catheter

Abstract

Provided is a catheter that uses flat wires, said flat wires being effective for making the catheter thin-walled and highly strong, in a reinforcement body and that is capable of preventing the ends of the reinforcement body from disassembling.　This catheter (1) is provided with a shaft (2) having a lumen (5) that runs from the distal end to the basal end, wherein: the shaft (2) has a reinforcement body (20) that is disposed in at least a part between the inner surface (11) of the shaft (2) forming the lumen (5) and the outer surface (31) of the shaft (2) and provided with tubularly braided wire materials (21); the reinforcement body (20) comprises round wire groups (24) consisting of a plurality of round wires (22) that are the wire materials (21) having a circular cross section and a plurality of flat wires (23) intersecting the round wire groups (24); and the cross-sectional area ratio A / B of the total cross-sectional area A of the plurality of round wire groups (24) to the total cross-sectional area B of the plurality of flat wires (23) is larger than 0.5.

Description

[Technical Field]

[0001] The present invention relates to a catheter for use in a lumen such as a blood vessel. [Background technology]

[0002] In recent years, catheters have been widely used for intraluminal treatments such as those of blood vessels because of their minimal surgical invasiveness. Catheters are required to be thin-walled while maintaining strength so that they can be inserted into narrow lumens and have a wide internal passage.

[0003] As a method for making a catheter strong and thin, a flat wire, which is a strip-shaped wire material made of a flat plate, is braided into a tubular shape and embedded in the catheter as a reinforcing member (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-144163 Summary of the Invention [Problem to be solved by the invention]

[0005] However, because flat wires have high strength, the cut ends of the flat wires tend to fall apart when braided. This can make it difficult to cut the catheter, or the reinforcing body cannot adhere to the tubular resin material when embedded in the resin material, potentially reducing the strength of the catheter. For this reason, catheters using flat wires as the reinforcing body generally require post-processing, such as welding the wires at the ends of the reinforcing body.

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a catheter that can prevent the ends of the reinforcing body from coming apart while using flat wire in the reinforcing body, which is effective in making the catheter thin and strong. [Means for solving the problem]

[0007] One aspect of a catheter that achieves the above object is a catheter having a shaft with a lumen that communicates from the distal end to the proximal end, wherein the shaft has a reinforcing body that is disposed at least partially between the inner surface of the shaft that forms the lumen and the outer surface of the shaft and that is provided with a tubularly braided wire material, and the reinforcing body comprises a group of round wires that are wire materials with a circular cross section, and a group of wire materials with a rectangular cross section that intersect with the group of round wires. and braided with the group of round wires. and a plurality of flat wires, wherein the cross-sectional area ratio of the total cross-sectional area of the plurality of round wire groups to the total cross-sectional area of the plurality of flat wires is greater than 0.5.

[0008] Another aspect of the catheter that achieves the above object is a catheter having a shaft with a lumen that communicates from the distal end to the proximal end, wherein the shaft has a reinforcing body that is disposed at least partially between the inner surface of the shaft that forms the lumen and the outer surface of the shaft and that is provided with a tubularly braided wire material, and the reinforcing body comprises a group of round wires that are wire materials with a circular cross section, and a group of round wires that intersect the group of round wires. and braided with the group of round wires. and a plurality of flat wires, wherein the ratio of the diameter of the round wire to the thickness of the flat wires is greater than 1.5.

[0009] Yet another aspect of the catheter that achieves the above object is a catheter having a shaft with a lumen that communicates from the distal end to the proximal end, wherein the shaft has a reinforcing body that is disposed between an inner surface of the shaft that forms the lumen and an outer surface of the shaft and that includes a plurality of wires braided into a tubular shape, the reinforcing body including a plurality of round wires that are wires with circular cross sections and a plurality of flat wires that are wires that intersect with the round wires, and wherein the cross-sectional area ratio of the total cross-sectional area of the plurality of round wires to the total cross-sectional area of the plurality of flat wires is greater than 0.5. The yield point of the material of the round wire is lower than the yield point of the material of the flat wire. It is characterized by: [Effects of the Invention]

[0010] The catheter configured as described above uses flat wires in the reinforcing body, which are effective in making the catheter thin-walled and strong, while the group of round wires that are applied to the reinforcing body together with the flat wires and intersect with the flat wires can prevent the ends of the reinforcing body from coming apart.

