Catheter and flow-blocking catheter

Abstract

The present invention provides a catheter, which comprises: a tubular element and a functional element; the tubular element includes an outer tube and an inner tube; the outer tube is sleeved outside the inner tube, a first cavity is formed between the outer tube and the inner tube, the outer tube includes an outer tube body and a first recess, and the first recess is located at the distal end of the outer tube body; the functional element is arranged on the tubular element, and at least part of the functional element is connected to the first recess. With such a setting, the compatibility and positioning ability of the catheter with the functional element can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, and in particular to a catheter and a flow-blocking catheter. Background Art

[0002] Stroke, mainly caused by blood clots in cerebral blood vessels, is a common disease that seriously threatens human health. It is the third leading cause of death in the world today and the leading cause of long-term disability in adults. At present, the treatment methods of direct thrombus aspiration with a suction catheter or stent-assisted thrombectomy are usually used in clinical practice to remove thrombi and achieve vascular recanalization. After the suction catheter reaches the thrombus location along the blood vessel, negative pressure is applied at the proximal end to suck the thrombus into the tube or adsorb it at the tube mouth and slowly drag it into the guide catheter, so that the blood vessel regains blood flow power; the stent thrombectomy device needs to cross the thrombus location, capture the thrombus with the stent mesh, and withdraw it into the support catheter to recanalize the blood vessel. After the stent is withdrawn into the support catheter, the support catheter, together with the stent and the captured thrombus, withdraws into the guide catheter. However, during the thrombus removal process, due to the impact of proximal blood flow, thrombi often fall off and flow to the distal blood vessels, or after successfully capturing the thrombus, in the process of operating the aspiration catheter or the thrombectomy stent to input the interventional treatment device (guide catheter or support catheter), broken thrombi flow to the distal end of the blood vessel to form a secondary occlusion, causing the operation to fail, and in severe cases, threatening the patient's life. For example, the myocardial necrosis rate caused by percutaneous coronary intervention (PCI) is as high as 16%-39%. The reason for this is mostly due to the escape of thrombi from the distal blood vessels during the interventional operation. In order to solve the problem caused by thrombus rupture during interventional treatment, the prior art usually uses a balloon guide catheter to temporarily block blood flow to assist in thrombectomy.

[0003] Usually during surgery, after the balloon guide catheter assists the thrombectomy device to reach the target location, contrast fluid is injected to allow the balloon to expand, adhere to the blood vessel wall, and temporarily block the blood flow; and after the thrombus is removed or drawn out of the blood vessel, the balloon is contracted and the balloon guide catheter is withdrawn to bring the thrombus out of the human body to achieve the effect of blood flow reconstruction. The balloon, as a functional element, is attached to the catheter, which often affects the overall compatibility and positioning of the catheter. In addition to balloon guide catheters, some catheters with functional elements such as flow blocking elements, electronic elements, imaging elements, and thrombectomy elements also have the problem that the functional elements affect the overall compatibility and positioning of the catheter.

[0004] At present, the catheter with functional elements in the prior art has the problems of poor compatibility and low positioning capability. Summary of the invention

[0005] The object of the present invention is to provide a catheter to solve the problems of poor compatibility and low positioning ability in existing catheters.

[0006] To solve the above technical problems, the present invention provides a catheter, which includes: a tubular element and a functional element;

[0007] The tubular element includes an outer tube and an inner tube;

[0008] The outer tube is sleeved outside the inner tube, a first cavity is formed between the outer tube and the inner tube, the outer tube includes an outer tube body and a first recess, and the first recess is located at the distal end of the outer tube body;

[0009] The functional element is arranged on the tubular element, and at least part of the functional element is connected to the first recess.

[0010] Preferably, the functional element is at least one of a flow blocking element, a visualization element, an electronic element, and an embolus removal element.

[0011] Preferably, the outer surface of the outer tube is recessed inward to form the first recess.

[0012] Preferably, the inner diameter of the first recess is less than or equal to the inner diameter of the outer tube body.

[0013] Preferably, the inner surface of the outer tube is recessed outward to form the first recess.

[0014] Preferably, the outer diameter of the first recess is less than or equal to the outer diameter of the outer tube body.

[0015] Preferably, the axial length of the first recess is 2-30 mm.

[0016] Preferably, the first recess sequentially includes a first transition zone and a first straight zone from the proximal end to the distal end, the first transition zone is a variable diameter zone, and at least one of the inner diameter and the outer diameter of the outer tube becomes larger or smaller in the variable diameter zone.

[0017] Preferably, the axial length of the first transition zone is 0 mm to 10 mm.

[0018] Preferably, the inner surface and / or the outer surface of the first transition zone forms a certain inclination angle with the axis of the outer tube body, and the inclination angle is 0°-90°.

[0019] Preferably, the inner surface and the outer surface of the first transition zone form the same inclination angle with the axis of the outer tube body.

[0020] Preferably, the ratio of the outer diameter of the first straight zone to the outer diameter of the outer tube body is 0.7-1.0.

[0021] Preferably, the outer diameter of the outer tube body is 1.0 mm to 3.7 mm, and the outer diameter of the first straight zone is 0.7 mm to 3.5 mm.

[0022] Preferably, the outer tube further includes a distal end portion of the outer tube, which is located at the distal end of the first recess. The outer diameter of the proximal end of the distal end portion of the outer tube is greater than the outer diameter of the distal end of the first recess, and the distal end portion of the outer tube is fixedly connected to the inner tube at the distal position.

[0023] Preferably, the distal end portion of the outer tube sequentially includes a second transition region and a second straight region from the proximal end to the distal end. The second transition region is a diameter-changing region, and in the diameter-changing region, at least one of the inner diameter and the outer diameter of the outer tube becomes larger or smaller.

[0024] Preferably, the inner tube includes an inner tube body and a second recess, and the second recess is located at the distal end of the inner tube body. The outer surface of the inner tube is recessed inward to form the second recess.

[0025] Preferably, the second recess sequentially includes a third transition region and a third straight region from the proximal end to the distal end. The third transition region is a diameter-changing region, and in the diameter-changing region, the outer diameter of the inner tube becomes smaller.

[0026] Preferably, the axial length of the second recess is 2 - 60 mm.

[0027] Preferably, the outer surface of the third transition region forms a certain inclination angle with the axis of the inner tube body, and the inclination angle is 0° - 90°. The axial length of the third transition region is 0 - 10 mm.

[0028] Preferably, the ratio of the outer diameter of the third straight region to the outer diameter of the inner tube body is greater than or equal to 0.6 and less than 1.0.

[0029] Preferably, the outer diameter of the inner tube body is 0.5 mm to 3.2 mm, and the outer diameter of the third straight region is greater than or equal to 0.3 mm and less than 3.2 mm.

[0030] Preferably, the most distal end of the outer tube body is called the first transition position, and the most distal end of the inner tube body is called the second transition position. The projection of the first transition position on the axis of the tubular element is located at the distal end of the projection of the second transition position on the axis of the tubular element;

[0031] The first recess sequentially includes a first transition region and a first straight region from the proximal end to the distal end;

[0032] The outer surface of the third transition region forms a first inclination angle with the axial direction of the tubular element, and the inner surface of the first transition region forms a second inclination angle with the axial direction of the tubular element. The first inclination angle is greater than or equal to the second inclination angle.

[0033] Preferably, the inner tube further includes a distal end portion of the inner tube, which is located at the distal end of the second recess.

[0034] Preferably, the axial length of the distal end portion of the inner tube is 1 - 500 mm.

[0035] Preferably, the outer diameter of the distal end of the inner tube is smaller than the outer diameter of the second recess, and the distal end of the inner tube is located at the distal end of the catheter.

[0036] Preferably, the distal end of the inner tube sequentially includes a fourth transition region and a fourth straight region from the proximal end to the distal end. The fourth transition region is a diameter-changing region, and at the diameter-changing region, the outer diameter of the inner tube becomes smaller.

[0037] Preferably, the outer diameter of the fourth straight region is 0.2 mm to 3.1 mm.

[0038] Preferably, the functional element is a flow-blocking element, and the proximal end of the flow-blocking element is fixed to the first recess.

[0039] Preferably, the flow-blocking element is a polymer film. When the first cavity is in a liquid-filled state, the flow-blocking element is in an expanded state; when the first cavity is in a vacuum state, the flow-blocking element is in a contracted state.

[0040] Preferably, the distal end of the flow-blocking element is fixedly connected to the inner tube.

[0041] Preferably, the flow-blocking element is arranged in the first recess, the proximal end and the distal end of the flow-blocking element are both fixedly connected to the outer tube, the distal end of the outer tube is connected to the inner tube, and a liquid passage hole for filling liquid into the flow-blocking element is provided on the first recess.

[0042] Preferably, the thickness of the polymer film is 0.05 mm to 0.15 mm.

[0043] Preferably, the material of the polymer film is any one of silica gel, polyurethane, latex, polyethylene, polytetrafluoroethylene, expanded polytetrafluoroethylene, or any mixture of any two or more of them.

[0044] Preferably, the inner tube includes an inner tube body and a second recess. The second recess is located at the distal end of the inner tube body, the outer diameter of the second recess is smaller than the outer diameter of the inner tube body, the functional element is a flow-blocking element, the proximal end of the flow-blocking element is fixedly connected to the first recess, and the distal end of the flow-blocking element is fixedly connected to the second recess.

[0045] Preferably, both the inner tube and the outer tube at least include a polymer layer, and the material of the polymer layer is one or several of polyether block polyamide, nylon, polyurethane, polytetrafluoroethylene, polyethylene, and polyolefin elastomer.

