An interventional fluid pumping device

Abstract

The application provides an interventional fluid pumping device, which comprises a body, a sheath and a sheath connecting unit; the distal end of the sheath connecting unit covers the proximal end of the body; a hollow inner cavity is formed in the sheath connecting unit, and the distal end of the sheath is arranged in the hollow inner cavity. The sheath connecting unit is arranged to connect the sheath and the body of the fluid pumping device, and the elements in the sheath connecting unit are isolated from blood, so that the elements and the adhesive material in the pumping system are prevented from being corroded by blood, and the problems of safety hidden danger and reduced connection strength caused by corrosion are solved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to an interventional fluid pumping device. Background Technology

[0002] In existing technologies, when a patient's heart function weakens and its pumping capacity is insufficient, a ventricular assist device (VAD) is often needed to assist the heart in pumping blood. This device pumps blood out of the heart and directs it to the aorta outside the heart, where it flows throughout the body. A VAD mainly consists of a catheter and a blood pumping device. The blood pumping device is located at the distal end of the catheter (the end furthest from the operator or physician). The catheter is inserted through the femoral, axillary, or carotid artery. The blood pumping device passes through the aorta, with its suction channel across the valve inserted into the left ventricle of the patient's heart, and its outflow channel located in the aorta. The impeller of the blood pumping device rotates, pumping blood from the left ventricle through the suction channel to the aorta. Alternatively, the blood pumping device can be inserted into the right ventricle of the patient's heart via a catheter through a vein such as the femoral vein, pumping blood from the right ventricle to the pulmonary artery. In existing technologies, the sheath assembly and the blood pumping device are only fixedly connected using methods such as injection molding or adhesive bonding. The injection molding and adhesive materials are exposed to the environment over a large area. For example, during intervention, blood comes into direct contact with the injection molding or adhesive materials over a large area. The weak alkalinity of the blood will gradually corrode the injection molding or adhesive materials, causing the connection strength of the sheath assembly to decrease, or even causing safety hazards such as disconnection, resulting in low equipment reliability. Summary of the Invention

[0003] In order to overcome at least one of the many problems in the related art, the present invention provides an interventional fluid pumping device.

[0004] The interventional fluid pumping device includes a body, a sheath, and a sheath connection unit.

[0005] The distal end of the sheath connecting unit covers the proximal end of the body, and the sheath connecting unit is coaxially arranged with the body;

[0006] The sheath connecting unit has a hollow inner cavity, and the distal end of the sheath is located inside the hollow inner cavity.

[0007] In one optional embodiment, the body includes a housing, and the distal end face of the sheath connecting unit is fixedly connected to the proximal end face of the housing; or,

[0008] The main body includes a housing and a proximal bearing seat, the proximal bearing seat being located at the proximal end of the housing, and the sheath connecting unit being fixedly sleeved on the outer peripheral wall of the proximal bearing seat; or,

[0009] The main body includes a housing and a proximal bearing seat. The proximal bearing seat is located at the proximal end of the housing. The distal end face of the sheath connecting unit is fixedly connected to the proximal end face of the housing, and the sheath connecting unit is fixedly sleeved on the outer peripheral wall of the proximal bearing seat.

[0010] In one optional embodiment, the sheath connection unit includes a distal first stepped hole;

[0011] The outer casing includes a proximal first step;

[0012] The distal first step hole is sleeved on the proximal first step; or, the distal first step hole is sleeved on the outer peripheral wall of the proximal bearing seat.

[0013] In one optional embodiment, the sheath connecting unit is provided with a proximal first stepped hole and a proximal second stepped hole, wherein the proximal second stepped hole is closer to the body than the proximal first stepped hole;

[0014] The inner diameter of the second proximal step hole is smaller than the inner diameter of the first proximal step hole.

[0015] In one optional embodiment, the distal end of the sheath is nested within the proximal first stepped hole and the proximal second stepped hole, with the proximal first stepped hole having a clearance fit with the distal end of the sheath.

[0016] In one optional embodiment, a proximal third step hole is further provided between the distal first step hole and the proximal second step hole, and the proximal third step hole and the distal first step hole are connected by a conical shell.

