Medical catheter

Abstract

The application provides a medical catheter, comprising: an inner layer, an outer layer, and a developing ring, the outer layer is sleeved outside the inner layer, the developing ring is arranged between the inner layer and the outer layer, the medical catheter comprises a head section, a developing section and a main body section from the distal end to the proximal end in sequence, the head section corresponds to the most distal end of the medical catheter to the most distal end of the developing ring, the developing section corresponds to the axial range of the developing ring, and the main body section corresponds to the proximal end of the developing section to the proximal end of the medical catheter, wherein the axial length of the head section is L1, the single-side wall thickness of the head section in the radial direction is h1, and 0.3≤L1≤33.32h1 2 -2.66h1+0.74. In this way, by controlling the axial length of the head section, the possibility of collapse, distortion or delamination of the head section in clinical operation is reduced, thereby improving the stability and safety performance of the catheter in the process of sucking thrombus.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and in particular to a medical catheter. Background Technology

[0002] Cerebrovascular interventional surgery has seen rapid development due to its advantages of minimal invasiveness, significant effects, and rapid postoperative recovery. In cerebrovascular interventional surgery, catheter-based products are primarily responsible for establishing surgical access, delivering implantable devices, injecting diagnostic reagents, and directly aspirating thrombi; their usage frequency is extremely high.

[0003] Commonly used catheters typically consist of a polymer inner layer, a metal reinforcement layer, a polymer outer layer, a distal radiopaque ring, and a proximal Luer connector. In practical design, to identify the distal end of the catheter, the radiopaque ring is placed at the farthest point of the catheter, i.e., the tip. Simultaneously, a certain gap exists between the radiopaque ring and the metal reinforcement layer. Furthermore, to ensure flexibility and non-invasiveness at the tip, the distal end of the catheter is made of a very soft material, which reduces the strength of the distal end and the junction between the radiopaque ring and the catheter.

[0004] In summary, the following risks may occur during actual clinical use: (1) Due to the excessive gap between the contrast ring and the enhancement layer, the contrast ring may fall into the blood vessel or the enhancement layer may be exposed on the outer layer of the catheter during the delivery of the device, thus scratching the blood vessel; (2) Due to the excessive length of the catheter tip, the catheter tip may be twisted and deformed during the aspiration of thrombi, thus affecting the aspiration efficiency; (3) Due to the excessive length of the catheter tip, delamination may occur at the junction of the inner and outer layers of material and the contrast ring at the tip. Summary of the Invention

[0005] The purpose of this invention is to provide a medical catheter that solves problems such as torsion and deformation of the catheter tip, breakage, and delamination at the junction of the inner and outer layers of the catheter and the radiopaque ring during use.

[0006] To achieve the above objectives, the present invention provides a medical catheter, comprising: an inner layer, an outer layer, and a radiopaque ring, wherein the outer layer is sleeved over the inner layer; and the radiopaque ring is disposed between the inner layer and the outer layer;

[0007] The medical catheter comprises, from distal to proximal, a head segment, a radiopaque segment, and a main body segment. The head segment corresponds to the distal end of the medical catheter to the distal end of the radiopaque ring. The radiopaque segment corresponds to the axial range of the radiopaque ring. The main body segment corresponds to the proximal end of the radiopaque segment to the proximal end of the medical catheter.

[0008] Wherein, the axial length of the head section is L1, and the radial wall thickness of the head section on one side is h1, then 0.3 ≤ L1 ≤ 33.32h1 is satisfied. 2-2.66h1+0.74.

[0009] Optionally, the single-side wall thickness h1 of the head section is 0.066~0.2mm.

[0010] Optionally, the single-side wall thickness h1 of the head section is 0.066~0.1mm.

[0011] Optionally, the axial length L1 of the head section is 0.3~1.5mm.

[0012] Optionally, the axial length L1 of the head section is 0.4~0.7mm.

