A medical catheter and its manufacturing method

Abstract

This application relates to a medical catheter and its manufacturing method, belonging to the field of medical interventional device technology. The catheter includes a tube body, a reinforcing skeleton, and a manipulation assembly. The reinforcing skeleton, located within the tube body, is a single, continuously spirally wound flat metal wire, with its long side extending radially along the tube body and its short side extending axially; the helical spacing in the proximal section is smaller than that in the distal section. The tube body, from the inside out, includes an inner liner, an elastic filler filling the helical gaps, a mesh braided layer, and an outer covering layer. This application, through its vertically wound flat metal wire structure, provides higher radial support strength, improves the catheter's resistance to collapse under bending or negative pressure conditions, reduces the risk of lumen occlusion, and helps achieve a smooth transition in tube body stiffness.

Description

Technical Field

[0001] This application relates to the field of medical interventional device technology, and in particular to a medical catheter and a method for manufacturing the same. Background Technology

[0002] During VA ECMO treatment, increased cardiac afterload can lead to left ventricular dilation and pulmonary edema, necessitating left ventricular drainage to prevent left ventricular expansion. The left ventricular drainage tube, a crucial interventional pathway, must be routed retrogradely via the femoral artery through the aortic arch and aortic valve into the left ventricle, a path involving complex non-linear anatomy.

[0003] In existing technologies, drainage catheters used for such surgeries face limitations in material mechanical properties during design. On the one hand, to allow the catheter to pass smoothly through tortuous blood vessels (such as the aortic arch) and minimize mechanical damage to the vessel wall and endocardium, the catheter needs to possess extremely high flexibility. On the other hand, to ensure drainage efficiency, the catheter must maintain an open lumen. However, existing catheters using spring tubes made of circular cross-section wire or relying solely on the hardness of polymer materials, when navigating large-angle bends, reduce wire density or use soft materials to achieve flexibility, leading to a significant decrease in the radial support force of the tube wall. Furthermore, to achieve functional differences in different sections, some catheters are constructed by splicing segments of different materials or structures. This not only increases manufacturing complexity but also makes stress concentration points easily form at the joints, posing a risk of breakage during long-term use.

[0004] The aforementioned technologies suffer from the drawback of catheter lumen collapse and occlusion when bent. Specifically, when the catheter in these technologies is subjected to bending moments within the blood vessel, the limited contact area between the circular cross-section metal skeleton and the catheter wall, coupled with the inability of the sparsely coiled structure to provide sufficient circumferential support, inevitably leads to flattening and deformation, or even permanent kinking, of the catheter cross-section under the combined effects of external tension and internal pressure. This collapse of the lumen cross-section directly results in a sharp reduction in the effective cross-sectional area of ​​the drainage channel, significantly decreasing drainage flow and potentially causing serious clinical complications such as left ventricular hypertension due to catheter blockage. Summary of the Invention

[0005] In order to solve the technical problem that the lumen of related catheters collapses and becomes blocked when bent, this application provides a medical catheter.

[0006] This application provides a medical catheter with the following technical solution: A medical catheter includes a tube body, a reinforcing skeleton, and a manipulating component. The tube body has a delivery cavity inside, and is divided into a first tube segment and a second tube segment connected axially. The reinforcing skeleton is disposed within the tube body and surrounds the delivery cavity. The reinforcing skeleton is an integrally continuous spirally wound flat metal wire. The flat metal wire has a rectangular cross-section with a long side and a short side. The long side extends parallel to the radial direction of the tube body, and the short side extends parallel to the axial direction of the tube body. The reinforcing skeleton has a first spiral pitch within the first tube segment and a second spiral pitch within the second tube segment, the first spiral pitch being smaller than the second spiral pitch. The manipulating component is connected to the tube body and configured to drive the second tube segment to deflect relative to the first tube segment.

