catheter

Abstract

The present invention provides a catheter that effectively applies flat wires, which are used to thin the wall of the catheter and have high strength, to a reinforcing body and is able to suppress the end spread of the reinforcing body. The catheter (1) has a shaft (2) having an inner cavity (5) extending from the front end to the base end, and a reinforcing body (20) having a wire (21) braided into a tubular shape. The reinforcing body (20) is disposed in at least a portion between the inner surface (11) of the shaft (2) forming the inner cavity (5) and the outer surface (31) of the shaft (2), and has: a group of circular wires (24) consisting of a plurality of circular wires (21), i.e., circular wires (22); and a plurality of flat wires (23) intersecting the group of circular wires (24), wherein the cross-sectional area ratio A / B of the total cross-sectional area A of the plurality of circular wire groups (24) relative to the total cross-sectional area B of the plurality of flat wires (23) is greater than 0.5.

Description

Technical Field

[0001] This invention relates to catheters used within the lumen of blood vessels and the like. Background Technology

[0002] In recent years, endovascular treatments using catheters have become widespread due to the need for minimal surgical trauma. There is a desire for catheters to remain strong and have thin walls, allowing insertion into narrow lumens while ensuring a wide internal passage.

[0003] As a method to make the catheter strong and thin-walled, a strip of wire (flat wire) made of flat plate is braided into a tube and embedded in the catheter as a reinforcement (see, for example, Patent Document 1).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2014-144163 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, due to the high strength of flat sheets, the cut ends of the flat sheets tend to loosen when braided. This makes it difficult to cut the conduit easily, or when embedding the reinforcement into the tubular resin material, the loose reinforcement cannot adhere tightly to the resin, potentially reducing the conduit's strength. Therefore, in conduits where flat sheets are typically used for reinforcement, post-processing such as welding the ends of the reinforcement is required.

[0009] The present invention was proposed to solve the above-mentioned problems, and aims to provide a catheter in which flat lines that are effective in thinning the catheter wall and increasing its strength are applied to the reinforcing body, and which can also suppress the end spread of the reinforcing body.

[0010] Methods for solving problems

[0011] One method of achieving the above-mentioned objective of the catheter includes a shaft having an inner lumen extending from a front end to a base end. The catheter is characterized in that the shaft has a reinforcing body disposed between at least a portion of the shaft forming the inner surface of the lumen and the outer surface of the shaft. The reinforcing body comprises a group of circular wires (i.e., round wires) and a group of rectangular wires intersecting the group of circular wires. The ratio of the total cross-sectional area of ​​the group of circular wires to the total cross-sectional area of ​​the flat wires is greater than 0.5.

[0012] Another way to achieve the above-mentioned purpose of the catheter is to have a shaft having an inner lumen extending from the front end to the base end. The catheter is characterized in that the shaft has a reinforcing body disposed between at least a portion of the shaft forming the inner surface of the inner lumen and the outer surface of the shaft, and has a wire braided into a tubular shape. The reinforcing body has a group of circular wires composed of multiple circular cross-section wires, i.e., round wires, and multiple flat wires intersecting the group of circular wires, wherein the ratio of the diameter of the circular wires to the thickness of the flat wires is greater than 1.5.

[0013] Another way to achieve the above-mentioned purpose of the catheter is to have a shaft having an inner lumen extending from a front end to a base end. The catheter is characterized in that the shaft has a reinforcing body disposed between at least a portion of the inner surface of the shaft forming the inner lumen and the outer surface of the shaft, and has a plurality of wires braided into a tubular shape. The reinforcing body has a plurality of wires with circular cross-sections, i.e., round wires, and wires intersecting the round wires, i.e., a plurality of flat wires. The 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.

[0014] Invention Effects

[0015] The catheter constructed in the above manner can also suppress the end spread of the reinforcement by using flat lines that are effective in making the catheter thin-walled and high-strength.