[0011] The cross-sectional area ratio may be greater than 1. This can enhance the effect of the group of round wires in the catheter, which makes it difficult for the end of the reinforcing body to come apart.

[0012] The yield point of the material of the round wires may be lower than the yield point of the material of the flat wires. This allows the round wires to be more easily plastically deformed than the flat wires and to maintain the braided shape more easily. Therefore, the flat wires, which are less susceptible to plastic deformation and tend to come apart, are held in place by the group of round wires, effectively preventing the end of the reinforcement from coming apart.

[0013] The number of the round wires may be greater than the number of the flat wires, thereby enabling the flat wires that tend to come apart to be held by the round wires, thereby effectively preventing the end of the reinforcing body from coming apart.

[0014] The intersecting wires do not have to be joined together. This prevents the reinforcing body from coming apart even if the intersecting wires are not joined together. This makes it easy to fabricate a thin-walled, high-strength catheter.

[0015] The flat wire may be a wire having a rectangular cross section, which increases the cross-sectional area of the flat wire and makes it possible to thin the flat wire and obtain a thin-walled, high-strength catheter.

[0016] Another aspect of the catheter configured as described above applies flat wire to the reinforcing body, which is effective in making the catheter thin-walled and strong, while also preventing the ends of the reinforcing body from coming apart by using round wires that are applied to the reinforcing body together with the flat wire and intersect with the flat wire. [Brief explanation of the drawings]

[0017] [Figure 1]FIG. 1 is a plan view showing a catheter according to an embodiment. [Figure 2] FIG. 1 is a longitudinal cross-sectional view taken along the central axis of a catheter according to an embodiment. [Figure 3] FIG. 1 is a longitudinal cross-sectional view showing a catheter according to an embodiment, taken along a line perpendicular to the central axis. [Figure 4] FIG. 2 is a plan view showing the outer layer of a catheter according to an embodiment. [Figure 5] 1A and 1B are cross-sectional views showing the wire rod of the reinforcing body, where (A) shows a round wire and (B) shows a flat wire. [Figure 6] FIG. 10 is a plan view showing, as a reference example, the state in which the wire material is separated at the end of the cut reinforcing body during the manufacturing process. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that dimensions in the drawings may be exaggerated for convenience of explanation and may differ from actual dimensions. Furthermore, in this specification and the drawings, components having substantially the same functions are designated by the same reference numerals, and redundant explanations will be omitted. In this specification, the side of the catheter 1 that is inserted into a biological lumen will be referred to as the "distal side," and the side that is operated will be referred to as the "proximal side."

[0019] The catheter 1 according to this embodiment is introduced into a blood vessel from the radial artery in the arm and then advanced into an artery in the lower limb for treatment, diagnosis, and the like. The artery in the lower limb is an artery near the aortoiliac artery bifurcation and on the more peripheral side. As shown in FIG. 1 , the catheter 1 has a long shaft 2, a hub 3 connected to the base end of the shaft 2, and a kink protector 4 provided at the connection between the shaft 2 and the hub 3.

[0020] As shown in Figures 1 to 4, the shaft 2 is a flexible tubular member having a central axis X extending from the base end to the tip end, and a lumen 5 formed therein from the base end to the tip end. A guidewire is inserted through the lumen 5 when the catheter 1 is inserted into a blood vessel. The lumen 5 can also be used as a passage for other medical devices such as the catheter 1, medicinal solutions, embolic substances, contrast agents, etc.

[0021] The effective length of the shaft 2 is not particularly limited and is appropriately set depending on the application of the catheter 1. When the catheter 1 is introduced into a blood vessel from the radial artery in the arm and inserted into an artery in the lower limb for treatment, diagnosis, or the like, the effective length of the shaft 2 is not particularly limited, but is preferably 1500 mm to 2600 mm, more preferably 1800 mm to 2300 mm, and even more preferably 2100 mm to 2300 mm. This allows the catheter 1 to reach the artery in the arm and the artery in the lower limb. The effective length of the shaft 2 is the length of a portion that can be inserted into a blood vessel, a sheath, or the like. In this embodiment, the effective length is the length along the central axis X from the tip of the anti-kink protector 4 to the tip of the shaft 2. The effective length of the shaft 2 is preferably 650 mm or more when the catheter 1 is introduced into a blood vessel from the femoral artery, and is preferably 300 mm or more when the catheter 1 is introduced into a blood vessel from the distal portion of the dorsalis pedis artery or the posterior tibial artery. That's fine too.