[0007] By adopting the above technical solution, the tube body is divided into a first section and a second section along the axial direction, with flat metal wires continuously wound into the tube body as a reinforcing skeleton. The flat metal wires in the first section have a smaller helical spacing, giving the first section higher radial support strength and axial stiffness, which is beneficial for efficiently transferring the thrust applied at the proximal end to the distal end. Simultaneously, the flat metal wires in the second section have a larger helical spacing, giving the second section lower bending stiffness, thus endowing the distal end of the conduit with better flexibility and deformation capacity. This integrated variable-spacing design helps maintain structural continuity and reduces the risk of stress concentration at joints. Combined with the "vertical winding" (long side radially) rectangular cross-section metal wires, the circumferential strength and anti-flattening ability of the tube body are improved, making the delivery cavity less prone to collapse when the conduit is bent or under pressure.

[0008] Optionally, the tube body includes an inner lining layer and an outer covering layer in a radially outward direction, and the reinforcing skeleton is disposed between the inner lining layer and the outer covering layer, and is spirally wound around the outer circumferential surface of the inner lining layer.

[0009] By adopting the above technical solution, the inner lining provides a smooth inner wall for the delivery cavity, which helps to reduce fluid resistance and friction when instruments pass through; the outer covering layer provides protection and encapsulation. The reinforcing skeleton is sandwiched between the two, forming a stable composite structure and improving the overall integrity of the tube.

[0010] Optionally, the tube body further includes a mesh braided layer, which coaxially covers the outer periphery of the reinforcing skeleton.

[0011] By adopting the above technical solution, the mesh braided layer enhances the torsional control capability of the catheter by utilizing its physical interlacing characteristics. When a rotational torque is applied to the proximal end, the mesh braided layer can assist in transmitting the torque to the distal end of the catheter, improving the rotational response performance of the catheter. At the same time, the braided layer and the internal helical skeleton form a composite support structure, which also helps to improve the high-pressure burst resistance of the catheter wall.

[0012] Optionally, the tube body further includes an elastic filler that fills the gaps between adjacent helical structures of the reinforcing skeleton.

[0013] By adopting the above technical solution, the elastic filler fills the helical gaps, improving the surface unevenness caused by the helical winding. This not only enhances the sealing performance of the pipe wall structure but also eliminates interlayer air gaps. The elastic filler couples the discrete helical skeleton with the inner and outer layer structures (such as the inner lining and the mesh braided layer) into a cooperating whole, effectively transferring and dispersing stress, and improving the structural integrity and bending resistance of the pipe wall.

[0014] Optionally, the control assembly includes: a control element and a traction wire connected to the control element; a traction channel for accommodating the traction wire is provided in the inner lining layer along the axial direction; wherein the control element is connected to one end of the first pipe segment opposite to the second pipe segment, and the traction wire is connected to one end of the second pipe segment opposite to the first pipe segment.

[0015] By adopting the above technical solution, a traction channel is prefabricated within the inner liner, which physically isolates the traction wire from the delivery cavity and the external reinforcing skeleton, helping to prevent interference or wear between the traction wire and other layers during movement. One end of the traction wire is connected to the manipulator, and the other end is anchored to the end of the relatively low-stiffness second tube segment. The operator can apply tension through the manipulator to drive the second tube segment to bend, improving the maneuverability of the catheter in complex vascular pathways.

[0016] Optionally, the tube body further includes a guide disposed within the traction channel, the guide being configured to limit the radial displacement of the traction wire within the traction channel.

[0017] By adopting the above technical solutions, the guide (such as wear-resistant liner or limiting ring) can constrain the movement path of the traction wire, prevent the traction wire from cutting the inner liner material under high tension (Cheese-wiring effect), and also reduce frictional resistance, extend the service life of the catheter and improve the handling feel.

[0018] Optionally, the reinforcing skeleton has a transition zone at the connection between the first pipe segment and the second pipe segment; the helical spacing of the reinforcing skeleton in the transition zone increases in the direction from the first pipe segment to the second pipe segment.

[0019] By adopting the above technical solution, the gradual design of the helical spacing can smoothly disperse the stress generated during bending, which helps to avoid stress concentration caused by sudden changes in stiffness, thereby reducing the risk of the catheter breaking or twisting at the connection and improving the smoothness of the catheter during bending transition.

[0020] Optionally, the pipe body has multiple drainage holes that penetrate the pipe wall.