[0016] Alternatively, the cross-sectional area ratio can be greater than 1. Therefore, the conduit can utilize the circular wire assembly to enhance the resistance of the reinforcing ends to loosening.

[0017] Alternatively, the yield point of the material of the round wire may be lower than that of the material of the flat wire. Therefore, the round wire is easier to plastically deform than the flat wire, and it is easier to maintain the braided shape. Thus, the round wire assembly can be used to hold back the flat wire, which may loosen due to its difficulty in plastic deformation, effectively suppressing the loosening of the reinforcement ends.

[0018] Alternatively, the number of round wires may be greater than the number of flat wires. This allows the round wires to hold the desired looseness of the flat wires, effectively suppressing the loosening of the reinforcing ends.

[0019] Alternatively, the intersecting wires may not be joined together. Thus, even if the intersecting wires are not joined together, the loosening of the reinforcement can be suppressed in this conduit. Therefore, thin-walled and high-strength conduits can be easily manufactured.

[0020] Alternatively, the flat wire can be a wire with a rectangular cross-section. This increases the cross-sectional area of ​​the flat wire, allowing it to be thinner and resulting in a thin-walled, high-strength conduit.

[0021] Another type of catheter constructed in accordance with the above method can also use a flat line that is applied to the reinforcement to make the catheter thin-walled and high-strength, and a round line that is applied to the reinforcement together with the flat line and intersects the flat line to suppress the end spread of the reinforcement. Attached Figure Description

[0022] Figure 1 This is a top view showing the conduit of an embodiment.

[0023] Figure 2 This is a longitudinal sectional view along the central axis of the conduit illustrating the embodiment.

[0024] Figure 3 This is a cross-sectional view of the catheter of the embodiment, orthogonal to the central axis.

[0025] Figure 4 This is a top view showing the outer layer of the conduit in a perspective embodiment.

[0026] Figure 5 This is a cross-sectional view of the wires showing the reinforcement; (A) shows a round wire, and (B) shows a flat wire.

[0027] Figure 6 This is a top view, as a reference example, showing the loose state of the wire at the end of the cut reinforcement during the manufacturing process. Detailed Implementation

[0028] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that, for ease of explanation, the dimensions in the drawings may be exaggerated and differ from the actual dimensions. Furthermore, in this specification and the accompanying drawings, constituent elements having substantially the same function are labeled with the same reference numerals, and repeated descriptions are omitted. In this specification, the side of the catheter 1 that is inserted into the lumen of the biological body is referred to as the "front end side," and the side where the operation is performed is referred to as the "base end side."

[0029] In this embodiment, catheter 1 is inserted into a blood vessel through the radial artery of the arm and then into an artery in the lower limb for treatment, diagnosis, etc. The arteries of the lower limb are those near the branches of the iliac artery and those closer to the distal end. For example... Figure 1 As shown, the conduit 1 has a long shaft 2, a hub 3 connected to the base end of the shaft 2, and an anti-torsion protection member 4 provided at the connection between the shaft 2 and the hub 3.

[0030] like Figures 1-4 As shown, shaft 2 is a flexible tubular component with a central axis X extending from the base to the front end, and an inner lumen 5 is formed inside from the base to the front end. The inner lumen 5 allows the guidewire to pass through when the catheter 1 is inserted into a blood vessel. In addition, the inner lumen 5 can also be used as a passage for other medical devices such as the catheter 1, medications, embolic substances, contrast agents, etc.

[0031] The effective length of shaft 2 is not particularly limited and is appropriately set according to the purpose of catheter 1. When catheter 1 is inserted into a blood vessel from the radial artery of the arm and into an artery of the lower limb for treatment, diagnosis, etc., the effective length of shaft 2 is not particularly limited, but preferably 1500mm to 2600mm, more preferably 1800mm to 2300mm, and even more preferably 2100mm to 2300mm. Thus, catheter 1 can reach the artery of the lower limb from the artery of the arm. It should be noted that the effective length of shaft 2 is the length of the portion that can be inserted into a blood vessel, sheath, etc. In this embodiment, the effective length is the length along the central axis X from the tip of the anti-torsion protection member 4 to the tip of shaft 2. When catheter 1 is inserted into a blood vessel from the femoral artery, the effective length of shaft 2 is preferably 650mm or more, and when inserted into a blood vessel from the distal end of the dorsalis pedis artery or posterior tibial artery, it is preferably 300mm or more.

