Catheter and method for producing catheter

Abstract

This catheter is provided with a tube (32) having a longitudinal direction and a radial direction. The tube (32) has: an inner layer (12) made from resin; a reinforcing layer (13) that is provided on the radially outer side of the inner layer (12) and in which a first metal wire material (15) and a second metal wire material (16) are disposed in a braided manner; and a resin outer layer (19) that is provided on the radially outer side of the reinforcing layer (13). The reinforcing layer (13) has: a bulging part (18) resulting from the first metal wire material (15) melted at an end part of the first metal wire material (15), and a bulging part (18) resulting from the second metal wire material (16) melted at an end part of the second metal wire material (16).

Description

Catheter and method for manufacturing the same

[0001] The present invention relates to a catheter having a tube with a reinforcing layer made of metal wire, and a method for manufacturing a catheter having a tube with a reinforcing layer made of metal wire.

[0002] Conventionally, catheters including a tube with a reinforcing layer made of metal wires have been known. For example, Patent Document 1 discloses a catheter including an inner layer made of resin, a braided body formed of first and second wires and disposed around the inner layer, and an outer layer made of resin and disposed around the braided body, where the first and second wires are joined at a joint where the tip of the first wire covers the side of the second wire. Patent Document 2 discloses a catheter including a tubular braided body in which a first set of metal wires and a second set of metal wires intersect at multiple intersections, where two wires are welded at a corner region including one of four corners when viewed from the outer periphery, and the weld is formed on the inner wire only in a portion of the width direction when viewed from the outer periphery.

[0003] JP 2014-033682 A JP 2022-150880 A

[0004] A tube having a reinforcing layer made of metal wire is usually constructed by disposing the reinforcing layer between an inner resin layer and an outer resin layer. A catheter equipped with such a tube is required to prevent the metal wire constituting the reinforcing layer from being exposed and damaging the body lumen during use.

[0005] The present invention has been made in consideration of the above circumstances, and its object is to provide a safe catheter having a tube with a reinforcing layer made of metal wire, and a method for manufacturing a catheter that can obtain a safe catheter having a tube with a reinforcing layer made of metal wire.

[0006] The catheter according to the first embodiment of the present invention, which has solved the above-mentioned problems, is as follows: [A1] A catheter including a tube having a longitudinal direction and a radial direction, the tube having a resin inner layer, a reinforcing layer disposed radially outside the inner layer and having a braided first metal wire and a second metal wire, and a resin outer layer disposed radially outside the reinforcing layer, the reinforcing layer having a bulge formed by melting the first metal wire at an end of the first metal wire and a bulge formed by melting the second metal wire at an end of the second metal wire. [A2] The catheter described in [A1], in which an intersection between the first metal wire and the second metal wire is present at an end of the reinforcing layer, and the bulge of the first metal wire and the bulge of the second metal wire are fused and integrated at the intersection. [A3] The catheter described in [A1] or [A2], in which the melting point of the first metal wire and the melting point of the second metal wire are the same. [A4] The catheter according to any one of [A1] to [A3], wherein the first metal wire and the second metal wire are made of the same metal. [A5] The catheter according to any one of [A1] to [A4], wherein the bulge portion of the first metal wire is coated with the resin of the outer layer from the outside to the inside in the radial direction of the first metal wire, and the bulge portion of the second metal wire is coated with the resin of the outer layer from the outside to the inside in the radial direction of the second metal wire. [A6] The catheter according to any one of [A1] to [A5], wherein the inner layer extends distally beyond the end of the metal wire.

[0007] A catheter according to a second embodiment of the present invention that solves the above-mentioned problems is as follows. [B1] A catheter including a tube having a longitudinal direction and a radial direction, the tube having a resin inner layer, a reinforcing layer arranged outside the inner layer and made of metal wire, and a resin outer layer arranged outside the reinforcing layer, with the resin of the outer layer being present in a portion extending from the outer side to the inner side in the radial direction of the metal wire. [B2] The catheter described in [B1], wherein the reinforcing layer has a bulge at an end of the metal wire. [B3] The catheter described in [B1], wherein the metal wire includes a first metal wire and a second metal wire, and the reinforcing layer is formed by arranging the first metal wire and the second metal wire in a braided shape. [B4] The catheter described in [B3], wherein the first metal wire and the second metal wire are melted and joined to each other at an intersection of the first metal wire and the second metal wire. [B5] The catheter according to [B3] or [B4], wherein the reinforcing layer has a bulge formed by melt-joining the ends of the first metal wire and the second metal wire at an intersection between the first metal wire and the second metal wire. [B6] The catheter according to [B2] or [B5], wherein the resin of the outer layer is present from the outside to the inside in the radial direction of the metal wire at the bulge in the tube. [B7] The catheter according to any of [B1] to [B6], wherein the inner layer extends distally beyond the ends of the metal wire.

[0008] The catheter manufacturing method of the present invention, which has solved the above-mentioned problems, is as follows. [C1] A catheter manufacturing method comprising the steps of: preparing a tube to be cut, the tube having a resin inner layer, a reinforcing layer made of metal wire and disposed outside the inner layer, and a resin outer layer disposed outside the reinforcing layer; a first laser irradiation step of irradiating the tube to be cut with a first laser to cut the metal wire in the reinforcing layer and melt the outer layer; a second laser irradiation step of irradiating the tube to be cut with a second laser after the first laser irradiation step to cut the inner layer and obtain a cut tube; and an assembly step of assembling a catheter from the cut tube. [C2] A catheter manufacturing method according to [C1], in which, in the first laser irradiation step, the metal wire is heated by irradiation with the first laser, and the heat is transferred to the outer layer, thereby melting the outer layer. [C3] A catheter manufacturing method according to [C1] or [C2], in which, in the first laser irradiation step, the end of the metal wire is melted by irradiation with the first laser, forming a bulge. [C4] A method for manufacturing a catheter according to any one of [C1] to [C3], wherein the metal wire includes a first metal wire and a second metal wire, and the reinforcing layer is formed by arranging the first metal wire and the second metal wire in a braided state. [C5] A method for manufacturing a catheter according to [C4], wherein the first metal wire and the second metal wire are composed of the same metal. [C6] A method for manufacturing a catheter according to [C4] or [C5], wherein, in the first laser irradiation step, the first metal wire and the second metal wire are melted by irradiation with the first laser and joined to each other at an intersection of the first metal wire and the second metal wire. [C7] A method for manufacturing a catheter according to [C6], wherein, in the first laser irradiation step, an end of the first metal wire and an end of the second metal wire are melted and joined to each other at an intersection of the first metal wire and the second metal wire, forming a bulge. [C8] The method for manufacturing a catheter according to any one of [C1] to [C7], wherein in the second laser irradiation step, the inner layer is cut at a position distal to the cut end of the metal wire. [C9] The method for manufacturing a catheter according to any one of [C1] to [C8], wherein the melting point of the resin of the inner layer is higher than the melting point of the resin of the outer layer.[C10] The method for manufacturing a catheter according to any one of [C1] to [C9], wherein a pulsed laser is used as the first laser and a pulsed laser having a narrower pulse width than the first laser is used as the second laser, or a continuous wave laser is used as the first laser and a pulsed laser is used as the second laser. [C11] The method for manufacturing a catheter according to [C10], wherein a nanosecond pulsed laser, a femtosecond pulsed laser, or a picosecond pulsed laser is used as the second laser. [C12] The method for manufacturing a catheter according to any one of [C1] to [C11], wherein the step of preparing the tube to be cut includes the steps of: arranging the reinforcing layer on the outside of the tubular inner layer; arranging the outer layer on the outside of the reinforcing layer to obtain a tube precursor; and heating the tube precursor to obtain the tube to be cut.

[0009] The catheter according to the first embodiment of the present invention includes a tube having a reinforcing layer made of metal wire, and a bulge formed at the end of the metal wire where the metal wire is melted. This prevents the end of the metal wire from becoming sharp, making it less likely for the metal wire to break through the outer layer that covers the outside of the reinforcing layer or to protrude from the distal end of the tube. This reduces the risk of the metal wire being exposed and damaging the body lumen, resulting in a highly safe catheter.

