a can be taken as the width W3 of the inner surface 112a of the connecting post 112 along the circumference of the proximal tube 110 (see...). Figure 8 ).

[0082] See Figure 7 The outer diameter reduction surface 113b has a second width W2 in the circumferential direction of the proximal tube 110, and the second width W2 gradually increases along the direction from the proximal tube 110 to the pump housing 210. This increases the connection area between the reduced diameter portion 113 and the distal end cover 213 of the pump housing 210, and increases the connection strength between the proximal tube 110 and the distal end cover 213 of the pump housing 210. Optionally, the minimum value of the second width W2 of the outer diameter reduction surface 113b is greater than the width W4 of the connecting post 112 in the circumferential direction along the outer surface 112b of the proximal tube 110 (see...). Figure 7 ).

[0083] See Figure 11 The inner diameter reduction surface 113a has a connecting line 103 that connects to the pump housing 210 and is closest to the central axis 110a of the proximal tube 110. Specifically, the connecting line 103 is located on the distal wall 210b of the pump housing 210; the distal wall 210b is located on the distal cover 213. The connecting lines 103 of the multiple inner diameter reduction surfaces 113a are all located on a first circle 104, the center of which is located on the central axis 110a. The proximal tube 110 has an inner diameter D. 1n The diameter φ of the first circle 104 is smaller than the inner diameter D of the proximal tube 110. 1n That is, φ < D 1nThis configuration increases the connection area between the reduced diameter section 113 and the distal end cover 213 of the pump housing 210, and also increases the connection strength between the proximal tube 110 and the distal end cover 213 of the pump housing 210.

[0084] Understandably, the smaller the diameter φ of the first circle 104, the closer the connecting line 103 of the inner diameter reduction surface 113a is to the central axis 110a of the proximal pipe 110, and the greater the contact area between the reduced diameter portion 113 and the distal wall 210b of the pump housing 210. However, if the diameter φ of the first circle 104 is too small, the inner diameter reduction surface 113a of the reduced diameter portion 113 may interfere with the rotating shaft 220. Therefore, this application limits the size of the bushing mounting hole 210c of the distal cover 213 of the pump housing 210. For example... Figure 8 As shown, the bushing mounting hole 210c penetrates the distal wall 210b of the pump housing 210. The diameter φ of the first circle 104 is larger than the hole diameter D4 of the bushing mounting hole 210c, i.e., φ > D4. This avoids interference between the reduced diameter part 113 and the rotating shaft 220, allows for the rotation of the rotating shaft 220, ensures the stable rotation of the impeller 300, guarantees the normal blood pumping of the blood pump 10, and facilitates the smooth passage of the distal end of the rotating shaft 220 through the bushing mounting hole 210c of the distal end cover 213, thus facilitating the assembly of the blood pump 10.

[0085] See Figure 8 and Figure 9 In some implementations, the inner diameter surface 113a has a first connection 101 connected to the inner surface of the connecting column 112. The first connection 101 is located on the distal side of the distal wall 210b of the pump housing 210, and there is an axial distance L between the first connection 101 and the distal wall 210b of the pump housing 210. The axial distance L is greater than 0 and less than or equal to 0.3 mm, i.e., 0 < L ≤ 0.3 mm. Thus, when blood is discharged outward from the proximal opening 110b, it is less likely to be blocked by the inner diameter surface 113a and flow backward, reducing the resistance to blood discharge from the proximal opening 110b and increasing the blood discharge velocity. The axial distance L can also be L ≤ 0.2 mm.

[0086] See Figure 8 and Figure 9In some embodiments, the outer diameter reduction surface 113b has a second connection 102 connected to the outer surface 112b of the connecting post 112, the second connection 102 being located near the inner diameter reduction surface 113a. In other words, the outer surface 112b of the connecting post 112 extends beyond the inner diameter reduction surface 113a in the direction from the distal end to the proximal end of the proximal tube 110. This allows the outer diameter reduction surface 113b to be further away from the inner diameter reduction surface 113a along the axial direction of the proximal tube 110 than the inner diameter reduction surface 113a. Thus, without increasing the outer diameter of the proximal tube 110, the radial thickness of the diameter reduction portion 113 along the proximal tube 110 can be increased, thereby increasing the strength of the diameter reduction portion 113 and increasing the connection strength between the proximal tube 110 and the pump housing 210.

[0087] In some embodiments of this application, the blood pump 10 may further include a flexible support (not shown in the drawings), which is fixedly connected to the distal end of the cannulation assembly 100. The flexible support can abut against the inner wall of tissue to position the distal end of the blood pump 10. The shape of the flexible support may be pigtail-shaped, spherical, arrow-shaped, or prismatic, etc. The flexible support has a guidewire channel inside, which allows an interventional guidewire to be inserted into the cannulation assembly 100 of the blood pump 10. It is understood that the flexible support is not essential.