[0017] In one optional embodiment, a filling unit is provided in the hollow inner cavity to fix the distal end of the sheath.

[0018] In one optional embodiment, a filling unit is provided in the gap between the proximal first step hole and the distal end of the sheath.

[0019] In one optional embodiment, the roughness of the outer wall surface of the sheath connecting unit is less than the roughness of the inner wall surface.

[0020] In one optional embodiment, the sheath connecting unit and the housing, and / or the sheath connecting unit and the proximal bearing housing, are connected by welding or thermal fusion.

[0021] In one optional embodiment, the sheath connecting unit is provided with at least one notch penetrating its outer peripheral wall.

[0022] The technical solution of the present invention has the following advantages or beneficial effects:

[0023] (1) This invention connects the sheath and the body of the fluid pumping device by setting an independent sheath connection unit. The sheath connection unit covers the proximal end of the body and the distal end of the sheath, thereby isolating the components inside the sheath connection unit from the blood. The sheath connection unit is corrosion-resistant, which can avoid the safety hazards caused by blood corroding the components and adhesive materials in the pumping system, and effectively solves the various problems caused by the injection molding or adhesive bonding methods used in the prior art to connect the sheath and the blood pumping device.

[0024] (2) In this invention, the sheath connecting unit is fixedly connected to the outer shell, or the sheath connecting unit is fixedly connected to the proximal bearing seat, or the sheath connecting unit is fixedly connected to both the outer shell and the proximal bearing seat. All of these connection methods effectively prevent or reduce blood from entering the hollow inner cavity of the sheath connecting unit, thereby avoiding or slowing down blood corrosion of the connection between the sheath and the sheath connecting unit, ensuring the safety and reliability of the device. Preferably, when the sheath connecting unit is simultaneously connected to both the outer shell and the proximal bearing seat, its contact surface has a bent shape to form a labyrinth seal structure, making it difficult for blood to enter the hollow inner cavity of the sheath connecting unit through this seal structure; that is, this assembly method has a better sealing effect.

[0025] (3) The inner diameter of the second proximal step hole of the present invention is smaller than the inner diameter of the first proximal step hole. The second proximal step hole can constrain the radial displacement of the sheath, thereby making the gap between the outer wall of the sheath and the first proximal step hole more uniform. The more uniform the gap, the easier it is to fill it with injection molding material or adhesive material, and the more uniform the distribution of the material is, thereby ensuring that the connection strength at all points on the outer wall of the sheath is basically equal, and ensuring the stability of the connection.

[0026] (4) In this invention, the proximal end of the main body is covered by a sheath connecting unit, and a filling material is placed in the gap between the first stepped hole at the proximal end and the distal end of the sheath. This fully utilizes the sheath connecting unit to prevent blood from entering the hollow inner cavity of the sheath connecting unit, avoiding corrosion of the filling material and eliminating the problem of reduced sheath connection strength. Furthermore, the filling material can effectively fix the proximal end of the sheath to the inner wall of the sheath connecting unit.

[0027] (5) The outer wall surface of the sheath connection unit of the present invention has low roughness, which allows blood to pass smoothly through the outer wall surface of the sheath connection unit, reducing the blood residence time at this point and lowering the incidence of thrombosis. In addition, the low surface roughness facilitates the removal of the fluid pumping device from the human body. At the same time, the inner wall surface of the sheath connection unit has a large surface roughness, which can increase the adhesion area of ​​the filling material and improve the connection strength between the sheath and the sheath connection unit. Attached Figure Description

[0028] The accompanying drawings are provided to better understand the invention and are not intended to unduly limit the scope of the invention. Wherein:

[0029] Figure 1 This is a cross-sectional schematic diagram of an interventional fluid pumping device according to an embodiment of the present invention;

[0030] Figure 2 This is a perspective view of an interventional fluid pumping device according to an embodiment of the present invention;

[0031] Figure 3 This is a partial perspective view of the proximal end of the interventional fluid pumping device according to an embodiment of the present invention;