[0032] The shaft 2 is composed of multiple layers, including an inner layer 10 forming the inner surface 11 of the inner cavity 5, a reinforcing body 20 disposed on the outside of the inner layer 10, and an outer layer 30 formed on the outside of the inner layer 10 and the reinforcing body 20.

[0033] The inner layer 10 has an inner cavity 5 formed inside. The material constituting the inner layer 10 can be thermoplastic resin, thermosetting resin, etc., preferably fluorinated resin such as polytetrafluoroethylene (PTFE) or low-friction material such as high-density polyethylene (HDPE).

[0034] The inner diameter of the inner layer 10 is not particularly limited, but is preferably 0.4mm to 1.2mm, more preferably 0.45mm to 0.7mm, and even more preferably 0.5mm to 0.6mm.

[0035] The reinforcing body 20 is formed by weaving multiple wires 21 into a tubular shape with gaps around the outer periphery of the inner layer 10. Each wire 21 has multiple round wires 22 with a circular cross-section and multiple flat wires 23 with a rectangular cross-section. The cross-section of the wire 21 is orthogonal to the direction in which it extends. The cross-section of the flat wires 23 can also be rectangular, elliptical, or oblong, but when comparing shapes with the same thickness and width, a rectangle with the largest cross-sectional area is preferred.

[0036] The circular wires 22 are formed by multiple wires to form a circular wire group 24. Each circular wire group 24 has one or more circular wires 22 arranged adjacent to each other in the circumferential direction of the shaft 2. The circular wire groups 24 extend in a spiral manner in the same direction on the outer periphery of the inner layer 10 and are separated at the same intervals in the circumferential direction of the shaft 2. The multiple circular wires 22 constituting each circular wire group 24 are arranged side by side without gaps in the circumferential direction of the shaft 2. It should be noted that the multiple circular wires 22 constituting each circular wire group 24 may also be arranged with a certain gap in the circumferential direction of the shaft 2. The number L1 of the circular wire groups 24 is the same as the number of flat wires 23, but may not be the same. The number L1 of the circular wire groups 24 is not particularly limited, and when one circular wire group 24 is set as one, it is, for example, 1 to 16, and in this embodiment, it is 4. The number N1 of the circular wires 22 in each circular wire group 24 is not particularly limited, and is, for example, 1 to 8, and in this embodiment, it is 4. In the case where a group of circular wires 24 contains multiple circular wires 22, since multiple circular wires 22 with small outer diameters can be used instead of one circular wire 22 with a large outer diameter, the increase in the wall thickness and outer diameter of the shaft 2 can be suppressed.

[0037] Flat threads 23 extend in the same direction along the outer periphery of the inner layer 10 in a spiral pattern, and are arranged at equal intervals along the circumferential direction of the axis 2. Multiple flat threads 23 extend in directions intersecting with the circular thread group 24, but in the opposite direction along the circumferential direction of the axis 2. The flat threads 23 and the circular thread group 24 are woven in an alternating or patterned manner, overlapping radially along the axis 2. Figure 3 As shown, when a single flat line is considered as one, the number L2 of flat lines 23 is not particularly limited, for example, it can be 1 to 16. The number L2 of flat lines 23 is the same as the number L1 of the circle group 24, but they may not be the same. Each flat line 23 is configured such that the direction of the short side of the rectangular cross-section is approximately the same as the radial direction of the axis 2.

[0038] The materials used to construct the round wire 22 and the flat wire 23 can be stainless steel, platinum (Pt) / tungsten (W) metal wire, resin fiber, carbon fiber, glass fiber, etc., or multiple of the above wires 21 can be used at the same time.