[0013] Optionally, the medical catheter further includes a reinforcing structure disposed between the inner layer and the outer layer and arranged axially on the proximal side of the radiopaque ring; the main body segment of the medical catheter further includes a connecting segment and a reinforcing segment from the distal end to the proximal end; the connecting segment corresponds to the distance from the proximal end of the radiopaque ring to the distal end of the reinforcing structure, and the reinforcing segment corresponds to the axial range of the reinforcing structure;

[0014] Wherein, the axial length of the connecting segment is L2, and the radial wall thickness on one side of the connecting segment is h2, then 0 ≤ L2 ≤ 4.71h2 is satisfied. 2 +1.73h2+0.465.

[0015] Optionally, the radial wall thickness h2 of the connecting segment on one side is 0.066~0.2mm.

[0016] Optionally, the radial wall thickness h2 of the connecting segment on one side is 0.076~0.2mm.

[0017] Optionally, the axial length L2 of the connecting segment is 0~0.7mm.

[0018] Optionally, the axial length L2 of the connecting segment is 0~0.5mm.

[0019] Optionally, the axial length L2 of the connecting segment is 0~0.3mm.

[0020] Optionally, the reinforcing structure may include a braided structure or a spring structure.

[0021] Optionally, the number of cross points per inch of the braided structure is controlled to be between 200 and 250.

[0022] Optionally, the outer diameter of the medical catheter is 1.7~1.79 mm.

[0023] Optionally, the medical catheter is used to aspirate blood clots.

[0024] In summary, the present invention provides a medical catheter, comprising: an inner layer, an outer layer, and a radiopaque ring, wherein the outer layer is sleeved outside the inner layer; the radiopaque ring is disposed between the inner layer and the outer layer; the medical catheter, from distal to proximal, sequentially comprises a tip section, a radiopaque section, and a main body section, wherein the tip section corresponds to the distance from the distal end of the medical catheter to the distal end of the radiopaque ring, the radiopaque section corresponds to the axial range of the radiopaque ring, and the main body section corresponds to the distance from the proximal end of the radiopaque section to the proximal end of the medical catheter; wherein the axial length of the tip section is L1, and the radial wall thickness on one side of the tip section is h1, satisfying 0.3 ≤ L1 ≤ 33.32h1 2 -2.66h1+0.74. Compared with existing catheters, it has the following advantages:

[0025] (1) By controlling the axial length of the tip, the possibility of catheter collapse, retraction and delamination of the inner and outer layers in clinical practice is reduced, thereby improving the stability and safety of the catheter.

[0026] (2) Furthermore, by controlling the axial length of the connecting segment, the possibility of the catheter collapsing or breaking during use is reduced, and the situation of the tip and the imaging segment falling into the patient's blood vessels is avoided, which further improves the clinical safety of the catheter. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of a medical catheter provided in an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of a medical catheter provided in Embodiment 1 of the present invention;

[0029] Figure 3 This is a schematic diagram of the structure of a medical catheter provided in Embodiment 2 of the present invention;

[0030] Figure 4 This is a schematic diagram of the structure of a medical catheter provided in Embodiment 3 of the present invention.

[0031] The labels in the accompanying drawings are explained as follows:

[0032] 1-Head section; 2-Developing section; 3-Connecting section; 4-Reinforcing section; 11-Inner layer; 12-Outer layer; 21-Developing ring; 41-Reinforcing structure. Detailed Implementation

[0033] To make the objectives, advantages, and features of this invention clearer, the 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 all in a very simplified form and are not drawn to scale, and are only used to facilitate and clarify the explanation of the embodiments of this invention. Furthermore, the structures shown in the drawings are often part of the actual structures. In particular, different figures may emphasize different aspects and may sometimes use different scales.

