catheter

Abstract

A catheter comprises at least a reinforcing member (2), which comprises a braided body formed by weaving a plurality of first wires extending in a first direction and a plurality of second wires extending in a second direction into a mesh shape, and is a tubular reinforcing member extending in the extending direction. The melting point of the plurality of first wires is higher than the melting point of the plurality of second wires by more than 500°C. At least one of the two end portions in the extending direction of the reinforcing member, a joint portion (5[n], 5[n+1]) is formed at a portion of a plurality of intersections where the plurality of first wires and the plurality of second wires intersect. The joint portion (5[n]) joins the mutually intersecting first wires (3[n]) and second wires (4[n]) by alloying the first wires (3[n]) and second wires (4[n]) at their respective contact portions.

Description

Technical Field

[0001] The present invention relates to catheters. Background Art

[0002] The catheter needs to have its front end properly reach the part to be treated within the blood vessel, so it requires good insertion properties. Therefore, various catheters with reinforcement structures for achieving such characteristics have been proposed. Patent document 1 discloses a catheter having a metal mesh containing stainless steel (SUS) wires as a reinforcement structure. In this catheter, the intersection of the first group of wires and the second group of wires of the metal mesh is irradiated with laser to be welded. Then, the metal mesh is irradiated with laser along the cutting line to cut the metal mesh. With this processing method, the end of the metal mesh is difficult to loosen. In addition, when welding based on laser irradiation, the first group of wires and the second group of wires are melted and alloyed at the contact part in order to maintain the strength of the weld part, which is preferred.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2005-230318 Summary of the Invention

[0006] To enhance the strength of the reinforcement structure, a metal mesh composed of multiple wires of different materials is sometimes used. For example, consider the case where two wires of different materials with significantly different melting points are irradiated with a laser using the aforementioned processing method. If the laser is irradiated with the intensity required to melt the wire with the higher melting point of the two wires (referred to as the first wire), the wire with the lower melting point (referred to as the second wire) will melt, potentially causing the second wire to break. On the other hand, if the laser is irradiated with the intensity required to melt the second wire, the first wire may not melt. In other words, in either case, since the first and second wires will not alloy without melting at the contact point, there is a problem that the strength of the weld may not be maintained.

[0007] An object of the present invention is to provide a catheter in which the end portion of a metal mesh is unlikely to become loose even when a plurality of wires having different melting points are used.

[0008] A catheter according to a first aspect of the present invention is characterized in that it includes at least a reinforcement member, the reinforcement member comprising a braided structure formed by interweaving a plurality of first wires extending in a first direction and a plurality of second wires extending in a second direction intersecting the first direction into a mesh shape, the reinforcement member being a tubular member extending in the extension direction, the plurality of first wires having a melting point higher than that of the plurality of second wires by at least 500° C., a joint portion being formed at a portion of a plurality of intersections where the plurality of first wires and the plurality of second wires intersect at at least one of both end portions of the reinforcement member in the extension direction, the joint portion joining the plurality of first wires and the plurality of second wires that intersect at a portion of the plurality of intersections, i.e., a first crossing wire and a second crossing wire, the first crossing wire and the plurality of second wires being joined by alloying at contact portions of the first crossing wire and the second crossing wire.

[0009] In the catheter, alloying is performed at the contact portions of the first and second cross wires, thereby joining the first and second cross wires to form a joint. Therefore, even when the catheter uses a braided structure composed of a plurality of first and second wires having different melting points as a reinforcement member, the ends of the reinforcement member in the extension direction are less likely to come loose.

[0010] In the first aspect, at least one of the ends of each of the plurality of first wire members and the plurality of second wire members in the extending direction may have a curved portion that curves relative to the extending direction. Even when the plurality of first wire members and the plurality of second wire members are bent at the curved portion, the catheter can maintain the mutually joined state of the plurality of first wire members and the plurality of second wire members by alloying at the joint portion.