[0032] Figure 4 This is a cross-sectional schematic diagram of a sheath connection unit according to an embodiment of the present invention;

[0033] Figure 5 This is a perspective view of a sheath connection unit according to an embodiment of the present invention;

[0034] Figure 6 This is a schematic diagram of sheath connection in the prior art. Detailed Implementation

[0035] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of the present invention, including various details to aid understanding. These details should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the invention. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0036] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0037] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0038] In existing technologies, blood pumping devices operate within a patient's body to assist blood flow to corresponding organs. In some blood pumping devices, as blood is pumped from distal to proximal, blood correspondingly enters the device from distal to proximal. Therefore, the device needs to inject perfusion fluid from both proximal and distal directions and discharge at least a portion of this perfusion fluid into the bloodstream. However, in some blood pumping devices, the perfusion fluid, such as glucose, injected into the device passes through the components and is entirely discharged into the body, causing discomfort to the patient. In particular, the entry of perfusion waste fluid containing abrasive particles into the body can lead to serious risks such as thrombosis. Furthermore, during operation, the friction pairs of bearings and other components generate significant heat, resulting in localized high temperatures. In practice, it is necessary to circulate the perfusion fluid to flush away the abrasive particles, heat, and thrombi from the pump motor. To achieve perfusion fluid circulation, perfusion and drainage pipes need to be installed in the blood pumping system. The infusion tube and drainage tube are housed within the sheath to form a sheath assembly. After the sheath assembly is connected to the proximal end of the blood pumping device, the infusion tube and drainage tube are respectively connected to corresponding pipelines within the blood pumping device. In existing technologies, the sheath assembly and the blood pumping device are fixedly connected only through encapsulation methods such as injection molding or adhesive bonding. The injection molding and adhesive materials are largely exposed to the environment; for example, during interventional procedures, blood comes into direct contact with a large area of ​​the encapsulation material. Figure 6 In the prior art shown, injection-molded or adhesive material 52 is disposed between the sheath and the blood pumping device to connect the two. This injection-molded or adhesive material 52 is extensively exposed to the environment, especially during intervention, where it comes into extensive contact with blood. The weak alkalinity of blood gradually corrodes the injection-molded or adhesive material, reducing the connection strength of the sheath assembly and even posing a risk of separation between the sheath and the blood pumping device, thus leading to low device reliability. Furthermore, during the gradual corrosion of the injection-molded or adhesive material 52, it is slowly released into the bloodstream, posing a safety hazard to the human body.

[0039] To address at least one of the aforementioned problems, the present invention provides an interventional fluid pumping device. The interventional fluid pumping device includes a body, a sheath, and a sheath connecting unit; the distal end of the sheath connecting unit covers the proximal end of the body, and the sheath connecting unit is coaxially arranged with the body; the sheath connecting unit has a hollow inner cavity, and the distal end of the sheath is located inside the hollow inner cavity.

[0040] like Figure 1In the illustrated embodiment, the fluid pumping device mainly comprises three parts: a body, a sheath 113, and a sheath connecting unit 116. The body includes a housing 108, and multiple components such as a magnet 103 and a winding 104 disposed inside the housing 108. In the above embodiment, the housing 108 is an independent part and can be individually processed before being assembled with components such as the magnet 103 and the winding 104. In other embodiments, to reduce the diameter of the fluid pumping device and improve its interventional performance, the stator core is used as the housing of the fluid pumping device; and in the interventional state, the outer wall surface of the stator core is in direct contact with blood or tissue. A rotating shaft 105 passes through the inside of the magnet 103. An impeller 101 is disposed at the distal end of the rotating shaft 105, and the impeller is disposed inside the blood channel 102. Driven by an electric current, the rotating shaft 105 drives the impeller 101 to rotate, thereby drawing blood from the distal end into the blood channel 102 and pumping the blood out through the outlet 201 on the outer wall of the blood channel 102. The distal end of the outer casing 108 is also provided with a distal bearing seat 109 and a distal bearing 106. The distal bearing 106 is assembled inside the distal bearing seat 109 and serves to pass through and support the rotating shaft 105. The distal bearing seat 109 is fixed to the distal end of the outer casing 108. A distal cap 107 is also provided between the blood channel 102 and the distal bearing seat 109, and the distal cap 107 is fitted onto the distal end of the outer casing 108. The proximal end of the outer casing 108 is also provided with a proximal bearing seat 111 and a proximal bearing 110. The proximal bearing 110 is mounted on the proximal bearing housing 111 and serves to pass through and support the rotating shaft 105. The proximal bearing housing 111 is mounted on the proximal end of the housing 108. A proximal end cap 112 is also provided on the body to close the proximal end of the body. In some embodiments, the proximal end cap 112 is embedded inside the proximal bearing housing 111.