[0046] Preferably, the outer tube and / or the inner tube further includes a reinforcing layer. The reinforcing layer is a wire braided structure, a wire helically wound structure, a cut tube, or any combination of any two or more of them, and the material of the reinforcing layer is stainless steel, nitinol alloy, cobalt-chromium alloy, or polymer.

[0047] Preferably, the outer tube and / or the inner tube is a three-layer structure, and the three-layer structure sequentially includes a first polymer layer, a reinforcing layer, and a second polymer layer from the inside to the outside.

[0048] Preferably, the catheter further includes a first radiopaque ring located at the distal end of the catheter.

[0049] Preferably, the catheter includes a second radiopaque ring located at a position on the inner tube corresponding to the position of the functional element.

[0050] Preferably, a second cavity is formed inside the inner tube, and the overall inner diameter of the second cavity is the same.

[0051] Preferably, the ratio of the inner diameter of the second cavity to the outer diameter of the outer tube body is 0.2 to 0.9.

[0052] Preferably, the inner diameter of the second cavity is 0.1 mm to 3.0 mm, and the outer diameter of the outer tube body is 0.5 mm to 3.7 mm.

[0053] Preferably, the outer surface of the first recess is an inclined surface with a gradually decreasing outer diameter, and the proximal end of the functional element is fixed to the inclined surface of the first recess.

[0054] Preferably, the end face of the distal end of the outer tube is a first inclined cut surface, the first inclined cut surface forms the outer surface of the first recess, the proximal end of the functional element is a second inclined cut surface that cooperates with the first inclined cut surface, and the first inclined cut surface and the second inclined cut surface are fixedly connected.

[0055] The present invention also provides a flow-blocking catheter, which includes: a tubular element and a flow-blocking element; the tubular element includes an outer tube and an inner tube; the outer tube is sleeved outside the inner tube, a first cavity is formed between the outer tube and the inner tube, the outer tube includes an outer tube body and a first recess, and the first recess is located at the distal end of the outer tube body; the flow-blocking element is arranged on the tubular element, and at least a part of the flow-blocking element is connected to the first recess.

[0056] Preferably, the flow-blocking element is a polymer film. When the first cavity is in a liquid-filled state, the flow-blocking element is in an expanded state; when the first cavity is in a vacuum state, the flow-blocking element is in a contracted state.

[0057] In summary, through the catheter of the present invention, at least one of the following beneficial effects can be achieved:

[0058] 1. A recess is provided on the outer tube and / or the inner tube of the catheter to accommodate at least part of the volume of the functional element, reduce the thickness of the connection position, partially or completely eliminate the influence of the functional element on the hardness of the catheter, ensure the flexibility of the catheter, and enable the catheter to be smoothly pushed in the blood vessel.

[0059] 2. A recess is provided on the outer tube and / or the inner tube of the catheter, reducing the overall thickness of the catheter. While ensuring that the inner cavity of the catheter is large enough, the outer diameter of the catheter is controlled not to be too large, enabling the inner cavity of the catheter to pass through medical devices with a relatively large volume, while also smoothly passing through tortuous blood vessels, reducing the stimulation to the blood vessel wall, and reaching a relatively high blood vessel position.

[0060] 3. The proximal end of the functional element is fixed to the outer tube, and the distal end of the functional element is fixed to the inner tube, further reducing the influence of the presence of the functional element on the overall outer diameter of the catheter and the flexibility performance of the catheter.

[0061] 4. The inner tube is also provided with a recess, ensuring that the volume of the cavity between the inner tube and the outer tube is large enough to ensure the function of the cavity. For example, in a balloon guide catheter, the cavity between the inner tube and the outer tube is a liquid passage cavity, and the volume of the liquid passage cavity affects the inflation and deflation rates of the balloon.

[0062] 5. The outer diameter of the distal end of the inner tube is smaller than the outer diameter of the proximal end of the inner tube body, making the flexibility performance of the catheter gradually increase from the proximal end to the distal end, ensuring the delivery and positioning ability of the catheter. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Those of ordinary skill in the art will understand that the provided drawings are used to better understand the present invention and do not constitute any limitation to the scope of the present invention. Among them:

[0064] Figure 1 is an overall schematic view of the inflated state of the catheter provided by a preferred embodiment of the present invention;

[0065] Figure 2 is an overall schematic view of the contracted state of the catheter provided by a preferred embodiment of the present invention;

[0066] Figure 3 is a cross-sectional view of the distal portion of the catheter provided by a preferred embodiment of the present invention;

[0067] Figure 4 is a cross-sectional view of the distal portion of the catheter provided by a preferred embodiment of the present invention;

[0068] Figure 5 is a cross-sectional view of the distal portion of the catheter provided by a preferred embodiment of the present invention;

[0069] Figure 6 is a cross-sectional view of the distal portion of the catheter provided by a preferred embodiment of the present invention;

[0070] Figure 7 is a cross-sectional view of the distal portion of the catheter provided by a preferred embodiment of the present invention;

[0071] Figure 8 is a cross-sectional view of the distal portion of the catheter provided by a preferred embodiment of the present invention;

[0072] Figure 9 is a cross-sectional view of the distal portion of the catheter provided by a preferred embodiment of the present invention;

[0073] Figure 10Overall schematic diagram of a catheter provided by a preferred embodiment of the present invention;

[0074] Figure 11 Cross-sectional view of the distal portion of a catheter provided by a preferred embodiment of the present invention;

[0075] Figure 12 Cross-sectional view of the distal portion of a catheter provided by a preferred embodiment of the present invention;

[0076] In the drawings:

[0077] 100: Tubular element; 200: Flow blocking element; 101: Outer tube; 102: Inner tube; 1011: Outer tube body; 1012: First recess; 1012-1: First transition zone; 1012-2: First flat zone; 1013: Distal end portion of the outer tube; 1013-1: Second transition zone; 1013-2: Second flat zone; 1014: Liquid passage hole; 1021: Inner tube body; 1022: Second recess; 1022-1: Third transition zone; 1022-2: Third flat zone; 1023: Distal end portion of the inner tube; 1023-1: Fourth transition zone; 1023-2: Fourth flat zone; 300: First transition position; 400: Second transition position. Detailed description of the specific embodiments

[0078] To make the objectives, advantages, and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are in a very simplified form and not drawn to scale, and are only used to conveniently and clearly assist in explaining the objectives of the embodiments of the present invention. In addition, the structures shown in the drawings are often part of the actual structures. In particular, the focus that each drawing needs to show is different, and sometimes different scales are used.

[0079] As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally used in the sense of including "and / or" unless the context clearly dictates otherwise. The term "proximal" is usually the end close to the operator, and the term "distal" is usually the end close to the patient and the lesion.

[0080] The core idea of the present invention is to provide a catheter, which includes: a tubular element and a functional element; the tubular element includes an outer tube and an inner tube; the outer tube is sleeved outside the inner tube, a first cavity is formed between the outer tube and the inner tube, the outer tube includes an outer tube body and a first recess, and the first recess is located at the distal end of the outer tube body; the functional element is arranged on the tubular element, and at least a part of the functional element is connected to the first recess. The functional element can be any element arranged on the catheter and performing a medical function, such as a flow-blocking element, a visualization element, an electronic element, a thrombus-removing element, etc. One end of the functional element can be connected to the catheter and the other end is free; or both ends can be connected to the catheter; or it can be integrally fixed to the catheter. In the following embodiments, the structure of the catheter provided by the present invention is described in detail with the flow-blocking element as a representative of the functional element, and the relationship between other types of functional elements and the catheter is similar to that of the flow-blocking element.

[0081] The following description is made with reference to the accompanying drawings.

[0082] Embodiment 1

[0083] This embodiment provides a catheter, Figure 1 、 Figure 2 is an overall schematic diagram of the catheter provided in Embodiment 1 of the present invention, Figure 3 、 Figure 4 is a cross-sectional view of the distal part of the catheter provided in Embodiment 1 of the present invention. As Figures 1-4 shown, the catheter provided by the present invention includes a tubular element 100 and a flow-blocking element 200. The tubular element 100 includes an outer tube 101 and an inner tube 102. The flow-blocking element 200 is fixed to the tubular element 100. The outer tube 101 is sleeved outside the inner tube 102, and a first cavity is formed between the outer tube 101 and the inner tube 102. The flow-blocking element 200 has an expanded state and a contracted state. Figure 1 and Figure 3 are respectively an overall schematic diagram and a cross-sectional view of the distal part when the flow-blocking element 200 presents an expanded state, Figure 2 and Figure 4 are respectively an overall schematic diagram and a cross-sectional view of the distal part when the flow-blocking element 200 presents a contracted state. The flow-blocking element 200 can be mutually converted between the expanded state and the contracted state; when the flow-blocking element 200 is in the expanded state, it blocks or reduces the blood flow in the blood vessel. As Figure 3 and Figure 4 shown, the outer tube 101 includes an outer tube body 1011 and a first recess 1012. The first recess 1012 is located at the distal end of the outer tube body 1011. The proximal end of the flow-blocking element 200 is fixed to the first recess 1012, and the distal end of the flow-blocking element 200 is fixed to the inner tube 102. The flow-blocking element 200 is fixed between the outer tube 101 and the inner tube 102, which can reduce the influence of the existence of the flow-blocking element 200 on the overall outer diameter of the catheter and the compliance performance of the catheter.

[0084] In this embodiment, the outer surface of the outer tube 101 is recessed inward to form a first recess 1012; in some other embodiments, the inner surface of the outer tube 101 is recessed outward to form the first recess 1012.

