Tong channel pipe and preparation method thereof

Abstract

The invention provides a forceps channel pipe and a preparation method thereof. The clamp channel pipe at least comprises a bent section and a main body section from the front end to the rear end in the axial direction, and the axial rigidity of the bent section is smaller than that of the main body section. The bending section comprises a bending section inner layer, a bending section middle layer and a bending section outer layer, and a spring winding layer formed by winding metal wires according to a preset screw pitch or a continuous first weaving layer formed by a plurality of metal weaving grids woven according to a first weaving mesh number is formed in the bending section middle layer penetrating through the bending section; the main body section comprises a main body section inner layer, a main body section outer layer and a main body section middle layer at least partially arranged between the main body section inner layer and the main body section outer layer, and the main body section middle layer is a continuous second woven layer formed by a plurality of metal woven grids woven according to a second weaving mesh number. On the premise that the structural complexity of the channel clamping pipe is not remarkably increased, different mechanical requirements of the channel clamping pipe at different positions are met, and the use performance of the channel clamping pipe under the complex operation working condition is improved.

Description

Technical Field

[0001] This invention relates to the field of medical treatment device technology, and in particular to a forceps tube and its preparation method. Background Technology

[0002] The endoscopic forceps cannula is a tubular component that runs through the insertion section of a flexible endoscope. Its primary function is to provide passage for various surgical instruments and to facilitate fluid injection and aspiration. Specifically, the forceps cannula in an endoscope is typically used for the entry and exit of diagnostic and therapeutic accessories such as biopsy forceps, snares, stone retrieval baskets, and high-frequency electrosurgical units. It also serves as a delivery channel for irrigation fluids or negative pressure aspiration, enabling procedures such as tissue sampling, foreign body removal, and lesion resection to be performed during endoscopic examinations or treatments. Therefore, the forceps cannula is a crucial functional structural component in endoscopic products, and its performance directly affects the smoothness of endoscope operation, safety, and overall lifespan.

[0003] In practical use, the forceps cannula, when bent, not only needs to maintain sufficient internal patency to ensure smooth passage of instruments and proper irrigation or aspiration of fluids, but also needs to maintain a stable structural shape after repeated bending to avoid problems such as collapse, flattening, or localized damage. If the forceps cannula's bending resistance is insufficient, it is prone to radial collapse in the bending area when the insertion part undergoes a large bending angle. This leads to a significant increase in resistance to pushing instruments, and may even result in instruments being unable to enter or exit smoothly, or obstruction of the irrigation or aspiration channel. In severe cases, this will directly affect the normal conduct of endoscopic examinations and treatments.

[0004] Furthermore, because the surgical instruments need to move back and forth frequently within the forceps cannula, there is constant frictional contact between the inner wall of the cannula and the instruments. Therefore, the forceps cannula also needs to have good self-lubricating and wear-resistant properties. If the inner wall of the forceps cannula is not sufficiently lubricated or has poor wear resistance, repeated insertion and withdrawal of the instruments can easily lead to accelerated wear of the inner wall. This will not only increase the resistance to pushing the instruments and reduce the feel of operation, but may also shorten the service life of the forceps cannula, and even cause risks such as inner wall damage and debris shedding.

[0005] In existing technologies, to improve the bending resistance or axial pushing performance of clamping tubes, a reinforcing structure is typically placed between the inner and outer layers of the clamping tube. However, these reinforcing structures often employ a single form or uniform parameter configuration along the axial direction of the clamping tube, failing to fully consider the significant differences in the mechanical functions performed by the clamping tube at different axial positions: for example, the bending region near the head emphasizes flexibility and bending resistance, while the main body region near the rear emphasizes axial pushing stability and structural support. Using a single reinforcing structure or a uniform parameter design can easily lead to over-performance in some areas and under-performance in others, resulting in a trade-off between bending and pushing performance, making it difficult to simultaneously meet multiple application requirements.

[0006] Therefore, how to optimize the design of the clamp pipe according to its mechanical requirements at different axial positions while ensuring the overall unobstructed flow and structural reliability of the clamp pipe remains an urgent technical problem to be solved. Summary of the Invention

[0007] In order to achieve at least one objective such as good self-lubrication, wear resistance and bending resistance of the above-mentioned clamping pipe, one embodiment of the first aspect of the present invention is a clamping pipe, which includes at least the following along its axial direction from the front end to the rear end: the clamping pipe includes at least the following along its axial direction from the front end to the rear end: a bending section and a main body section, wherein the axial stiffness of the bending section is less than the axial stiffness of the main body section.

[0008] The curved section includes an inner layer, a middle layer, and an outer layer. The middle layer extends through the curved section and is formed as a spring layer formed by winding metal wires according to a predetermined pitch or as a continuous first braided layer formed by multiple metal braided meshes woven according to a first braiding mesh number.

[0009] The main body segment includes an inner layer, an outer layer, and an intermediate layer at least partially disposed between the inner and outer layers. The intermediate layer is a continuous second braided layer formed by multiple metal braided meshes woven according to a second braiding count.

[0010] In one possible implementation of the first aspect, the main body segment includes a first main body segment and a second main body segment; the first main body segment has a first main body segment inner layer, a first main body segment middle layer and a first main body segment outer layer, and the second main body segment has a second main body segment inner layer and a second main body segment outer layer.

[0011] In one possible implementation of the first aspect, the hardness of the outer layer of the second main body segment is not lower than the hardness of the outer layer of the first main body segment, and the hardness difference between the two is between (0 and 10) D.

[0012] In one possible implementation of the first aspect, the inner diameter of the first main body segment is 1.00 mm to 3.00 mm, and the wall thickness is 0.06 mm to 0.30 mm.

[0013] In one possible implementation of the first aspect, the inner diameter of the second main body segment is 1.00 mm to 3.00 mm, and its wall thickness is 0.06 mm to 0.30 mm.

[0014] In one possible implementation of the first aspect, a second body segment intermediate layer is provided between the second body segment inner layer and the second body segment outer layer, and the number of weaves of the second intermediate weave layer used to weave the second body segment intermediate layer is lower than or equal to the number of weaves of the first intermediate weave layer used to weave the first body segment intermediate layer.

[0015] In one possible implementation of the first aspect, the main body segment is a continuous one-piece structure, and the intermediate layer of the main body segment is disposed through the inner layer and the outer layer of the main body segment, wherein the weave count of the intermediate layer of the main body segment gradually decreases or remains constant from the front end to the rear end.

[0016] In one possible implementation of the first aspect, the predetermined pitch of the spring layer gradually increases from the front end to the rear end or remains constant.

[0017] In one possible embodiment of the first aspect, the spring layer is made of a heat-treated single-wire or double-wire spring, the wire diameter of the spring is 0.01mm to 0.5mm, the predetermined pitch is 0.1mm to 1.0mm, and the length of the spring layer is 30mm to 80mm.