[0011] In the first embodiment, the second front end portion of the second cross wire, which is closer to the front end than the joining portion, may be wound around the first cross wire. In this case, the catheter can more firmly join the first cross wire and the second cross wire.

[0012] In the first embodiment, the catheter may include: an inner tube having a cylindrical shape centered on the central axis of the reinforcement member and disposed within the inner lumen of the reinforcement member; and an outer tube having a cylindrical shape centered on the central axis and covering the outer side of the reinforcement member. The inner tube can prevent a thread, etc., from becoming entangled in the reinforcement member when passing through the inner lumen of the reinforcement member. Furthermore, the outer tube can prevent the reinforcement member from being exposed. Thus, the catheter can reduce the possibility of the reinforcement member becoming entangled in a blood vessel when the catheter is passed through the blood vessel.

[0013] In the first embodiment, the inner tube may have a higher light transmittance than the outer tube. When laser light is irradiated to heat and join the plurality of first strands and the plurality of second strands, heat generated by absorption of the laser light by the inner tube can be suppressed. Consequently, the catheter can reduce the possibility of the inner tube melting or breaking due to heat.

[0014] In the first embodiment, the inner tube may be made of polytetrafluoroethylene. In this case, an inner tube with high transmittance can be easily realized.

[0015] In the first embodiment, the first intersecting wire may be arranged on one side of the second intersecting wire in a third direction perpendicular to the first and second directions. In this case, the first and second intersecting wires can be easily joined by laser irradiation from one side in the third direction. Furthermore, when laser irradiation is used to form the joint, more laser energy can be supplied to the first wire, which has a higher melting point, thereby melting the first wire. Furthermore, the supply of laser energy to the second wire, which has a lower melting point, can be suppressed, thereby melting and fusing the second wire.

[0016] In the first embodiment, one of the plurality of first wires and the plurality of second wires may have a circular cross-sectional shape, and the other of the plurality of first wires and the plurality of second wires may have a rectangular cross-sectional shape. Furthermore, in the first embodiment, the plurality of first wires may have a circular cross-sectional shape, and the plurality of second wires may have a rectangular cross-sectional shape. In this case, the catheter can easily perform the step of alloying the contact portions of the first and second intersecting wires to form a joint.

[0017] In the first embodiment, the absorption coefficient of the plurality of first wires may be greater than the absorption coefficient of the plurality of second wires. In this case, even when the first and second wires are joined by a single laser irradiation, the first and second wires can be appropriately melted and alloyed, and then joined.

[0018] In the first aspect, the composition of the second cross wires excluding the junction may be the same regardless of the distance from the junction. In this case, the catheter can stably maintain the composition of the second wires, thereby maintaining the strength of the braid.

[0019] In the first embodiment, the plurality of first wires may be made of tungsten, and the plurality of second wires may be made of stainless steel. In this case, the braided structure allows for excellent insertion of the catheter. Furthermore, since tungsten has excellent radiation shielding properties, the position of the catheter within the body can be easily confirmed by irradiation.