[0085] In this embodiment, the outer diameter of the first recess 1012 is smaller than the outer diameter of the outer tube main body 1011, the inner diameter of the first recess 1012 is smaller than the inner diameter of the outer tube main body 1011, and the proximal end of the flow blocking element 200 is fixed to the outer surface of the first recess 1012; in some other embodiments, the outer diameter of the first recess 1012 is smaller than the outer diameter of the outer tube main body 1011, the inner diameter of the first recess 1012 is equal to the inner diameter of the outer tube main body 1011, and the proximal end of the flow blocking element 200 is fixed to the outer surface of the first recess 1012; in some other embodiments, the outer diameter of the first recess 1012 is equal to the outer diameter of the outer tube main body 1011, the inner diameter of the first recess 1012 is larger than the inner diameter of the outer tube main body 1011, and the proximal end of the flow blocking element 200 is fixed to the inner surface of the first recess 1012; in some other embodiments, the outer diameter of the first recess 1012 is smaller than the outer diameter of the outer tube main body 1011, the inner diameter of the first recess 1012 is larger than the inner diameter of the outer tube main body 1011, and the proximal end of the flow blocking element 200 is fixed to the inner surface or the outer surface of the first recess 1012.

[0086] In all embodiments, the axial length of the first recess 1012 is 2 - 20 mm; in this embodiment, the axial length of the first recess 1012 is 12 mm; in some other embodiments, the axial length of the first recess 1012 is 2 mm; in some other embodiments, the axial length of the first recess 1012 is 5 mm; in some other embodiments, the axial length of the first recess 1012 is 10 mm; in some other embodiments, the axial length of the first recess 1012 is 15 mm; in some other embodiments, the axial length of the first recess 1012 is 20 mm. Providing a recess on the outer tube 101 of the catheter can be used to accommodate at least part of the volume of the flow blocking element 200, can reduce the thickness of the connection position, partially or completely eliminate the influence of the flow blocking element on the hardness of the catheter, ensure the flexibility of the catheter, and enable the catheter to be smoothly pushed in the blood vessel. At the same time, it can reduce the overall thickness of the catheter, control the outer diameter of the catheter not to be too large while ensuring that the inner cavity of the catheter is large enough, enable the inner cavity of the catheter to pass through medical devices with a larger volume while still being able to smoothly pass through tortuous blood vessels, reduce the stimulation to the blood vessel wall, and reach a relatively high blood vessel position.

[0087] Such as Figure 3 、 Figure 4As shown, in this embodiment, the first recess 1012 includes a first transition region 1012-1 and a first straight region 1012-2 in sequence from the proximal end to the distal end. The inner diameter of the first transition region 1012-1 transitions from the inner diameter of the outer tube body 1011 to the inner diameter of the first straight region 1012-2, and the outer diameter of the first transition region 1012-1 transitions from the outer diameter of the outer tube body 1011 to the outer diameter of the first straight region 1012-2. The first transition region 1012-1 is a variable diameter region. At the first transition region 1012-1, both the inner diameter and the outer diameter of the outer tube 101 become smaller. In some other embodiments, the outer diameter of the first recess 1012 is smaller than the outer diameter of the outer tube body 1011, the inner diameter of the first recess 1012 is equal to the inner diameter of the outer tube body 1011, the outer diameter of the first transition region 1012-1 transitions from the outer diameter of the outer tube body 1011 to the outer diameter of the first straight region 1012-2, and the inner diameter of the first transition region 1012-1 is equal to the inner diameter of the outer tube body 1011 and the inner diameter of the first recess 1012. The first transition region 1012-1 is a variable diameter region. At the first transition region 1012-1, the outer diameter of the outer tube 101 becomes smaller. In some other embodiments, the outer diameter of the first recess 1012 is equal to the outer diameter of the outer tube body 1011, the inner diameter of the first recess 1012 is larger than the inner diameter of the outer tube body 1011, the inner diameter of the first transition region 1012-1 transitions from the inner diameter of the outer tube body 1011 to the inner diameter of the first straight region 1012-2, and the outer diameter of the first transition region 1012-1 is equal to the outer diameter of the outer tube body 1011 and the outer diameter of the first recess 1012. The first transition region 1012-1 is a variable diameter region. At the first transition region 1012-1, the inner diameter of the outer tube 101 becomes larger.

[0088] As Figure 3 、 Figure 4As shown, in this embodiment, the inner surface and the outer surface of the first transition region 1012-1 are inclined surfaces that form an angle with the axis of the outer tube body 1011 (or with the tubular element 100), and the inclination angles are the same, both being 45°. In some other embodiments, the inner surface and the outer surface of the first transition region 1012-1 are inclined surfaces that form an angle with the axis of the outer tube body 1011 (or with the tubular element 100), and the inclination angles are the same, both being any angle greater than 0 and less than or equal to 90°; in some other embodiments, the inner surface and the outer surface of the first transition region 1012-1 are inclined surfaces that form an angle with the axis of the outer tube body 1011 (or with the tubular element 100), and the inclination angles are the same, both being 60°; in some other embodiments, the inner surface and the outer surface of the first transition region 1012-1 are inclined surfaces that form an angle with the axis of the outer tube body 1011 (or with the tubular element 100), and the inclination angles are the same, both being 5°; in some other embodiments, the inner surface and the outer surface of the first transition region 1012-11 are inclined surfaces that form an angle with the axis of the outer tube body 1011 (or with the tubular element 100), and the inclination angles are the same, both being 85°; in some other embodiments, both the inner surface and the outer surface of the first transition region 1012-1 are surfaces perpendicular to the axis of the outer tube body 1011 (or with the tubular element 100); in some other embodiments, the inner surface of the first transition region 1012-11 is parallel to the axis of the outer tube body 1011 (or with the tubular element 100), and the outer surface of the first transition region 1012-1 is an inclined surface that forms an angle with the axis of the outer tube body 1011 (or with the tubular element 100), and the inclination angle can be greater than 0° and less than 90°, such as 5°, 15°, 30°, 40°, 45°, 60°, 75°, 85°; in some other embodiments, the inner surface of the first transition region 1012-1 is parallel to the axis of the outer tube body 1011 (or with the tubular element 100), and the outer surface of the first transition region 1012-1 is a surface perpendicular to the axis of the outer tube body 1011 (or with the tubular element 100); in some other embodiments, the outer surface of the first transition region 1012-1 is parallel to the axis of the outer tube body 1011 (or with the tubular element 100), and the inner surface of the first transition region 1012-1 is an inclined surface that forms an angle with the axis of the outer tube body 1011 (or with the tubular element 100), and the inclination angle can be any angle greater than 0° and less than or equal to 90°, such as 5°, 15°, 30°, 40°, 45°, 60°, 75°, 85°; in some other embodiments, the outer surface of the first transition region 1012-1 is parallel to the axis of the outer tube body 1011 (or with the tubular element 100), and the inner surface of the first transition region 1012-1 is a surface perpendicular to the axis of the outer tube body 1011 (or with the tubular element 100).In all embodiments, the axial length of the first transition region 1012-1 is 0 - 10 mm; in this embodiment, the axial length of the first transition region 1012-1 is 4 mm; in some other embodiments, the axial length of the first transition region 1012-1 is 0 mm; in some other embodiments, the axial length of the first transition region 1012-1 is 3 mm; in some other embodiments, the axial length of the first transition region 1012-1 is 5 mm; in some other embodiments, the axial length of the first transition region 1012-1 is 8 mm; in some other embodiments, the axial length of the first transition region 1012-1 is 10 mm.

[0089] In all embodiments, the outer diameter of the outer tube body 1011 is 1.0 mm to 3.7 mm, the outer diameter of the first straight region 1012-2 is 0.7 mm to 3.5 mm, and the ratio of the outer diameter of the first straight region 1012-2 to the outer diameter of the outer tube body 1011 is 0.7 to 1.0; in this embodiment, the outer diameter of the outer tube body 1011 is 2.8 mm, the outer diameter of the first straight region 1012-2 is 2.6 mm, and the ratio of the outer diameter of the first straight region 1012-2 to the outer diameter of the outer tube body 1011 is 0.928; in some other embodiments, the outer diameter of the outer tube body 1011 is 3.7 mm, the outer diameter of the first straight region 1012-2 is 2.8 mm, and the ratio of the outer diameter of the first straight region 1012-2 to the outer diameter of the outer tube body 1011 is 0.757; in some other embodiments, the outer diameter of the outer tube body 1011 is 3.5 mm, the outer diameter of the first straight region is 3.5 mm, and the ratio of the outer diameter of the first straight region 1012-2 to the outer diameter of the outer tube body 1011 is 1.0; in some other embodiments, the outer diameter of the outer tube body 1011 is 1.0 mm, the outer diameter of the first straight region 1012-2 is 0.7 mm, and the ratio of the outer diameter of the first straight region 1012-2 to the outer diameter of the outer tube body 1011 is 0.7.

[0090] In all embodiments, the overall length of the catheter is 80 - 160 cm; in this embodiment, the overall length of the catheter is 130 cm; in some other embodiments, the overall length of the catheter is 80 cm; in some other embodiments, the overall length of the catheter is 160 cm; in some other embodiments, the overall length of the catheter is 115 cm; in some other embodiments, the overall length of the catheter is 110 cm; in some other embodiments, the overall length of the catheter is 140 cm; in some other embodiments, the overall length of the catheter is 150 cm.