[0041] like Figure 1In the illustrated embodiment, the distal end of the sheath connecting unit 116 covers the proximal end of the main body, and the sheath connecting unit 116 is coaxially arranged with the main body. The sheath connecting unit 116 has a hollow inner cavity, and the distal end of the sheath 113 is fixedly disposed inside the hollow inner cavity. The sheath connecting unit 116 is an independent solid component, which can be fitted onto the proximal end of the main body after the main body is assembled to achieve coverage of the proximal end. The sheath connecting unit 116 can be made of biocompatible metallic or non-metallic materials. Preferably, it is made of SUS316L series material. When using metallic materials such as SUS316L, the sheath connecting unit with a preset structural shape and size can be obtained through machining; when using non-metallic materials, the sheath connecting unit with a preset structural shape and size can be obtained through injection molding or additive manufacturing. In some embodiments, the sheath also has an infusion tube 114 and a drainage tube 115 inside. The sheath assembly comprises a sheath 113, an infusion tube 114, and a drainage tube 115. When the sheath assembly is connected to the main body, the infusion tube 114 and the drainage tube 115 are respectively connected to the corresponding infusion fluid flow channels within the main body, thereby allowing the infusion fluid to enter the main body from the infusion tube 114 and the waste infusion fluid to be discharged from the main body to the drainage tube 115. Regardless of whether the sheath connection unit is made of metallic or non-metallic materials, a hollow inner cavity needs to be further provided inside the sheath connection unit to fix the distal end of the sheath 113. As can be seen from the above description, this invention connects the sheath and the main body of the fluid pumping device by setting an independent sheath connection unit. The sheath connection unit covers the proximal end of the main body and the distal end of the sheath, thereby isolating the components inside the sheath connection unit from the blood. The sheath connection unit is corrosion resistant, which can avoid safety hazards caused by blood corrosion of components and adhesive materials in the pumping system. It effectively solves the various problems caused by the injection molding or adhesive bonding methods used in the prior art to connect the sheath and the blood pumping device.