[0018] In one possible implementation of the first aspect, the wall thickness of the inner layer of the curved section and the inner layer of the main body section is 0.01 mm to 0.10 mm, and the wall thickness of the outer layer of the curved section and the outer layer of the main body section is 0.05 mm to 0.20 mm.

[0019] In one possible implementation of the first aspect, the outer layer of the main body segment is made of a polymer material with a hardness higher than that of the outer layer of the curved segment.

[0020] In one possible implementation of the first aspect, the first weave count of the first braided layer is greater than the second weave count of the second braided layer.

[0021] In one possible implementation of the first aspect, the shape of the metal woven mesh of the first woven layer and / or the second woven layer is rhomboid.

[0022] In one possible embodiment of the first aspect, the metal wire used to weave the metal mesh has a size of 0.001 inch to 0.004 inch and a mesh count of 60 to 100.

[0023] In one possible implementation of the first aspect, the axial length of the first braided layer is less than the axial length of the second braided layer.

[0024] In one possible implementation of the first aspect, the metal wire is one or a combination of stainless steel, carbon steel, cast iron, copper, aluminum, nickel, and iron-chromium-aluminum alloys.

[0025] In one possible embodiment of the first aspect, the clamp tube includes a front end section, the front end section includes an inner front end section layer and an outer front end section layer, the wall thickness of the inner front end section layer is 0.01 mm to 0.10 mm, and the wall thickness of the outer front end section layer is 0.05 mm to 0.20 mm.

[0026] In one possible embodiment of the first aspect, the inner layer of the front end segment, the inner layer of the curved segment, and the inner layer of the main body segment are wherein the inner layer of the curved segment is made of a fluorinated polymer material or a modified polyolefin material, the surface static friction coefficient of the inner layer is not greater than 0.20, and the wall thickness of the inner layer is 0.01 mm to 0.10 mm.

[0027] In one possible implementation of the first aspect, the outer layer of the front end segment is made of the same polymer material as the outer layer of the curved segment.

[0028] In one possible implementation of the first aspect, when the inner diameter of the clamp tube is 2.0 mm to 3.0 mm, the intermediate layer of the bent section is a spring-loaded layer; when the inner diameter of the clamp tube is 1.0 mm to 2.0 mm, the intermediate layer of the bent section is a first braided layer.

[0029] A second embodiment of the present invention discloses a method for preparing a clamp channel tube, used to prepare a clamp channel tube as described in any of the foregoing embodiments, the method comprising the following steps:

[0030] S1: Take the inner single-lumen tube and put it on the mandrel support to make the inner single-lumen tube fit tightly with the mandrel;

[0031] S2: A spring layer and a braided layer formed by multiple continuous metal braided meshes are respectively provided along the axial direction on the surface of the inner single-cavity tube, and the gap between the spring layer and the braided layer is controlled to not exceed 0.1mm;

[0032] S3: A first outer single-cavity tube and a second outer single-cavity tube are respectively sleeved on the outside of the spring layer and the braided layer along the axial direction. The length of the first outer single-cavity tube is greater than the axial length of the spring layer and its end extends to the surface of the inner single-cavity tube. The length of the second outer single-cavity tube is greater than the axial length of the braided layer and its end extends to the surface of the inner single-cavity tube.

[0033] S4: A shrink tube is sleeved on the outside of the first outer single-lumen tube and the second outer single-lumen tube, and the outer single-lumen tube is pre-shrinked and fixed. The first outer single-lumen tube and the second outer single-lumen tube are hot-melted and welded from top to bottom along the axial direction. The first outer single-lumen tube and the second outer single-lumen tube are melted and penetrated into the gap between the braided layer and the spring layer and fit with the inner single-lumen tube to achieve an integrated combination.

[0034] S5: Peel off the shrink tube and remove the mandrel, and cut the mandrel according to the preset size to obtain the clamp tube.

[0035] In one embodiment of the second aspect, the hot melt welding includes welding via a reflow method.

[0036] In one embodiment of the second aspect, the heat-treated coiled spring layer is axially sleeved on the outer periphery of the inner single-cavity tube, and the pitch of the coiled spring layer is set according to a predetermined variation law, thereby forming radial support on the outside of the inner single-cavity tube.

[0037] In one embodiment of the second aspect, the metal wires are woven using a "one-over-two" or "two-over-two" weaving method to form a woven layer.

[0038] In one embodiment of the second aspect, the length of the shrink tube at least completely covers the first outer tube and the second outer tube.

[0039] A third embodiment of the present invention discloses an endoscope including the forceps tube described in any of the embodiments of the first aspect.

[0040] Therefore, this invention achieves targeted reinforcement by functionally configuring the intermediate reinforcement structure along the axial direction of the guide tube, allowing the bending section and the main body section to employ different intermediate layer structures. In the bending section of the guide tube, a bending section intermediate layer composed of coiled springs is provided, ensuring that this area maintains necessary radial support while possessing good axial flexibility and bending resistance, thus meeting the requirements for frequent, large-angle bending of the guide tube at this location. In the main body section, an intermediate layer is formed by at least partially setting multiple metal braided mesh layers between the inner and outer layers of the main body section, giving the main body section higher axial stability and resistance to compressive deformation during axial pushing and retraction. By configuring different types of intermediate reinforcement structures along the axial direction in the same guide tube, this invention avoids the performance trade-offs caused by using a single reinforcement form in traditional guide tubes. Bending performance and pushing performance are no longer mutually restrictive, but rather optimized in their respective functional sections, thus achieving a synergistic improvement rather than a compromise in both.

[0041] Furthermore, since the spring structure and the metal braided mesh structure have fundamental differences in force transmission path and deformation mode, the above-mentioned axially partitioned structure with different bending performance can effectively disperse stress concentration when the clamp tube is repeatedly bent, reduce the risk of fatigue damage in local areas, and help improve the structural reliability and service life of the clamp tube during long-term use.

[0042] Therefore, this invention, by functionalizing the clamping tube, satisfies the different mechanical requirements of the clamping tube at different positions without significantly increasing the structural complexity of the clamping tube, thereby improving the performance of the clamping tube under complex operating conditions. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the overall structure of a clamping tube according to the present invention.

[0045] Figure 2 This is a schematic diagram of the overall structure of another type of clamp tube according to the present invention.

[0046] Figure 3 This is a schematic diagram of the overall structure of another type of clamp tube according to the present invention.

[0047] Figure 4This is a schematic diagram of the overall structure of another type of clamp tube according to the present invention.

[0048] Figure 5 This is a schematic diagram of the overall structure of another type of clamp tube according to the present invention.

[0049] Figure 6 This is a schematic diagram of the overall structure of another type of clamp tube according to the present invention.

[0050] Figure 7 This is a schematic diagram showing the performance test comparison results in Comparative Example 1 of the present invention.