[0039] The round wire 22 and the flat wire 23 can be made of the same material, but are preferably different. Preferably, the yield point of the material of the round wire 22 is lower than that of the material of the flat wire 23. The round wire 22 deforms beyond its yield point in the braided state. That is, the round wire 22 undergoes plastic deformation during braiding, forming the reinforcement 20 with a lower restoring force to its original shape compared to the flat wire 23. The flat wire 23, in the braided state, has greater residual internal stress than the round wire 22, and forms the reinforcement 20 with a higher restoring force to its original shape compared to the round wire 22.

[0040] As an example, the round wire 22 and the flat wire 23 are made of different stainless steels, with the yield point of the round wire 22 being lower than that of the flat wire 23. The round wire 22 is made of, for example, SUS316, and the flat wire 23 is made of, for example, SUS304-WPB.

[0041] When the total cross-sectional area of ​​all the circular wires 22 constituting the reinforcing body 20 is defined as A, and the total cross-sectional area of ​​all the flat wires 23 constituting the reinforcing body 20 is defined as B, it is preferable that A / B is greater than 0.5, more preferably 0.74 or more, more preferably greater than 1, further preferably 1.4 or more, and even more preferably 2.0 or more. It is preferable that A / B is 2.1 or less, more preferably less than 2.1, and even more preferably 2.09 or less. This ensures the total cross-sectional area of ​​the circular wires 22 and improves the effect of maintaining the end shape of the cut reinforcing body 20 by utilizing the plastically deformed circular wires 22. It should be noted that the cross-sectional area of ​​the wire 21 is the area of ​​the section orthogonal to the extension direction of the wire 21.

[0042] In addition, such as Figure 5 As shown, when the diameter of the circular wire 22 is defined as D and the thickness of the flat wire 23 (the length of the shorter side of the rectangular cross-section) is defined as T, it is preferable that D / T is greater than 1.5, more preferably 2.0 or more, and even more preferably 4.0 or more. This ensures the diameter of the circular wire 22 sufficiently and improves the effect of maintaining the end shape of the cut reinforcement 20 by utilizing the plastically deformed circular wire 22. It should be noted that the diameter D of the circular wire 22 is the diameter of the cross-section orthogonal to the extension direction of the circular wire 22. The thickness T of the flat wire 23 is the length of the shorter side of the rectangular cross-section orthogonal to the extension direction of the flat wire 23. The width W of the flat wire 23 is the length of the longer side of the rectangular cross-section orthogonal to the extension direction of the flat wire 23.

[0043] The diameter D of the circular line 22 is not particularly limited, but is preferably 0.020mm to 0.080mm, more preferably 0.025mm to 0.060mm, and even more preferably 0.030mm to 0.040mm.

[0044] The thickness T of the flat line 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 line 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.

[0045] like Figures 2-4As shown, the outer layer 30 is a tubular component that covers the outer periphery of the inner layer 10 and the reinforcing body 20. The outer layer 30 forms the radially outer surface 31 of the shaft 2.

[0046] The outer diameter of the outer layer 30 is not particularly limited, but is preferably 0.7mm to 1.3mm, more preferably 0.8mm to 1.2mm, and even more preferably 0.86mm to 1.1mm.

[0047] The outer layer 30 can be made of materials such as polyolefins (e.g., polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomers, or mixtures thereof), polyvinyl chloride, polyamide, polyester elastomers, polyamide elastomers, polyurethane, polyimide, fluoropolymers, or mixtures thereof, as well as thermoplastic resins and thermosetting resins such as epoxy resins. X-ray-resistant materials can also be mixed into the outer layer 30.