[0010] In the catheter according to the second embodiment of the present invention, the tube has a reinforcing layer made of metal wire, and the resin of the outer layer is present in a portion extending from the outside to the inside in the radial direction of the metal wire, so that the outer layer and the reinforcing layer are firmly bonded together, making it difficult for the outer layer to peel off, resulting in a catheter with excellent safety.

[0011] The catheter manufacturing method of the present invention makes it possible to form a bulge at the end of the metal wire and to firmly bond the outer layer and reinforcing layer of the tube, thereby providing a catheter with excellent safety.

[0012] 1 shows a schematic diagram of the step of preparing a tube to be cut, the first laser irradiation step, and the second laser irradiation step in the manufacturing method of a catheter of the present invention. It shows an example of a side view of a cut tube obtained in the second laser irradiation step and a tube provided in a catheter of the present invention. It shows a III-III cross-sectional view of the cut tube and the tube shown in FIG. 2. It shows another example of a side view of a cut tube obtained in the second laser irradiation step and a tube provided in a catheter of the present invention. It shows a V-V cross-sectional view of the cut tube and the tube shown in FIG. 4. It shows an example of a catheter obtained by the manufacturing method of the present invention and a catheter of the present invention, and a side view of the catheter.

[0013] The present invention will be described in detail below based on the following embodiments. However, the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the above and below-described purposes, and all such modifications are included within the technical scope of the present invention. In addition, hatching and component symbols may be omitted in each drawing for convenience. In such cases, reference should be made to the specification or other drawings. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, as priority is given to helping understand the features of the present invention.

[0014] A catheter according to a first embodiment of the present invention comprises a tube having a reinforcing layer in which metal wires are arranged in a braided state, and the reinforcing layer has bulges at the ends of the braided metal wires where the metal wires are fused. Because the catheter according to the first embodiment of the present invention comprises a tube having a reinforcing layer configured in this manner, the ends of the metal wires are not sharp, making it less likely that the metal wires will break through the outer layer that covers the outside of the reinforcing layer or protrude from the distal end of the tube. This makes it less likely that the exposed metal wires will damage the body lumen, resulting in a highly safe catheter.

[0015] A catheter according to a second embodiment of the present invention comprises a tube having a reinforcing layer made of metal wire, the reinforcing layer being disposed outside a resin inner layer, a resin outer layer being disposed outside the reinforcing layer, and the resin of the outer layer extending from the outside to the inside in the radial direction of the metal wire of the reinforcing layer. Because the catheter according to the second embodiment of the present invention comprises a tube having a reinforcing layer configured in this manner, the outer layer and the reinforcing layer are firmly bonded together, making the outer layer less likely to peel off even when a strong shear force is applied between them. This prevents the metal wire from being exposed during use, resulting in a catheter with excellent safety.

[0016] The catheters according to the first and second embodiments can be suitably manufactured by the method for manufacturing a catheter of the present invention. Hereinafter, the method for manufacturing a catheter of the present invention will be described first with reference to FIGS. 1 to 6.

[0017] Fig. 1 shows a schematic diagram of a method for manufacturing a catheter according to an embodiment of the present invention, Fig. 2 shows an example of a side view of a cut tube obtained by the manufacturing method of the present invention, Fig. 3 shows a III-III cross-sectional view of the cut tube shown in Fig. 2, Fig. 4 shows another example of a side view of a cut tube obtained by the manufacturing method of the present invention, Fig. 5 shows a V-V cross-sectional view of the cut tube shown in Fig. 4, and Fig. 6 shows a side view of an example of a catheter obtained by the manufacturing method of the present invention. Fig. 1 shows a schematic diagram of the step of preparing a tube to be cut, the first laser irradiation step, and the second laser irradiation step of the method for manufacturing a catheter of the present invention.

[0018] A method for manufacturing a catheter according to an embodiment of the present invention includes the steps of: preparing a tube to be cut 11 having a resin inner layer 12, a reinforcing layer 13 arranged on the outside of the inner layer 12 and composed of metal wires 14, and a resin outer layer 19 arranged on the outside of the reinforcing layer 13; a first laser irradiation step of irradiating the tube to be cut 11 with a first laser 21 to cut the metal wires 14 in the reinforcing layer 13 and melt the outer layer 19; a second laser irradiation step of irradiating the tube to be cut 11 with a second laser 22 after the first laser irradiation step to cut the inner layer 12 and obtain a cut tube 20; and an assembly step of assembling a catheter from the cut tube 20. In Figure 1, the step of preparing a tube to be cut is shown in Figure 1(A), the first laser irradiation step is shown in Figures 1(B) and 1(C), and the second laser irradiation step is shown in Figures 1(C) and 1(D). 1, 2 and 4, the reinforcing layer 13 is covered by the outer layer 19 and is not exposed, but is shown by a solid line for ease of understanding.

[0019] In the process of preparing the tubes to be cut, a tube having a reinforcing layer 13 made of metal wires 14 is prepared as the target for cutting with a laser. As shown in FIG. 1A , the tube to be cut 11 has a longitudinal direction and a radial direction, and includes a resin inner layer 12, a reinforcing layer 13 made of metal wires 14 and disposed radially outward of the inner layer 12, and a resin outer layer 19 disposed radially outward of the reinforcing layer 13. The longitudinal direction refers to the direction in which the tube to be cut 11 extends, and the tube to be cut 11 has an inner lumen extending longitudinally. The radial direction refers to a direction perpendicular to the longitudinal direction, extending radially from the center of the tube to be cut 11. Note that the description of the configuration of the tube to be cut 11 also applies to the configuration of the tube to be cut 20. Furthermore, in the description of the catheter manufacturing method in this specification, the term "tube" may be used to refer to both the tube to be cut 11 and the tube to be cut 20.

[0020] The types of resins constituting the inner layer 12 and the outer layer 19 are not particularly limited, but the outer layer 19 is preferably made of a thermoplastic resin. The inner layer 12 may be made of a thermoplastic resin or a thermosetting resin, but is preferably made of a thermoplastic resin. When the inner layer 12 or the outer layer 19 is made of a thermoplastic resin, the resin constituting the inner layer 12 or the outer layer 19 has a melting point. When the inner layer 12 is made of a thermosetting resin, the resin constituting the inner layer 12 has a decomposition point.

[0021] Examples of resins that can be used to form the inner layer 12 and the outer layer 19 include synthetic resins such as polyester resins such as polyethylene terephthalate, polyamide resins such as nylon, polyolefin resins such as polyethylene and polypropylene, aromatic polyether ketone resins such as PEEK, polyurethane resins, polyether polyamide resins, polyimide resins, polyamide imide resins, fluorine-based resins such as PTFE, PFA, and ETFE, polyvinyl chloride resins, and silicone resins. The inner layer 12 and the outer layer 19 may be made of the same resin or different resins.

[0022] The reinforcing layer 13 is formed by arranging metal wires 14 in a predetermined pattern and is disposed between the inner layer 12 and the outer layer 19. Examples of materials that can be used for the metal wires 14 of the reinforcing layer 13 include stainless steels such as SUS304 and SUS316, carbon steel, platinum, nickel, cobalt, chromium, titanium, tungsten, gold, nickel-titanium alloys, cobalt-chromium alloys, and tungsten alloys, with stainless steel being preferred. The metal wires 14 may be solid wires or stranded wires.

[0023] The arrangement pattern of the metal wires 14 in the reinforcing layer 13 is not particularly limited, and examples include a spiral, mesh, braid, etc. Among these, the metal wires 14 in the reinforcing layer 13 are preferably arranged in a braided pattern as shown in Figures 1, 2, and 4, which can effectively increase the rigidity of the tube. In this case, the metal wires 14 preferably include first metal wires 15 and second metal wires 16, and the reinforcing layer 13 is preferably formed by arranging the first metal wires 15 and the second metal wires 16 in a braided pattern. Preferably, the first metal wires 15 extend in a clockwise spiral from one side to the other in the longitudinal direction of the tube 11 to be cut, and the second metal wires 16 extend in a counterclockwise spiral from one side to the other in the longitudinal direction of the tube 11 to be cut. Preferably, the first metal wires 15 and the second metal wires 16 intersect each other at one or more locations. A plurality of first metal wires 15 may be provided, and a plurality of second metal wires 16 may be provided.