[0020] A second aspect of the present invention is a method for manufacturing a catheter comprising at least a reinforcing member, the reinforcing member comprising a braided body formed by interweaving a plurality of first wires extending in a first direction and a plurality of second wires extending in a second direction intersecting the first direction into a mesh shape, the reinforcing member being cylindrical in shape and extending in the extending direction, the plurality of first wires having a melting point higher than that of the plurality of second wires by 500° C. or more, the reinforcing member forming a joint portion at at least one of both end portions in the extending direction at a portion of a plurality of intersections where the plurality of first wires and the plurality of second wires intersect, the joint portion joining the first wire [n] and the second wire [n] that intersect each other at a joint intersection [n] among the plurality of intersections by alloying the first wire [n] and the second wire [n] at the joint intersection [n] on one side of the second wire [n] in a third direction orthogonal to the first and second directions, the manufacturing method comprising: 1. An irradiation step of irradiating a first irradiation area [n] at the junction intersection [n] with a laser beam from the side of the third direction, which includes at least a portion of the junction area [n] where the first wire [n] and the second wire [n] overlap when the braid is viewed from the side of the third direction, and a portion of the second wire [n] that does not overlap with the first wire [n], so that the first wire [n] and the second wire [n] overlap at the junction intersection [n]. The first wire material [n] is alloyed and joined at the point [n], and a portion of the second wire material [n] on the side of the second direction relative to the joining intersection [n] is melted; and a second irradiation step, after the irradiation of the laser based on the first irradiation step, the first wire material [n] is cut at the position of the second irradiation area [n] by irradiating the second irradiation area [n] separated from the joining intersection [n] to the side of the first direction with respect to the joining intersection [n] with the laser from the side of the third direction.

[0021] The laser irradiation in the first irradiation step first heats and melts a portion of the first wire [n]. Subsequently, the second wire [n] is heated and melted, fusing it. Simultaneously, the melted first and second wires [n] are alloyed and joined. The laser irradiation in the second irradiation step heats and fuses the first wire [n]. This makes it difficult for the reinforcement member to come loose in at least one of its extension directions through the joint.

[0022] In the above-described manufacturing method, a single laser irradiation in the first irradiation step allows simultaneous alloying of the first and second wires [n] and fusing of the second wire [n]. This reduces the likelihood of a decrease in the accuracy of the positional relationship between the joining portion and the fusing position of the second wire. Furthermore, the laser energy is initially supplied to the first wire [n], with the remaining energy supplied to the second wire [n]. Therefore, even when the melting point of the first wire is 500°C or higher than that of the second wire, a single laser irradiation can efficiently achieve both the joining of the first and second wires [n] and the fusing of the first wire [n].

[0023] In the second aspect, at least one of the first irradiation step and the second irradiation step may be performed such that energy supplied to the braid by irradiation with laser light changes over time.

[0024] In this case, since heat transfer to the vicinity of the laser irradiation region in the first and second strands can be suppressed, melting, evaporation, and disappearance of the first and second strands near the laser irradiation region can be prevented.

[0025] In the second aspect, at least one of the first irradiation step and the second irradiation step may include a pre-irradiation step of irradiating with laser light of relatively low intensity and a post-irradiation step of irradiating with laser light of relatively high intensity after the pre-irradiation step.

[0026] In this case, it is possible to more effectively prevent the first and second strands from melting, evaporating, or disappearing in the vicinity of the laser irradiation region.

[0027] In the second aspect, at least one of the first irradiation step and the second irradiation step may be performed intermittently multiple times.

[0028] In this case, it is possible to more effectively prevent the first and second strands from melting, evaporating, or disappearing in the vicinity of the laser irradiation region.

[0029] In the second form, it may also be that, among the multiple intersections, at the first intersection where the first wire [n+1] adjacent to the first wire [n] on the other side of the second direction intersects with the second wire [n], the first wire [n+1] is arranged on one side of the third direction relative to the second wire [n], and at the second intersection where the second wire [n+1] adjacent to the second side of the first direction intersects with the first wire [n] among the multiple intersections, the second wire [n+1] is arranged on one side of the third direction relative to the first wire [n].

[0030] The conduit can suppress, through the second strand [n+1], the movement of the first strand [n] toward one side of the third direction when the first strand [n] and the second strand [n] are joined at the joining intersection [n]. Furthermore, the conduit can suppress, through the first strand [n+1], the movement of the second strand [n] toward one side of the third direction when the first strand [n] and the second strand [n] are joined at the joining intersection [n].