[0048] like Figure 1 As shown, the hub 3 liquid-tightly fixes the base end of the shaft 2 using adhesives, heat fusion, or clamps (not shown). The hub 3 functions as an insertion port for guidewires, medical devices into the lumen 5, and an injection port for medications, embolic substances, contrast agents, etc., into the lumen 5. It also functions as a holding part when manipulating the catheter 1. The material of the hub 3 is not particularly limited; for example, thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyacrylate, and methacrylate-butene-styrene copolymer are preferred.

[0049] The anti-torsion protection component 4 is made of an elastic material surrounding the shaft 2, which inhibits the twisting of the shaft 2 at the connection between the shaft 2 and the hub 3. The anti-torsion protection component 4 can preferably be made of materials such as natural rubber, silicone resin, polyamide elastomer, or polyester elastomer.

[0050] Next, the manufacturing method of the catheter 1 in this embodiment will be described.

[0051] First, prepare a long core wire with an outer diameter equal to the inner diameter of the inner layer 10. Next, form the inner layer 10 on the core wire. The inner layer 10 can also be formed by extrusion molding or impregnation molding. Alternatively, the core wire can be inserted into the inner cavity 5 of the inner layer 10, which serves as a tube.

[0052] Then, as Figure 4As shown, the reinforcement 20 is formed to cover at least a portion of the inner layer 10. The reinforcement 20 is formed by continuously winding multiple round wires 22 and flat wires 23 onto the inner layer 10 using a braiding machine. The flat wires 23 maintain the formed shaft 2 as a thin-walled structure and impart high strength to the shaft 2. In the braided state, the flat wires 23 have greater residual internal stress than the round wires 22, thus constituting the reinforcement 20 with a greater restoring force to its original shape compared to the round wires 22. The round wires 22 deform beyond their yield point in the braided state. That is, the round wires 22 undergo plastic deformation during braiding, forming the reinforcement 20 with a stable state where the restoring force to its original shape is smaller compared to the flat wires 23.

[0053] Next, the end of the reinforcing body 20 is cut off. At this time, as... Figure 6 As shown in the reference example, the cut end of a flat wire 23 with high strength and a high yield point is prone to loosening due to its own restoring force. Here, loosening refers to the expansion of a reinforcing wire wound into a tubular shape (e.g., wire 21) to more than five times its outer diameter in its natural state. However, in this embodiment, since the flat wire 23 intersects with a round wire 22 that has low internal stress and is stable due to plastic deformation, the shape of the cut end of the flat wire 23 is maintained by the round wire 22. Therefore, the reinforcement 20 can suppress the loosening of the cut end of the wire 21 (round wire 22 and flat wire 23).

[0054] Next, press the reinforcing body 20 from the outer peripheral side to embed the inner peripheral side of the reinforcing body 20 into the inner layer 10. Then, as... Figures 2-3 As shown, an outer layer 30 is formed on the outside of the inner layer 10 and the reinforcing body 20. The method of forming the outer layer 30 is not particularly limited. For example, the outer layer 30 can also be formed by extrusion molding or by dip molding. Alternatively, the outer layer 30 can also be formed by wrapping a heat-shrinkable tube around a tube body, which serves as the material for the outer layer 30, on the outside of the inner layer 10 and the reinforcing body 20, and then heating it. The tube body softens or melts upon heating 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. Then, the heat-shrinkable tube is removed after heat shrinkage.

[0055] After the outer layer 30 is formed, the core wire is pulled out from the inner cavity 5 of the inner layer 10. Then, the hub 3, the anti-torsion protection 4, and other components (such as the front chip) can be installed on the shaft 2 to complete the conduit 1. Alternatively, the front chip can be installed and shaped from the beginning.

[0056] As described above, the conduit 1 of this embodiment is a conduit 1 having a shaft 2 having an inner cavity 5 extending from the front end to the base end. The shaft 2 has at least a portion disposed between the inner surface 11 of the shaft 2 forming the inner cavity 5 and the outer surface 31 of the shaft 2 and has a reinforcing body 20 having a wire 21 braided into a tubular shape. The reinforcing body 20 has a circular wire group 24 composed of multiple circular wires 21, i.e., circular wires 22, and multiple flat wires 23 composed of rectangular wires 21 that intersect the circular wire group 24. The cross-sectional area ratio A / B of the total cross-sectional area A of the multiple circular wire groups 24 to the total cross-sectional area B of the multiple flat wires 23 is greater than 0.5.