[0051] Figure 8 This is a schematic diagram showing the performance test comparison results in Comparative Example 1 of the present invention. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this disclosure clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0053] Example 1

[0054] like Figure 1 As shown, the clamp tube 10 includes at least a curved section 200 and a main body section 300 along its axial direction from the front end to the rear end. The curved section 200 is located in the front end region of the clamp tube 10 and is used to adapt to the bending changes of the insertion path during the use of the endoscope, thereby ensuring that the treatment instrument can pass smoothly and avoiding tube collapse. The main body section 300 is located at the rear end of the curved section 200 and is used to connect the endoscope operating part. Its main function is to provide sufficient axial pushing capacity while ensuring the overall bending resistance of the tube body, so as to facilitate the assembly and use of the clamp tube 10. The axial stiffness of the curved section 200 is less than the axial stiffness of the main body section 300.

[0055] like Figure 2As shown, the curved section 200 includes an inner layer 210, a middle layer 220, and an outer layer 230. The inner layer 210 forms the cavity through which the treatment instrument passes. The middle layer 220 is disposed between the inner layer 210 and the outer layer 230 and extends through the curved section 200. The middle layer 220 is formed as a spring layer made of metal wire wound according to a predetermined pitch or as a continuous first braided layer formed by multiple metal braided meshes woven according to a first braiding mesh number. The spring layer or the first braided layer can provide radial support force to the tube when the curved section 200 bends, preventing the cavity from collapsing in the bent state, and at the same time enabling the curved section 200 to generate a large bending angle in the axial direction to meet clinical operation requirements. The main body segment 300 includes an inner layer 310, an outer layer 330, and an intermediate layer 320 at least partially disposed between the inner layer 310 and the outer layer 330. The intermediate layer 320 is formed with a continuous second braided layer consisting of a plurality of metal braided meshes woven according to a second braiding count.

[0056] Specifically, the inner diameter of the inner layer 210 of the bending section is 1.00mm to 3.00mm, the wall thickness of the inner layer 210 of the bending section is 0.01mm to 0.10mm, and the axial length of the inner layer 210 of the bending section is consistent with the length of the bending section 200, the length of which is 30mm to 80mm. The intermediate layer 220 of the bending section is disposed on the outside of the inner layer 210 of the bending section, and is used to provide necessary radial support force for the guide tube 10 when the bending section 200 bends. The intermediate layer 220 of the bending section is a spring layer wound with metal wire with a predetermined pitch of 0.1mm to 1.0mm. The spring layer is continuously disposed along the axial direction of the bending section 200, and its length is consistent with the length of the bending section 200.

[0057] In this embodiment, when the inner diameter of the guide tube 10 is 1.0mm~2.0mm, the inner diameter of the inner layer 210 of the curved section is also 1.0mm~2.0mm, and the intermediate layer 210 of the curved section is formed as the first braided layer formed by multiple metal braided meshes. At this time, the intermediate layer 220 of the curved section and the intermediate layer 320 of the main body section can use metal wires of the same material and have the same or similar braid count.

[0058] In this embodiment, when the inner diameter of the clamp tube 10 is 2.0mm~3.0mm, the inner diameter of the inner layer 210 of the bending section is also 2.0mm~3.0mm. The middle layer 210 of the bending section is a spring layer continuously arranged along the axial direction. The spring layer is formed by winding metal wire according to a predetermined pitch of 0.1mm~1.0mm. At this time, the inner layer 210 of the bending section has stronger bending resistance.

[0059] In this embodiment, the first and second braid counts are not equal, and the first braid count is greater than the second braid count. The metal wires in the first and second braid layers can be the same or different in size, and the materials can be the same or different. Preferably, the metal wires are stainless steel wires or nickel-titanium wires.

[0060] In this embodiment, the spring layer can be made of a single-wire spring or a double-wire spring. The wire used for the spring has a diameter ranging from 0.01mm to 0.50mm, the predetermined pitch of the spring ranges from 0.1mm to 1.0mm, and the length of the spring layer is 30mm to 80mm. This ensures flexibility while effectively preventing collapse of the cavity during bending. By incorporating the spring in the bending section 200, the bending section 200 maintains a stable channel shape after repeated bending, improving the reliability of the forceps tube 10 during clinical use.

[0061] In this embodiment, the metal wire can be round or flat, that is, the cross-sectional shape of the metal wire is circular or rectangular.

[0062] In this embodiment, the intermediate layer 220 of the curved section can be a coiled spring that has undergone heat treatment by a predetermined method.

[0063] In this embodiment, the metal wire can be selected from one or more of stainless steel, carbon steel, cast iron, copper, aluminum, nickel, and iron-chromium-aluminum alloys.

[0064] In this embodiment, the shape of the metal braided mesh of the first braided layer and / or the second braided layer is rhomboid or approximately rhomboid.

[0065] In this embodiment, the axial length of the first braided layer is less than the axial length of the second braided layer.

[0066] In this embodiment, the outer layer 230 of the curved section covers the outside of the inner layer 220 of the curved section, forming the outer surface of the curved section 200 and directly contacting the outside environment. The inner layer 210 of the curved section is made of a biocompatible polymer material with slippery properties to ensure that the inner wall of the curved section 200 has a low coefficient of friction, thereby improving the performance of the treatment device.

[0067] In this embodiment, the outer layer 230 of the curved section has a wall thickness of 0.05mm to 0.20mm. The length range of the inner layer 210 and the outer layer 230 of the curved section is consistent with that of the middle layer 220 of the curved section, that is, the length is generally set to 30mm to 80mm.

[0068] In this embodiment, the main body segment 300 includes an inner layer 310, an outer layer 330, and an intermediate layer 320 at least partially disposed between the inner layer 310 and the outer layer 330. The inner layer 310 forms a through-hole treatment instrument channel, and the intermediate layer 320 is formed as a woven layer with multiple continuous metal woven meshes made of metal wire. The multiple metal woven meshes formed by the intermediate layer 320 have a certain support capacity in both the radial and axial directions, which can significantly improve the bending resistance and axial rigidity of the main body segment 300, thereby making it less prone to excessive bending or instability during the advancement, retraction, and assembly of the clamp tube 10.

[0069] In this embodiment, the inner layer 310 of the main body section is used to form a through treatment instrument channel. The axial length of the inner layer of the main body section is 550mm to 650mm. The inner diameter of the inner layer 310 of the main body section is consistent with that of the inner layer 210 of the curved section, with a value range of 1.00mm to 3.00mm, thereby avoiding the formation of steps during the transition of the treatment instrument.

[0070] In this embodiment, the wall thickness of the inner layer 210 of the curved section is 0.01mm to 0.10mm, and the wall thickness of the outer layer 230 of the curved section is 0.05mm to 0.20mm; the wall thickness of the inner layer 310 of the main body section is 0.01mm to 0.10mm, and the wall thickness of the outer layer 310 of the main body section is 0.05mm to 0.20mm. The axial length of the outer layer 330 of the main body section is consistent with the length of the main body section 300.