[0022] The shaft 2 is composed of multiple layers, including an inner layer 10 that forms the inner surface 11 of the lumen 5, a reinforcing body 20 that is arranged outside the inner layer 10, and an outer layer 30 that is formed outside the inner layer 10 and the reinforcing body 20.

[0023] The inner layer 10 has a lumen 5 formed therein. The material constituting the inner layer 10 can be a thermoplastic resin, a thermosetting resin, or the like, and preferably a fluorine-based resin such as polytetrafluoroethylene (PTFE), or a low-friction material such as high-density polyethylene (HDPE), or the like.

[0024] The inner diameter of the inner layer 10 is not particularly limited, but is preferably 0.4 mm to 1.2 mm, more preferably 0.45 mm to 0.7 mm, and even more preferably 0.5 mm to 0.6 mm.

[0025] The reinforcing member 20 is formed by braiding a plurality of wires 21 around the outer periphery of the inner layer 10 in a tubular shape with gaps between them. The wires 21 include a plurality of round wires 22 with circular cross sections and a plurality of flat wires 23 with rectangular cross sections. The cross section of the wires 21 is a cross section perpendicular to the direction in which the wires 21 extend. The cross section of the flat wires 23 may be rectangular, elliptical, or oval, but when comparing shapes with the same thickness and width, a rectangle is preferred as it has the largest cross-sectional area.

[0026] A plurality of wires form one round wire group 24. Each round wire group 24 has one or more round wires 22 arranged adjacent to each other in the circumferential direction of the shaft 2. The round wire groups 24 extend spirally in the same direction around the outer periphery of the inner layer 10 and are arranged at equal intervals in the circumferential direction of the shaft 2. The plurality of round wires 22 constituting each round wire group 24 are arranged side by side without any gaps in the circumferential direction of the shaft 2. The plurality of round wires 22 constituting each round wire group 24 may be arranged with some gaps in the circumferential direction of the shaft 2. The number L1 of the round wire groups 24 matches the number of flat wires 23, but does not have to match. When one round wire group 24 is counted as one wire, the number L1 of the round wire groups 24 is not particularly limited, but may be, for example, 1 to 16 wires, and is 4 wires in this embodiment. The number N1 of the round wires 22 in each round wire group 24 is not particularly limited, but is, for example, 1 to 8, and in this embodiment, is 4. When one round wire group 24 includes multiple round wires 22, multiple round wires 22 with small outer diameters can be used instead of one round wire 22 with a large outer diameter, which prevents the wall thickness and outer diameter of the shaft 2 from becoming large.

[0027] The flat wires 23 are each a single wire that extends in the same direction around the outer periphery of the inner layer 10 in a spiral pattern and are spaced apart at equal intervals in the circumferential direction of the shaft 2. The extension direction of the flat wires 23 is opposite to the extension direction of the round wire groups 24 in the circumferential direction of the shaft 2 so as to intersect with the round wire groups 24. The flat wires 23 and the round wire groups 24 are braided so that their overlapping arrangement in the radial direction of the shaft 2 alternates or has a pattern. As shown in FIG. 3 , the number L2 of the flat wires 23 is not particularly limited when one flat wire is counted as one wire, but may be, for example, 1 to 16. The number L2 of the flat wires 23 is the same as the number L1 of the round wire groups 24, but this does not necessarily have to be the same. Each flat wire 23 is arranged so that the direction of the short side of its rectangular cross section is approximately aligned with the radial direction of the shaft 2.

[0028] The round wire 22 and the flat wire 23 may be made of metal wire such as stainless steel, platinum (Pt) or tungsten (W), resin fiber, carbon fiber, glass fiber, or the like, or a plurality of these wires 21 may be used in combination.