[0034] As used herein, the singular forms “a,” “an,” and “the” include plural objects; the term “or” is generally used to mean “and / or”; the term “a number” is generally used to mean “at least one”; and the term “at least two” is generally used to mean “two or more”. Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as “first,” “second,” or “third” may explicitly or implicitly include one or at least two of that feature. “One end” and “the other end,” and “proximal end” and “distal end” generally refer to two corresponding parts, including not only endpoints. “Proximal end” generally represents the direction closer to the surgeon during surgery, and “distal end” generally represents the direction closer to the lesion during surgery. The terms “installed,” “connected,” and “joined” should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral part; as a direct connection or an indirect connection through an intermediate medium; or as a connection within two components or an interaction between two components. Furthermore, as used in this specification, the phrase "one element is disposed on another element" generally only indicates that there is a connection, coupling, cooperation, or transmission relationship between the two elements, and the connection, coupling, cooperation, or transmission between the two elements can be direct or indirect through an intermediate element. It should not be construed as indicating or implying a spatial positional relationship between the two elements, i.e., one element can be located arbitrarily inside, outside, above, below, or to the side of another element, unless otherwise explicitly stated. The terms "above," "below," "top," and "bottom" generally refer to relative positional relationships arranged according to the direction of gravity; the terms "vertical" or "vertical direction" generally refer to the direction of gravity, which is generally perpendicular to the ground; "horizontal" or "horizontal plane direction" generally refers to a direction parallel to the ground. Those skilled in the art can understand the specific meaning of the above terms in this specification according to the specific circumstances.

[0035] The purpose of this invention is to provide a medical catheter that solves problems such as torsion and deformation of the catheter tip, breakage, and delamination at the junction of the inner and outer layers of the catheter and the radiopaque ring during use.

[0036] The following description refers to the accompanying drawings.

[0037] Example 1

[0038] Please refer to Figures 1 to 2 This embodiment provides a medical catheter, which includes an inner layer 11, an outer layer 12, and a radiopaque ring 21. The outer layer 12 is sleeved outside the inner layer 11. The radiopaque ring 21 is disposed between the inner layer 11 and the outer layer 12. From distal to proximal, the medical catheter includes a head segment 1, a radiopaque segment 2, and a main body segment. The head segment 1 corresponds to the distal end of the medical catheter to the distal end of the radiopaque ring 21. The radiopaque segment 2 corresponds to the axial range of the radiopaque ring 21. The main body segment corresponds to the proximal end of the radiopaque segment 2 to the proximal end of the medical catheter. Further, the medical catheter also includes a reinforcing structure 41, which is disposed between the inner layer 11 and the outer layer 12 and is axially arranged on the proximal side of the radiopaque ring 21. From distal to proximal, the main body segment of the medical catheter also includes a connecting segment 3 and a reinforcing segment 4. The connecting segment 3 corresponds to the proximal end of the radiopaque ring 21 to the distal end of the reinforcing structure 41, and the reinforcing segment 4 corresponds to the axial range of the reinforcing structure 41. It needs to be explained that, in Figures 1 to 4 In the illustrated example, the proximal end represents the direction closer to the doctor during the procedure, and the distal end represents the direction closer to the lesion during the procedure. The outer layer 12 is made of soft polymer materials such as thermoplastic polyurethane (TPU), polyether-polyamide copolymer (Pebax), rubber, and silicone; the inner layer 11 is made of one or more of polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyolefin (POE), and polyethylene (PE). Those skilled in the art can configure the materials of the inner layer 11 and the outer layer 12 according to the purpose of the catheter, and the present invention is not limited thereto.

[0039] Furthermore, the developing ring 21 can be a closed ring or an open ring made of platinum, iridium, tungsten, or their alloys. Figures 1 to 4 In the illustrated example, the imaging ring 21 is fitted onto the outer surface of the inner layer 11. As those skilled in the art will understand, the imaging ring 21 serves to locate the distal end of the catheter. Therefore, the imaging ring 21 is an annular shape that fits the surface of the catheter. Of course, in other embodiments, the imaging ring 21 may also be other components with the same function, and its shape may also be other reasonable shapes. The present invention is not limited to these.