[0071] In this embodiment, the wall thickness of the inner layer 210 of the curved section is equal to the wall thickness of the inner layer 310 of the main body section, and the wall thickness of the outer layer 230 of the curved section is equal to the wall thickness of the outer layer of the main body section.

[0072] In this embodiment, the spring layer is made of a single-wire or double-wire spring that has undergone heat treatment. The wire diameter of the spring is 0.01mm to 0.5mm, the predetermined pitch is 0.1mm to 1.0mm, and the length of the spring layer is 30mm to 80mm.

[0073] In this embodiment, the intermediate layer 320 of the main body section is composed of multiple continuous metal braided meshes formed by the cross-weaving of multiple metal wires. The metal wires are woven together at a preset braiding angle along the axial direction of the main body section 300, forming multiple mesh structures between adjacent wires, thus creating a continuous braided layer. The metal wires are arranged at an inclined cross relative to the axis of the main body section 300, providing support for the guide tube in the radial direction while maintaining a certain degree of flexibility in the axial direction. The size of the metal wires used for braiding ranges from 0.001 inch to 0.004 inches, the mesh count is 60 to 100, and the braiding length remains consistent with the length of the main body section 300. The metal braided mesh design prevents excessive bending of the main body section 300 during advancement, retraction, and assembly, thereby improving the overall pushing performance and structural stability of the guide tube 10.

[0074] In this embodiment, the metal woven mesh is woven with a single filament, but it can also be woven with two filaments. The weaving method is not limited to multiple rhombuses or approximate rhombuses woven by pressing one and picking one, pressing two and picking two, or pressing two and picking two.

[0075] In this embodiment, the inner layer 310 of the main body section uses the same material as the inner layer 210 of the bending section. It can be a low-friction polymer material with good biocompatibility, and its surface static friction coefficient can be no greater than 0.20. The type can be a fluorinated polymer material, etc., and the specific material type is not limited.

[0076] In this embodiment, the outer layer 230 of the bending section is made of a polymer material with low hardness, good fatigue resistance, and good aging resistance. Alternatively, a material with a low coefficient of friction and good biocompatibility may be coated on its inner polymer wall. The specific type of material is not limited in this embodiment. Preferably, the material of the outer layer 230 of the bending section can be TPU with a hardness of 70A~90A, PEBAX with a hardness of 20D~50D, or silicone rubber (such as polydimethylsiloxane PDMS) with a Shore hardness of 60A~80A, etc.

[0077] Example 2

[0078] The clamping tube in this embodiment is basically the same as that in Embodiment 1. The structure from the front end to the rear end includes a bent section 200 and a main body section 300. The difference is that... Figure 3As shown, the main body segment 300 in this embodiment includes a first main body segment 31 and a second main body segment 32. The first main body segment 31 has a first main body segment inner layer 311, a first main body segment middle layer 312, and a first main body segment outer layer 313. The second main body segment 32 has a second main body segment inner layer 321 and a second main body segment outer layer 323. The first main body segment 31 has an inner diameter of 1.00mm to 3.00mm, a wall thickness of 0.06mm to 0.30mm, and a length ranging from 550mm to 650mm. The second main body segment 32 has an inner diameter of 1.00mm to 3.00mm, a wall thickness of 0.06mm to 0.30mm, and a length of 100mm to 200mm. By employing a two-layer structure in the second main body segment 32, the amount of material used can be reduced and the manufacturing process simplified without significantly affecting the overall performance.

[0079] In this embodiment, the inner layer 311 of the first main body segment is part of the necessary passage for the surgical instrument to enter. The inner layer 311 is composed of a biocompatible polymer material with a low coefficient of friction to reduce the friction between the surgical instrument and the inner wall. The wall thickness of the inner layer 311 is 0.01mm to 0.10mm. The length of the inner layer 311 is consistent with that of the outer layer 313 of the first main body segment, and can be set between 550mm and 650mm. The outer layer 313 of the first main body segment can be composed of a polymer material with low hardness, good fatigue resistance, and good aging resistance. The wall thickness of the outer layer 313 is 0.05mm to 0.20mm, and the length is 550mm to 650mm. The outer layer 313 can be made of a polymer material with high hardness, good fatigue resistance, and good aging resistance; the specific material type is not limited. The braided wire size of the intermediate layer 312 of the first main body section is 0.001 inch to 0.004 inch; the braid count of the intermediate layer 312 of the first main body section is between 60 and 100; the braid length of the intermediate layer 312 of the first main body section is 550 mm to 650 mm; the cross-sectional shape of the braided wire of the intermediate layer 312 of the first main body section can be circular or rectangular; the material of the intermediate layer 312 of the first main body section is a high temperature resistant material, such as stainless steel, carbon steel, cast iron, copper, aluminum, nickel, and one or more combinations of iron-chromium-aluminum alloys.

[0080] In this embodiment, the second main body segment 32 is configured as a straight or weakly curved section that does not participate in the main bending action when formed as the flexible insertion part of an endoscope. The inner diameter of the second main body segment 32 is 1.00 mm to 3.00 mm, and the wall thickness is 0.06 mm to 0.30 mm. The wall thickness of the inner layer 321 of the second main body segment is set to 0.01 mm to 0.10 mm, and its axial length ranges from 100 mm to 200 mm. The inner layer 321 of the second main body segment can be made of a polymer material with good biocompatibility and a low coefficient of friction; the specific material type is not limited. The wall thickness of the outer layer 323 of the second main body segment is set to 0.05 mm to 0.20 mm, and its axial length ranges from 100 mm to 200 mm. It can be made of a polymer material with good fatigue resistance and aging resistance; the specific material type is not limited.

[0081] In this embodiment, the hardness of the outer layer 323 of the second main body segment is not lower than the hardness of the outer layer 313 of the first main body segment, and the hardness difference between the two is between (0 and 10)D. For example, the hardness of the outer layer 323 of the second main body segment can be selected according to the overall performance requirements of the entire clamp tube 10 to improve the axial pushing ability and bending resistance of the second main body segment 32.

[0082] In this embodiment, the outer layer 313 of the first main body segment and / or the outer layer 323 of the second main body segment can be selected from polyether block amide (PEBAX) with a Shore hardness of 50D to 75D or medical-grade thermoplastic polyurethane (TPU) with a Shore hardness of about 55D or polyamide material (PA11, PA12) with medium hardness obtained by adjusting the formula, etc.

[0083] Example 3

[0084] The clamp tube in this embodiment is basically the same as that in embodiment 2. The structure from the front end to the rear end includes: a curved section 200 and a main body section 300. The main body section 300 includes a first main body section 31 and a second main body section 32. The difference is that: Figure 4 As shown, a second main body segment intermediate layer 322 is provided between the second main body segment inner layer 321 and the second main body segment outer layer 323. The weave count of the second intermediate braided layer used to weave the second main body segment intermediate layer 322 is lower than the weave count of the first intermediate braided layer used to weave the first main body segment intermediate layer 312. This enables, for example, the second main body segment 32 to still have a certain degree of bending and pushing resistance even when the second main body segment inner layer 323 is made of a polymer material with a lower hardness than the first main body segment outer layer 313.