[0029] The round wires 22 and the flat wires 23 may be made of the same material, but are preferably made of different materials. The yield point of the material of the round wires 22 is preferably lower than the yield point of the material of the flat wires 23. The round wires 22 are deformed beyond their yield point when braided. That is, the round wires 22 are plastically deformed when braided, and constitute the reinforcing body 20 in a state where their restoring force to their original shape is smaller than that of the flat wires 23. The flat wires 23, when braided, remain with a larger internal stress than the round wires 22, and constitute the reinforcing body 20 in a state where their restoring force to their original shape is larger than that of the round wires 22.

[0030] For example, the round wire 22 and the flat wire 23 are made of different stainless steels, and the yield point of the material of the round wire 22 is lower than the yield point of the material of the flat wire 23. The material of the round wire 22 is, for example, SUS316, and the material of the flat wire 23 is, for example, SUS304-WPB.

[0031] If the sum of the cross-sectional areas (total cross-sectional area) of all the round wires 22 constituting the reinforcing body 20 is defined as A and the sum of the cross-sectional areas (total cross-sectional area) of all the flat wires 23 constituting the reinforcing body 20 is defined as B, A / B is preferably greater than 0.5, more preferably 0.74 or more, more preferably greater than 1, even more preferably 1.4 or more, and even more preferably 2.0 or more. A / B is preferably 2.1 or less, more preferably less than 2.1, and even more preferably 2.09 or less. This ensures a sufficient total cross-sectional area of the round wires 22, thereby improving the effect of maintaining the shape of the cut end of the reinforcing body 20 by the plastically deformed round wires 22. The cross-sectional area of the wire rod 21 is the area of a cross section perpendicular to the extension direction of the wire rod 21.

[0032] As shown in FIG. 5, when the diameter of the round wire 22 is defined as D and the thickness of the flat wire 23 (the length of the short side of the rectangular cross section) as T, D / T is preferably greater than 1.5, more preferably 2.0 or greater, and even more preferably 4.0 or greater. This ensures a sufficient diameter of the round wire 22, improving the effect of maintaining the shape of the end of the cut reinforcement body 20 by the plastically deformed round wire 22. The diameter D of the round wire 22 is the diameter in a cross section perpendicular to the extension direction of the round wire 22. The thickness T of the flat wire 23 is the length of the short side of the rectangular cross section in a cross section perpendicular to the extension direction of the flat wire 23. The width W of the flat wire 23 is the length of the long side of the rectangular cross section in a cross section perpendicular to the extension direction of the flat wire 23.

[0033] The diameter D of the round wire 22 is not particularly limited, but is preferably 0.020 mm to 0.080 mm, more preferably 0.025 mm to 0.060 mm, and even more preferably 0.030 mm to 0.040 mm.

[0034] The thickness T of the flat wire 23 is not particularly limited, but is preferably 0.010 mm to 0.040 mm, more preferably 0.010 mm to 0.030 mm, and even more preferably 0.015 mm to 0.020 mm. The width W of the flat wire 23 is not particularly limited, but is preferably 0.045 mm to 0.250 mm, more preferably 0.045 mm to 0.200 mm, and even more preferably 0.045 mm to 0.140 mm.

[0035] 2 to 4, the outer layer 30 is a tubular member that covers the outer periphery of the inner layer 10 and the reinforcing body 20. The outer layer 30 forms an outer surface 31 that is the radially outer surface of the shaft 2.

[0036] The outer diameter of the outer layer 30 is not particularly limited, but is preferably 0.7 mm to 1.3 mm, more preferably 0.8 mm to 1.2 mm, and even more preferably 0.86 mm to 1.1 mm.

[0037] Examples of materials that can be used to form the outer layer 30 include polymeric materials such as polyolefin (e.g., polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these), polyvinyl chloride, polyamide, polyester elastomer, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, and fluororesin, as well as thermoplastic resins such as mixtures of these, and thermosetting resins such as epoxy resin. The outer layer 30 may be mixed with a radiopaque material.