[0091] In this embodiment, the flow blocking element 200 is a polymer film. The first cavity is used to pass or withdraw liquid, so as to control the transition between the expanded state and the contracted state of the flow blocking element 200. The liquid that the first cavity is used to pass or withdraw includes contrast liquid, physiological saline, etc. When the first cavity is in a liquid-filled state, the flow blocking element 200 is in an expanded state; when the first cavity is in a vacuum state, the flow blocking element 200 is in a contracted state. In this embodiment, the thickness of the polymer film is 0.10 mm; in some other embodiments, the thickness of the polymer film is 0.05 mm - 0.15 mm, such as 0.05 mm, 0.08 mm, 0.12 mm, 0.15 mm. In this embodiment, the material of the polymer film is silica gel; in some other embodiments, the material of the polymer film is polyurethane; in some other embodiments, the material of the polymer film is latex; in some other embodiments, the material of the polymer film is polyethylene; in some other embodiments, the material of the polymer film is polytetrafluoroethylene; in some other embodiments, the material of the polymer film is expanded polytetrafluoroethylene; in some other embodiments, the material of the polymer film is a mixture of polyurethane and polyethylene, and the material ratio is 2:1; in some other embodiments, the material of the polymer film is a mixture of polytetrafluoroethylene and expanded polytetrafluoroethylene, and the material ratio is 1:1; in some other embodiments, the material of the polymer film is a mixture of silica gel, polyurethane and polyethylene, and the material ratio is 1:1:1. In this embodiment, the proximal end of the flow blocking element 200 is connected to the first straight region 1012-2, and the connection method can be bonding, binding or fusion connection; in some other embodiments, the proximal end of the flow blocking element 200 can be connected to the first transition region 1012-1, and the connection method can be bonding, binding or fusion connection.

[0092] In this embodiment, the inner tube 102 has a three-layer structure, which from the inside out are the first polymer layer, the reinforcing layer, and the second polymer layer in sequence. The material of the first polymer layer is polytetrafluoroethylene, the reinforcing layer is a wire braided structure, and the material of the reinforcing layer is stainless steel. The second polymer layer is axially spliced by polyether block polyamide, nylon, polyurethane, polyethylene, and polyolefin elastomer; the outer tube 101 has a single polymer layer, and the material of the outer tube 101 is polyether block polyamide. In some other embodiments, both the inner tube 102 and the outer tube 101 have a three-layer structure, which from the inside out are the first polymer layer, the reinforcing layer, and the second polymer layer in sequence; in some other embodiments, the inner tube 102 has a single-layer polymer structure and the outer tube 101 has a three-layer structure; in some other embodiments, the inner tube 102 has a three-layer structure and the outer tube 101 has a two-layer polymer structure. In some other embodiments, the reinforcing layer of the inner tube 102 and / or the outer tube 101 is a wire helically wound structure; in some other embodiments, the reinforcing layer of the inner tube 102 and / or the outer tube 101 is a cut pipe; in some other embodiments, the reinforcing layer of the inner tube 102 and / or the outer tube 101 is a combination of a wire braided structure and a wire helical structure; in some other embodiments, the reinforcing layer of the inner tube 102 and / or the outer tube 101 is a combination of a wire braided structure and a cut pipe; in some other embodiments, the reinforcing layer of the inner tube 102 and / or the outer tube 101 is a combination of a cut pipe and a wire helical structure. In some other embodiments, the material of the reinforcing layer of the inner tube 102 and / or the outer tube 101 includes nitinol; in some other embodiments, the material of the reinforcing layer of the inner tube 102 and / or the outer tube 101 includes cobalt-chromium alloy; in some other embodiments, the material of the reinforcing layer of the inner tube 102 and / or the outer tube 101 includes polymer; in some other embodiments, the material of the reinforcing layer of the inner tube 102 and / or the outer tube 101 is a combination of nitinol and stainless steel; in some other embodiments, the material of the reinforcing layer of the inner tube 102 and / or the outer tube 101 is a combination of nitinol and polymer.

[0093] In this implementation, the catheter includes a first imaging ring, and the first imaging ring is located at the head of the catheter; the catheter further includes a second imaging ring, and the second imaging ring is located at a position on the inner tube 102 corresponding to the position of the flow blocking element 200.

[0094] In this embodiment, a second cavity is formed inside the inner tube 102 of the catheter, and the overall inner diameter of the second cavity is the same. In all embodiments, the inner diameter of the second cavity is 0.1 mm to 3.0 mm, and the outer diameter of the outer tube body 1011 is 0.5 mm to 3.7 mm; in this embodiment, the inner diameter of the second cavity is 2.3 mm, the outer diameter of the outer tube body 1011 is 2.8 mm, and the ratio of the inner diameter of the second cavity to the outer diameter of the outer tube body 1011 is 0.821; in some other embodiments, the inner diameter of the second cavity is 0.1 mm, the outer diameter of the outer tube body 1011 is 0.5 mm, and the ratio of the inner diameter of the second cavity to the outer diameter of the outer tube body 1011 is 0.2; in some other embodiments, the inner diameter of the second cavity is 3.0 mm, the outer diameter of the outer tube body 1011 is 3.6 mm, and the ratio of the inner diameter of the second cavity to the outer diameter of the outer tube body 1011 is 0.833; in some other embodiments, the inner diameter of the second cavity is 2.7 mm, the outer diameter of the outer tube body 1011 is 3.0 mm, and the ratio of the inner diameter of the second cavity to the outer diameter of the outer tube body 1011 is 0.9; in some other embodiments, the inner diameter of the second cavity is 2.5 mm, the outer diameter of the outer tube body 1011 is 3.7 mm, and the ratio of the inner diameter of the second cavity to the outer diameter of the outer tube body 1011 is 0.676. In this embodiment, the second cavity is used for passing medical devices.

[0095] In this embodiment, there is an angular transition between the outer tube body 1011 and the first recess 1012, and between the first transition region 1012-1 and the first flat region 1012-2; in some other embodiments, there may be a smooth transition with a curvature between the outer tube body 1011 and the first recess 1012, and / or between the first transition region 1012-1 and the first flat region 1012-2. In this embodiment, the first flat region 1012-2 is a flat region with a smooth surface; in some other embodiments, the first flat region 1012-2 may be a tubular structure with an uneven structure, a groove structure or a curved structure on the surface, but with the same overall inner and outer diameters.

[0096] Embodiment 2

[0097] This embodiment provides a catheter. Figure 5 It is a cross-sectional view of the distal part of the catheter provided in Embodiment 2. Figure 5 The flow blocking element 200 of the shown catheter is in an expanded state. As Figure 5As shown, the overall structure of the catheter provided in the second embodiment is similar to that of the first embodiment, which will not be elaborated here. Different from the first embodiment, the inner tube 102 of the catheter provided in the second embodiment includes an inner tube main body 1021 and a second recess 1022. The second recess 1022 is located at the distal end of the inner tube main body 1021, and the outer diameter of the second recess 1022 is smaller than the outer diameter of the inner tube main body 1021. The proximal end of the flow blocking element 200 is fixed to the first recess 1012, and the distal end of the flow blocking element 200 is fixed to the second recess 1022. By providing a recess on the inner tube 102 of the catheter, at least part of the volume of the flow blocking element 200 can be accommodated, which can reduce the thickness at the connection position, partially or completely eliminate the influence of the flow blocking element on the hardness of the catheter, ensure the flexibility of the catheter, enable the catheter to be smoothly pushed in the blood vessel, and by providing a recess on the inner tube 102, the softness of the distal end of the catheter is increased, further enhancing the delivery performance of the catheter in the blood vessel.

[0098] In all embodiments, the axial length of the second recess 1022 is 2 - 60 mm; in this embodiment, the axial length of the second recess 1022 is 30 mm; in some other embodiments, the axial length of the second recess 1022 is 2 mm; in some other embodiments, the axial length of the second recess 1022 is 10 mm; in some other embodiments, the axial length of the second recess 1022 is 25 mm; in some other embodiments, the axial length of the second recess 1022 is 45 mm; in some other embodiments, the axial length of the second recess 1022 is 60 mm.

[0099] As Figure 5As shown, the second recess 1022 sequentially includes a third transition zone 1022-1 and a third flat zone 1022-2 from the proximal end to the distal end. The outer diameter of the third transition zone 1022-1 transitions from the outer diameter of the inner tube body 1021 to the outer diameter of the third flat zone 1022-2. The third transition zone 1022-1 is a variable-diameter zone, and at the third transition zone 1022-1, the outer diameter of the inner tube 102 becomes smaller. Similar to the first transition zone 1012-1 of the first recess 1012, the outer surface of the third transition zone 1022-1 is an inclined surface that forms a certain angle with the axis of the inner tube body 1021 (or with the tubular element 100), and the angle of the inclined surface is 10°; in some other embodiments, the outer surface of the third transition zone 1022-1 is an inclined surface that forms a certain angle with the axis of the inner tube body 1021 (or with the tubular element 100), and the angle of the inclined surface is 5°; in some other embodiments, the outer surface of the third transition zone 1022-1 is an inclined surface that forms a certain angle with the axis of the inner tube body 1021 (or with the tubular element 100), and the angle of the inclined surface is 15°; in some other embodiments, the outer surface of the third transition zone 1022-1 is an inclined surface that forms a certain angle with the axis of the inner tube body 1021 (or with the tubular element 100), and the angle of the inclined surface is 25°; in some other embodiments, the outer surface of the third transition zone 1022-1 is an inclined surface that forms a certain angle with the axis of the inner tube body 1021 (or with the tubular element 100), and the angle of the inclined surface is 20°; in some other embodiments, the outer surface of the third transition zone 1022-1 is a surface perpendicular to the axis of the inner tube body 1021 (or with the tubular element 100). In some embodiments, the inner surface of the third transition zone 1022-1 is parallel to the axis of the inner tube body 1021 (or with the tubular element 100), and the outer surface of the third transition zone 1022-1 is an inclined surface that forms a certain angle with the axis of the inner tube body 1021 (or with the tubular element 100), and the inclined angle can be any angle from 0 to 90°, such as 5°, 15°, 30°, 40°, 45°, 60°, 75°, 85°; in some other embodiments, the inner surface of the third transition zone 1022-1 is parallel to the axis of the inner tube body 1021 (or with the tubular element 100), and the outer surface of the third transition zone 1022-1 is a surface perpendicular to the axis of the inner tube body 1021 (or with the tubular element 100); in some other embodiments, the inner surface of the third transition zone 1022-1 is an inclined surface that forms a certain angle with the axis of the inner tube body 1021 (or with the tubular element 100), and the inclined angle can be any angle from 0 to 90°, such as 5°, 15°, 30°, 40°, 45°, 60°, 75°, 85°; in some other embodiments, the inner surface of the third transition zone 1022-1 is a surface perpendicular to the axis of the inner tube body 1021 (or with the tubular element 100).In all embodiments, the axial length of the third transition zone 1022-1 is 0-10 mm; in this embodiment, the axial length of the third transition zone 1022-1 is 5 mm; in some other embodiments, the axial length of the third transition zone 1022-1 is 0 mm; in some other embodiments, the axial length of the third transition zone 1022-1 is 3 mm; in some other embodiments, the axial length of the third transition zone 1022-1 is 5 mm; in some other embodiments, the axial length of the third transition zone 1022-1 is 8 mm; in some other embodiments, the axial length of the third transition zone 1022-1 is 10 mm.