[0085] Example 4

[0086] In this embodiment, the clamping tube is basically the same as in Embodiment 3, except that the mesh count of the second intermediate braided layer used to braid the second main body segment intermediate layer 322 is equal to the mesh count of the first intermediate braided layer used to braid the first main body segment intermediate layer 312. This embodiment can be achieved by changing the size of the metal wires in the first intermediate braided layer and the second braided layer, the type of metal wire material, etc., which is not limited here. As long as it can be achieved, for example, when the inner layer 323 of the second main body segment is made of a polymer material with a lower hardness than the outer layer 313 of the first main body segment, the second main body segment 32 still has a certain degree of bending resistance and pushing performance.

[0087] Example 5

[0088] The clamping tube in this embodiment is basically the same as that in embodiment 2, except that: in order to ensure the overall structural consistency of the clamping tube 10 and simplify the manufacturing process, the outer layer 313 of the first main body segment and the outer layer 323 of the second main body segment are made of the same material and have the same wall thickness. For example, the outer layer 313 of the first main body segment and the outer layer 323 of the second main body segment are made of a polymer material with low hardness, good fatigue resistance and aging resistance.

[0089] Example 6

[0090] The clamping tube in this embodiment is basically the same as that in embodiment 2. The structure from the front end to the rear end includes: a bent section 200 and a main body section 300. The difference is that: Figure 5As shown, in this embodiment, the main body segment 300 is a continuous one-piece structure. The length of the curved segment 200 is 31mm to 90mm, and the length of the main body segment 300 is 650mm to 850mm. A middle layer 320 of the main body segment is disposed between the inner layer 310 and the outer layer 330 of the main body segment. The weave count of the middle layer 320 gradually decreases from the front end to the rear end of the guide tube 10. The middle layer 220 of the curved segment is a spring layer, which is axially wound around the outer side of the inner layer 210 of the curved segment and covered by the outer layer 230 of the curved segment. The predetermined pitch of the spring layer of the middle layer 220 gradually changes along the axial direction of the guide tube 10. During winding, the predetermined pitch of the spring layer gradually increases from the front end to the rear end of the guide tube 10. The gradually increasing predetermined pitch ensures good bending resistance in the bending section. Since the bending resistance requirement gradually decreases in the approximately 1mm to 10mm region at the front end of the bending section 200 during actual use, a larger predetermined pitch is set in this region to achieve a reasonable match between overall performance and structural design. Similarly, the braid count of the intermediate layer 320 of the main body section gradually decreases from the front end to the rear end of the guide tube 10. As the braid count gradually decreases, the main body section 300 forms different reinforcement densities at different axial positions. This results in the intermediate layer 320 having higher radial support capacity near the front end and relatively lower reinforcement near the rear end, thereby improving the overall axial compliance of the intermediate layer 320. By providing a spring-loaded intermediate layer with a gradually changing pitch in the bending section 200 and a gradually changing braid count intermediate layer in the main body section 300, the guide tube 10 of this embodiment can form differentiated mechanical property distributions at different axial positions, improving the rationality of the structural design.

[0091] Example 7

[0092] The clamp tube in this embodiment is basically the same as that in embodiment 6. The difference is that the braid count of the middle layer 320 of the main body section remains unchanged from the front end to the rear end in this embodiment. In this embodiment, the requirement for bending resistance of the bending section 200 gradually decreases in the axial direction towards the front end in a region of about 1mm to 10mm during actual use, thereby achieving a reasonable match between overall performance and structural design. For example, the size of the metal wire selected gradually decreases from the front end to the rear end.

[0093] Example 8

[0094] The clamping tube in this embodiment is basically the same as that in embodiment 6, except that the predetermined pitch of the spring layer in this embodiment remains constant from the front end to the rear end. In this embodiment, the issue of gradually decreasing bending resistance requirements in the approximately 1mm to 10mm region at the front end of the bending section 200 during actual use can be addressed by selecting the size and material type of the metal wire, thereby achieving a reasonable match between overall performance and structural design. For example, the predetermined pitch of the spring layer selected from the front end to the rear end remains constant, while the size of its metal wire gradually increases.

[0095] Example 9

[0096] The clamping tube in this embodiment is basically the same as that in Embodiment 1. The structure from the front end to the rear end includes a bent section 200 and a main body section 300. The difference is that... Figure 6 As shown, in this embodiment, the forceps channel 10 further includes a front end section 400, which includes an inner front end section 410 and an outer front end section 420. The axial length of the front end section 400 is 1mm to 10mm, and the length of the outer front end section 420 is consistent with the axial length of the front end section 400. The inner front end section 410 forms the inner wall of the channel through which surgical instruments enter the forceps channel 10. The material of the inner front end section 410 is a biocompatible polymer material with a low coefficient of friction, which can reduce the frictional resistance of the surgical instruments during advancement. The wall thickness of the inner front end section 410 is 0.01mm to 0.10mm. The outer front end section 420 forms the external covering structure of the front end section 400 and forms a bundled or fixed connection with other components when the forceps channel 10 is assembled into a whole. The outer front end section 420 can be made of a polymer material with low hardness, good fatigue resistance, and good aging resistance, and its wall thickness is 0.05mm to 0.20mm.

[0097] In this embodiment, the inner layer 410 of the front end section, the inner layer 210 of the bending section, and the inner layer 310 of the main body section are made of polymer materials with the same or similar static friction coefficients. The materials can be fluorinated polymer materials with good biocompatibility and low friction coefficients, and the wall thickness of each inner layer is kept consistent. The outer layer 420 of the front end section and the outer layer 230 of the bending section are made of polymer materials with the same or similar hardness and / or the same or similar compatibility, possessing good fatigue resistance and aging resistance, so as to form a stable connection through hot melt welding during the manufacturing process. The material hardness of the outer layer 330 of the main body section is higher than that of the outer layer 230 of the bending section, and the specific material type is not limited.

[0098] In this embodiment, for example, the outer layer 420 of the front end section and the outer layer 230 of the curved section can be made of thermoplastic polyurethane (TPU) with a Shore hardness of 70A to 90A, or polyether block amide (PEBAX) with a Shore hardness of 20D to 50D, or linear low-density polyethylene (LLDPE), or low-hardness medical-grade polyvinyl chloride (PVC), or silicone rubber with a Shore hardness of 60A to 80A, etc.

[0099] In this embodiment, the outer layer 330 of the main body segment can be selected from polyether block amide (PEBAX) with a Shore hardness of 50D to 75D, medical-grade thermoplastic polyurethane (TPU) with a Shore hardness of about 55D, or polyamide materials (PA11, PA12) with medium hardness obtained by adjusting the formula.

[0100] Example 10

[0101] The clamp tube in this embodiment is basically the same as that in embodiment 6, except that the outer layer 420 of the front end section, the outer layer 230 of the bending section, and the outer layer 330 of the main body section are made of polymer materials with the same or approximately the same hardness.