[0024] Although there are no particular limitations on the inner diameter of the tube to be cut 11, considering that the cutting tube 20 will be used as a catheter, the inner diameter of the tube to be cut 11 is preferably, for example, about 0.25 mm to 3.50 mm. The outer diameter of the tube to be cut 11 is preferably, for example, about 0.30 mm to 3.80 mm. The thickness of the tube to be cut 11 is preferably, for example, about 0.05 mm to 0.30 mm.

[0025] The tube to be cut 11, i.e., a tube having a reinforcing layer 13 of metal wires 14, can be obtained, for example, by arranging the reinforcing layer 13 on the outside of a cylindrical inner layer 12, and then arranging an outer layer 19 on the outside of that. Therefore, the process of preparing the tube to be cut preferably includes a process of arranging the reinforcing layer on the outside of the cylindrical inner layer (reinforcing layer arranging process) and a process of arranging the outer layer on the outside of the reinforcing layer (outer layer arranging process).

[0026] In the reinforcing layer placement step, it is preferable to first place a tubular inner layer 12 on the outside of the core material, and then place a reinforcing layer 13 on the outside of that. The inner layer 12 is preferably placed outside the core material, in contact with the outer surface of the core material. Therefore, it is preferable to provide a step of preparing the tubular inner layer 12 to be placed outside the core material prior to the reinforcing layer placement step. In this step, for example, the tubular inner layer 12 may be formed by extrusion molding and then placed on the outside of the core material, or the tubular inner layer 12 may be formed outside the core material by inserting the core material into the lumen of the tubular inner layer 12. Alternatively, the tubular inner layer 12 can be formed by applying a resin to the outside of the core material. For example, the tubular inner layer 12 can be formed by immersing the core material in a paint-like resin. A metal rod or the like can be used as the core material.

[0027] In the reinforcing layer arrangement step, a reinforcing layer 13 made of metal wires 14 is arranged on the outside of the cylindrical inner layer 12. The reinforcing layer 13 arranged on the outside of the inner layer 12 may be cylindrical or sheet-shaped. In the former case, the cylindrical reinforcing layer 13 is arranged on the outside of the inner layer 12. In the latter case, it is preferable to wind the sheet-shaped reinforcing layer 13 around the outside of the cylindrical inner layer 12. It is preferable to arrange the reinforcing layer 13 so that it goes around the outside of the cylindrical inner layer 12.

[0028] In the outer layer disposing step, the outer layer 19 is disposed on the outside of the reinforcing layer 13. The outer layer 19 disposed on the outside of the reinforcing layer 13 may be cylindrical or sheet-shaped. In the former case, the cylindrical outer layer 19 is disposed on the outside of the reinforcing layer 13. In the latter case, it is preferable to wrap the sheet-shaped outer layer 19 around the outside of the reinforcing layer 13.

[0029] The tube to be cut 11 may be the tube obtained in the outer layer disposing step as is, or preferably a tube obtained by heating the tube obtained in the outer layer disposing step. Therefore, in the outer layer disposing step, it is preferable to obtain a tube precursor by disposing the outer layer 19 on the outside of the reinforcing layer 13, and then preferably to provide a step (heating step) of heating the tube precursor to obtain the tube to be cut. The heating step causes the inner surface of the outer layer 19 to adhere to the reinforcing layer 13, which makes it easier to melt the outer layer 19 in the subsequent first laser irradiation step. For example, melting a portion of the inner surface of the outer layer 19 allows the outer layer 19 to adhere to the reinforcing layer 13. The outer layer 19 may be made of a heat-shrinkable film, in which case heating the outer layer 19 makes it even easier to adhere the outer layer 19 to the reinforcing layer 13.

[0030] The tube precursor is heated by a heating means such as a heater or a welding device. The tube precursor may be heated, for example, by placing the tube precursor in a heating furnace or by applying hot air to the tube precursor, or by applying ultrasonic waves or high frequency waves to the tube precursor to heat the tube precursor by ultrasonic welding or high frequency welding.

[0031] When the process for preparing the tube to be cut includes a reinforcing layer disposing step and an outer layer disposing step, or further includes a heating step, the obtained tube may be cut as appropriate. For example, the tube obtained in the reinforcing layer disposing step may be cut to adjust its length before the outer layer disposing step, or the tube obtained in the outer layer disposing step may be cut to adjust its length before the heating step, or the tube obtained in the outer layer disposing step or the heating step may be cut to adjust its length to provide the tube to be cut 11.

[0032] In the first laser irradiation step, as shown in FIG. 1B , a first laser 21 is irradiated onto the tube 11 to be cut, thereby cutting the metal wire 14 of the reinforcing layer 13. FIG. 1C shows the tube 11 to be cut after the metal wire 14 of the reinforcing layer 13 has been cut. The first laser 21 emits light of a wavelength that can be absorbed by the metal wire 14. By irradiating the tube 11 to be cut with the first laser 21, the energy of the first laser 21 is absorbed by the metal wire 14, thereby cutting the metal wire 14 of the reinforcing layer 13. Specifically, the energy of the first laser 21 is absorbed by the metal wire 14, thereby heating the metal wire 14 and melting it. In the first laser irradiation step, it is preferable to cut the reinforcing layer 13 in a circular direction around the tube 11 to be cut, which preferably separates the reinforcing layer 13 in the longitudinal direction of the tube 11 to be cut.

[0033] In the first laser irradiation step, it is preferable to cut the metal wire 14 and melt the outer layer 19 by irradiating the first laser 21. This allows the outer layer 19 and the reinforcing layer 13 to be firmly bonded together, making it less likely for the outer layer 19 to peel off even when a strong shear force is applied between the outer layer 19 and the reinforcing layer 13. In addition, the end of the metal wire 14 cut by the first laser 21 is more likely to be covered with the resin of the outer layer 19, preventing the cut end of the metal wire 14 from being exposed. Therefore, when the catheter is used, peeling of the outer layer 19 and exposure of the metal wire 14 are prevented, thereby improving the safety of the resulting catheter. Note that the cut end of the metal wire 14 refers to the end of the metal wire 14 cut by the first laser 21.

[0034] The outer layer 19 may melt when the energy of the first laser 21 is directly absorbed by the resin constituting the outer layer 19. However, it is preferable that the outer layer 19 melt when the metal wire 14 is heated by irradiation with the first laser 21 and the heat is transferred to the outer layer 19. This causes the resin constituting the outer layer 19 to melt preferentially in the area in contact with the metal wire 14, firmly bonding the outer layer 19 and the reinforcing layer 13. As a result, the integrity of the tube after laser cutting can be improved, particularly in the area near the laser cut. Furthermore, the end of the metal wire 14 cut by the first laser 21 is more likely to be entirely covered with the resin of the outer layer 19, thereby improving the safety of the resulting catheter. Meanwhile, the portion of the outer layer 19 that does not overlap with the metal wire 14 is prevented from being directly transferred heat from the metal wire 14, thereby preventing the entire outer layer 19 from melting. In the first laser irradiation step, the outer layer 19 may be melted and cut by irradiation with the first laser 21.

[0035] In the first laser irradiation step, it is preferable that the resin of the outer layer 19 is present from the outside to the inside in the radial direction of the metal wire 14 by irradiation with the first laser 21. In Figures 3 and 5, the resin of the outer layer 19 is present from the outside to the inside in the radial direction of the metal wire 14 at the end of the metal wire 14 cut by the first laser 21. When the metal wire 14 is heated by irradiation with the first laser 21 and heat is transferred to the outer layer 19, and the resin of the outer layer 19 melts, the resin of the outer layer 19 can be present in this manner. Even if the resin of the outer layer 19 is present only on the outside in the radial direction of the metal wire 14 before irradiation with the first laser 21, the metal wire 14 is heated by irradiation with the first laser 21, heat is transferred to the outer layer 19, and the resin of the outer layer 19 melts, so that the resin of the outer layer 19 flows in a molten state to the inside in the radial direction of the metal wire 14, and the resin of the outer layer 19 can be present all the way to the inside in the radial direction of the metal wire 14. This more firmly bonds the outer layer 19 and the reinforcing layer 13. Therefore, in the cut tube 20, it is preferable that the resin of the outer layer 19 is present from the outside to the inside in the radial direction of the metal wire 14 at the end of the metal wire 14, and it is more preferable that the resin of the outer layer 19 is present around the entire circumference of the metal wire 14 in a vertical cross section in the extension direction of the metal wire 14.