[0100] In some embodiments, the outer diameter of the inner tube body 1021 is 0.5 mm to 3.2 mm, the outer diameter of the third straight zone 1022-2 is 0.3 m to 3.2 mm, and the ratio of the outer diameter of the third straight zone 1022-2 to the outer diameter of the outer tube body 1011 is 0.6 to 1.0; in this embodiment, the outer diameter of the inner tube body 1021 is 2.8 mm, the outer diameter of the third straight zone 1022-2 is 2.4 mm, and the ratio of the outer diameter of the third straight zone 1022-2 to the outer diameter of the outer tube body 1011 is 0.857; in some other embodiments, the outer diameter of the inner tube body 1021 is 3.2 mm, the outer diameter of the third straight zone 1022-2 is 3.2 mm, and the ratio of the outer diameter of the third straight zone 1022-2 to the outer diameter of the inner tube body 1021 is 1.0; in some other embodiments, the outer diameter of the inner tube body 1021 is 0.5 mm, the outer diameter of the third straight zone 1022-2 is 0.3 mm, and the ratio of the outer diameter of the third straight zone 1022-2 to the outer diameter of the inner tube body 1021 is 0.6; in some other embodiments, the outer diameter of the inner tube body 1021 is 1.0 mm, the outer diameter of the third straight zone 1022-2 is 0.8 mm, and the ratio of the outer diameter of the third straight zone 1022-2 to the outer diameter of the inner tube body 1021 is 0.8; in some other embodiments, the outer diameter of the inner tube body 1021 is 2.0 mm, the outer diameter of the third straight zone 1022-2 is 1.8 mm, and the ratio of the outer diameter of the third straight zone 1022-2 to the outer diameter of the inner tube body 1021 is 0.9.

[0101] As Figure 5As shown, at the distalmost end of the outer tube body 1011 of the catheter provided in the second embodiment, there is a first transition position 300. In this embodiment, the first transition position 300 is the position where the outer diameter and inner diameter of the outer tube 101 of the catheter begin to change; in some other embodiments, the first transition position 300 is the position where the outer diameter and / or inner diameter of the outer tube 101 of the catheter begin to change. At the distalmost end of the inner tube body 1021 of the catheter, there is a second transition position 400. In this embodiment, the second transition position 400 is the position where the outer diameter of the inner tube of the catheter begins to change; in some other embodiments, the second transition position 400 can also be the position where the outer diameter and inner diameter of the inner tube 102 of the catheter begin to change. In the catheter, the first transition position 300 can be a surface having the same cross-sectional shape as the cross-sectional shape at the distalmost end position of the outer tube body 1011, and the second transition position 400 can be a surface having the same cross-sectional shape as the cross-sectional shape at the distalmost end position of the inner tube body 1021. For the convenience of description herein, they are uniformly referred to as the first transition position 300 and the second transition position 400. In this embodiment, the projection of the first transition position 300 in the axial direction of the tubular element 100 is located at the distal end of the projection of the second transition position 400 in the axial direction of the tubular element 100, and the outer surface of the third transition zone 1022-1 forms a first inclination angle with the axial direction of the tubular element 100, and the inner surface of the first transition zone 1012-1 forms a second inclination angle with the axial direction of the tubular element 100, and the first inclination angle is greater than or equal to the second inclination angle. In this embodiment, the inner diameter of the outer tube 101 of the catheter begins to decrease at the first transition position 300, and the outer diameter of the inner tube 102 of the catheter begins to decrease at the second transition position 400. By setting the projection of the first transition position 300 in the axial direction of the tubular element 100 to be located at the distal end of the projection of the second transition position 400 in the axial direction of the tubular element 100, and setting the inclination angle of the third transition zone 1022-1 with respect to the catheter axis to be greater than the inclination angle of the first transition zone 1012-1 with respect to the catheter axis, it can be ensured that the volume of the first cavity does not become too small due to the decrease in the inner diameter of the outer tube 101. When the first cavity is used for the passage or withdrawal of liquid, the efficiency of liquid passage or withdrawal is ensured.

[0102] In this embodiment, both the inner tube 102 and the outer tube 101 have a three-layer structure, which are, from the inside out, the first polymer layer, the reinforcing layer, and the second polymer layer. The material of the first polymer layer of the inner tube 102 is polytetrafluoroethylene and polyolefin elastomer. The reinforcing layer of the inner tube 102 is a wire spiral winding structure, and the material of the reinforcing layer is nitinol alloy. The second polymer layer of the inner tube 102 is a splicing structure in the axial direction of polyether block polyamide, nylon, polyurethane, polytetrafluoroethylene, polyethylene, polyether block polyamide mixed with a friction coefficient reducing additive, and polyolefin elastomer; the first polymer material of the outer tube 101 is polytetrafluoroethylene, the reinforcing layer of the outer tube 101 is a wire braided structure, and the material of the reinforcing layer is polymer wire. The second polymer layer of the outer tube 101 is a splicing structure in the axial direction of polyether block polyamide, nylon, polyurethane, polyethylene, and polyolefin elastomer.

[0103] In this embodiment, the catheter includes a first radiopaque ring located at the distal end of the catheter.

[0104] In this embodiment, there is an angular transition between the inner tube body 1021 and the second recess 1022, and between the third transition region 1022-1 and the third straight region 1022-2; in some other embodiments, there may be a smooth transition with a curvature between the inner tube body 1021 and the second recess 1022, and / or between the third transition region 1022-1 and the third straight region 1022-2. In this embodiment, the third straight region 1022-2 is a straight region with a smooth surface; in some other embodiments, the third straight region 1022-2 may be a tubular structure with a concavo-convex structure, a groove structure, or a curved structure on the surface, but with the same overall inner and outer diameters.

[0105] Embodiment III

[0106] This embodiment provides a catheter. Figure 6 It is a cross-sectional view of the distal part of the catheter provided in Embodiment III. Figure 6 The flow blocking element 200 of the shown catheter is in an expanded state. As Figure 6As shown, the overall structure of the catheter provided in the third embodiment is similar to that in the second embodiment, which will not be elaborated here. Different from the second embodiment, the inner tube 102 of the catheter provided in the third embodiment includes an inner tube main body 1021, a second recess 1022, and a distal end portion 1023 of the inner tube. The second recess 1022 is located at the distal end of the inner tube main body 1021, and the outer diameter of the second recess 1022 is smaller than the outer diameter of the inner tube main body 1021. The proximal end of the flow blocking element 200 is fixed to the first recess 1012, and the distal end of the flow blocking element 200 is fixed to the second recess 1022. The distal end portion 1023 of the inner tube is located at the distal end of the second recess 1022, the outer diameter of the distal end portion 1023 of the inner tube is smaller than the outer diameter of the second recess 1022, and the distal end portion 1023 of the inner tube is located at the head end of the catheter. The presence of the distal end portion 1023 of the inner tube makes the flexibility of the catheter gradually increase from the proximal end to the distal end, ensuring the delivery and placement ability of the catheter.

[0107] As Figure 6 shown, the distal end portion 1023 of the inner tube sequentially includes a fourth transition zone 1023-1 and a fourth straight zone 1023-2 from the proximal end to the distal end. The outer diameter of the fourth transition zone 1023-1 transitions from the outer diameter of the third straight zone 1022-2 to the outer diameter of the fourth straight zone. The fourth transition zone 1023-1 is a variable diameter zone, and at the fourth transition zone 1023-1, the outer diameter of the inner tube 102 becomes smaller. In some embodiments, the outer diameter of the fourth straight zone 1023-2 is 0.2 mm - 3.1 mm; in this embodiment, the outer diameter of the fourth straight zone 1023-2 is 2.0 mm; in some other embodiments, the outer diameter of the fourth straight zone 1023-2 is 0.2 mm; in some other embodiments, the outer diameter of the fourth straight zone 1023-2 is 1.5 mm; in some other embodiments, the outer diameter of the fourth straight zone 1023-2 is 3.1 mm. In this embodiment, the outer diameter of the fourth straight zone 1023-2 is smaller than the outer diameter of the second recess 1022, and the inner diameter of the fourth straight zone 1023-2 is equal to the inner diameter of the second recess 1022; in some other embodiments, the outer diameter of the fourth straight zone 1023-2 is smaller than the outer diameter of the second recess 1022, and the inner diameter of the fourth straight zone 1023-2 is larger than the inner diameter of the second recess 1022. By providing a fourth straight zone 1023-2 with a smaller outer diameter at the distal end of the inner tube 102 than at the proximal end, the hardness of the distal end of the catheter can be further reduced, the passing ability of the catheter in the blood vessel can be enhanced, the risk of the distal end of the catheter puncturing the blood vessel can be reduced, and the placement performance can be improved.