[0038] 1, the proximal end of the shaft 2 is liquid-tightly fixed to the hub 3 by adhesive, heat fusion, or a fastener (not shown), etc. The hub 3 functions as an insertion port for a guide wire or medical device into the lumen 5, an injection port for a medicinal solution, an embolic substance, a contrast agent, etc. into the lumen 5, and also functions as a gripping portion when operating the catheter 1. The material of the hub 3 is not particularly limited, but suitable examples include thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer.

[0039] The anti-kink protector 4 is made of an elastic material and is provided so as to surround the periphery of the shaft 2, and prevents kinking of the shaft 2 at the connection portion between the shaft 2 and the hub 3. Suitable materials for the anti-kink protector 4 include, for example, natural rubber, silicone resin, polyamide elastomer, and polyester elastomer.

[0040] Next, a method for manufacturing the catheter 1 according to this embodiment will be described.

[0041] First, a long core wire is prepared, the outer diameter of which is equal to the inner diameter of the inner layer 10. Next, the inner layer 10 is formed on the core wire. The inner layer 10 may be formed by extrusion molding or dip molding. Alternatively, the core wire may be inserted into the lumen 5 of the inner layer 10, which is a tubular body.

[0042] Thereafter, as shown in FIG. 4 , the reinforcing body 20 is formed so as to cover at least a portion of the inner layer 10. The reinforcing body 20 is formed by continuously winding a plurality of round wires 22 and flat wires 23 onto the inner layer 10 using a braider. The flat wires 23 can impart high strength to the shaft 2 while maintaining a thin wall of the resulting shaft 2. In the braided state, the flat wires 23 retain a greater internal stress than the round wires 22, and constitute the reinforcing body 20 in a state in which they have a greater restoring force to their original shape than the round wires 22. In the braided state, the round wires 22 are deformed beyond their yield point. In other words, the round wires 22 are plastically deformed during braiding, and constitute the reinforcing body 20 in a stable state in which they have a smaller restoring force to their original shape than the flat wires 23.

[0043] Next, the ends of the reinforcing body 20 are cut. At this time, the cut ends of the flat wires 23, which have high strength and a high yield point, tend to spread and break apart due to their own restoring force, as shown in the reference example of FIG. 6. Here, "spreading" refers to the expansion of a reinforcing wire (e.g., wire material 21) wound into a tubular shape to more than five times its outer diameter in its natural state. However, in this embodiment, the flat wires 23 intersect with the round wires 22, which have undergone plastic deformation and are stable with small internal stresses, so the shape of the cut ends of the flat wires 23 is maintained by the round wires 22. Therefore, the reinforcing body 20 can suppress the spread of the wire materials 21 (round wires 22 and flat wires 23) at the cut ends.

[0044] Next, the reinforcing body 20 is pressed from the outer peripheral surface side, and the inner peripheral surface side of the reinforcing body 20 is embedded in the inner layer 10. Thereafter, as shown in FIGS. 2 and 3 , the outer layer 30 is formed on the outside of the inner layer 10 and the reinforcing body 20. The method for forming the outer layer 30 is not particularly limited. For example, the outer layer 30 may be formed by extrusion molding or dip molding. Alternatively, the outer layer 30 may be formed by placing a tubular body, which will be the material for the outer layer 30, on the outside of the inner layer 10 and the reinforcing body 20, and then covering the tubular body with a heat-shrinkable tube and heating it. The tubular body softens or melts when heated, and is tightly bonded to the outside of the inner layer 10 and the reinforcing body 20 by the shrinkage force of the heat-shrinkable tube. Thereafter, the heat-shrinkable tube is removed.

[0045] After the outer layer 30 is formed, the core wire is pulled out from the lumen 5 of the inner layer 10. Thereafter, the hub 3 and the anti-kink protector 4 are attached to the shaft 2, and other components (e.g., a distal tip) are attached as needed to complete the catheter 1. Alternatively, the distal tip may be attached from the beginning before molding.