[0036] 3 , when the first metal wire 15 and the second metal wire 16 are melted and integrated to form the bulge 18, it is preferable that the resin of the outer layer 19 is present from the radial outside to the radial inside of the bulge 18. Alternatively, it is preferable that the resin of the outer layer 19 is present from the radial outside of the metal wire 14 located on the radial outside of the first metal wire 15 and the second metal wire 16 to the radial inside of the metal wire 14 located on the radial inside.

[0037] In the first laser irradiation step, a portion of the inner layer 12 may melt. For example, the metal wire 14 may be heated by irradiation with the first laser 21, and the heat may be transferred to the inner layer 12, thereby melting a portion of the inner layer 12. Note that in the first laser irradiation step, it is preferable to suppress melting of the inner layer 12 as much as possible, and it is more preferable that the inner layer 12 does not melt. It is also preferable that the inner layer 12 is not cut in the first laser irradiation step. In this regard, it is preferable that the inner layer 12 and the outer layer 19 are made of different resins.

[0038] From the above viewpoints, the melting point or decomposition point of the resin of the inner layer 12 is preferably higher than the melting point of the resin of the outer layer 19. Since the resin of the inner layer 12 is preferably a thermoplastic resin, the melting point of the resin of the inner layer 12 is more preferably higher than the melting point of the resin of the outer layer 19. The difference between the melting point or decomposition point of the resin of the inner layer 12 and the melting point of the resin of the outer layer 19 is preferably 30°C or more, more preferably 40°C or more, and even more preferably 50°C or more. There are no particular limitations on the upper limit of the difference between the melting point or decomposition point of the resin of the inner layer 12 and the melting point of the resin of the outer layer 19, and it may be, for example, 300°C or less, 250°C or less, 200°C or less, or 150°C or less.

[0039] The inner layer 12 is preferably made of a resin with a relatively high melting point or high decomposition point, such as a fluororesin, polyimide resin, polyamideimide resin, silicone resin, or aromatic polyether ketone resin. By using such a resin, the inner surface of the tube formed from the inner layer 12 can be made smooth and the inner surface of the tube can be made resistant to damage and have sufficient strength. On the other hand, the outer layer 19 is preferably made of a resin with a relatively low melting point, such as a polyester resin, polyamide resin, polyolefin resin, polyurethane resin, or polyether polyamide resin.

[0040] It is preferable that the first laser 21 does not directly heat the resin of the inner layer 12. Therefore, it is preferable that the first laser 21 does not oscillate at a wavelength that is absorbed by the resin of the inner layer 12. It is also preferable that the first laser 21 does not directly heat the resin of the outer layer 19. Therefore, it is preferable that the first laser 21 does not oscillate at a wavelength that is absorbed by the resin of the outer layer 19.

[0041] In the first laser irradiation step, the end of the metal wire 14 is preferably melted by irradiation with the first laser 21 to form a bulge 18. That is, it is preferable that a so-called molten ball is formed at the end of the metal wire 14. This prevents the end of the metal wire 14 from becoming sharp, making it less likely that the metal wire 14 will break through the outer layer 19 or protrude from the cut end of the tube. As a result, the metal wire 14 is less likely to injure the body lumen, thereby improving the safety of the resulting catheter. Note that the end of the metal wire 14 refers to the portion near the cut end of the metal wire 14, including the end of the metal wire 14 cut by the first laser 21.

[0042] 2 and 4 show an example in which the metal wires 14 of the reinforcing layer 13 are arranged in a braided shape, i.e., the metal wires 14 include first metal wires 15 and second metal wires 16, and the first metal wires 15 and second metal wires 16 are arranged in a braided shape to form the reinforcing layer 13, and bulges 18 are formed at the ends of the first metal wires 15 and the second metal wires 16. Fig. 2 shows an example in which the bulges 18 formed at the ends of the first metal wires 15 and the second metal wires 16 are joined at the intersections 17 of the first metal wires 15 and the second metal wires 16. Fig. 4 shows an example in which bulges 18 are formed independently at the ends of the first metal wires 15 and the second metal wires 16. 2 and 4 show side views of the cut tube 20 after the inner layer 12 has been cut in the second laser irradiation step.

[0043] When the metal wires 14 of the reinforcing layer 13 are arranged in a braided state, it is preferable that the first metal wires 15 and the second metal wires 16 are melted by irradiation with the first laser 21 and joined to each other at the intersections 17 of the first metal wires 15 and the second metal wires 16. This prevents the first metal wires 15 and the second metal wires 16 cut by the first laser 21 from coming apart, and allows the reinforcing layer 13 to be stably held in a braided state.

[0044] In the first laser irradiation step, as shown in Fig. 2, the first laser 21 is preferably used to fuse and join the ends of the first metal wire 15 and the second metal wire 16 at the intersection 17 between the first metal wire 15 and the second metal wire 16, forming a bulge 18. This allows the first metal wire 15 and the second metal wire 16 to be more firmly joined at the intersection 17 between the first metal wire 15 and the second metal wire 16, and also makes it easier to form a relatively large bulge 18. This makes it more unlikely that the metal wire 14 will break through the outer layer 19 or protrude from the cut end of the cut tube 20, thereby further improving the safety of the resulting catheter.

[0045] The first metal wire 15 and the second metal wire 16 may be made of the same metal or different metals. However, it is preferable that the first metal wire 15 and the second metal wire 16 are made of the same metal because it is easy for the first metal wire 15 and the second metal wire 16 to melt and be firmly joined together. This allows the metals of the first metal wire 15 and the second metal wire 16 to be compatible with each other when the first metal wire 15 and the second metal wire 16 are melt-joined, and the first metal wire 15 and the second metal wire 16 can be integrated at the intersection 17. As a result, the bulge 18 formed at the intersection 17 of the first metal wire 15 and the second metal wire 16 can be formed as a homogeneous molten ball. It is also preferable that the melting point of the first metal wire 15 is the same as the melting point of the second metal wire 16, since this makes it easier for the first metal wire 15 and the second metal wire 16 to melt and be firmly joined to each other.

[0046] The bulge 18 of the metal wire 14 is preferably thicker than the remaining portion of the metal wire 14 (see FIGS. 3 and 5). That is, the bulge 18 of the metal wire 14 is preferably longer in the radial direction of the tube than the remaining portion of the metal wire 14. Hereinafter, the radial length of the metal wire 14 is referred to as the thickness of the metal wire 14. Forming the bulge 18 in this manner reduces the likelihood of damaging the body lumen even if the distal end of the metal wire 14 contacts the body lumen. Furthermore, even if a strong shear force is applied between the inner layer 12 or outer layer 19 and the reinforcing layer 13, the bulge 18 acts as a stopper, making it less likely that the outer layer 19 or the reinforcing layer 13 will peel off. The bulging portion 18 of the metal wire 14 is preferably formed to bulge outward at least in the radial direction from the portion of the metal wire 14 other than the bulging portion 18 .

[0047] The metal wire 14 is preferably strip-shaped. That is, the thickness of the metal wire 14 is preferably formed to be shorter than the width of the metal wire 14 (specifically, the width of the metal wire 14 as viewed from the outside of the tube 11 to be cut). By forming the reinforcing layer 13 from the strip-shaped metal wire 14, the thickness of the reinforcing layer 13 can be made thin, and the wall thickness of the tube 11 to be cut can be made thin. Furthermore, at the intersection 17 between the first metal wire 15 and the second metal wire 16, the first metal wire 15 and the second metal wire 16 can be stably overlapped, making it easy to firmly melt and join the first metal wire 15 and the second metal wire 16.

[0048] The width of the metal wire 14 is preferably at least two times the thickness of the metal wire 14, more preferably at least three times, and preferably not more than ten times, more preferably not more than eight times, and even more preferably not more than six times. For example, the metal wire 14 may have a thickness of about 3 μm to 100 μm and a width of about 10 μm to 500 μm.