[0040] Furthermore, the reinforcing structure 41 includes a woven structure or a spring structure. Figures 1 to 4In the illustrated example, the reinforcing structure 41 is a braided or spring-like structure fitted onto the outer surface of the inner layer 11. However, in some other embodiments, the reinforcing structure 41 may also be other components with the same function; this invention is not limited in this regard. Preferably, the reinforcing structure 41 is made of metal wire or polymer filament. The metal wire may be stainless steel wire, nickel-titanium wire, tungsten wire, etc.; the polymer filament may be polyamide, high-density polyethylene, polyimide, PVDF, PTFE, etc. Those skilled in the art can select appropriate materials according to the actual application of the catheter; this invention is not limited in this regard.

[0041] Please continue to refer to this. Figures 1 to 2 In the medical catheter provided in this embodiment, the axial length of the tip segment 1 is L1, and the wall thickness of the tip segment 1 on one side along the axial direction is h1, which satisfies 0.3≤L1≤33.32h1 2 -2.66h1+0.74. It should be noted that... Figures 1 to 4 In the illustrated example, the axial direction is left-right. In the above relationship, the axial length L1 of the tip 1 is affected by its unilateral wall thickness h1, which in turn is related to its material. Therefore, different materials of the tip 1 are suitable for different axial length ranges of L1. This embodiment reduces the possibility of catheter collapse, breakage, and delamination during use by controlling the axial length L1 of the tip 1, thereby improving the catheter's performance and clinical safety.

[0042] As an optional implementation, the axial wall thickness h1 of the head segment 1 is 0.066~0.2mm, preferably 0.066~0.1mm, and correspondingly, the axial length L1 of the head segment 1 is 0.3~1.5mm, preferably 0.35~1mm, and more preferably 0.4~0.7mm. The axial wall thickness h1 refers to the radial distance from the outer surface of the outer layer 12 to the inner surface of the inner layer 11, and the axial length L1 refers to the axial distance from the farthest end of the contrast ring 21 to the farthest end of the catheter. When the axial length L1 of the head segment 1 exceeds the upper limit of the axial length range, the catheter is prone to collapse and retraction during thrombus aspiration, thus affecting the aspiration efficiency. When the axial length L1 of the head segment 1 is lower than the lower limit of the axial length range, material delamination between the inner layer 11 and the outer layer 12 is likely to occur during use, causing the contrast ring 21 to be exposed, damaging the catheter structure, and increasing the risk of the contrast ring 21 detaching. It should be noted that different materials of the head section 1 are suitable for different axial length ranges of L1. However, it is necessary to ensure that when the axial length L1 of the head section 1 is within a suitable axial length range, the catheter is less likely to collapse, retract, or delaminate during use, thereby improving the suction efficiency and safety performance of the catheter.

[0043] Furthermore, if the axial length of the connecting segment 3 is L2 and the wall thickness of one side of the connecting segment 3 along the axial direction is h2, then 0 ≤ L2 ≤ 4.71h2 is satisfied. 2 +1.73h² + 0.465. It should be noted that in the above formula, the axial length L2 of the connecting segment 3 is affected by its unilateral wall thickness h2, which in turn is related to its material. Therefore, different materials of the connecting segment 3 are suitable for different ranges of axial length L2. This embodiment reduces the possibility of catheter collapse or breakage during use by controlling the axial length L2 of the connecting segment 3, thereby preventing the tip 1 and the visualized segment 2 from dislodging into the patient's blood vessels and improving the clinical safety of the catheter.