[0031] In the second aspect, the present invention may further include a third irradiation step, wherein after the irradiation of the laser beam in the second irradiation step, the first irradiation area [n+1] including at least a portion on one side of the second direction of the joint area [n+1] where the first wire [n+1] and the second wire [n+1] overlap when the braid is viewed from one side of the third direction and a portion of the second wire [n+1] that does not overlap with the first wire [n+1] is irradiated with the laser beam from the one side of the third direction at a junction point [n+1] where the first wire [n+1] and the second wire [n+1] intersect. The first wire material [n+1] and the second wire material [n+1] are alloyed and joined at the joining intersection [n+1], and a portion of the second wire material [n+1] on the side of the second direction relative to the joining intersection [n+1] is melted; and a fourth irradiation step, after the laser irradiation of the third irradiation step, the second irradiation area [n+1] of the first wire material [n+1] separated to the side of the first direction relative to the joining intersection [n+1] is irradiated with laser from the side of the third direction, thereby cutting the first wire material [n+1] at the position of the second irradiation area [n+1].

[0032] In this case, the first wire [n+1] and the second wire [n+1] can be joined and fused.

[0033] In the second aspect, the junction intersection [n] and the junction intersection [n+1] may be arranged side by side in the extending direction.

[0034] In this case, the reinforcing member can be cut in a direction perpendicular to the extending direction.

[0035] In the second aspect, in the first irradiation step and the second irradiation step, the laser beam may be irradiated while a laminar flow of an inert gas is blown toward the reinforcing member.

[0036] In this case, it is possible to suppress the occurrence of oil bathing and oxidation of the first and second strands due to laser irradiation.

[0037] In the second form, it may also be that there is a front process, in which a cylindrical inner layer tube is arranged around the cylindrical metal wire extending in the extension direction, and the metal wire and the inner layer tube are arranged in the inner cavity of the reinforcement member, and in the first irradiation process and the second irradiation process, the braided body of the reinforcement member prepared by the front process is irradiated with laser, and there is also a post process, in which a cylindrical outer layer tube is arranged around the reinforcement member after the laser irradiation in the second irradiation process.

[0038] In this case, a catheter comprising a reinforcement member, an inner tube, and an outer tube can be manufactured. In particular, the use of metal wire facilitates the manufacture of a catheter comprising a thin inner tube. Furthermore, the use of metal wire prevents laser light irradiating the reinforcement member from passing through the inner cavity of the reinforcement member and reaching the opposite side, thereby reducing the possibility of the reinforcement member on the opposite side being melted by the laser.

[0039] In the second aspect, the light transmittance of the inner layer tube may be higher than the light transmittance of the outer layer tube.

[0040] In this case, the heat generated by the inner tube due to absorption of the laser light can be suppressed, thereby reducing the possibility that the inner tube will melt and break due to heat generated by the laser irradiation, thereby reducing the possibility that the first and second strands will melt and join at locations other than the joining portion.

[0041] In the second aspect, the thermal conductivity of the metal wire may be 350 to 450 W / mK.

[0042] That is, since heat diffusion is promoted by using a material with high thermal conductivity in the metal wire, local temperature rise of the metal wire can be suppressed by thermal diffusion. Therefore, the possibility of melting the inner layer tube due to the temperature rise of the metal wire can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a diagram showing the catheter 1 and the connector 9 .

[0044] Figure 2 It is a diagram showing the catheter 1 .

[0045] Figure 3 It is a diagram showing the reinforcement member 2 in the expanded state.

[0046] Figure 4 It is a perspective view showing an enlarged portion of the reinforcement member 2 in the unfolded state.

[0047] Figure 5 This is a diagram showing the vicinity of the front end portion of the reinforcement member 2 in the deployed state.

[0048] Figure 6 It will Figure 5 A magnified stereogram of a portion of the image.

[0049] Figure 7 This is a photograph of the joint 5 of the reinforcing member 2 .

[0050] Figure 8 This is a photograph of a cross section of the joining portion 5[x].

[0051] Figure 9 Schematic diagram showing a cross section of a joined portion obtained by a conventional method.