[0088] 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.

[0089] 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 cannula assembly comprising a proximal tube provided with a proximal opening; an impeller rotatably arranged in the cannula assembly; and a drive unit comprising a pump housing and a rotating shaft; the pump housing is connected with the proximal tube; the rotating shaft is rotatably mounted on the pump housing, and the rotating shaft penetrates through the pump housing and has a connecting end accommodated in the cannula assembly, the connecting end being fixedly connected with the impeller; wherein the proximal tube has an outer tube diameter D 1w ; the pump housing has an outer housing diameter D 2w , and D 2w <D 1w .

2. The blood pump of claim 1, wherein, The blood pump further comprises at least one of the following features: The tube outer diameter D 1w is sized 5.4 mm ≤ D 1w ≤ 6.5 mm; The shell outer diameter D 2w is 5 mm ≤ D 2w ≤ 6 mm; The pipe outer diameter D 1w And the shell outer diameter D 2w The difference ΔD is 0.15mm≤ΔD≤0.4mm; The pump housing comprises a housing and a distal end cover connected to a distal end of the housing, and the distal end cover and the proximal tube are in an integral structure.

3. The blood pump of claim 1, wherein, The pump housing has an outer peripheral wall and a distal end wall; the proximal tube comprises a tube body and a plurality of connecting columns connected to a proximal end of the tube body, and the proximal tube is provided with the proximal opening between adjacent two connecting columns; the proximal end of the connecting column is provided with a reduced diameter portion, the reduced diameter portion has an outer reduced diameter surface, and the outer reduced diameter surface connects the outer surface of the connecting column and the outer peripheral wall; The reduced diameter portion further has an inner reduced diameter surface, and the inner reduced diameter surface connects the inner surface of the connecting column and the distal end wall.

4. The blood pump of claim 3, wherein, At least one of the outer reduced diameter surface and the inner reduced diameter surface is arranged as an inclined surface or an arc surface.

5. The blood pump of claim 4, wherein, The inner tapered surface is a circular arc surface, a circle where the inner tapered surface is located has a radius R, the radius R and an outer diameter D of the proximal tube satisfy R>0.5×(D 1w , an outer diameter D of the pump shell satisfies D 2w , and the three satisfy R>0.5×(D 1w -D 2w ).

6. The blood pump of claim 3, wherein, The inner reduced diameter surface has a first connection position connected with the inner surface of the connecting column, and the first connection position is located on the distal side of the distal end wall of the pump housing; the first connection position and the distal end wall of the pump housing have an axial distance L, and 0 < L ≤ 0.3 mm; And / or, the outer reduced diameter surface has a second connection position connected with the outer surface of the connecting column, and the second connection position is located on the proximal side of the inner reduced diameter surface.

7. The blood pump of claim 3, wherein, The proximal tube also has a tube inner diameter D 1n ; the inner tapered surface has an abutment line abutting the pump housing and being closest to the central axis of the proximal tube; the abutment lines of the plurality of inner tapered surfaces are all located on a first circle, the first circle having a center located on the central axis and having a diameter φ, and φ < D 1n .

8. The blood pump of any one of claims 3 to 7, characterized in that The blood pump further comprises at least one of the following features: The inner reduced diameter surface has a first width along the circumferential direction of the proximal tube, and the first width gradually increases along the direction from the inner surface of the connecting column to the central axis of the proximal tube; The outer reduced diameter surface has a second width along the circumferential direction of the proximal tube, and the second width gradually increases along the direction from the proximal tube to the pump housing; The connecting position of the distal end wall and the outer peripheral wall is provided with a rounded surface, and the inner reduced diameter surface is connected with the rounded surface.

9. The blood pump of any of claims 1 to 7, characterized in that The cannula assembly further comprises a cannula, and the distal end of the cannula is provided with a distal opening; the proximal end of the cannula is fixedly connected with the proximal tube; Alternatively, the cannula assembly further comprises a cannula and a distal tube; the proximal end of the cannula is fixedly connected with the proximal tube; the distal tube is fixedly connected with the distal end of the cannula, and the distal tube is provided with a distal opening.

10. A ventricular assist system, characterized by The ventricular assist system comprises an interventional guide wire, a guide sheath and the blood pump according to any one of claims 1 to 9; the interventional guide wire comprises a first portion and a second portion connected with each other; the first portion can be arranged in the cannula assembly of the blood pump; and the second portion can be arranged between the outer surface of the drive unit and the inner surface of the guide sheath. The second portion of the intervention guidewire has a guidewire diameter D S The guide sheath has a sheath inner diameter D h The sheath inner diameter D h is related to the outer diameter D 1w of the proximal tube, the outer diameter D 2w of the pump housing, and the guidewire diameter D S such that D 2w + D S ≤ D h < D 1w + D S .

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