[0046] As described above, the catheter 1 according to this embodiment is a catheter 1 comprising a shaft 2 having a lumen 5 that extends from the tip to the base end, and the shaft 2 has a reinforcing body 20 comprising wire material 21 braided into a tubular shape and arranged at least partially between the inner surface 11 of the shaft 2 that forms the lumen 5 and the outer surface 31 of the shaft 2, and the reinforcing body 20 has a round wire group 24 consisting of a plurality of round wires 22 that are wire material 21 with a circular cross section, and a plurality of flat wires 23 that are wire material 21 with a rectangular cross section and intersect with the round wire group 24, and the cross-sectional area ratio A / B of the total cross-sectional area A of the plurality of round wire groups 24 to the total cross-sectional area B of the plurality of flat wires 23 is greater than 0.5.

[0047] Alternatively, the catheter 1 according to this embodiment is a catheter 1 comprising a shaft 2 having a lumen 5 that extends from the tip to the base end, wherein the shaft 2 has a reinforcing body 20 that is disposed in at least a portion between the inner surface 11 of the shaft 2 that forms the lumen 5 and the outer surface 31 of the shaft 2 and comprises tubularly braided wire material 21, and the reinforcing body 20 has a group of round wires 24 consisting of a plurality of round wires 22 that are wire materials 21 with circular cross sections, and a plurality of flat wires 23 that are wire materials 21 with rectangular cross sections and intersect with the group of round wires 24, and the ratio D / T of the diameter D of the round wires 22 to the thickness T of the flat wires 23 exceeds 1.5.

[0048] The catheter 1 configured as described above applies the flat wires 23 to the reinforcing body 20, which are effective in making the catheter 1 thin and strong, while the group of round wires 24, which are applied to the reinforcing body 20 together with the flat wires 23 and intersect with the flat wires 23, prevents the end of the reinforcing body 20 from fraying. This makes it easy to process a thin-walled, high-strength catheter 1. "Fraying" here means that when the reinforcing wires (wire material of the reinforcing body 20) are cut, the maximum outer diameter of the end of the reinforcing body 20 becomes five or more times the outer diameter of the middle part of the reinforcing body 20 when it is not frayed.

[0049] Furthermore, the cross-sectional area ratio A / B may be greater than 1. This can enhance the effect of the group of round wires 24 making the end portions of the reinforcing body 20 less likely to come apart.

[0050] Furthermore, the yield point of the material of the round wires 22 is lower than the yield point of the material of the flat wires 23. As a result, the round wires 22 are more susceptible to plastic deformation than the flat wires 23, and are therefore more likely to maintain the braided shape. Therefore, the flat wires 23, which are less susceptible to plastic deformation and tend to come apart, are held in place by the group of round wires 24, effectively preventing the end of the reinforcing member 20 from coming apart.

[0051] Furthermore, the number of round wires 22 is greater than the number of flat wires 23. This allows the flat wires 23 that tend to come apart to be held by the round wires 22, effectively preventing the end of the reinforcing body 20 from coming apart.

[0052] Furthermore, the intersecting wires 21 are not joined together by welding, adhesive, etc. Even if the intersecting wires 21 are not joined together, the catheter 1 can prevent the reinforcing member 20 from coming apart. This makes it easy to process a thin-walled, high-strength catheter 1.

[0053] The effective length of the shaft 2 is 2100 mm or more, which allows the catheter 1 to easily reach the arteries in the arm and the lower limbs.

[0054] The flat wire 23 is a wire material having a rectangular cross section, which increases the cross-sectional area of the flat wire 23, making it possible to make the flat wire 23 thinner and thus obtain a catheter 1 that is thin and has high strength.

[0055] As a variant, the wires of the round wire 22 and the flat wire 23 may be braided together. In the braided catheter configured as described above, the flat wire 23, which is effective in making the catheter thin and strong, is applied to the reinforcing body 20, while the round wire 22, which is applied to the reinforcing body 20 together with the flat wire 23 and intersects with the flat wire 23, can prevent the end of the reinforcing body 20 from coming apart. [Example]

[0056] Examples of the present invention and comparative examples will be described below, but the present invention is not limited to these examples.

[0057] Shafts 2 were produced in Examples 1 to 5 and Comparative Example 1 shown in Table 1, and during the production process, the ends of the cut reinforcing members 20 were observed to see if they fell apart. In all of Examples 1 to 5 and Comparative Example 1, the material of the round wire 22 was SUS316, and the material of the flat wire 23 was SUS304-WPB.