[0102] Example 11

[0103] This embodiment provides an endoscope having an insertion section, wherein a tubular component penetrating the insertion section is a forceps channel tube as described in any of Embodiments 1 to 10. When applied to the endoscope, this forceps channel tube can be used for the entry and exit of diagnostic and therapeutic accessories such as biopsy forceps, snares, stone retrieval baskets, and high-frequency electrosurgical units. It also serves as a delivery channel for irrigation fluid or negative pressure aspiration, thereby enabling procedures such as tissue sampling, foreign body removal, and lesion resection to be performed during endoscopic examination or treatment.

[0104] This endoscope has the same beneficial technical effects as any of the aforementioned embodiments, and will not be described again here.

[0105] Example 12

[0106] The method for preparing the clamp tube disclosed in this embodiment can be used to prepare the clamp tube 10 described in any of the aforementioned embodiments 1 to 10. The preparation method includes the following steps:

[0107] S1: Take the inner single-lumen tube and put it on the mandrel support to make the inner single-lumen tube fit tightly with the mandrel;

[0108] S2: A spring layer and a braided layer formed by multiple continuous metal braided meshes are respectively provided along the axial direction on the surface of the inner single-cavity tube, and the gap between the spring layer and the braided layer is controlled to not exceed 0.1mm;

[0109] S3: A first outer single-cavity tube and a second outer single-cavity tube are respectively sleeved on the outside of the spring layer and the braided layer along the axial direction. The length of the first outer single-cavity tube is greater than the axial length of the spring layer and its end extends to the surface of the inner single-cavity tube. The length of the second outer single-cavity tube is greater than the axial length of the braided layer and its end extends to the surface of the inner single-cavity tube.

[0110] S4: A shrink tube is sleeved on the outside of the first outer single-lumen tube and the second outer single-lumen tube, and the outer single-lumen tube is pre-shrinked and fixed. The first outer single-lumen tube and the second outer single-lumen tube are hot-melted and welded from top to bottom along the axial direction. The first outer single-lumen tube and the second outer single-lumen tube are melted and penetrated into the gap between the braided layer and the spring layer and fit with the inner single-lumen tube to achieve an integrated combination.

[0111] S5: Peel off the shrink tube and remove the mandrel, and cut the mandrel according to the preset size to obtain the clamp tube.

[0112] In one embodiment, the hot melt welding is performed by reflow welding, which involves non-contact heating of the joining area to cause the polymer material to remelt and form a continuous fused structure at the interface.

[0113] In one embodiment, the welding temperature during reflow is 180°C to 220°C, and the speed is 0.7 mm / s to 1.4 mm / s.

[0114] In one embodiment, the heat-treated coiled spring layer is axially sleeved onto the outer periphery of the inner single-cavity tube. The pitch of the coiled spring layer is set according to a predetermined variation pattern, thereby forming radial support on the outside of the inner single-cavity tube. Specifically, the predetermined variation pattern can be that the pitch gradually decreases from the front end to the rear end.

[0115] In one embodiment, the metal wires are woven using a "one-over-two" or "two-over-two" weaving method to form a woven layer.

[0116] In one embodiment, the length of the shrink tube at least completely covers the first outer tube and the second outer tube.

[0117] The preparation method of this embodiment is based on the processes of sleeve, braiding, spring configuration and hot melt welding. By controlling the welding temperature, welding rate and axial length relationship of each layer structure, the layer structure of the tube can achieve a stable integrated combination during the forming process, which can effectively improve the overall reliability and industrial production applicability of the product.

[0118] Application Example 1

[0119] The specific steps of the preparation method of the clamp tube provided in Embodiment 12 of the present invention are as follows:

[0120] Take an inner single-cavity tube with a length of 1000mm, insert a mandrel with a length of 1300mm from one end of the inner single-cavity tube, so that the mandrel is located inside the inner single-cavity tube, and adjust it so that the inner single-cavity tube and the mandrel are tightly fitted in the axial direction, thereby forming a stable support state.

[0121] The mandrel assembly with the inner single-cavity tube is placed on a 16-spindle braiding machine. Pre-specified flat metal wires are selected as braiding wires and braided in a 1-to-2 braiding pattern. The braiding mesh number is set and the braiding length is set to be greater than 1000mm so that the braided layer formed by multiple metal braided meshes completely covers the corresponding area of ​​the inner single-cavity tube.

[0122] The completed braided filaments are axially defined into a braided area of ​​600mm in length. The braided filaments at both ends of the braided area are spot-welded and fixed using a fiber laser welding machine to prevent the braided filaments from loosening. Subsequently, the excess braided filaments are trimmed and removed using the laser welding machine to make the edges of the braided layer neat.

[0123] Take a heat-treated flat metal wire and wind it to form a coiled spring with a length of 50mm and a predetermined fixed pitch. Sleeve the coiled spring axially onto one side of the trimmed braided layer and adjust the position of the coiled spring so that the axial gap between the coiled spring layer and the braided layer is controlled to be less than 0.1mm.

[0124] Take a first outer single-lumen tube with a length of 65mm and axially fit it onto the spring layer covered by the spring, so that one end is flush with the joint between the spring and the braided layer, and the other end completely extends beyond the area of ​​the spring layer and covers part of the inner single-lumen tube; then take a second outer single-lumen tube with a length of 750mm and axially fit it onto the braided layer area, so that one end is also flush with the joint between the spring layer and the braided layer, and the other end completely extends beyond the braided layer area and covers part of the inner single-lumen tube.

[0125] First, a 100mm long shrink tube is fitted over the docking area between the first and second outer single-lumen tubes. The air blowing chamber is opened and the temperature is set to 200℃ to pre-shrink the shrink tube, thereby achieving initial positioning and fixation of the first and second outer single-lumen tubes. Then, the shrink tube is removed. Next, a 1000mm long shrink tube is taken and fitted over the pre-shrinked and fixed product to ensure that the shrink tube completely covers the first and second outer single-lumen tubes. The shrink tube at the end of the first outer single-lumen tube away from the spring is then pre-shrinked and fixed.

[0126] The product with the shrink tube attached is placed into the welding equipment, and the product posture is adjusted so that the first outer single-lumen tube is located radially outside the second outer single-lumen tube. Then, the welding temperature is set to 180℃~220℃, the welding speed is set to 0.7mm / s~1.4mm / s, and the welding equipment is started, so that the first outer single-lumen tube and the second outer single-lumen tube melt and fuse together under heating conditions. At the same time, the molten material penetrates into the gap area between the braided layer and the spring layer, thereby achieving an integrated bond.

[0127] After welding, the shrink tube on the outside of the product is removed, and the formed clamp tube is taken out from the mandrel. Then, taking the side near the spring area as a reference, the length of the non-spring area is measured to be 10mm, and the excess tube is cut off with a blade, keeping the cut surface flat during the cutting process. Similarly, taking the side near the braided area as a reference, the length of the non-braided area is measured to be 110mm, and the excess tube is cut off, also ensuring that the cut surface is flat, thus obtaining the final formed clamp tube product.