[0042] In one optional embodiment, the body includes a housing 108, and the distal end face of the sheath connecting unit 116 is fixedly connected to the proximal end face of the housing; or, the body includes a housing 108 and a proximal bearing seat 111, the proximal bearing seat 111 being disposed at the proximal end of the housing 108, and the sheath connecting unit 116 being fixedly sleeved on the outer peripheral wall of the proximal bearing seat 111; or, the body includes a housing 108 and a proximal bearing seat 111, the proximal bearing seat 111 being disposed at the proximal end of the housing 108, the distal end face of the sheath connecting unit 116 being fixedly connected to the proximal end face of the housing 108, and the sheath connecting unit 116 being fixedly sleeved on the outer peripheral wall of the proximal bearing seat 111. Figure 3 and4 In the illustrated embodiment, the proximal end of the housing 108 includes an end face 301, and the distal end of the sheath connecting unit includes a distal end face 407. When the sheath connecting unit covers the proximal end of the body, the end face 301 and the distal end face 407 are fitted together, and the sheath connecting unit 116 can be connected to the housing 108 by means such as welding or thermal fusion. Preferably, a stepped structure can be provided at the proximal end of the housing 108 to facilitate the fitting and fixing of the sheath connecting unit. In some embodiments, the body includes the housing 108 and a proximal bearing seat 111, the inner diameter of the proximal end of the housing 108 is adapted to the outer diameter of the proximal end bearing seat 111, and the proximal end bearing seat 111 is embedded in the inner diameter of the proximal end of the housing 108. Exemplarily, the proximal end bearing seat 111 and the housing 108 can be connected by welding, threaded connection, or thermal fusion connection, etc. Of course, the proximal end bearing seat 111 can also be connected to the proximal end of the housing 108 by other assembly methods. The sheath connecting unit 116 is fixedly sleeved on the outer peripheral wall 302 of the proximal bearing seat 111. For example... Figure 1 and 3 As shown, a portion of the proximal bearing housing 111 is disposed within the inner hole of the proximal end of the housing 108, while the other portion protrudes from the inner hole of the housing 108, thus forming a stepped structure between the proximal and outer ends of the housing 108. Correspondingly, a distal first stepped hole 402 is formed at the left end of the sheath connecting unit. The inner wall of the distal first stepped hole 402 mates with the outer peripheral wall 302 of the proximal bearing housing 111 to assemble the sheath connecting unit onto the proximal end of the body. The sheath connecting unit and the proximal bearing housing 111 can be fixed by methods such as welding, thermal fusion, or threaded connection. In other embodiments, the body includes a housing 108 and a proximal bearing seat 111. The proximal bearing seat 111 is located at the proximal end of the housing 108 and partially exposes the inner hole of the housing 108, forming a stepped structure with the housing 108. The distal end face of the sheath connecting unit 116 is fixedly connected to the proximal end face 301 of the housing 108, and the sheath connecting unit 116 is fixedly sleeved on the outer peripheral wall 302 of the proximal bearing seat 111. Compared with the previous two embodiments, in this embodiment, the sheath connecting unit is connected to both the housing 108 and the proximal bearing seat 111. The connection surface can be fixed by welding, heat fusion, or threaded connection. This connection method has a larger contact area, thereby effectively improving the assembly strength of the sheath connecting unit. More advantageously, when the sheath connecting unit is connected to both the housing and the proximal bearing seat, its contact surface has a bent shape (see...). Figure 1The mid-section view shows the seam between the proximal end of the main body and the sheath connecting unit, forming a labyrinth seal structure that prevents blood from entering the hollow cavity of the sheath connecting unit through the bent seam of the mating surface. Furthermore, regardless of whether the sheath connecting unit is fixedly connected to the outer shell, the proximal bearing seat, or both, the mating surfaces effectively prevent or reduce blood from entering the hollow cavity of the sheath connecting unit, thereby avoiding or slowing down blood corrosion of the connection between the sheath and the sheath connecting unit, ensuring the safety and reliability of the device.

[0043] In one optional embodiment, the sheath connecting unit includes a distal first stepped hole 402; the outer shell includes a proximal first step (not shown in the figure); the distal first stepped hole 402 is fitted onto the proximal first step; or, the distal first stepped hole is fitted onto the outer peripheral wall 302 of the proximal bearing seat. In some embodiments, the outer shell 108 is often made of a corrosion-resistant material. In this case, it is preferable to fix the sheath connecting unit onto the outer shell 108, thereby effectively utilizing the corrosion resistance of the outer shell to prevent blood from corroding the pumping device body and preventing it from entering the interior of the sheath connecting unit. To this end, a stepped structure can be machined on the outer shell 108, and the interior of the distal first stepped hole 402 of the sheath connecting unit is fitted and fixed with the outer peripheral wall of the stepped structure. At the same time, the distal end face 407 of the sheath connecting unit is fitted and fixed with the radially extending end face of the stepped structure of the outer shell. Similar to the sealing principle described above, the stepped structure on the outer shell creates two mating connection surfaces. These two surfaces form a bent labyrinth seal structure, effectively preventing blood from entering the mating surfaces and preventing blood from corroding the internal assembly structure of the sheath connection unit, thus ensuring connection stability. In some embodiments, the proximal inner hole of the sheath connection unit is further provided with a chamfer or fillet 401, facilitating the fitting of the sheath connection unit onto the body.