[0044] As an optional implementation, the single-sided wall thickness h2 of the connecting segment 3 along the axial direction is 0.066~0.2mm, preferably 0.076~0.2mm, and correspondingly, the axial length L2 of the connecting segment 3 is 0~1mm, further, the axial length L2 of the connecting segment 3 is 0~0.7mm, preferably 0~0.5mm, more preferably 0~0.3mm, wherein the single-sided wall thickness h2 refers to the radial distance from the outer surface of the outer layer 12 to the inner surface of the inner layer 11, and the axial length L2 refers to the axial distance from the nearest end of the developing ring 21 to the farthest end of the reinforcing structure 41. During clinical treatment, the inventors discovered that because the imaging ring 21 in imaging segment 2 and the reinforcing structure 41 in reinforcing segment 4 are both made of metal or polymer materials, their strength is higher than that of the tip segment 1. However, due to limitations in manufacturing processes, imaging segment 2 and reinforcing segment 4 cannot be precisely fitted together. Therefore, the connecting segment 3, as part of the connection between imaging segment 2 and reinforcing segment 4, becomes a weak point in the catheter structure. Its axial length L2 needs to be controlled during manufacturing. When the axial length L2 of connecting segment 3 exceeds the upper limit of the axial length range, the catheter is prone to collapse and breakage during use, causing tip segment 1 and imaging segment 2 to detach into the patient's blood vessels, resulting in serious clinical accidents. It should be noted that different materials for connecting segment 3 are suitable for different axial length ranges of L2. However, it is necessary to ensure that when the axial length L2 of connecting segment 3 is within a suitable range, the catheter is less likely to collapse or break during use, thus preventing tip segment 1 and imaging segment 2 from detaching into the patient's blood vessels, thereby further improving the clinical safety performance of the catheter.

[0045] It should be noted that the above-mentioned relationship between the axial length L1 of the head segment 1 and the single-sided wall thickness h1 of the head segment 1 along the axial direction, as well as the relationship between the axial length L2 of the connecting segment 3 and the single-sided wall thickness h2 of the connecting segment 3 along the axial direction, are all obtained based on fitting experimental data. Of course, in some other embodiments, the relationship between the axial length L1 of the head segment 1 and the single-sided wall thickness h1 of the head segment 1 along the axial direction, as well as the relationship between the axial length L2 of the connecting segment 3 and the single-sided wall thickness h2 of the connecting segment 3 along the axial direction, can also be other forms of relationship. Those skilled in the art can configure it according to the actual situation, and the present invention is not limited thereto.

[0046] Please refer to Figure 2 In the medical catheter provided in this embodiment, the inner layer 11 is made of low-density polyethylene (LLDPE), the outer layer 12 is made of thermoplastic polyurethane (TPU), the radiopaque ring 21 is a closed-loop structure made of platinum-iridium alloy, and the reinforcing structure 41 is a braided structure made of stainless steel wire. Due to the influence of the materials of the inner layer 11 and the outer layer 12, the axial wall thickness h1 of the tip 1 is 0.8~1.15mm, preferably 0.9~1.1mm, and correspondingly, the axial length L1 of the tip 1 is 0.4~0.8mm, preferably 0.45~0.7mm. This configuration limits the lower limit of the axial length L1 of the tip 1 to ensure that the inner and outer layer materials can wrap the radiopaque ring 21, reducing the probability of its delamination; and limits the upper limit of the axial length L1 of the tip 1 to ensure that the tip 1 has good strength and can maintain its shape during thrombus aspiration, preventing collapse.

[0047] Furthermore, the axial wall thickness h2 of the connecting segment 3 is 0.8~1.15mm, preferably 0.9~1.1mm, and correspondingly, the axial length L2 of the connecting segment 3 is 0~0.5mm, preferably 0~0.4mm, and more preferably 0~0.3mm. This configuration limits the upper limit of the axial length L2 of the connecting segment 3, reduces the impact of this weak area on the head segment 1 and the radiopaque segment 2, reduces the risk of the radiopaque ring 21 dislodging in the blood vessel, and improves the clinical safety of the catheter.