[0108] In some other embodiments, the distal end portion 1023 of the inner tube may include 2 to 10 transition zones and straight zones, which are arranged at intervals in sequence, so that the outer diameter of the distal end portion 1023 of the inner tube gradually decreases. The outer diameter of the distal end portion 1013 of the outer tube may gradually decrease from 3 mm at the proximal end to 0.6 mm at the distal end. In some other embodiments, the distal end portion 1023 of the inner tube includes 5 transition zones and straight zones arranged at intervals in sequence, and the outer diameter of the distal end portion 1013 of the outer tube decreases from 2.7 mm at the proximal end to 0.9 mm at the distal end; in some other embodiments, the distal end portion 1023 of the inner tube includes 10 transition zones and straight zones arranged at intervals in sequence, and the outer diameter of the distal end portion 1013 of the outer tube decreases from 3.0 mm at the proximal end to 0.6 mm at the distal end; in some other embodiments, the distal end portion 1023 of the inner tube includes 2 transition zones and straight zones arranged at intervals in sequence, and the outer diameter of the distal end portion 1013 of the outer tube decreases from 2.4 mm at the proximal end to 1.65 mm at the distal end. In some other embodiments, the distal end portion 1013 of the outer tube is a tapered tubular structure with a gradually decreasing outer diameter, and the outer diameter of the distal end portion 1013 tapers; in some embodiments, the outer diameter of the distal end portion 1013 of the outer tube tapers from 3 mm at the proximal end to 0.6 mm at the distal end; in some embodiments, the outer diameter of the distal end portion 1013 of the outer tube tapers from 2.5 mm at the proximal end to 0.6 mm at the distal end; in some embodiments, the outer diameter of the distal end portion 1013 of the outer tube tapers from 2 mm at the proximal end to 0.9 mm at the distal end.

[0109] In this embodiment, the projection of the first transition position 300 on the axial direction of the tubular element 100 is located at the distal end of the projection of the second transition position 400 on the axial direction of the tubular element 100.

[0110] In this embodiment, the inner tube 102 has a three-layer structure, which are, from the inside to the outside, the first polymer layer, the reinforcing layer, and the second polymer layer. The outer tube 101 has a two-layer structure. The outer layer of the outer tube 101 is a polymer layer, and the inner layer of the outer tube 101 is a reinforcing layer. The reinforcing layer of the outer tube 101 is a cut pipe.

[0111] In this embodiment, the catheter includes a second imaging ring, and the second imaging ring is disposed at a position of the inner tube 102 corresponding to the position of the flow blocking element 200.

[0112] In this embodiment, there is an angular transition between the second recess 1022 and the distal end portion 1023 of the inner tube, and between the fourth transition zone 1023-1 and the fourth straight zone 1023-2; in some other embodiments, there may be a smooth transition with a radian between the second recess 1022 and the distal end portion 1023 of the inner tube, and / or between the fourth transition zone 1023-1 and the fourth straight zone 1023-2. In this embodiment, the fourth straight zone 1023-2 is a straight zone with a smooth surface; in some other embodiments, the fourth straight zone 1023-2 may be a tubular structure with uneven structures, groove structures or curved structures on the surface, but with the same overall inner and outer diameters.

[0113] Embodiment Four

[0114] Embodiment Four provides a catheter, Figure 7 is a cross-sectional view of the distal portion of the catheter provided in Embodiment Four, Figure 7 the flow blocking element 200 of the shown catheter is in an expanded state. As Figure 7 shown, the overall structure of the catheter provided in Embodiment Four is similar to that of Embodiment Two and will not be elaborated here. Different from Embodiment Two, in the catheter provided in Embodiment Four, the first transition zone 1012-1 of the first recess 1012 is a reduced-diameter region perpendicular to the axis of the tubular element 100, that is, the outer surface and the inner surface of the first transition zone 1012-1 are both at 90° to the axis of the tubular element 100. The axial length of the first transition zone 1012-1, which is the thickness of the pipe material at this location, is 0.1 mm, and the axial length of the first recess 1012 is 5 mm.

[0115] In this embodiment, the projection of the first transition position 300 on the axis of the tubular element 100 is located at the distal end of the projection of the second transition position 400 on the axis of the tubular element 100.

[0116] In this embodiment, the inner tube 102 has a three-layer structure, which is, from the inside out, a first polymer layer, a reinforcing layer, and a second polymer layer. The outer tube 101 has a two-layer structure. The outer layer of the outer tube 101 is a polymer layer, and the inner layer of the outer tube 101 is a reinforcing layer. The reinforcing layer of the outer tube 101 is a cut pipe.

[0117] In this embodiment, the catheter includes a first imaging ring, and the first imaging ring is located at the head end of the catheter; the catheter further includes a second imaging ring and a third imaging ring. The second imaging ring and the third imaging ring are provided at positions on the inner tube 102 opposite to the position of the flow blocking element 200. The second imaging ring is located at the distal position of the flow blocking element 200, and the third imaging ring is located at the proximal position of the flow blocking element 200.

[0118] Embodiment Five

[0119] Embodiment Five provides a catheter, Figure 8Cross-sectional view of the distal portion of the catheter provided for Example 4 Figure 8 The flow blocking element 200 of the catheter shown is in an expanded state. As Figure 8 shown, the overall structure of the catheter provided in Example 5 is similar to that in Example 4, which will not be elaborated here. The difference from Example 4 is that in the catheter provided in Example 5, the third transition region 1022-1 of the second recess 1012 is a reduced-diameter region perpendicular to the axis of the tubular element 100, that is, the outer surface and the inner surface of the third transition region 1022-1 are both at 90° to the axis of the tubular element 100. The axial length of the first transition region 1013-1 is 0.5 mm, and the axial length of the first recess 1012 is 8 mm. The first transition region 1012-1 of the first recess 1012 is a reduced-diameter region perpendicular to the axis of the tubular element 100, that is, the outer surface of the first transition region 1012-1 is at 90° to the axis of the tubular element 100. The axial length of the third transition region 1022-1 is 0 mm, and the axial length of the second recess 1022 is 20 mm. In this embodiment, the inner diameter of the second recess 1022 is the same as the inner diameter of the inner tube body 1021, and the thickness of the distal end of the inner tube 102 is less than the thickness of the inner tube body 1021. In some other embodiments, the outer diameter of the second recess 1022 is less than the outer diameter of the inner tube body 1021, the inner diameter of the second recess 1022 is greater than the inner diameter of the inner tube body 1021, and the thickness of the distal end of the inner tube is less than the thickness of the inner tube body 1021; in some other embodiments, the outer diameter of the second recess 1022 is less than the outer diameter of the inner tube body 1021, and the inner diameter of the second recess 1022 is less than the inner diameter of the inner tube body 1021.

[0120] In this embodiment, the projection of the first transition position 300 on the axis of the tubular element 100 is located at the distal end of the projection of the second transition position 400 on the axis of the tubular element 100.

[0121] In this embodiment, the inner tube 102 is a double-layer structure, which is the first polymer layer and the second polymer layer from the inside outwards. The outer tube 101 is a single-layer polymer structure.

[0122] In this embodiment, the catheter includes a second imaging ring and a third imaging ring. The second imaging ring and the third imaging ring are sleeved on the inner tube 102 at positions adapted to the flow blocking element 200. The second imaging ring is located at the distal end position of the flow blocking element 200, and the third imaging ring is located at the proximal end position of the flow blocking element 200.

[0123] As Figure 9As shown, in some other embodiments, in the second recess 1022, the third transition region 1022-1 is a reduced-diameter region perpendicular to the axis of the tubular element 100, that is, both the outer surface and the inner surface of the third transition region 1022-1 are at 90° to the axis of the tubular element 100. The axial length of the third transition region 1022-1 is 0.05 mm, and the axial length of the second recess 1022 is 8 mm. In the first recess 1012, the inner surface and the outer surface of the first transition region 1012-1 are inclined surfaces at a certain angle to the axis of the tubular element 100, and the inclination angles are the same, both being 40°.