[0044] In one optional embodiment, the sheath connecting unit is provided with a proximal first stepped hole 405 and a proximal second stepped hole 404, wherein the proximal second stepped hole is closer to the body than the proximal first stepped hole; the inner diameter of the proximal second stepped hole 404 is smaller than the inner diameter of the proximal first stepped hole 405. Figure 1In the illustrated embodiment, in the assembled state, the sheath is fitted within the proximal first stepped hole and the proximal second stepped hole. In an optional embodiment, when the distal end of the sheath is nested within the proximal first stepped hole and the proximal second stepped hole, the proximal first stepped hole and the distal end of the sheath have a clearance fit. Preferably, the diameter of the proximal first stepped hole is 0.05-0.3 mm larger than the outer diameter of the sheath. Compared to a method where the sheath connecting unit does not have a second stepped hole, in this embodiment, because the inner diameter of the proximal second stepped hole is smaller, it can constrain the radial displacement of the sheath, thereby making the gap between the outer wall of the sheath and the proximal first stepped hole more uniform, that is, the distance between the outer wall of the sheath and the proximal first stepped hole is substantially equal. In some embodiments, the more uniform the gap, the easier it is to fill it with injection molding material or adhesive material, and the more uniform the distribution of the material, thereby ensuring that the connection strength at all points on the outer wall of the sheath is substantially equal, ensuring the stability of the connection.

[0045] In an optional embodiment, a proximal third step hole 406 is further provided between the distal first step hole 402 and the proximal second step hole 404, and the proximal third step hole is connected to the distal first step hole by a conical shell 403. Preferably, the diameter of the proximal third step hole 406 is 0.05-0.3 mm larger than the outer diameter of the sheath. Figure 1 and 4 In the illustrated embodiment, the proximal dimension of the sheath connecting unit needs to match the outer diameter of the sheath, while the distal dimension needs to match the proximal dimension of the body, so that the overall sheath connecting unit presents as shown in the figure. Figure 4 The aforementioned left-large, right-small structure. To ensure the pumping system has a streamlined overall shape for easy instrument intervention and withdrawal from the body, in one embodiment of the invention, a conical housing 403 is provided between the proximal third-step hole and the distal first-step hole to achieve a dimensional transition. This results in the pumping device having a streamlined shape at the distal end of the sheath.

[0046] In one optional embodiment, a filling unit is provided in the hollow inner cavity to fix the distal end of the sheath. In another optional embodiment, a filling unit is provided in the gap between the proximal first stepped hole and the distal end of the sheath. Figure 1 In the illustrated embodiment, filling units 117 may be provided at various locations within the hollow cavity of the sheath connecting unit. Exemplarily, the filling units may be adhesive materials, etc. For example, see adhesive. Figure 1As shown, the adhesive fills the cavity formed by the sheath connection unit and the proximal cap 112, thereby fixing components such as the sheath, infusion tube, and drainage tube to the proximal end of the body. In particular, when the adhesive fills the gap between the proximal first step hole and the distal end of the sheath, it effectively fixes the proximal end of the sheath to the inner wall of the sheath connection unit. As described above, when the proximal end of the body is covered by the sheath connection unit, blood is isolated from the outside of the hollow cavity of the sheath connection unit, meaning blood cannot enter the hollow cavity. Therefore, there is no need to worry about blood entering the hollow cavity and corroding the adhesive material, thus achieving a stable connection at the distal end of the sheath and ensuring good safety and reliability of the fluid pumping device.

[0047] In one optional embodiment, the roughness of the outer wall surface of the sheath connection unit is less than that of the inner wall surface. In some embodiments, the roughness of the outer wall surface is as small as possible, preferably Ra0.8 or less, thereby allowing blood to pass smoothly through the outer wall surface of the sheath connection unit, reducing the blood's residence time there, and thus reducing the incidence of thrombosis. Furthermore, lower surface roughness facilitates the removal of the fluid pumping device from the body. In some embodiments, an anticoagulant and / or lubricating and / or antibacterial coating may be provided on the outer wall surface. In some embodiments, the surface roughness of the inner wall surface is as large as possible, preferably Ra3.2 or greater, and may be roughened if necessary. A larger surface roughness increases the adhesion area of ​​the filler material, improving the connection strength between the sheath and the sheath connection unit.