[0057] Alternatively, the conduit 1 in this embodiment is a conduit 1 having a shaft 2 having an inner cavity 5 extending from the front end to the base end. The shaft 2 has at least a portion disposed between the inner surface 11 of the shaft 2 forming the inner cavity 5 and the outer surface 31 of the shaft 2, and has a reinforcing body 20 having a wire 21 braided into a tubular shape. The reinforcing body 20 has a group 24 of circular wires 21 (circular cross-section), i.e., circular wires 22, and a group of flat wires 23 consisting of rectangular cross-section wires 21 and intersecting the group 24. The ratio of the diameter D of the circular wires 22 to the thickness T of the flat wires 23 is D / T, which exceeds 1.5.

[0058] The conduit 1 constructed in the above manner, with its flat wire 23 effectively reducing the wall thickness and increasing the strength of the conduit 1, can also suppress the loosening of the end of the reinforcing body 20 by using a group of round wires 24 that are applied to the reinforcing body 20 together with the flat wire 23 and intersect with the flat wire 23. Therefore, a thin-walled and high-strength conduit 1 can be easily manufactured. Here, loosening refers to the maximum outer diameter of the end of the reinforcing body 20 when the reinforcing wire (the wire material of the reinforcing body 20) is cut, becoming more than 5 times the outer diameter of the middle part of the unloosened reinforcing body 20.

[0059] Alternatively, the cross-sectional area ratio A / B can be greater than 1. This allows the use of the circular wire group 24 to improve the resistance of the ends of the reinforcing body 20 to loosening.

[0060] Furthermore, the yield point of the material of the round wire 22 is lower than that of the material of the flat wire 23. Therefore, the round wire 22 is easier to plastically deform than the flat wire 23, and it is easier to maintain the braided shape. Thus, the round wire group 24 can be used to hold the flat wire 23, which is difficult to plastically deform and may loosen, effectively suppressing the loosening of the ends of the reinforcement 20.

[0061] Furthermore, the number of round wires 22 is greater than the number of flat wires 23. As a result, the round wires 22 can be used to hold the flat wires 23 in place, thereby effectively preventing the ends of the reinforcing body 20 from becoming loose.

[0062] Furthermore, the intersecting wires 21 are not joined together by welding, bonding, or other methods. Even without joining the intersecting wires 21, the conduit 1 can prevent the reinforcement 20 from loosening. Therefore, a thin-walled, high-strength conduit 1 can be easily manufactured.

[0063] In addition, the effective length of shaft 2 is over 2100 mm. As a result, catheter 1 can easily reach the arteries of the lower limb from the arteries of the arm.

[0064] Furthermore, the flat wire 23 is a wire with a rectangular cross-section. As a result, the cross-sectional area of ​​the flat wire 23 is increased, which allows the flat wire 23 to be thinned, resulting in a thin-walled and high-strength conduit 1.

[0065] As a variation, the round wires 22 and the flat wires 23 can also be braided together. In the case of the braided conduit constructed in the above manner, the flat wires 23, which are effective in making the conduit thin-walled and high-strength, are applied to the reinforcing body 20. The round wires 22, which are applied to the reinforcing body 20 together with the flat wires 23 and intersect with the flat wires 23, can also be used to suppress the loosening of the ends of the reinforcing body 20.

[0066] Example

[0067] The following describes embodiments and comparative examples of the present invention. It should be noted that the present invention is not limited to these embodiments.

[0068] Shaft 2 of Examples 1-5 and Comparative Example 1 shown in Table 1 was prepared. During the preparation process, it was observed whether the ends of the cut reinforcement 20 were loose. In Examples 1-5 and Comparative Example 1, the material of the round wire 22 was SUS316, and the material of the flat wire 23 was SUS304-WPB.