[0021] By adopting the above technical solution, the tube body has the function of suction or drainage of catheter fluid, so that when the catheter is inserted into the body (such as the heart chamber), the flow area of ​​the fluid can be increased through the drainage hole on the side wall, the drainage efficiency can be improved, and the drainage failure caused by the single opening being blocked by tissue can be prevented.

[0022] A second aspect of this application provides a method for manufacturing a medical catheter, comprising the following steps: S1, providing a mandrel, and covering the outer periphery of the mandrel with an inner liner; wherein the inner liner has a pre-formed traction channel extending axially; S2, spirally winding a flat metal wire around the outer periphery of the inner liner to form a reinforcing skeleton; wherein the flat metal wire has a rectangular cross-section, the rectangular cross-section having a long side and a short side, the extension direction of the long side being parallel to the radial direction of the tube body, and the extension direction of the short side being parallel to the axial direction of the tube body; the reinforcing skeleton has a first helical pitch in a first tube segment, and the reinforcing skeleton has a second helical pitch in a second tube segment, the first helical pitch being smaller than the second helical pitch; S3, covering the outer periphery of the reinforcing skeleton with a thermoplastic filler. The material is subjected to a first heat treatment, which melts and flows the thermoplastic filler material and fills the gaps between adjacent spirals of the flat metal wire. After cooling and solidification, it forms an elastic filler. S4, a mesh braided layer is provided on the outer periphery of the reinforcing skeleton and the elastic filler. S5, a second heat treatment and core pulling are performed. An outer covering layer is wrapped around the outer periphery of the mesh braided layer, and a second heat treatment is performed to fuse the outer covering layer, the mesh braided layer, the reinforcing skeleton, and the inner lining layer into a tube. Then the core is pulled out. S6, an operating component is installed. A traction wire is threaded through the traction channel of the inner lining layer and connected to the second tube section of the tube body away from the first tube section. The operating component is installed on the first tube section away from the second tube section.

[0023] By adopting the above technical solution and employing a layer-by-layer construction process from the inside out, firstly, in steps S1 and S2, a variable-spacing skeleton is directly wound onto the inner liner layer with prefabricated channels to form a skeleton. The filling process in step S3 fills the spiral gaps, eliminating unevenness on the skeleton surface and providing a smooth and dense load-bearing foundation for the braided layer in step S4 and the outer covering layer in step S5, preventing subsequent covering layer collapse or air gaps. Finally, through the fusion bonding in step S5, the inner liner, skeleton, filler, braided layer, and outer layer are deeply coupled into a single, peel-resistant solid tube wall. This ensures excellent bending, torsional, and pressure resistance of the conduit while significantly improving the product's structural reliability. Furthermore, without interfering with the continuity of the skeleton, the integration of bending adjustment functions is efficiently achieved, enabling high-quality, high-yield manufacturing of complex structure conduits.

[0024] Optionally, the manufacturing method further includes, after step S6, step S7: drilling holes in the side wall of the tube to form a plurality of drainage holes that penetrate the tube wall and communicate with the delivery cavity.

[0025] By adopting the above technical solution, drilling (such as laser drilling or mechanical drilling) is performed after the overall structure of the tube is formed and solidified. This makes the edges of the drainage holes neater and the positions more precise, which helps to reduce the deformation or blockage caused by the pre-reserved holes during the tube melting and forming process, thereby improving the effectiveness of the drainage function.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. This application employs a technical solution combining axially segmented tubing, variable-pitch spiral winding of a single flat metal wire as a reinforcing skeleton, and control components to construct an integrated variable-stiffness conduit structure. The reinforcing skeleton utilizes a vertically wound structure of flat metal wire with the long side radially aligned and the short side axially aligned. This provides high radial support strength to improve resistance to negative pressure collapse while reducing the wall thickness, thus achieving a larger delivery cavity cross-section for the same outer diameter and improving fluid delivery efficiency. Simultaneously, this skeleton, combined with the smaller spiral pitch of the first segment and the larger spiral pitch of the second segment, achieves a smooth transition of the conduit's mechanical properties along the axial direction, ensuring thrust transmission at the proximal end while providing good flexibility and directional bending capability at the distal end. This solution significantly improves the conduit's maneuverability and throughput while reducing the risk of splicing breakage.