[0049] The irradiation width of the first laser 21 (the length over which the first laser 21 is irradiated in the longitudinal direction of the tube 11 to be cut) is preferably 5 times or less, more preferably 3 times or less, even more preferably 2 times or less, and even more preferably 1 time or less, the width of the metal wire 14. This makes it easy to cut the metal wire 14 at a desired location in the longitudinal direction of the tube 11 to be cut when the first laser 21 is irradiated. Furthermore, when forming a bulge 18 at the end of the metal wire 14, it is possible to prevent the bulge 18 from being formed excessively large. There is no particular lower limit to the irradiation width of the first laser 21, and the irradiation width of the first laser 21 may be 0.01 times or more, 0.05 times or more, or 0.1 times or more the width of the metal wire 14, or may be narrower than these.

[0050] After the first laser irradiation step, a second laser irradiation step is performed. In the second laser irradiation step, a second laser 22 is irradiated onto the tube 11 to be cut, as shown in Fig. 1(C), to cut the inner layer 12, thereby obtaining a cut tube 20 as shown in Fig. 1(D). This makes it easier to form a clean cut surface of the cut tube 20. The second laser 22 emits light of a wavelength that can be absorbed by the resin of the inner layer 12. By irradiating the tube 11 to be cut after irradiation with the first laser 21 with the second laser 22, the energy of the second laser 22 is absorbed by the resin of the inner layer 12, thereby cutting the inner layer 12.

[0051] In the second laser irradiation step, the tube 11 to be cut may be irradiated with the second laser 22 without removing the cut pieces of the reinforcing layer 13 cut in the first laser irradiation step, or the tube 11 to be cut may be irradiated with the second laser 22 after removing the cut pieces of the reinforcing layer 13 cut in the first laser irradiation step. In the latter case, it is preferable to also remove the outer layer 19 arranged on the outside of the cut pieces of the reinforcing layer 13. The cut pieces of the reinforcing layer 13 refer to the pieces of the reinforcing layer 13 that are removed by cutting with the first laser 21.

[0052] In the second laser irradiation step, the outer layer 19 may also be cut by irradiating with the second laser 22. In this case, it is preferable that the second laser 22 also oscillates at a wavelength that can be absorbed by the resin of the outer layer 19.

[0053] In the second laser irradiation step, the metal wire 14 of the reinforcing layer 13 may also be cut by irradiating it with a second laser 22. In this case, it is preferable that the second laser 22 also oscillates at a wavelength that can be absorbed by the metal wire 14. In the first laser irradiation step, it is preferable to cut the reinforcing layer 13 around the circumferential direction of the tube 11 to be cut, that is, to cut the reinforcing layer 13 so as to separate it in the longitudinal direction of the tube 11 to be cut. However, in case a portion of the metal wire 14 is not cut, the remaining metal wire 14 may be cut in the second laser irradiation step. Alternatively, after cutting the reinforcing layer 13 so as to separate it in the longitudinal direction of the tube 11 to be cut in the first laser irradiation step, the separated cut piece of the reinforcing layer 13 may be cut together with the inner layer 12 or further together with the outer layer 19 in the second laser irradiation step.

[0054] In the second laser irradiation step, it is preferable to cut the inner layer 12 distal to the cut end of the metal wire 14. If the outer layer 19 is present distal to the cut end of the metal wire 14, it is preferable to cut the inner layer 12 and the outer layer 19 distal to the cut end of the metal wire 14. By cutting the tube 11 to be cut with the second laser 22 after irradiation with the first laser 21 in this manner, protrusion of the metal wire 14 from the cut end of the cut tube 20 is prevented. Furthermore, cutting of the bulge 18 at the end of the metal wire 14 by the second laser 22 is prevented. As a result, the metal wire 14 is less likely to damage the body lumen, thereby improving the safety of the resulting catheter. When the distal portion of a catheter is formed from the cut tube 20, the presence of the inner layer 12 distal to the cut end of the metal wire 14 makes it easier to insert a guidewire or other treatment tool into the lumen of the catheter (cut tube 20). In addition, the tip side of the cut end of the metal wire 14 means the side of the cut piece of the reinforcing layer 13 (the side removed by cutting) of the tube 11 to be cut after irradiation with the first laser 21, rather than the cut end of the metal wire 14; in the cut tube 20, this means that there is a section at the longitudinal end (the end cut by the second laser 22) that has the inner layer 12 and does not have the metal wire 14.

[0055] In the second laser irradiation step, it is preferable to cut the inner layer 12 at a distance that is preferably at least 0.1 times, more preferably at least 0.2 times, and even more preferably at least 0.3 times the width of the metal wire 14 distal from the cut end of the metal wire 14, and it is also preferable to cut the inner layer 12 at a distance that is preferably at most 3.0 times, more preferably at most 2.0 times, and even more preferably at most 1.5 times the width of the metal wire 14 distal from the cut end of the metal wire 14. By cutting the tube 11 to be cut with the second laser 22 in this manner, it is possible to prevent the metal wire 14 from protruding from the cut end of the tube 20 while ensuring as much of the section of the tube 20 where the reinforcing layer 13 is present as possible.

[0056] When cutting with the second laser 22, it is desirable that the cut surface of the tube 20 be as clean as possible. That is, it is desirable that the irradiation of the second laser 22 does not cause the tube 11 to melt over a wide area or create large irregularities on the cut surface. It is also desirable that the vicinity of the cut end of the tube 20 does not collapse radially inward. From the perspective of cutting the tube, it is preferable to use a pulsed laser as the second laser 22, and more preferably a short-pulse laser. This prevents heat from diffusing from the irradiated area of ​​the second laser 22 to the surrounding area when the tube 11 is irradiated with the second laser 22, thereby preventing the tube 11 from melting over a wide area and allowing the cut surface of the tube 20 to be cleanly formed.

[0057] On the other hand, the first laser 21 used in the first laser irradiation step is preferably a long-pulse laser or a continuous-wave laser. This allows heat to be transmitted not only to the irradiated portion of the metal wire 14 but also to the surrounding metal wire 14 and outer layer 19 when the first laser 21 is irradiated onto the metal wire 14. As a result, the irradiation of the first laser 21 not only cuts the metal wire 14 but also facilitates heat transfer from the metal wire 14 to melt the outer layer 19. This also makes it easy to form a bulge 18 (molten ball) at the end of the metal wire 14.

[0058] From the above viewpoints, it is preferable to use a pulsed laser as the first laser 21 and a pulsed laser having a narrower pulse width than the first laser 21 as the second laser 22. Alternatively, it is preferable to use a continuous wave laser as the first laser 21 and a pulsed laser as the second laser 22. The pulsed laser used as the first laser 21 is preferably a millisecond pulsed laser or a microsecond pulsed laser. The pulsed laser used as the second laser 22 is preferably a nanosecond pulsed laser, a femtosecond pulsed laser, or a picosecond pulsed laser, and more preferably a femtosecond pulsed laser or a picosecond pulsed laser. A millisecond pulsed laser is a laser with a pulse width of 1 millisecond or more and less than 1 second, a microsecond pulsed laser is a laser with a pulse width of 1 microsecond or more and less than 1 millisecond, a nanosecond pulsed laser is a laser with a pulse width of 1 nanosecond or more and less than 1 microsecond, a femtosecond pulsed laser is a laser with a pulse width of 1 femtosecond or more and less than 1 nanosecond, and a picosecond pulsed laser is a laser with a pulse width of 1 picosecond or more and less than 1 femtosecond.

[0059] Known lasers can be used as the first laser 21 and the second laser 22. There are no particular limitations on the laser medium, and solid-state lasers, liquid lasers, gas lasers, fiber lasers, semiconductor lasers, chemical lasers, free lasers, etc. can be used.

[0060] In the assembly process, a catheter is assembled from the cut tube 20. Examples of the catheter include a guiding catheter, an electrode catheter, an ablation catheter, a balloon catheter, a mapping catheter, a microcatheter, and a stent delivery system.

[0061] The catheter has an operating section on the proximal side and a tube (shaft) provided distal to the operating section, and the cutting tube 20 can be used for at least a part of the tube (shaft) of the catheter. The cutting tube 20 is preferably assembled as a catheter so that the cut end faces the distal side. Both one and the other longitudinal ends of the cutting tube 20 may be cut by the first laser irradiation step and the second laser irradiation step described above.

[0062] An example of the configuration of a catheter will be described with reference to Fig. 6. Fig. 6 shows an example of the configuration of a guiding catheter as a catheter 31. The catheter 31 has a tube 32 and an operating section 33 provided on the proximal side of the tube 32. The cutting tube 20 is used as the tube 32.