[0048] As a preferred embodiment, please continue to refer to Figure 2When the materials and structures of the inner layer 11, outer layer 12, contrast ring 21, and reinforcing structure 41 are completely identical, and the inner diameter of the catheter is controlled at 0.055±0.002 inches, the outer diameter at 1.7~1.79 mm, the overall length of the catheter at 115~135 cm, and the number of intersections per inch of the reinforcing structure 41 at 200~250, the axial wall thickness h1 of the head segment 1 is 0.9~1.1 mm, and the axial length L1 is 0.45~0.7 mm; the axial wall thickness h2 of the connecting segment 3 is 0.9~1.1 mm, and the axial length L2 is 0~0.3 mm. With this configuration, during the delivery of medical devices such as stents, coils, and membranes, the head segment 1 will not delaminate, and the contrast ring 21 will not detach, demonstrating good safety. Simultaneously, during thrombus aspiration, the shape of the head segment 1 remains intact without collapse, maintaining aspiration efficiency. It should be noted that, as those skilled in the art will understand, the conduit is an annular component, the inner diameter of which is the radial distance between the inner surfaces of the radially symmetrical inner layer 11, and the outer diameter of which is the radial distance between the outer surfaces of the radially symmetrical outer layer 12.

[0049]

Example 2

[0050] This embodiment provides a medical catheter that has the same components as the medical catheter provided in Embodiment 1, namely, it also includes: an inner layer 11, an outer layer 12, and a radiopaque ring 21, wherein the outer layer 12 is sleeved outside the inner layer 11; the radiopaque ring 21 is disposed between the inner layer 11 and the outer layer 12; the medical catheter includes, from distal to proximal, a head segment 1, a radiopaque segment 2, and a main body segment, wherein the head segment 1 corresponds to the distal end of the medical catheter to the distal end of the radiopaque ring 21, and the radiopaque segment 2 corresponds to the axial range of the radiopaque ring 21. The main body segment corresponds to the distance from the proximal end of the radiopaque segment 2 to the proximal end of the medical catheter. Further, the medical catheter also includes a reinforcing structure 41, which is disposed between the inner layer 11 and the outer layer 12 and arranged axially on the proximal side of the radiopaque ring 21. The main body segment of the medical catheter also includes a connecting segment 3 and a reinforcing segment 4 from the distal end to the proximal end. The connecting segment 3 corresponds to the distance from the proximal end of the radiopaque ring 21 to the distal end of the reinforcing structure 41, and the reinforcing segment 4 corresponds to the axial range of the reinforcing structure 41. Simultaneously, the axial length L1 of the head segment 1 and the axial wall thickness h1 of the head segment 1 on one side also satisfy 0.3 ≤ L1 ≤ 33.32h1. 2 -2.66h1+0.74; The axial length L2 of connecting segment 3 and the single-sided wall thickness h2 of connecting segment 3 along the axial direction also satisfy 0≤L2≤4.71h2 2 +1.73h2+0.465.

[0051] Unlike Example 1, please refer to Figure 3 In the medical catheter provided in this embodiment, the inner layer 11 is made of polytetrafluoroethylene (PTFE), the outer layer 12 is made of thermoplastic polyurethane (TPU), the imaging ring 21 is a closed-loop structure made of platinum-iridium alloy, and the reinforcing structure 41 is a spring structure made of wound nickel-titanium alloy wire. Due to the influence of the materials of the inner layer 11 and the outer layer 12, the axial wall thickness h1 of the tip 1 is 0.8~1.15mm, preferably 0.9~1.1mm, and correspondingly, the axial length L1 of the tip 1 is 0.4~0.8mm, preferably 0.45~0.7mm. Furthermore, the axial wall thickness h2 of the connecting section 3 is 0.8~1.15mm, preferably 0.9~1.1mm, and correspondingly, the axial length L2 of the connecting section 3 is 0~0.5mm, preferably 0~0.4mm, more preferably 0~0.3mm.