[0058] In Example 1, the arrangement of the round wires 22 was such that the number L1 of the round wire groups 24 was 8 and the number N1 of the round wires 22 constituting each round wire group 24 was 2, but after braiding, two adjacent round wire groups 24 were joined together, so that the number L1 of the round wire groups 24 was actually 4 and the number N1 of the element wires of the round wires 22 constituting each round wire group 24 was 4.

[0059] As a result, in Examples 1 to 5 in which the cross-sectional area ratio A / B was greater than 0.5 and less than 2.1, the ends of the cut reinforcing body 20 did not come apart (or hardly came apart), compared to Comparative Example 1 in which the cross-sectional area ratio A / B was less than 0.5. Also, in Examples 1 to 5 in which the thickness ratio D / T was greater than 1.5, the ends of the cut reinforcing body 20 did not come apart (or hardly came apart), compared to Comparative Example 1 in which the thickness ratio D / T was 1.5 or less.

[0060] [Table 1]

[0061] The present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art within the technical spirit of the present invention. For example, the catheter 1 may be inserted into a blood vessel other than an artery in the arm. The catheter 1 may also be used for treatment or diagnosis of blood vessels other than arteries in the lower limbs. The catheter 1 may also be inserted into the bile duct, trachea, esophagus, urethra, or other body lumen or body cavity to perform treatment, diagnosis, etc.

[0062] This application is based on Japanese Patent Application No. 2021-26036 filed on February 22, 2021, the disclosures of which are incorporated by reference in their entirety. [Explanation of symbols]

[0063] 1 catheter 2 shafts 5 lumens 10 Inner layer 11 Inner surface 20 Reinforcement 21 Wire rod 22 Round wire 23 Flat Line 24 Round Wire Group 30 outer layer 31 External surface A Total cross-sectional area of round wire B Total cross-sectional area of the flat wire D diameter of round wire T Flat wire thickness W Width of the horizontal line

Claims

1. A catheter having a shaft with a lumen communicating from the distal end to the proximal end, The shaft a reinforcing member disposed at least partially between the inner surface of the shaft forming the lumen and the outer surface of the shaft and including a tubular braided wire; the reinforcing body includes a group of round wires made up of a plurality of round wires each having a circular cross section, and a plurality of flat wires intersecting the group of round wires and braided with the group of round wires, A catheter characterized in that a cross-sectional area ratio of a total cross-sectional area of the plurality of round wire groups to a total cross-sectional area of the plurality of flat wires is greater than 0.

5.

2. The catheter of claim 1 , wherein the cross-sectional area ratio is greater than one.

3. A catheter having a shaft with a lumen communicating from the distal end to the proximal end, The shaft a reinforcing member disposed at least partially between the inner surface of the shaft forming the lumen and the outer surface of the shaft and including a tubular braided wire; the reinforcing body includes a group of round wires made up of a plurality of round wires each having a circular cross section, and a plurality of flat wires intersecting the group of round wires and braided with the group of round wires, A catheter characterized in that the ratio of the diameter of the round wire to the thickness of the flat wire is greater than 1.

5.

4. The catheter according to any one of claims 1 to 3, characterized in that the yield point of the material of the round wire is lower than the yield point of the material of the flat wire.

5. The catheter according to any one of claims 1 to 4, wherein the number of said round wires is greater than the number of said flat wires.

6. 6. The catheter according to claim 1, wherein the intersecting wires are not joined to each other.

7. 7. The catheter according to claim 1, wherein the flat wire is a wire having a rectangular cross section.

8. A catheter having a shaft with a lumen communicating from the distal end to the proximal end, The shaft a reinforcing member disposed at least partially between the inner surface of the shaft forming the lumen and the outer surface of the shaft and including a tubular braided wire; The reinforcing body includes a plurality of round wires that are wire rods having circular cross sections, and a plurality of flat wires that are wire rods that intersect with the round wires, a cross-sectional area ratio of a total cross-sectional area of the plurality of round wires to a total cross-sectional area of the plurality of flat wires is greater than 0.5; A catheter characterized in that the yield point of the material of the round wire is lower than the yield point of the material of the flat wire.

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