[0069] It should be noted that in Embodiment 1, a braiding machine is set to braid, and the round yarn 22 is configured such that the number of round yarn groups 24 is L1 of 8, and the number of round yarn 22 constituting each round yarn group 24 is N1 of 2. After braiding, the two adjacent round yarn groups 24 are combined together. In fact, the number of round yarn groups 24 is L1 of 4, and the number of round yarn 22 constituting each round yarn group 24 is N1 of 4.

[0070] As a result, compared with Comparative Example 1, where 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 were found to be non-loose (or almost non-loose). Furthermore, compared with Comparative Example 1, where the thickness ratio D / T was greater than 1.5, the ends of the cut reinforcing body 20 were found to be non-loose (or almost non-loose).

[0071]

[0072] It should be noted that 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 scope of the technical concept of the present invention. For example, catheter 1 can also be inserted into a blood vessel other than an artery in the arm. In addition, catheter 1 can also be used for treatment and diagnosis of blood vessels other than arteries in the lower limbs. Furthermore, catheter 1 can also be inserted into the bile duct, trachea, esophagus, urethra, or other biological cavities for treatment, diagnosis, etc.

[0073] This application is based on Japanese Patent Application No. 2021-26036, filed on February 22, 2021, the entire disclosure of which is incorporated herein by reference.

[0074] Explanation of reference numerals in the attached figures

[0075] 1. Catheter

[0076] 2-axis

[0077] 5. Inner cavity

[0078] 10 Inner Layer

[0079] 11 Inner Surface

[0080] 20 Enhanced Body

[0081] 21 Wire

[0082] 22 circles

[0083] 23 Flat lines

[0084] 24 circular line groups

[0085] 30 Outer layer

[0086] 31 Outer surface

[0087] A. Total cross-sectional area of ​​circle

[0088] B. Total cross-sectional area of ​​the flat line

[0089] The diameter of circle D

[0090] Thickness of T-flat line

[0091] W width of the flat line

Claims

1. A catheter comprising a shaft having an inner lumen extending from a distal end to a base end, characterized in that, The shaft has a reinforcing body disposed at least a portion of the shaft forming the inner surface of the cavity and the outer surface of the shaft, and includes a wire braided into a tubular shape. The reinforcing body has a group of circular wires composed of multiple circular cross-section wires, and multiple flat wires intersecting the group of circular wires. The ratio of the total cross-sectional area of ​​the multiple circular wire groups to the total cross-sectional area of ​​the multiple flat wires is greater than 0.

5. The yield point of the material of the round wire is lower than that of the material of the flat wire.

2. The catheter according to claim 1, characterized in that, The cross-sectional area ratio is greater than 1.

3. The catheter according to claim 1 or 2, characterized in that... The number of circular lines is greater than the number of flat lines.

4. The catheter according to claim 1 or 2, characterized in that, The intersecting wires do not interlock with each other.

5. The catheter according to claim 1 or 2, characterized in that, The flat wire is a wire with a rectangular cross-section.

6. A catheter comprising a shaft having an inner lumen extending from a distal end to a base end, characterized in that, The shaft has a reinforcing body disposed at least a portion of the shaft forming the inner surface of the cavity and the outer surface of the shaft, and includes a wire braided into a tubular shape. The reinforcing body has a group of circular wires composed of multiple circular cross-section wires, and multiple flat wires intersecting the group of circular wires. The ratio of the diameter of the circular wire to the thickness of the flat wire is greater than 1.

5. The yield point of the material of the round wire is lower than that of the material of the flat wire.

7. The catheter according to claim 6, characterized in that... The number of circular lines is greater than the number of flat lines.

8. The catheter according to claim 6 or 7, characterized in that, The intersecting wires do not interlock with each other.

9. The catheter according to claim 6 or 7, characterized in that, The flat wire is a wire with a rectangular cross-section.

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