[0027] 2. This application, through its built-in traction channel and guide, enables the control of the traction wire to be transmitted to the flexible distal end with minimal loss, which is beneficial to improving the reproducibility and smoothness of bending actions, and also enhances the overall reliability and safety through structural isolation.

[0028] 3. This application further covers the variable-pitch spiral reinforcement skeleton with a mesh braided layer, forming a dual reinforcement system. The inner flat spiral skeleton focuses on providing radial support and anti-flattening ability, while the outer mesh braided layer focuses on providing excellent torsional control and axial connection force. The composite structure of inner spiral and outer braid helps to suppress kinking or kinking that may occur when the catheter travels in tortuous blood vessels. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of a medical catheter according to an embodiment of this application.

[0030] Figure 2 This is a partial structural cross-sectional view of the medical catheter according to an embodiment of this application, mainly used to show the structure of the tube body, flat metal wire, inner lining layer, and mesh braided layer.

[0031] Figure 3 This is a partial structural diagram of a medical catheter according to an embodiment of this application, mainly used to illustrate structures such as flat metal wires.

[0032] Figure 4 This is a partial structural perspective view of a medical catheter according to an embodiment of this application, mainly used to show the structure of the manipulation components and guides.

[0033] Figure 5 This is a flowchart of a method for manufacturing a medical catheter according to an embodiment of this application.

[0034] Explanation of reference numerals in the attached figures: 10. Pipe body; 11. First pipe section; 12. Second pipe section; 13. Conveying chamber; 14. Transition zone; 20. Inner lining layer; 21. Traction channel; 30. Reinforced skeleton; 31. Long side; 32. Short side; 33. Elastic filling material; 40. Mesh woven layer; 50. Outer coating layer; 60. Control assembly; 61. Control element; 62. Traction wire; 70. Guide components. Detailed Implementation

[0035] It should be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "proximal," "distal," "axial," "radial," "inner," and "outer," etc., indicating orientation or positional relationship, are based on the orientation shown in the accompanying drawings or the orientation of the medical device in its normal use state (e.g., "proximal" refers to the end operated by the operator, and "distal" refers to the end inserted into the patient's body). These terms are only for the convenience of describing the invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0036] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail.

[0037] This application provides a medical catheter that can be used in medical settings, such as as a left ventricular drainage tube, for percutaneous insertion into a patient's vascular system and extension to the left ventricle to assist the heart in pumping blood.

[0038] Reference Figure 1 The medical catheter provided in this application mainly includes a slender and flexible tube body 10, a manipulation component 60 connected to the proximal end of the tube body 10, and a composite reinforcement structure disposed inside the tube body 10. The tube body 10 has a proximal end (the end closer to the operator) and a distal end (the end farther from the operator). Along the axial direction, the tube body 10 is mainly divided into a first tube segment 11 and a second tube segment 12. The first tube segment 11 is located on the proximal side and is longer, mainly used as a delivery channel; the second tube segment 12 is located on the distal side and is relatively shorter, serving as an adjustable bending section to enter the heart. The first tube segment 11 and the second tube segment 12 are connected by a transition zone 14. Furthermore, several drainage holes (of prior art, not shown in the figure) are provided on the sidewall of the second tube segment 12. These drainage holes connect the delivery cavity 13 inside the tube body 10 with the external environment, used to introduce external blood.

[0039] Reference Figure 2 and Figure 3This further illustrates the hierarchical structure of the tube body 10. The tube body 10 comprises, from the inside out: an inner liner 20, a reinforcing skeleton 30, a mesh braided layer 40, and an outer covering layer 50. The inner liner 20, located at the innermost layer, is made of a biocompatible polymer material with a low coefficient of surface friction, such as polytetrafluoroethylene (PTFE) or ethylene-tetrafluoroethylene copolymer (ETFE). The use of a biocompatible material in the inner liner 20 allows it to directly contact human blood or tissue, which helps reduce the probability of the material inducing a coagulation or inflammatory reaction in the body. The use of a low coefficient of surface friction material helps reduce the frictional resistance of fluid flowing within the delivery cavity 13, thereby improving the smoothness of blood delivery. A traction channel 21 is integrated within the tube wall or on the outer surface of the inner liner 20. This traction channel 21 extends axially and is used to accommodate a traction wire for controlling the bending of the catheter. The reinforcing skeleton 30 is spirally wound around the outer peripheral surface of the inner liner 20. In this embodiment, the reinforcing skeleton 30 is made of a single flat metal wire, which may be made of nickel-titanium shape memory alloy. The flat metal wire has a rectangular cross-section, which defines the long side 31 and the short side 32.