[0063] The operation unit 33 preferably has a treatment port 34 that communicates with the inner cavity of the tube 32. A guide wire or a treatment device can be inserted through the treatment port 34. The operation unit 33 may also have a fluid injection port 35 for a drug, contrast agent, or the like. The fluid injection port 35 communicates with the inner cavity of the tube 32, and by injecting a drug, contrast agent, or the like from the fluid injection port 35, the drug, contrast agent, or the like can be supplied into the body through the tube 32.

[0064] Next, a catheter according to a first embodiment of the present invention and a catheter according to a second embodiment of the present invention will be described with reference to Fig. 6 and Figs. 2 to 5. Fig. 6 shows an example of the configuration of a guiding catheter as an example of a catheter of the present invention, Fig. 2 shows an example of a side view of the distal portion of a tube provided in the catheter shown in Fig. 6, Fig. 3 shows a III-III cross-sectional view of the tube shown in Fig. 2, Fig. 4 shows another example of a side view of the distal portion of a tube provided in the catheter shown in Fig. 6, and Fig. 5 shows a V-V cross-sectional view of the tube shown in Fig. 4. Examples of catheters include guiding catheters, electrode catheters, ablation catheters, balloon catheters, mapping catheters, microcatheters, stent delivery systems, and the like, and the type is not particularly limited.

[0065] The catheter 31 has a tube 32 and an operating section 33 provided on the proximal side of the tube 32. For details of the operating section 33, please refer to the above description.

[0066] The tube 32 has a longitudinal direction extending from the proximal side to the distal side and a radial direction perpendicular to the longitudinal direction. The longitudinal direction of the tube 32 refers to the direction in which the tube 32 extends, and the tube 32 has an inner lumen extending in the longitudinal direction. The radial direction refers to the direction perpendicular to the longitudinal direction, extending radially from the center of the tube 32. The longitudinal direction of the catheter 31 is also determined based on the longitudinal direction of the tube 32. The catheter 31 and the tube 32 have a proximal side and a distal side as one and the other sides of the longitudinal direction. The proximal side refers to the side of the catheter 31 that is closest to the user, i.e., the operator, and the distal side refers to the opposite side of the proximal side, i.e., the direction toward the treatment target.

[0067] The cut tube 20 obtained by the catheter manufacturing method of the present invention can be applied as the tube 32 used in the catheter 31. However, the tube 32 provided in the catheter 31 according to the embodiment of the present invention is not limited to the cut tube 20 obtained by the catheter manufacturing method of the present invention.

[0068] 2 to 5, the tube 32 has a resin inner layer 12, a reinforcing layer 13 arranged outside the inner layer 12 and made of metal wires 14, and a resin outer layer 19 arranged outside the reinforcing layer 13. The reinforcing layer 13 is arranged radially outside the inner layer 12, and the outer layer 19 is arranged radially outside the reinforcing layer 13. In FIGS. 2 and 4, the reinforcing layer 13 is covered by the outer layer 19 and is not exposed, but for ease of understanding, the reinforcing layer 13 is represented by a solid line.

[0069] A catheter according to a first embodiment will be described. In a catheter 31 according to the first embodiment, the metal wires 14 of the reinforcing layer 13 of the tube 32 are arranged in a braided state. This increases the rigidity of the tube 32. Specifically, the metal wires 14 include first metal wires 15 and second metal wires 16, and the reinforcing layer 13 is formed by arranging the first metal wires 15 and second metal wires 16 in a braided state.

[0070] The reinforcing layer 13 has bulges 18 at the ends of the first metal wires 15 where the first metal wires 15 are melted, and bulges 18 at the ends of the second metal wires 16 where the second metal wires 16 are melted. The bulges 18 can be formed as molten balls of the first metal wires 15 or the second metal wires 16. By forming the bulges 18 at the ends of the first metal wires 15 and the second metal wires 16 in this manner, the ends of the first metal wires 15 and the second metal wires 16 are not sharp, making it less likely that the first metal wires 15 and the second metal wires 16 will break through the outer layer 19 or protrude from the distal end of the tube 32. This makes it less likely that the first metal wires 15 and the second metal wires 16 will be exposed and cause injury to the body lumen, resulting in a highly safe catheter. The bulge portion 18 may be formed on at least one of the proximal end and distal end of the metal wire 14 (specifically, the first metal wire 15 and the second metal wire 16), but it is preferable that the bulge portion 18 be formed at least on the distal end of the metal wire 14.

[0071] In the first embodiment, as shown in Fig. 4, the bulge portion 18 may be formed independently at the end of the first metal wire 15 and the end of the second metal wire 16. However, as shown in Fig. 2, the bulge portion 18 is preferably formed at the intersection 17 of the first metal wire 15 and the second metal wire 16. Specifically, the intersection 17 of the first metal wire 15 and the second metal wire 16 is preferably present at the end of the reinforcing layer 13, and the bulge portion 18 of the first metal wire 15 and the bulge portion 18 of the second metal wire 16 are preferably fused and integrated at the intersection 17. This allows the first metal wire 15 and the second metal wire 16 to be more firmly joined at the intersection 17 of the first metal wire 15 and the second metal wire 16, and also makes it easier to form the bulge portion 18 to be relatively large. That is, a relatively large bulge 18 can be formed at the intersection 17, which is the end of the first metal wire 15 and the second metal wire 16. This makes it less likely that the first metal wire 15 and the second metal wire 16 will break through the outer layer 19 or protrude from the end of the tube 32, thereby further improving the safety of the resulting catheter.

[0072] As described above, if the first metal wires 15 and the second metal wires 16 are fused and integrated at the intersections 17 of the first metal wires 15 and the second metal wires 16, the first metal wires 15 and the second metal wires 16 do not come apart at the end of the reinforcing layer 13, and the reinforcing layer 13 can be stably held in a braided state. For example, even if a metal ring is provided at the end of the reinforcing layer 13 and the end of the reinforcing layer 13 is not fixed to the metal ring, the first metal wires 15 and the second metal wires 16 can be prevented from coming apart. In this respect, the tube 32 does not need to have a metal ring to which the first metal wires 15 and the second metal wires 16 are fixed at the end of the reinforcing layer 13.

[0073] A catheter according to a second embodiment will now be described. In a catheter 31 according to the second embodiment, the tube 32 has a portion in which the resin of the outer layer 19 is present from the outside to the inside in the radial direction of the metal wire 14. In FIGS. 3 and 5 , the resin of the outer layer 19 is present at the end of the metal wire 14 from the outside to the inside in the radial direction of the metal wire 14. Because the tube 32 has a portion in which the resin of the outer layer 19 is present from the outside to the inside in the radial direction of the metal wire 14, the outer layer 19 and the reinforcing layer 13 are firmly bonded together, making it less likely for the outer layer 19 to peel off even when a strong shear force is applied between the outer layer 19 and the reinforcing layer 13. Therefore, a catheter including the tube 32 is less likely to expose the metal wire 14 during use, resulting in excellent safety. In the tube 32, it is preferable that the resin of the outer layer 19 is present around the entire circumference of the metal wire 14 in a cross section perpendicular to the extension direction of the metal wire 14.

[0074] In the second embodiment, too, the reinforcing layer 13 preferably has bulges 18 at the ends of the metal wires 14. By forming the reinforcing layer 13 in this manner, the ends of the metal wires 14 in the reinforcing layer 13 do not become sharp, making it less likely that the metal wires 14 will break through the outer layer 19 or protrude from the end of the tube 32. The bulges 18 may be formed at least at one of the proximal and distal ends of the metal wires 14, but it is preferable that the bulges 18 be formed at least at the distal end of the metal wires 14.

[0075] In the second embodiment, the arrangement pattern of the metal wires 14 in the reinforcing layer 13 is not particularly limited, and examples thereof include a spiral, a mesh, and a braid. Among these, the metal wires 14 in the reinforcing layer 13 are preferably arranged in a braid as shown in Figures 2 and 4, which can effectively increase the rigidity of the tube 32. In this case, the metal wires 14 preferably include first metal wires 15 and second metal wires 16, and the reinforcing layer 13 is preferably formed by arranging the first metal wires 15 and the second metal wires 16 in a braid.