[0128] Comparative Example 1

[0129] The forceps channel prepared in Application Example 1 of this invention and existing forceps channels on the market were assembled into products of the same model. Under the same test conditions, the products equipped with the forceps channels of Application Example 1 and the existing forceps channels were all bent to 180°. Subsequently, biopsy forceps of the same specifications were inserted into the two types of forceps channels respectively. Three biopsy forceps 180° insertion force tests and three biopsy forceps 180° withdrawal force tests were performed on each type of forceps channel, and the insertion force and withdrawal force values ​​obtained in each test were recorded. All test results are summarized as shown in Figure 7. Figure 8 As shown.

[0130] Figure 7 This section compares the forceps channel provided in Application Example 1 of the present invention with existing forceps channels on the market in terms of 180° insertion forceps. The solid line represents the forceps channel provided in Application Example 1 of the present invention, and the dashed line represents existing forceps channels on the market. Figure 4 It can be seen that, under the same test conditions, the 180° insertion force of the biopsy forceps provided in Example 1 of this invention is generally less than the insertion force of existing forceps on the market.

[0131] Figure 8 This section compares the forceps delivery tube provided in Application Example 1 of the present invention with existing forceps delivery tubes on the market in terms of 180° pull-out forceps. The solid line represents the forceps delivery tube provided in Application Example 1 of the present invention, and the dashed line represents existing forceps delivery tubes on the market. Figure 8 It can be seen that the 180° pull-out force of the biopsy forceps provided in Application Example 1 of the present invention is generally less than the pull-out force of existing forceps on the market.

[0132] Based on the above test results, it can be shown that the clamp tube provided in the application example of the present invention has good self-lubricating properties due to the use of a material with good biocompatibility and low coefficient of friction in its inner layer. This effectively reduces the frictional resistance between the treatment instrument and the inner wall of the clamp tube when the instrument is in a bent state. The smaller insertion and extraction forces help reduce the wear of the inner wall of the clamp tube and effectively extend the service life of the clamp tube.

[0133] Comparative Example 2

[0134] The clamp tube prepared in Application Example 1 of this invention and commercially available clamp tubes were assembled into products of the same model. Under the same test conditions, repeated bending tests were conducted on the products equipped with the two types of clamp tubes. During the test, the patency of the clamp tubes in the two products was tested at 0, 5000, 10000, 15000, 20000, 25000, and 30000 bends, respectively.

[0135] The unobstructedness test method is as follows: under the corresponding number of bends, attempt to pass a cleaning brush with a front diameter of 1.8 mm through the inner cavity of the clamp tube, and record whether it can pass smoothly. The bending fatigue test results are summarized in Table 1 below.

[0136] Table 1

[0137]

[0138] As can be seen from the test results shown in Table 1, during the entire test cycle from 0 to 30,000 bends, both the clamp tube provided in Application Example 1 of this invention and existing clamp tubes on the market can ensure that the cleaning brush with a front diameter of 1.8 mm can pass through smoothly without any obvious cavity collapse or channel blockage.

[0139] The test results above show that the forceps tube provided in Application Example 1 of the present invention can meet the requirements of at least 30,000 bends under repeated bending conditions, and its overall bending resistance is comparable to that of existing forceps tubes on the market, which can meet the needs of clinical use.

[0140] Comparative Example 3

[0141] The clamp tube prepared in Application Example 1 of this invention and commercially available clamp tubes were assembled into products of the same model, and repeated bending tests were conducted under the same test conditions. The following performance states of the two products were recorded and compared at 0, 5000, 10000, 15000, 20000, 25000, and 30000 bends:

[0142] (1) Whether the module image display is normal;

[0143] (2) Illumination intensity value;

[0144] (3) The bending angle of the upper bend and the bending angle of the lower bend;

[0145] (4) Appearance and structure of the snake-bone rubber. The relevant test results are summarized in Tables 2-1 and 2-2 below.

[0146] Table 2-1

[0147]

[0148] Table 2-2

[0149]

[0150] According to the results shown in Tables 2-1 and 2-2, during the entire repeated bending test, the product assembled with a pliers tube provided in Application Example 1 of the present invention maintained normal module image display compared with existing pliers tube assembled products on the market, with no significant differences.

[0151] Regarding illumination intensity, the two products showed certain numerical differences at various test nodes. However, the product assembled with the clamp-tube provided in Application Example 1 of this invention maintained an illumination intensity above 20, which meets normal usage requirements. Considering that the illumination system may also be affected by factors such as the quality of the optical fiber itself, the aforementioned differences in illumination intensity are not entirely attributable to the clamp-tube structure.

[0152] Regarding bending performance, the product assembled with a pliers tube provided in Example 1 of this invention can achieve an upper bend angle of about 220° at most test nodes, which is better than existing pliers tube assembled products on the market (whose upper bend angle is mostly about 210°); the lower bend angle of both products can reach about 130°, with no significant difference.

[0153] The product assembled with the forceps tube provided in Application Example 1 of this invention showed no obvious abnormalities after repeated bending, unlike commercially available products assembled with forceps tubes. This indicates that the forceps tube provided in Application Example 1 of this invention does not adversely affect the overall serpentine structure and appearance of the endoscope insertion section. In contrast, the existing forceps tubes used in Comparative Examples 1 to 3 are formed using UV soft adhesive bonding or thermosetting processes.

[0154] The clamp tube provided in Application Example 1 of this invention, while ensuring that all other performance aspects are normal when applied to medical treatment instruments such as endoscopes, facilitates a larger upward bending angle, thereby expanding the product's visibility and operational range to a certain extent.

[0155] In summary, the comparative tests of Comparative Examples 1 to 3 verify that the clamp tube provided by the embodiments of the present invention maintains good bending resistance and overall compatibility with medical treatment instruments such as endoscopes, while its inner wall has good self-lubricating properties, which can effectively reduce the insertion and extraction forces of treatment instruments in a bent state, and help improve the service life and operation performance of the product.

[0156] It should be understood that the material types, hardness ranges, and wall thickness ranges listed in this embodiment are only used to illustrate preferred implementations of the present invention.

[0157] For those skilled in the art, any equivalent technical solution obtained through material substitution, blending, plasticizing, or structural parameter adjustment, without departing from the requirement that the segmented hardness and inner and outer layer functions of this invention meet the mechanical requirements, should fall within the protection scope of this invention.

[0158] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0159] It is further understood that although the operations are described in a specific order in the accompanying drawings in the embodiments of the present invention, this should not be construed as requiring these operations to be performed in the specific order or serial order shown, or requiring all the operations shown to obtain the desired result. In certain environments, multitasking and parallel processing may be advantageous.