[0052] With this configuration, the imaging ring 21 can be better wrapped by the inner layer 11 and the outer layer 12, preventing delamination. At the same time, the tip 1 has good strength, ensuring that the catheter can maintain its shape and not collapse during thrombus aspiration. Furthermore, the tip 1 and imaging segment 2 will not fall into the blood vessel during use, avoiding medical accidents and improving the clinical safety performance of the catheter.

[0053]

Example 3

[0054] This embodiment provides a medical catheter that has the same components as the medical catheters provided in Embodiments 1 and 2, namely, it also includes: an inner layer 11, an outer layer 12, and a radiopaque ring 21. The outer layer 12 is sleeved outside the inner layer 11; the radiopaque ring 21 is disposed between the inner layer 11 and the outer layer 12; the medical catheter includes, from distal to proximal, a head segment 1, a radiopaque segment 2, and a main body segment. The head segment 1 corresponds to the distal end of the medical catheter to the distal end of the radiopaque ring 21, and the radiopaque segment 2 corresponds to the axis of the radiopaque ring 21. The main body segment corresponds to the distance from the proximal end of the radiopaque segment 2 to the proximal end of the medical catheter. Further, the medical catheter also includes a reinforcing structure 41, which is disposed between the inner layer 11 and the outer layer 12 and arranged axially on the proximal side of the radiopaque ring 21. The main body segment of the medical catheter also includes a connecting segment 3 and a reinforcing segment 4 from the distal end to the proximal end. The connecting segment 3 corresponds to the distance from the proximal end of the radiopaque ring 21 to the distal end of the reinforcing structure 41, and the reinforcing segment 4 corresponds to the axial range of the reinforcing structure 41. Simultaneously, the axial length L1 of the head segment 1 and the axial wall thickness h1 of the head segment 1 on one side also satisfy 0.3 ≤ L1 ≤ 33.32h1. 2-2.66h1+0.74; The axial length L2 of connecting segment 3 and the single-sided wall thickness h2 of connecting segment 3 along the axial direction also satisfy 0≤L2≤4.71h2 2 +1.73h2+0.465.

[0055] Unlike Embodiment 1 and Embodiment 2, please refer to Figure 4 In the medical catheter provided in this embodiment, the inner layer 11 is made of low-density polyethylene (LLDPE) and polytetrafluoroethylene (PTFE), and the outer layer 12 is made of thermoplastic polyurethane (TPU) and polyether-polyamide copolymer (Pebax). The imaging ring 21 is a closed-loop structure made of platinum-iridium alloy, and the reinforcing structure 41 is a braided structure made of stainless steel wire. Due to the influence of the materials of the inner layer 11 and the outer layer 12, the axial wall thickness h1 of the tip section 1 is 0.8~1.15mm, preferably 0.9~1.1mm, and correspondingly, the axial length L1 of the tip section 1 is 0.4~0.8mm, preferably 0.45~0.7mm. Furthermore, the axial wall thickness h2 of the connecting section 3 is 0.8~1.15mm, preferably 0.9~1.1mm, and correspondingly, the axial length L2 of the connecting section 3 is 0~0.5mm, preferably 0~0.4mm, and more preferably 0~0.3mm.

[0056] With this configuration, the imaging ring 21 can be better wrapped by the inner layer 11 and the outer layer 12, preventing delamination. At the same time, the tip 1 has good strength, ensuring that the catheter can maintain its shape and not collapse during thrombus aspiration. Furthermore, the tip 1 and imaging segment 2 will not fall into the blood vessel during use, avoiding medical accidents and improving the clinical safety performance of the catheter.