[0076] In the second embodiment, the reinforcing layer 13 is preferably configured such that the first metal wires 15 and the second metal wires 16 are melted and bonded to each other at intersections 17 between the first metal wires 15 and the second metal wires 16. This prevents the first metal wires 15 and the second metal wires 16 from coming apart, and the reinforcing layer 13 can be stably held in a braided state. More preferably, the first metal wires 15 and the second metal wires 16 are melted and bonded to each other at least at intersections 17 between the first metal wires 15 and the second metal wires 16 at the proximal end and / or distal end of the reinforcing layer 13. In this case, a metal ring is provided at the end of the reinforcing layer 13, and the first metal wires 15 and the second metal wires 16 can be prevented from coming apart without fixing the end of the reinforcing layer 13 to the metal ring. Therefore, also in the second embodiment, the tube 32 does not need to be provided with a metal ring to which the first metal wire 15 and the second metal wire 16 are fixed at the end of the reinforcing layer 13. The intersection 17 at the proximal end of the reinforcing layer 13 means the intersection 17 closest to the proximal end of the reinforcing layer 13. The intersection 17 at the distal end of the reinforcing layer 13 means the intersection 17 closest to the distal end of the reinforcing layer 13.

[0077] In the second embodiment, as shown in Fig. 2, the reinforcing layer 13 preferably has a bulge 18 formed by melt-joining the end of the first metal wire 15 and the end of the second metal wire 16 at the intersection 17 between the first metal wire 15 and the second metal wire 16. This makes it more difficult for the metal wire 14 to break through the outer layer 19 or protrude from the end of the tube 32, thereby further improving the safety of the resulting catheter.

[0078] A preferred embodiment of the catheter according to the first and second embodiments will now be described. In the reinforcing layer 13, the first metal wire 15 and the second metal wire 16 may be made of the same metal or different metals. However, it is preferable that the first metal wire 15 and the second metal wire 16 be made of the same metal. This allows the metals of the first metal wire 15 and the second metal wire 16 to be compatible with each other when they are melted and joined at the intersection 17 between them, thereby integrating the first metal wire 15 and the second metal wire 16 at the intersection 17. Furthermore, the bulge 18 formed at the intersection 17 between the first metal wire 15 and the second metal wire 16 can be formed as a homogeneous molten ball. From a similar perspective, it is also preferable that the melting point of the first metal wire 15 is the same as the melting point of the second metal wire 16.

[0079] 3 and 5 , the bulge 18 of the metal wire 14 is preferably thicker than the rest of the metal wire 14. Furthermore, the thickness of the bulge 18 of the first metal wire 15 is preferably thicker than the rest of the first metal wire 15, and the thickness of the bulge 18 of the second metal wire 16 is preferably thicker than the rest of the second metal wire 16. The thicknesses of the metal wire 14, the first metal wire 15, and the second metal wire 16 refer to the lengths of the metal wire 14, the first metal wire 15, and the second metal wire 16, respectively, in the radial direction of the tube 32. Forming the bulge 18 in this manner makes it less likely that the end of the metal wire 14 will damage the body lumen even if it comes into contact with the body lumen. Furthermore, even if a strong shear force is applied between the inner layer 12 or outer layer 19 and the reinforcing layer 13, the bulging portion 18 acts as a stopper, making it difficult for the outer layer 19 or the reinforcing layer 13 to peel off.

[0080] The thickness of the bulging portion 18 of the metal wire 14 other than the intersection 17 is preferably thicker than the thickness of the metal wire 14 other than the bulging portion 18. In this case, the thickness of the metal wire 14 other than the intersection 17 is preferably 1.2 times or more, more preferably 1.5 times or more, and preferably 5.0 times or less, more preferably 4.0 times or less of the thickness of the metal wire 14 other than the bulging portion 18.

[0081] 3, when the bulge 18 is formed at the intersection 17 of the first metal wire 15 and the second metal wire 16, it is preferable that the thickness of the bulge 18 is thicker than the combined thickness of the first metal wire 15 and the second metal wire 16. In this case, the thickness of the bulge 18 is preferably 1.2 times or more, more preferably 1.3 times or more, and preferably 4.0 times or less, more preferably 3.0 times or less, of the combined thickness of the first metal wire 15 and the second metal wire 16.

[0082] As shown in Figure 5, when the bulge 18 is formed at a location other than the intersection 17 between the first metal wire 15 and the second metal wire 16, it is preferable that the thickness of the bulge 18 be thicker than the thickness of a single first metal wire 15 or second metal wire 16. In this case, the thickness of the bulge 18 at the end of the first metal wire 15 is preferably 1.2 times or more, more preferably 1.5 times or more, and preferably 5.0 times or less, and more preferably 4.0 times or less, the thickness of the first metal wire 15 other than the bulge 18. The thickness of the bulge 18 at the end of the second metal wire 16 is preferably 1.2 times or more, more preferably 1.5 times or more, and preferably 5.0 times or less, and more preferably 4.0 times or less, the thickness of the second metal wire 16 other than the bulge 18.

[0083] It is preferable that the bulge 18 does not protrude significantly from the metal wire 14, as viewed from the outside of the tube 32, except at the intersection 17. In the portions of the metal wire 14 other than the intersection 17, the bulge 18 does not protrude from the metal wire 14, as viewed from the outside of the tube 32, or the length by which the bulge 18 protrudes from the metal wire 14 is preferably 0.3 times or less, more preferably 0.2 times or less, and even more preferably 0.1 times or less, the width of the metal wire 14. At the end of the metal wire 14, the length of the bulge 18 in the extension direction of the metal wire 14 is preferably 0.3 times or more, more preferably 0.5 times or more, and preferably 3.0 times or less, and more preferably 2.0 times or less, the width of the metal wire 14.

[0084] When the metal wires 14 include a first metal wire 15 and a second metal wire 16, the bulge 18 at the end of the first metal wire 15 excluding the intersection 17 preferably does not protrude from the first metal wire 15, or the length by which the bulge 18 protrudes from the first metal wire 15 is 0.3 times or less, more preferably 0.2 times or less, and even more preferably 0.1 times or less, the width of the first metal wire 15, as viewed from outside the tube 32. Furthermore, at the end of the second metal wire 16 excluding the intersection 17, the bulge 18 does not protrude from the second metal wire 16, or the length by which the bulge 18 protrudes from the second metal wire 16 is 0.3 times or less, more preferably 0.2 times or less, and even more preferably 0.1 times or less, the width of the second metal wire 16, as viewed from outside the tube 32.

[0085] At the end of the metal wire 14, the length of the bulge 18 in the extension direction of the metal wire 14 is preferably at least 0.3 times the width of the metal wire 14, more preferably at least 0.5 times, and preferably at most 3.0 times, and more preferably at most 2.0 times. When the metal wire 14 includes a first metal wire 15 and a second metal wire 16, at the end of the first metal wire 15, the length of the bulge 18 in the extension direction of the first metal wire 15 is preferably at least 0.3 times the width of the first metal wire 15, more preferably at least 0.5 times, and preferably at most 3.0 times, and more preferably at most 2.0 times. At the end of the second metal wire 16, the length of the bulge 18 in the extension direction of the second metal wire 16 is preferably at least 0.3 times the width of the second metal wire 16, more preferably at least 0.5 times, and preferably at most 3.0 times, and more preferably at most 2.0 times.

[0086] In the tube 32, it is preferable that the resin of the outer layer 19 is present from the outside to the inside in the radial direction of the metal wire 14 in the bulge 18. This more firmly bonds the outer layer 19 and the reinforcing layer 13, making it less likely that the outer layer 19 will peel off even if a strong shear force is applied between the outer layer 19 and the reinforcing layer 13. This further prevents the metal wire 14 from being exposed, thereby improving the safety of the catheter. It is more preferable that the resin of the outer layer 19 is present around the entire circumference of the bulge 18 in a cross section perpendicular to the extension direction of the metal wire 14 in the tube 32.

[0087] When the metal wire 14 includes a first metal wire 15 and a second metal wire 16, the bulge 18 of the first metal wire 15 is preferably covered with the resin of the outer layer 19 from the outside to the inside in the radial direction of the first metal wire 15, and the bulge 18 of the second metal wire 16 is preferably covered with the resin of the outer layer 19 from the outside to the inside in the radial direction of the second metal wire 16. In the tube 32, it is more preferable that the resin of the outer layer 19 exists around the entire circumference of the first metal wire 15 in a vertical cross section taken along the extension direction of the first metal wire 15, and it is more preferable that the resin of the outer layer 19 exists around the entire circumference of the second metal wire 16 in a vertical cross section taken along the extension direction of the second metal wire 16.