[0160] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features, or different combinations of the above technical features can be made. These modifications, substitutions and combinations do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A clamp tube characterized by, The clamping tube, along its axial direction from the front end to the rear end, includes at least: The curved section and the main body section, wherein the axial stiffness of the curved section is less than the axial stiffness of the main body section; The curved section includes an inner layer, a middle layer, and an outer layer. The middle layer extends through the curved section and is formed with a spring layer made of metal wire wound according to a predetermined pitch or a continuous first braided layer formed by multiple metal braided meshes woven according to a first braiding mesh number. The main body segment includes an inner layer, an outer layer, and an intermediate layer at least partially disposed between the inner and outer layers. The intermediate layer is formed with a continuous second braided layer consisting of a plurality of metal braided meshes woven according to a second braiding count.

2. The cannulation tube of claim 1, wherein, The main body segment includes a first main body segment and a second main body segment; the first main body segment has a first main body segment inner layer, a first main body segment middle layer and a first main body segment outer layer, and the second main body segment has a second main body segment inner layer and a second main body segment outer layer.

3. The cannulation tube of claim 2, wherein, The hardness of the outer layer of the second main body segment is not lower than that of the outer layer of the first main body segment, and the hardness difference between the two is between (0 and 10) D.

4. The fistula tube of claim 2, wherein, The inner diameter of the first main body segment and the second main body segment is 1.00mm to 3.00mm, and the wall thickness of the first main body segment and the second main body segment is 0.06mm to 0.30mm.

5. The fistula tube of claim 2, wherein, A second intermediate layer is provided between the inner layer of the second main body segment and the outer layer of the second main body segment. The number of weaves of the second intermediate weave layer used to weave the second intermediate weave layer of the second main body segment is lower than or equal to the number of weaves of the first intermediate weave layer used to weave the first intermediate weave layer of the first main body segment.

6. The fistula tube of claim 1, wherein, The main body segment is a continuous one-piece structure, and the middle layer of the main body segment is disposed between the inner layer and the outer layer of the main body segment. The weave count of the middle layer of the main body segment gradually decreases or remains unchanged from the front end to the rear end.

7. The fistula tube of claim 6, wherein, The predetermined pitch of the spring layer gradually increases from the front end to the rear end or remains constant.

8. The fistula tube of claim 1, wherein, The spring layer is made of a single-wire or double-wire spring that has undergone heat treatment. The wire diameter of the spring is 0.01mm to 0.5mm, the predetermined pitch is 0.1mm to 1.0mm, and the length of the spring layer is 30mm to 80mm.

9. The fistula tube of claim 1, wherein, The inner layer of the curved section has a wall thickness of 0.01mm to 0.10mm, and the outer layer of the curved section has a wall thickness of 0.05mm to 0.20mm; the inner layer of the main body section has a wall thickness of 0.01mm to 0.10mm, and the outer layer of the main body section has a wall thickness of 0.05mm to 0.20mm.

10. The fistula tube of claim 1, wherein, The inner layer of the curved section and the inner layer of the main body section are made of the same polymer material.

11. The fistula tube of claim 1, wherein, The hardness of the material of the outer layer of the main body section is not lower than that of the material of the outer layer of the bending section.

12. The fistula tube of claim 1, wherein, The first weave count of the first weave layer is greater than the second weave count of the second weave layer.

13. The clamping pipe according to claim 12, characterized in that, The metal woven mesh of the first woven layer and / or the second woven layer is diamond-shaped.

14. The clamping pipe according to claim 13, characterized in that, The metal wires used to weave the metal mesh are 0.001 inch to 0.004 inch in size and have a mesh count of 60 to 100.

15. The clamp-type conduit according to claim 14, characterized in that, The axial length of the first braided layer is less than the axial length of the second braided layer.

16. The method for preparing the clamp tube according to claim 1, characterized in that, The metal wire is one or a combination of stainless steel, carbon steel, cast iron, copper, aluminum, nickel, and iron-chromium-aluminum alloys.

17. The clamping pipe according to claim 1, characterized in that, The clamp tube includes a front end section, which includes an inner layer and an outer layer. The wall thickness of the inner layer is 0.01mm to 0.10mm, and the wall thickness of the outer layer is 0.05mm to 0.20mm.

18. The clamping pipe according to claim 17, characterized in that, The inner layer of the front end section, the inner layer of the curved section, and the inner layer of the main body section are all made of the same polymer material.

19. The clamping pipe according to claim 17, characterized in that, The outer layer of the front end section is made of the same polymer material as the outer layer of the curved section.

20. The clamping pipe according to claim 1, characterized in that, When the inner diameter of the clamp tube is 2.0mm to 3.0mm, the middle layer of the bending section is a spring layer; when the inner diameter of the clamp tube is 1.0mm to 2.0mm, the middle layer of the bending section is the first braided layer formed by multiple metal braided meshes.

21. A method for preparing a clamping tube, used to prepare a clamping tube as described in any one of claims 1 to 20, characterized in that, The preparation method includes the following steps: S1: Take the inner single-lumen tube and put it on the mandrel support to make the inner single-lumen tube fit tightly with the mandrel; S2: A spring layer and a plurality of continuous metal braided meshes are respectively provided on the surface of the inner single-cavity tube along the axial direction, and the gap between the spring layer and the braided layer is controlled to not exceed 0.1mm; S3: A first outer single-cavity tube and a second outer single-cavity tube are respectively sleeved on the outside of the spring layer and the braided layer along the axial direction. The length of the first outer single-cavity tube is greater than the axial length of the spring layer and its end extends to the surface of the inner single-cavity tube. The length of the second outer single-cavity tube is greater than the axial length of the braided layer and its end extends to the surface of the inner single-cavity tube. S4: A shrink tube is sleeved on the outside of the first outer single-lumen tube and the second outer single-lumen tube, and the outer single-lumen tube is pre-shrinked and fixed. The first outer single-lumen tube and the second outer single-lumen tube are hot-melted and welded from top to bottom along the axial direction. The first outer single-lumen tube and the second outer single-lumen tube are melted and penetrated into the gap between the braided layer and the spring layer and fit with the inner single-lumen tube to achieve an integrated combination. S5: Peel off the shrink tube and remove the mandrel, and cut the mandrel according to the preset size to obtain the clamp tube.

22. The method for preparing the clamp tube according to claim 21, characterized in that, The hot melt welding includes welding via reflow.

23. The method for preparing the clamp tube according to claim 21, characterized in that, The heat-treated coiled spring layer is axially sleeved onto the outer periphery of the inner single-cavity tube. The pitch of the coiled spring layer is set according to a predetermined variation law, thereby forming radial support on the outside of the inner single-cavity tube.

24. The method for preparing the clamp tube according to claim 21, characterized in that, The metal wires are woven using a "one-over-two" or "two-over-two" weaving method to form a woven layer.

25. The method for preparing the clamp tube according to claim 21, characterized in that, The length of the shrink tube at least completely covers the first outer tube and the second outer tube.

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