[0124] Embodiment Six

[0125] This embodiment provides a catheter. Figure 10 It is an overall schematic diagram of the catheter provided in Embodiment Six of the present invention. Figure 11 It is a cross-sectional view of the distal part of the catheter provided in Embodiment Six of the present invention. As Figure 10 、 Figure 11 shown, the catheter provided by the present invention includes a tubular element 100 and a flow-blocking element 200. The tubular element 100 includes an outer tube 101 and an inner tube 102. The flow-blocking element 200 is fixed to the outer tube 101 in the tubular element 100. The outer tube 101 is sleeved outside the inner tube 102, and a first cavity is formed between the outer tube 101 and the inner tube 102. The flow-blocking element 200 has an expanded state and a contracted state, and the flow-blocking element 200 can be mutually converted between the expanded state and the contracted state. When the flow-blocking element 200 is in the expanded state, the blood flow in the blood vessel is blocked or reduced. As Figure 11 shown, the outer tube 101 includes an outer tube body 1011 and a first recess 1012. The first recess 1012 is located at the distal end of the outer tube body 1011. The flow-blocking element 200 is fixed to the first recess 1012. A liquid passage hole 1014 is formed in the first recess 1012. The first cavity is used to pass or withdraw liquid to control the expansion and contraction of the flow-blocking element 200. When the first cavity is in a liquid-filled state, the flow-blocking element 200 is in an expanded state. When the first cavity is in a vacuum state, the flow-blocking element 200 is in a contracted state. The liquid passage hole 1014 is used to pass liquid. The liquid in the first cavity enters the flow-blocking element 200 through the liquid passage hole 1014 to expand the flow-blocking element 200 or is withdrawn from the flow-blocking element 200 to contract the flow-blocking element 200. In Embodiments One to Five, the first recess 1012 has been described in detail and will not be elaborated here.

[0126] As Figure 11As shown, in this embodiment, the outer tube 101 further includes a distal end portion 1013 of the outer tube. The distal end portion 1013 of the outer tube is located at the distal end of the first recess 1012. The outer diameter of the proximal end of the distal end portion 1013 of the outer tube is greater than the outer diameter of the distal end of the first recess 1012. The distal end of the distal end portion 1013 of the outer tube is fixedly connected to the inner tube 102. The distal end portion 1013 of the outer tube sequentially includes a second transition zone 1013-1 and a second straight zone 1013-2 from the proximal end to the distal end. The inner diameter of the second straight zone 1013-2 is greater than the inner diameter of the first straight zone 1012-2. The outer diameter of the second straight zone 1013-2 is greater than the outer diameter of the first straight zone 1012-2. The inner diameter and the outer diameter of the second transition zone 1013-1 gradually transition from the inner diameter and the outer diameter of the first straight zone 1012-2 to the inner diameter and the outer diameter of the second straight zone 1013-2 from the proximal end to the distal end. The second transition zone 1013-1 is a reduced-diameter zone. At the reduced-diameter zone, both the inner diameter and the outer diameter of the outer tube 101 increase. In some other embodiments, the inner diameter of the second straight zone 1013-2 is equal to the inner diameter of the first straight zone 1012-2. The outer diameter of the second straight zone 1013-2 is greater than the outer diameter of the first straight zone 1012-2. The outer diameter of the second transition zone 1013-1 gradually transitions from the outer diameter of the first straight zone 1012-2 to the outer diameter of the second straight zone 1013-2 from the proximal end to the distal end. The inner diameter of the second transition zone 1013-1 remains unchanged. The second transition zone 1013-1 is a reduced-diameter zone. At the reduced-diameter zone, the outer diameter of the outer tube 101 increases. The combination of the distal end portion 1013 of the outer tube and the first recess can form depressions in the shape of a V, a frame, an arc, a polygon, an irregular shape, etc. on the outer tube 101. In this embodiment, both the proximal end and the distal end of the flow blocking element 200 are connected to the first straight zone 1012-2. The connection method can be bonding, binding, or fusion connection. In some other embodiments, the proximal end of the flow blocking element 200 can be connected to the first transition zone 1012-1, and / or the distal end of the flow blocking element 200 can be connected to the second transition zone 1013-1. The connection method can be bonding, binding, or fusion connection.

[0127] In this embodiment, the inner surface and the outer surface of the second transition region 1013-1 are inclined surfaces at an angle with the axis of the tubular element 100, and the inclined angles are the same, both being 60°. In some other embodiments, the inner surface and the outer surface of the second transition region 1013-1 are inclined surfaces at an angle with the axis of the tubular element 100, and the inclined angles can be the same or different, and the inclined angle can be any angle from 0° to 90°, such as 5°, 15°, 30°, 40°, 45°, 60°, 75°, 85°; in some other embodiments, the inner surface and the outer surface of the second transition region 1013-1 are both surfaces perpendicular to the axis of the tubular element 100; in some other embodiments, the inner surface of the second transition region 1013-1 is parallel to the axis of the tubular element 100, and the outer surface of the second transition region 1013-1 is an inclined surface at an angle with the axis of the tubular element 100, and the inclined angle can be any angle from 0° to 90°, such as 5°, 15°, 30°, 40°, 45°, 60°, 75°, 85°; in some other embodiments, the inner surface of the second transition region 1013-1 is parallel to the axis of the tubular element 100, and the outer surface of the second transition region 1013-1 is a surface perpendicular to the axis of the tubular element 100; in all embodiments, the axial length of the second transition region 1013-1 is 0-10 mm; in this embodiment, the axial length of the second transition region 1013-1 is 5 mm; in some other embodiments, the axial length of the second transition region 1013-1 is 0 mm; in some other embodiments, the axial length of the second transition region 1013-1 is 3 mm; in some other embodiments, the axial length of the second transition region 1013-1 is 8 mm; in some other embodiments, the axial length of the second transition region 1013-1 is 10 mm. In all embodiments, the axial length of the distal end portion 1013 of the outer tube is 1-15 mm; in this embodiment, the axial length of the distal end portion 1013 of the outer tube is 10 mm; in some other embodiments, the axial length of the distal end portion 1013 of the outer tube is 1 mm; in some other embodiments, the axial length of the distal end portion 1013 of the outer tube is 8 mm; in some other embodiments, the axial length of the distal end portion 1013 of the outer tube is 12 mm; in some other embodiments, the axial length of the distal end portion 1013 of the outer tube is 15 mm.

[0128] In all embodiments, the outer diameter of the second straight region 1013-2 is 1.0-3.7 mm. In this embodiment, the outer diameter of the second straight region 1013-2 is 2.8 mm. In some other embodiments, the outer diameter of the second straight region 1013-2 is 1.0 mm; in some other embodiments, the outer diameter of the second straight region 1013-2 is 2.0 mm; in some other embodiments, the outer diameter of the second straight region 1013-2 is 3.0 mm; in some other embodiments, the outer diameter of the second straight region 1013-2 is 3.7 mm;

[0129] In this embodiment, the distal end portion 1013 of the outer tube is connected to the inner tube 102 ( Figure 11 not shown in the figure), closing the distal end of the first cavity and preventing liquid passing through the first cavity from leaking from the distal end of the catheter, thereby controlling the expansion and contraction of the flow blocking element 200. Therefore, there is a reduced-diameter region (not shown in the figure) at the distal end of the distal end portion 1013 of the outer tube, and the outer diameter of the reduced-diameter region gradually decreases from the proximal end to the distal end so as to be connected to the inner tube 102. The position where the distal end portion 1013 of the outer tube is connected to the inner tube 102 may be the most distal position of the inner tube 102 or a position within the inner tube 102.

[0130] As Figure 11 shown, the inner tube 102 of the catheter provided in this embodiment includes an inner tube body 1021 and a second recess 1022 from the proximal end to the distal end. The second recess 1022 is located at the distal end of the inner tube body 1021, and the outer diameter of the second recess 1022 is smaller than the outer diameter of the inner tube body 1021. In Embodiments 2 to 5, the second recess 1022 has been described in detail and will not be elaborated here. In some other embodiments, the inner tube 102 of the catheter may be a straight tube structure with the same inner and outer diameters from the proximal end to the distal end; in some other embodiments, the inner tube 102 of the catheter may include an inner tube body 1021, a second recess 1022 located at the distal end of the inner tube body 1021, and an inner tube distal end portion 1023 located at the distal end of the second recess 1022, wherein the outer diameter of the second recess 1022 is smaller than the outer diameter of the inner tube body 1021, and the outer diameter of the distal end portion 1013 of the outer tube is smaller than the outer diameter of the second recess 1022.

[0131] In this embodiment, the projection of the first transition position 300 in the axial direction of the tubular element 100 is located at the distal end of the projection of the second transition position 400 in the axial direction of the tubular element 100.

[0132] In this embodiment, the inner tube 102 has a three-layer structure, which is, from the inside out, a first polymer layer, a reinforcing layer, and a second polymer layer. The outer tube 101 has a two-layer structure, the outer layer of the outer tube 101 is a polymer layer, and the inner layer of the outer tube 101 is a polymer layer.

[0133] In this embodiment, the catheter includes a first radiopaque ring sleeved outside the inner tube and located at the head end of the catheter; the catheter further includes a second radiopaque ring sleeved at a position of the inner tube 102 corresponding to the position of the flow blocking element 200.

[0134] As Figure 12 shown, in some other embodiments, in the distal end portion 1013 of the outer tube, the second transition region 1013-1 is a reduced-diameter region perpendicular to the axial direction of the tubular element 100, that is, both the outer surface and the inner surface of the second transition region 1013-1 are at 90° to the axial direction of the tubular element 100.

[0135] In this embodiment, there is an angular transition between the first recess 1012 and the distal end portion of the outer tube 1013, and between the second transition region 1013-1 and the second straight region 1013-2; in some other embodiments, there may be a smooth transition with a radian between the first recess 1012 and the distal end portion of the outer tube 1013, and / or between the second transition region 1013-1 and the second straight region 1013-2. In this embodiment, the second straight region 1013-2 is a straight region with a smooth surface; in some other embodiments, the second straight region 1013-2 may be a tubular structure with a concavo-convex structure, a groove structure or a curved structure on the surface, but with the same overall inner and outer diameters.

[0136] Embodiment Seven

[0137] This embodiment provides a catheter. In this embodiment, the outer surface of the first recess 1012 is an inclined surface with a gradually decreasing outer diameter, and the proximal end of the flow blocking element 200 is fixed to the inclined surface of the first recess 1012, that is, the first recess 1012 has only the first transition region 1012-1 and no first straight region 1012-2.