[0040] Reference Figure 3 The reinforcing skeleton 30 adopts a vertical winding structure. Specifically, the extension direction of the long side 31 is parallel to the radial direction of the tube body 10, and the extension direction of the short side 32 is parallel to the axial direction of the tube body 10. The length of the long side 31 is greater than that of the short side 32, for example, the ratio between the two can be between 2:1 and 6:1, specifically, it can be 4:1. This structure utilizes the height of the long side 31 to provide radial support, which helps to resist the deformation of the tube body during negative pressure suction. At the same time, the narrower short side 32 reduces the axial coverage width, which helps to maintain the flexibility of the tube body. In addition, the reinforcing skeleton 30 has a variable spacing feature: in the first tube section 11, the flat metal wires are arranged in a small-spacing state to provide axial stiffness and torque transmission capability; in the second tube section 12, the flat metal wires are arranged in a large-spacing state to give this section bending flexibility; the transition zone 14 realizes a gradient transition of the spacing.

[0041] Refer again Figure 3 The tube body 10 also includes an elastic filler 33. Figure 3Only a portion of the elastic filler 33 is shown to indicate its filling location. The elastic filler 33 fills the helical gaps between adjacent turns of the reinforcing skeleton 30. In the second tube segment 12 with a larger helical spacing, the elastic filler 33 fills the gaps between the metal wires. The elastic filler 33 is made of a soft polymer material with a lower hardness than the outer covering layer 50. After filling, the outer surface of the elastic filler 33 is substantially flush with the top outer surface of the long side 31, thus forming a flat cylindrical intermediate support surface. The mesh braided layer 40 is coaxially covered on this flat surface and is composed of multiple metal wires or high-strength fibers interwoven together, forming a composite reinforcement system with the reinforcing skeleton 30. The outer covering layer 50 covers the outermost layer and is bonded to the internal structure through a hot-melt process. Different materials with different hardness can be selected for the outer covering layer 50 corresponding to the first tube segment 11 and the second tube segment 12.

[0042] Reference Figure 4 The tube body 10 is equipped with an operating component 60 and guides 70. The operating component 60 is located outside the body and includes an operating element 61 and a traction wire 62 connected to the operating element 61. The traction wire 62 passes through the aforementioned traction channel 21, and its distal end is fixed to the end of the second tube segment 12. Within the region of the second tube segment 12, a plurality of guides 70 are also spaced apart in the traction channel 21. The guides 70 are fixed to the inner wall of the channel, constraining the traction wire 62 to a position close to the tube wall. When the operator drives the operating element 61, the traction wire 62, with the assistance of the guides 70, converts the tension into a bending moment. It should be noted that the direction of bending depends on the position of the traction channel 21 on the circumference of the tube wall. When the traction wire 62 is pulled, the tube will deflect to the side where the traction channel 21 is located, thereby achieving the bending of the tube in a specific direction.

[0043] The implementation principle of the medical catheter in this embodiment is as follows: The catheter utilizes the difference in the moment of inertia of the cross sections by vertically winding a flat metal wire (long side 31 along the radial direction) to provide radial support strength to improve the resistance to negative pressure while maintaining axial flexibility. This is beneficial for obtaining a larger delivery cavity 13 cross section within a limited outer diameter. Through the variable spacing design of a single skeleton, combined with the elastic filler 33 in the outer layer, the mechanical properties of the catheter are transitioned axially: the proximal end (first tube segment 11) has relatively high stiffness due to its dense winding, which is beneficial for the transmission of pushing and rotating operations; the distal end (second tube segment 12) has relatively low stiffness due to its sparse winding, which, combined with the soft elastic filler 33, is beneficial for compliance when entering the ventricle. The combination of the mesh braided layer 40 and the spiral reinforcing skeleton 30 further improves the anti-kinking performance of the tube body and reduces the risk of kinking in tortuous blood vessels.