[0057] In summary, this invention provides a medical catheter, comprising: an inner layer, an outer layer, and a radiopaque ring, wherein the outer layer is sleeved outside the inner layer; the radiopaque ring is disposed between the inner layer and the outer layer, and the radiopaque ring is spaced axially from the distal end of the medical catheter; the medical catheter is divided into a head segment and a radiopaque segment from the distal end to the proximal end, the head segment corresponding to the distal end of the medical catheter to the distal end of the radiopaque ring, and the radiopaque segment corresponding to the axial range of the radiopaque ring; wherein the axial length of the head segment is L1, and the radial wall thickness on one side of the head segment is h1, satisfying 0.3 ≤ L1 ≤ 33.32h1 2-2.66h1+0.74. This configuration, by controlling the axial length of the tip, reduces the likelihood of catheter collapse, retraction, and delamination of the inner and outer layers in clinical practice, thereby improving the stability and safety of the catheter. Furthermore, by controlling the axial length of the connecting section, it reduces the possibility of catheter collapse or breakage during use, preventing the tip and contrasting sections from detaching into the patient's blood vessels, further enhancing the clinical safety of the catheter.

[0058] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A medical catheter, characterized in that, include: The system comprises an inner layer, an outer layer, and a developing ring, wherein the outer layer is sleeved over the inner layer; and the developing ring is disposed between the inner layer and the outer layer. The medical catheter comprises, from distal to proximal, a head segment, a radiopaque segment, and a main body segment. The head segment corresponds to the distal end of the medical catheter to the distal end of the radiopaque ring. The radiopaque segment corresponds to the axial range of the radiopaque ring. The main body segment corresponds to the proximal end of the radiopaque segment to the proximal end of the medical catheter. Wherein, the axial length of the head section is L1, and the radial wall thickness of the head section on one side is h1, then 0.3 ≤ L1 ≤ 33.32h1 is satisfied. 2 -2.66h1+0.

74.

2. The medical catheter as described in claim 1, characterized in that, The radial wall thickness h1 of the head section is 0.066 to 0.2 mm on one side.

3. The medical catheter as described in claim 2, characterized in that, The radial wall thickness h1 of the head section is 0.066 to 0.1 mm on one side.

4. The medical catheter as described in claim 1, characterized in that, The axial length L1 of the head section is 0.3 to 1.5 mm.

5. The medical catheter as described in claim 4, characterized in that, The axial length L1 of the head section is 0.4 to 0.7 mm.

6. The medical catheter as described in claim 1, characterized in that, The medical catheter further includes a reinforcing structure disposed between the inner layer and the outer layer, and arranged axially on the proximal side of the radiopaque ring; the main body segment of the medical catheter further includes a connecting segment and a reinforcing segment from the distal end to the proximal end; the connecting segment corresponds to the distance from the proximal end of the radiopaque ring to the distal end of the reinforcing structure, and the reinforcing segment corresponds to the axial range of the reinforcing structure; Wherein, the axial length of the connecting segment is L2, and the radial wall thickness on one side of the connecting segment is h2, then 0 ≤ L2 ≤ 4.71h2 is satisfied. 2 +1.73h2+0.

465.

7. The medical catheter as described in claim 6, characterized in that, The radial wall thickness h2 of the connecting section is 0.066 to 0.2 mm on one side.

8. The medical catheter as described in claim 7, characterized in that, The radial wall thickness h2 of the connecting section is 0.076 to 0.2 mm on one side.

9. The medical catheter as described in claim 6, characterized in that, The axial length L2 of the connecting section is 0 to 0.7 mm.

10. The medical catheter as described in claim 9, characterized in that, The axial length L2 of the connecting section is 0 to 0.5 mm.

11. The medical catheter as claimed in claim 10, characterized in that, The axial length L2 of the connecting section is 0 to 0.3 mm.

12. The medical catheter as claimed in claim 6, characterized in that, The reinforcing structure includes a braided structure or a spring structure.

13. The medical catheter as described in claim 12, characterized in that, The number of cross points per inch in the braided structure is controlled between 200 and 250.

14. The medical catheter as claimed in claim 1, characterized in that, The outer diameter of the medical catheter is 1.7–1.79 mm.

15. The medical catheter as described in any one of claims 1 to 14, characterized in that, The medical catheter is used to aspirate blood clots.

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