[0048] In one optional embodiment, the sheath connecting unit and the outer casing, and / or the sheath connecting unit and the proximal bearing housing, are connected by welding or thermal fusion. In some embodiments, when the sheath connecting unit is made of a non-metallic material, it can be connected to the corresponding component by thermal fusion. When it is made of a metallic material, it can be connected by welding.

[0049] In one optional embodiment, the sheath connecting unit is provided with at least one notch 501 penetrating its outer peripheral wall. For example... Figure 4 In the illustrated embodiment, the left flared end of the sheath connection unit has at least one notch to allow passage of the infusion tube or other pipelines.

[0050] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art, after considering the specification and practicing the technical solutions disclosed in this application, will readily conceive of other embodiments of this disclosure. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary technical means in the art not disclosed in this disclosure. The specification and embodiments are considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0051] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. An interventional fluid pumping device, characterized in that: Includes the main body, sheath, and sheath connecting unit; The distal end of the sheath connecting unit covers the proximal end of the main body, isolating the internal components of the sheath connecting unit from the external environment. The sheath connecting unit is coaxially arranged with the main body. The sheath connecting unit has a hollow inner cavity, and the distal end of the sheath is located inside the hollow inner cavity. The sheath connecting unit is provided with a proximal first stepped hole and a proximal second stepped hole; The inner diameter of the second proximal step hole is smaller than the inner diameter of the first proximal step hole; the second proximal step hole constrains the radial displacement of the sheath.

2. The interventional fluid pumping device according to claim 1, characterized in that, The body includes a shell, and the distal end face of the sheath connecting unit is fixedly connected to the proximal end face of the shell; or, the body includes a shell and a proximal bearing seat, the proximal bearing seat is disposed at the proximal end of the shell, and the sheath connecting unit is fixedly sleeved on the outer peripheral wall of the proximal bearing seat; or, the body includes a shell and a proximal bearing seat, the proximal bearing seat is disposed at the proximal end of the shell, the distal end face of the sheath connecting unit is fixedly connected to the proximal end face of the shell, and the sheath connecting unit is fixedly sleeved on the outer peripheral wall of the proximal bearing seat.

3. The interventional fluid pumping device according to claim 2, characterized in that, The sheath connection unit includes a distal first stepped hole; The outer casing includes a proximal first step; The distal first step hole is sleeved on the proximal first step; or, the distal first step hole is sleeved on the outer peripheral wall of the proximal bearing seat.

4. The interventional fluid pumping device according to claim 3, characterized in that, The second proximal step hole is closer to the body than the first proximal step hole.

5. The interventional fluid pumping device according to claim 4, characterized in that, The distal end of the sheath is nested within the proximal first stepped hole and the proximal second stepped hole, with the proximal first stepped hole having a clearance fit with the distal end of the sheath.

6. The interventional fluid pumping device according to claim 5, characterized in that, A third proximal step hole is provided between the distal first step hole and the proximal second step hole, and the proximal third step hole is connected to the distal first step hole by a conical shell.

7. The interventional fluid pumping device according to any one of claims 1-6, characterized in that, The hollow inner cavity is provided with a filling unit to fix the distal end of the sheath.

8. The interventional fluid pumping device according to claim 7, characterized in that, A filling unit is provided in the gap between the proximal first step hole and the distal end of the sheath.

9. The interventional fluid pumping device according to any one of claims 1-6, characterized in that, The roughness of the outer wall surface of the sheath connecting unit is less than the roughness of the inner wall surface.

10. The interventional fluid pumping device according to any one of claims 1-6, characterized in that, The sheath connecting unit and the outer shell, and / or the sheath connecting unit and the proximal bearing seat, are connected by welding or thermal fusion.

11. The interventional fluid pumping device according to any one of claims 1-6, characterized in that, The sheath connecting unit is provided with at least one notch that penetrates its outer peripheral wall.

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