[0088] 3, when the bulge 18 is formed at the intersection 17 of the first metal wire 15 and the second metal wire 16, it is preferable that the resin of the outer layer 19 exists from the radially outer side to the radially inner side of the bulge 18. Alternatively, it is preferable that the resin of the outer layer 19 exists from the radially outer side of the metal wire 14 of the first metal wire 15 and the second metal wire 16 that is located on the radially outer side to the radially inner side of the metal wire 14 of the first metal wire 15 and the second metal wire 16.

[0089] The inner layer 12 preferably extends distally beyond the end of the metal wire 14. In this case, the inner layer 12 may extend proximally beyond the proximal end of the metal wire 14, or may extend distally beyond the distal end of the metal wire 14, but it is preferable that at least the inner layer 12 extends distally beyond the distal end of the metal wire 14. In other words, it is preferable that the inner layer 12 extends distally beyond the distal end of the reinforcing layer 13. This prevents the metal wire 14 from protruding from the end of the tube 32, making it less likely that the metal wire 14 will damage the body lumen, thereby improving the safety of the catheter.

[0090] In the tube 32, the inner layer 12 and the outer layer 19 may extend distally beyond the end of the metal wire 14, and the inner layer 12 and the outer layer 17 may extend distally beyond the distal end of the reinforcing layer 13. The inner layer 12 (or further the outer layer 19) preferably extends distally beyond the end of the metal wire 14 or the distal end of the reinforcing layer 13 by at least 0.1 times, more preferably at least 0.2 times, and even more preferably at least 0.3 times the width of the metal wire 14, and preferably extends distally beyond the end of the metal wire 14 or the distal end of the reinforcing layer 13 by at most 3.0 times, more preferably at most 2.0 times, and even more preferably at most 1.5 times the width of the metal wire 14.

[0091] For details of other configurations of the tube 32, such as the size of the tube 32, the constituent resins and physical properties of the inner layer 12 and outer layer 19, the constituent materials, arrangement, and shape of the reinforcing layer 13 and metal wire 14, please refer to the descriptions of the tube to be cut 11 and the tube to be cut 20 described above.

[0092] This application claims the benefit of priority based on Japanese Patent Application Nos. 2024-045123 and 2024-045124, filed on March 21, 2024. The entire contents of the specifications of Japanese Patent Application Nos. 2024-045123 and 2024-045124, filed on March 21, 2024, are incorporated herein by reference.

[0093] 11: Tube to be cut 12: Inner layer 13: Reinforcement layer 14: Metal wire 15: First metal wire 16: Second metal wire 17: Intersection 18: Bulging portion 19: Outer layer 20: Cutting tube 21: First laser 22: Second laser 31: Catheter 32: Tube 33: Operation portion 34: Treatment port 35: Fluid injection port

Claims

1. A catheter equipped with a tube having a longitudinal direction and a radial direction, the tube having an inner layer made of resin, a reinforcing layer provided radially outside the inner layer and having a braided arrangement of first and second metal wires, and an outer layer made of resin provided radially outside the reinforcing layer, the reinforcing layer having a bulge at an end of the first metal wire where the first metal wire is melted, and a bulge at an end of the second metal wire where the second metal wire is melted.

2. A catheter as described in claim 1, wherein an intersection of the first metal wire and the second metal wire is present at the end of the reinforcing layer, and at the intersection, the bulge of the first metal wire and the bulge of the second metal wire are fused together.

3. The catheter according to claim 2, wherein the melting point of the first metal wire is the same as that of the second metal wire.

4. The catheter according to claim 2, wherein the first metal wire and the second metal wire are made of the same metal.

5. A catheter as claimed in any one of claims 1 to 4, wherein the bulge of the first metal wire is covered with the resin of the outer layer from the outside to the inside in the radial direction of the first metal wire, and the bulge of the second metal wire is covered with the resin of the outer layer from the outside to the inside in the radial direction of the second metal wire.

6. A catheter having a tube with a longitudinal direction and a radial direction, the tube having an inner layer made of resin, a reinforcing layer made of metal wire and arranged on the outside of the inner layer, and an outer layer made of resin and arranged on the outside of the reinforcing layer, and having a portion where the resin of the outer layer is present from the outside to the inside of the metal wire in the radial direction.

7. The catheter according to claim 6, wherein the reinforcing layer has a bulge at the end of the metal wire.

8. The catheter according to claim 6, wherein the metal wires include a first metal wire and a second metal wire, and the reinforcing layer is formed by arranging the first metal wire and the second metal wire in a braided form.

9. A catheter according to claim 8, wherein the first metal wire and the second metal wire are melted and joined to each other at the intersections of the first metal wire and the second metal wire.

10. A catheter as described in claim 8, wherein the reinforcing layer has a bulge formed at the intersection of the first metal wire and the second metal wire by melting and joining the end of the first metal wire and the end of the second metal wire to each other.

11. A catheter according to claim 7 or 10, wherein the tube has an outer layer of resin present in the bulging portion from the outside to the inside in the radial direction of the metal wire.

12. A catheter according to any one of claims 1 to 4 and 6 to 10, wherein the inner layer extends further toward the distal end than the end of the metal wire.

13. A method for manufacturing a catheter, comprising: a step of preparing a tube to be cut, the tube having an inner layer made of resin, a reinforcing layer made of metal wire and placed outside the inner layer, and an outer layer made of resin and placed outside the reinforcing layer; a first laser irradiation step of irradiating the tube to be cut with a first laser to cut the metal wire in the reinforcing layer and melt the outer layer; a second laser irradiation step of irradiating the tube to be cut with a second laser after the first laser irradiation step to cut the inner layer and obtain a cut tube; and an assembly step of assembling a catheter from the cut tube.

14. A method for manufacturing a catheter as described in claim 13, wherein in the first laser irradiation step, the metal wire is heated by irradiation with the first laser, and the heat is transferred to the outer layer, thereby melting the outer layer.

15. A method for manufacturing a catheter as set forth in claim 13, wherein in the first laser irradiation step, the end of the metal wire is melted by irradiation with the first laser to form a bulge.

16. A method for manufacturing a catheter as described in claim 13, wherein the metal wire material includes a first metal wire material and a second metal wire material, and the reinforcing layer is formed by arranging the first metal wire material and the second metal wire material in a braided form.

17. The method for manufacturing a catheter according to claim 16, wherein the first metal wire and the second metal wire are made of the same metal.

18. A method for manufacturing a catheter as described in claim 16, wherein in the first laser irradiation step, the first metal wire and the second metal wire are melted by irradiation with the first laser and joined to each other at the intersection of the first metal wire and the second metal wire.

19. A method for manufacturing a catheter as described in claim 18, wherein in the first laser irradiation step, the end of the first metal wire and the end of the second metal wire are melt-joined at the intersection of the first metal wire and the second metal wire to form a bulge portion.

20. A method for manufacturing a catheter as set forth in any one of claims 13 to 19, wherein in the second laser irradiation step, the inner layer is cut further to the tip side than the cut end of the metal wire.

21. A method for manufacturing a catheter according to any one of claims 13 to 19, wherein the melting point of the resin of the inner layer is higher than the melting point of the resin of the outer layer.

22. A method for manufacturing a catheter according to any one of claims 13 to 19, wherein a pulsed laser is used as the first laser and a pulsed laser having a narrower pulse width than the first laser is used as the second laser, or a continuous wave laser is used as the first laser and a pulsed laser is used as the second laser.

23. The method for manufacturing a catheter according to claim 22, wherein the second laser is a nanosecond pulse laser, a femtosecond pulse laser, or a picosecond pulse laser.

24. A method for manufacturing a catheter according to any one of claims 13 to 19, wherein the step of preparing the tube to be cut includes the steps of: arranging the reinforcing layer on the outside of the cylindrical inner layer; arranging the outer layer on the outside of the reinforcing layer to obtain a tube precursor; and heating the tube precursor to obtain the tube to be cut.

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