[0044] Reference Figure 5This application also provides a method for manufacturing the above-mentioned medical catheter, which is prepared by an integrated molding process from the inside out. The method includes the following steps: S1, preparing an inner liner assembly. A long mandrel with an outer diameter matching the inner diameter of the target delivery cavity 13 is provided. An inner liner 20 is applied to the surface of the mandrel, and an axially extending traction channel 21 is prefabricated or integrated on the inner liner 20. S2, winding a variable-pitch reinforcing skeleton. A single flat metal wire is provided and spirally wound around the outer surface of the inner liner 20 with its long side 31 radially and its short side 32 axially to form a reinforcing skeleton 30. During the winding process, according to the pre-set length and flexibility requirements of different tube segments, the winding pitch is changed by program control of the winding equipment, so that a small-pitch arrangement is formed in the region corresponding to the first tube segment 11, a large-pitch arrangement is formed in the region corresponding to the second tube segment 12, and a transition zone 14 with a gradual change in pitch is formed between the two. S3, filling with elastic filler. An elastic filler 33 is filled into the spiral gap of the reinforcing skeleton 30. Specifically, using extrusion coating or reflow processes, soft polymer materials are filled into the large gaps, particularly in the second section 12, and leveled to make the outer surface of the elastic filler 33 flush with the outer surface of the flat metal wire, improving the flatness of the structural surface. S4, Weaving a mesh layer. A mesh layer 40 is woven on the outer surface of the reinforced skeleton 30 and the elastic filler 33 after filling and leveling. Since step S3 has created a flat base surface, it is beneficial for the adhesion of the mesh layer 40. S5, Hot-melt lamination of the outer coating layer. A polymer outer sleeve is fitted onto the outer surface of the mesh layer 40 as the substrate of the outer coating layer 50, and temperature and pressure are applied to melt the outer coating layer 50 and fuse it through the mesh holes to form a single unit with the internal structure. S6, Post-processing. The core rod is extracted after cooling. Since the above manufacturing process is usually carried out on a continuous long tube, the manufactured tubular structure needs to be measured and cut according to the catheter length specifications required for clinical surgery (e.g., the insertion depth required for adult or pediatric types), and a drainage hole is machined on the side wall of the second tube segment 12. S7. Assemble the manipulation assembly. Insert the traction wire 62 into the traction channel 21, install the guide 70, and connect the traction wire 62 to the proximal manipulation assembly 60 and the distal fixation point.

[0045] The manufacturing method of this application embodiment is implemented in the following principle: the continuous variable-pitch winding in step S2 is combined with the elastic filling in step S3. The continuous winding method reduces stress concentration at the variable stiffness connection. The elastic filler 33 introduced in step S3 fills the gaps between the large-pitch helical skeletons and improves the flatness of the skeleton surface. This treatment helps prevent the braided filaments from getting stuck in the gaps, so that the subsequent mesh braided layer 40 and the outer covering layer 50 can form a smooth and continuous support interface, thereby enhancing the bonding force between the layers and facilitating the preparation of a conduit with uniform mechanical properties.

[0046] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A medical catheter, characterized in that, include: The pipe body (10) has a conveying cavity (13) inside; the pipe body (10) is divided into a first pipe section (11) and a second pipe section (12) connected along the axial direction. A reinforcing skeleton (30) is disposed within the tube body (10) and surrounds the conveying cavity (13). The reinforcing skeleton (30) is an integrally continuous spirally wound flat metal wire. The flat metal wire has a rectangular cross-section with a long side (31) and a short side (32). The extension direction of the long side (31) is parallel to the radial direction of the tube body (10), and the extension direction of the short side (32) is parallel to the axial direction of the tube body (10). The reinforcing skeleton (30) has a first spiral pitch in the first tube segment (11) and a second spiral pitch in the second tube segment (12). The first spiral pitch is smaller than the second spiral pitch. A manipulation component (60), connected to the tube body (10), is configured to drive the second tube segment (12) to deflect relative to the first tube segment (11).