[0138] In some other embodiments, the end face of the distal end of the outer tube is a first inclined cut surface, the first inclined cut surface forms the outer surface of the first recess 1012, the proximal end of the flow blocking element 200 is a second inclined cut surface that mates with the first inclined cut surface, and the first inclined cut surface and the second inclined cut surface are fixedly connected. That is, the first recess 1012 has only the first transition region 1012-1 and no first straight region 1012-2, and the slopes of the inclined cut surfaces of the proximal end of the flow blocking element 200 and the inclined cut surface of the distal end of the outer tube are the same, and they can be mated and fixedly connected to each other.

[0139] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention in any way. Any changes and modifications made by those of ordinary skill in the art of the present invention based on the above disclosure are within the protection scope of the claims.

Claims

1. A catheter, characterized in that, Comprising: A tubular element and a functional element; The tubular element includes an outer tube and an inner tube; The outer tube is sleeved outside the inner tube, a first cavity is formed between the outer tube and the inner tube, the outer tube includes an outer tube body and a first recess, and the first recess is located at the distal end of the outer tube body; The functional element is arranged on the tubular element, and at least part of the functional element is connected to the first recess; The first recess successively includes a first transition zone and a first straight zone from the proximal end to the distal end. The first transition zone is a variable-diameter zone. At the variable-diameter zone, from the proximal end to the distal end, the outer diameter of the outer tube becomes smaller; The inner tube includes an inner tube body and a second recess, the second recess is located at the distal end of the inner tube body, and the outer surface of the inner tube is recessed inward to form the second recess; The second recess successively includes a third transition zone and a third straight zone from the proximal end to the distal end. The third transition zone is a variable-diameter zone. At the variable-diameter zone, from the proximal end to the distal end, the outer diameter of the inner tube becomes smaller; A second cavity is formed inside the inner tube, and the inner diameter of the second cavity is the same as a whole.

2. The catheter according to claim 1, characterized in that, The functional element is at least one of a flow blocking element, a developing element, an electronic element, and an embolus removal element.

3. The catheter according to claim 1, characterized in that, The outer surface of the outer tube is recessed inward to form the first recess.

4. The catheter according to claim 3, characterized in that, The inner diameter of the first recess is less than or equal to the inner diameter of the outer tube body.

5. The catheter according to claim 1, characterized in that, The inner surface of the outer tube is recessed outward to form the first recess.

6. The catheter according to claim 5, characterized in that, The outer diameter of the first recess is less than or equal to the outer diameter of the outer tube body.

7. The catheter according to claim 1, characterized in that, The axial length of the first recess is 2 - 30 mm.

8. The catheter according to claim 1, characterized in that, The axial length of the first transition zone is 0 mm to 10 mm.

9. The catheter according to claim 1, characterized in that, The inner surface and / or the outer surface of the first transition zone forms a certain inclination angle with the axis of the outer tube body, and the inclination angle is 0° - 90°.

10. The catheter according to claim 9, characterized in that, The inner surface and the outer surface of the first transition zone form the same inclination angle with the axis of the outer tube body.

11. The catheter according to claim 1, characterized in that, The ratio of the outer diameter of the first straight zone to the outer diameter of the outer tube body is 0.7 - 1.

0.

12. The catheter according to claim 11, characterized in that, The outer diameter of the outer tube body is 1.0 mm to 3.7 mm, and the outer diameter of the first straight zone is 0.7 mm to 3.5 mm.

13. The catheter according to claim 1, characterized in that, The outer tube further includes an outer tube distal end portion, the outer tube distal end portion is located at the distal end of the first recess, the outer diameter of the proximal end of the outer tube distal end portion is greater than the outer diameter of the distal end of the first recess, and the outer tube distal end portion is fixedly connected to the inner tube at the distal position.

14. The catheter according to claim 13, characterized in that, The outer tube distal end portion successively includes a second transition zone and a second straight zone from the proximal end to the distal end. The second transition zone is a variable-diameter zone. At the variable-diameter zone, from the proximal end to the distal end, the outer diameter of the outer tube becomes larger.

15. The catheter according to claim 1, characterized in that, The axial length of the second recess is 2 - 60 mm.

16. The catheter according to claim 1, characterized in that, The outer surface of the third transition zone forms a certain inclination angle with the axis of the inner tube body, the inclination angle is 0° - 90°, and the axial length of the third transition zone is 0 - 10 mm.

17. The catheter according to claim 1, characterized in that, The ratio of the outer diameter of the third straight zone to the outer diameter of the inner tube body is greater than or equal to 0.6 and less than 1.

0.

18. The catheter according to claim 17, wherein, The outer diameter of the inner tube body is 0.5 mm to 3.2 mm, and the outer diameter of the third straight zone is greater than or equal to 0.3 mm and less than 3.2 mm.

19. The catheter according to claim 1, wherein, The farthest end of the outer tube body is called the first transition position, and the farthest end of the inner tube body is called the second transition position. The projection of the first transition position in the axial direction of the tubular element is located at the distal end of the projection of the second transition position in the axial direction of the tubular element. The outer surface of the third transition zone forms a first inclination angle with the axial direction of the tubular element, and the inner surface of the first transition zone forms a second inclination angle with the axial direction of the tubular element. The first inclination angle is greater than or equal to the second inclination angle.

20. The catheter according to claim 1, wherein, The inner tube further includes a distal end portion of the inner tube, and the distal end portion of the inner tube is located at the distal end of the second recess.

21. The catheter according to claim 20, wherein, The axial length of the distal end portion of the inner tube is 1 - 500 mm.

22. The catheter according to claim 20, wherein, The outer diameter of the distal end portion of the inner tube is smaller than the outer diameter of the second recess, and the distal end portion of the inner tube is located at the head end of the catheter.

23. The catheter according to claim 20, wherein, The distal end portion of the inner tube sequentially includes a fourth transition zone and a fourth straight zone from the proximal end to the distal end. The fourth transition zone is a diameter-changing zone, and at the diameter-changing zone, from the proximal end to the distal end, the outer diameter of the inner tube becomes smaller.

24. The catheter according to claim 23, wherein, The outer diameter of the fourth straight zone is 0.2 mm to 3.1 mm.

25. The catheter according to claim 2, wherein, The functional element is a flow-blocking element, and the proximal end of the flow-blocking element is fixed to the first recess.

26. The catheter according to claim 25, wherein, The flow-blocking element is a polymer film. When the first cavity is in a liquid-filled state, the flow-blocking element is in an expanded state; when the first cavity is in a vacuum state, the flow-blocking element is in a contracted state.

27. The catheter according to claim 25, wherein, The distal end of the flow-blocking element is fixedly connected to the inner tube; Or, The flow-blocking element is arranged in the first recess. The proximal end and the distal end of the flow-blocking element are both fixedly connected to the outer tube. The distal end of the outer tube is connected to the inner tube, and a liquid passage hole for filling the flow-blocking element with liquid is provided on the first recess.

28. The catheter according to claim 26, wherein, The thickness of the polymer film is 0.05 mm to 0.15 mm, and / or the material of the polymer film is any one of silicone, polyurethane, latex, polyethylene, polytetrafluoroethylene, expanded polytetrafluoroethylene, or any mixture of any two or more of them.

29. The catheter according to claim 1, wherein, The outer diameter of the second recess is smaller than the outer diameter of the inner tube body. The functional element is a flow-blocking element. The proximal end of the flow-blocking element is fixedly connected to the first recess, and the distal end of the flow-blocking element is fixedly connected to the second recess.

30. The catheter according to claim 1, wherein, Both the inner tube and the outer tube at least include a polymer layer, and the material of the polymer layer is one or several of polyether block polyamide, polyurethane, polytetrafluoroethylene, polyethylene, polyolefin elastomer.

31. The catheter according to claim 30, wherein, The outer tube and / or the inner tube further includes a reinforcing layer. The reinforcing layer is a wire braided structure, a wire helically wound structure, a cut tube, or any combination of any two or more of them. The material of the reinforcing layer is stainless steel, nitinol alloy, cobalt-chromium alloy, or polymer.

32. The catheter according to claim 31, wherein, The outer tube and / or the inner tube is a three-layer structure, and the three-layer structure sequentially includes a first polymer layer, a reinforcing layer, and a second polymer layer from the inside to the outside.

33. The catheter according to claim 1, wherein, The catheter further includes a first radiopaque ring, and the first radiopaque ring is located at the head end of the catheter. And / or, The catheter includes a second radiopaque ring, and the second radiopaque ring is located at a position on the inner tube corresponding to the position of the functional element.

34. The catheter according to claim 1, wherein, The ratio of the inner diameter of the second cavity to the outer diameter of the outer tube body is 0.2 to 0.

9.

35. The catheter according to claim 34, wherein, The inner diameter of the second cavity is 0.1 mm to 3.0 mm, and the outer diameter of the outer tube body is 0.5 mm to 3.7 mm.

36. The catheter according to claim 1, wherein, The outer surface of the first recess is an inclined surface with a gradually decreasing outer diameter, and the proximal end of the functional element is fixed to the inclined surface of the first recess.

37. The catheter according to claim 36, wherein, The end face of the distal end of the outer tube is a first inclined cutting surface, the first inclined cutting surface forms the outer surface of the first recess, the proximal end of the functional element is a second inclined cutting surface that cooperates with the first inclined cutting surface, and the first inclined cutting surface and the second inclined cutting surface are fixedly connected.

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