2. The medical catheter according to claim 1, characterized in that, The tube body (10) includes an inner lining layer (20) and an outer covering layer (50) in a radial outward direction. The reinforcing skeleton (30) is disposed between the inner lining layer (20) and the outer covering layer (50) and is spirally wound around the outer circumferential surface of the inner lining layer (20).

3. The medical catheter according to claim 1, characterized in that, The tube body (10) also includes a mesh braided layer (40), which coaxially covers the outer periphery of the reinforcing skeleton (30).

4. The medical catheter according to claim 2, characterized in that, The tube body (10) also includes an elastic filler (33) that fills the gaps between adjacent spirals of the reinforcing skeleton (30).

5. The medical catheter according to claim 2, characterized in that, The control assembly (60) includes: a control element (61) and a traction wire (62) connected to the control element (61); the inner lining layer (20) has a traction channel (21) in the axial direction for accommodating the traction wire (62); wherein the control element (61) is connected to one end of the first pipe segment (11) away from the second pipe segment (12), and the traction wire (62) is connected to one end of the second pipe segment (12) away from the first pipe segment (11).

6. The medical catheter according to claim 5, characterized in that, The tube body (10) also includes a guide (70) disposed within the traction channel (21) and configured to limit the radial displacement of the traction wire (62) within the traction channel (21).

7. The medical catheter according to claim 1, characterized in that, The reinforcing skeleton (30) has a transition zone (14) at the connection between the first pipe segment (11) and the second pipe segment (12); the spiral spacing of the reinforcing skeleton (30) in the transition zone (14) increases in the direction from the first pipe segment (11) to the second pipe segment (12).

8. The medical catheter according to claim 1, wherein the tube body (10) has a plurality of drainage holes penetrating the tube wall.

9. A method for manufacturing a medical catheter, characterized in that, Includes the following steps: S1. A mandrel is provided, and an inner liner (20) is covered around the outer periphery of the mandrel; wherein the inner liner (20) is prefabricated with a traction channel (21) extending along the axial direction. S2. A flat metal wire is spirally wound around the outer periphery of the inner liner (20) to form a reinforcing skeleton (30); wherein the flat metal wire has a rectangular cross-section, the rectangular cross-section having a long side (31) and a short side (32), the extension direction of the long side (31) being parallel to the radial direction of the mandrel, and the extension direction of the short side (32) being parallel to the axial direction of the mandrel; the reinforcing skeleton (30) has a first spiral spacing in a first region of the inner liner (20), and the reinforcing skeleton (30) has a second spiral spacing in a second region of the inner liner (20), the first spiral spacing being smaller than the second spiral spacing; S3. The thermoplastic filler material is wrapped around the outer periphery of the reinforcing skeleton (30) and subjected to a first heat treatment, so that the thermoplastic filler material melts and flows and fills the gaps between adjacent spirals of the flat metal wires, and forms an elastic filler (33) after cooling and solidification. S4. A mesh weave layer (40) is provided on the outer periphery of the reinforcing skeleton (30) and the elastic filler (33). S5, second heat treatment and core pulling; wherein, an outer covering layer (50) is wrapped around the outer periphery of the mesh braided layer (40), and a second heat treatment is performed to fuse the outer covering layer (50), the mesh braided layer (40), the reinforcing skeleton (30) and the inner lining layer (20) into a tube (10); then the core rod is pulled out to form a conveying cavity (13). S6. Install the control assembly (60); wherein the traction wire (62) is threaded through the traction channel (21) of the inner lining layer (20) and connected to the second region of the inner lining layer (20); the control element (61) is installed in the first region of the inner lining layer (20) and connected to the traction wire (62).

10. The manufacturing method according to claim 9, characterized in that, Step S6 is followed by: S7, drilling a hole in the side wall of the tube (10) to form a plurality of drainage holes that penetrate the tube wall and connect to the delivery cavity (13).

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