[0052] Figure 10 1 is a flowchart showing a method for manufacturing the catheter 1 .

[0053] Figure 11 This is a diagram showing the long wire material 10 prepared in the previous step.

[0054] Figure 12 This is an enlarged perspective view of a portion of the reinforcement member 2 in a deployed state during the manufacturing process of the catheter 1 .

[0055] Figure 13 This is a diagram showing the vicinity of the junction intersection Qc[n] as viewed from the first direction.

[0056] Figure 14A It is a diagram showing a process of forming the bonding portion 5[n] by laser irradiation.

[0057] Figure 14B It is a diagram showing a process of forming the bonding portion 5[n] by laser irradiation.

[0058] Figure 15A This is an explanatory diagram for explaining the output mode of the laser beam.

[0059] Figure 15B This is an explanatory diagram for explaining the output mode of the laser beam.

[0060] Figure 16A This is a diagram showing a process in which the first wire 3[n] is melted by laser irradiation.

[0061] Figure 16B This is a diagram showing a process in which the first wire 3[n] is melted by laser irradiation.

[0062] Figure 17A This is a diagram showing a state when the first wire 3[n] is melted.

[0063] Figure 17B This is a diagram showing a state when the first wire 3[n] is melted.

[0064] Figure 18This is a diagram showing a post-process of arranging the outer layer tube 7.

[0065] Figure 19A It is an explanatory diagram for explaining the output mode of the laser beam in a modified example.

[0066] Figure 19B It is an explanatory diagram for explaining the output mode of the laser beam in a modified example. DETAILED DESCRIPTION

[0067] <Overview of Catheter 1>

[0068] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 、 Figure 2 As shown, the catheter 1 includes a reinforcement member 2, an inner tube 6, and an outer tube 7. Hereinafter, the direction in which the catheter 1 extends will be referred to as the "extension direction." The end corresponding to one side of the catheter 1 in the extension direction will be referred to as the "front end 1D." The end corresponding to the other side of the catheter 1 in the extension direction will be referred to as the "base end 1P." The catheter 1 has an internal lumen 6L for passing a wire or the like. The lumen 6L extends in the extension direction between the front end 1D and the base end 1P of the catheter 1. It is used to connect a wire or the like to the base end 1P of the catheter 1 through a connector 9 of the catheter 1. A reinforcement tube 90 reinforces the area near the connection between the base end 1P of the catheter 1 and the connector 9. On a plane perpendicular to the extension direction, the radial direction based on a line segment passing through the center of the cross section of the catheter 1 (referred to as the "center line C") will be referred to as the third direction. In the third direction, the side closer to the center line C of the catheter 1 will be referred to as the "inner side," and the side separated from the center line C of the catheter 1 will be referred to as the "outer side."

[0069] <Reinforcement member 2>

[0070] The reinforcement member 2 is a flexible cylindrical member. The reinforcement member 2 reinforces the strength of the catheter 1 in the extension direction. The reinforcement member 2 extends from the distal end 1D to the proximal end 1P of the catheter 1 along the extension direction. The reinforcement member 2 is formed by interweaving a plurality of metal wires into a braid 20 (see Figure 3 ) is formed into a cylindrical shape and its two ends are cut off. The center line C passes through the center of the braid 20 and extends in the extension direction.

[0071] Figure 3 、 Figure 4The figure shows a state where a portion of the braid 20 is unfolded. The braid 20 has a plurality of first wires 30 and a plurality of second wires 40. The plurality of first wires 30 extend along a first direction intersecting the extension direction. The plurality of second wires 40 extend along a second direction intersecting the extension direction and the first direction. The braid 20 is a metal mesh in which the plurality of first wires 30 and the plurality of second wires 40 are interwoven into a mesh shape, with two wires each crossing over the other. This is a so-called twill weave metal mesh. Figure 4 As shown in FIG, the direction perpendicular to the first direction and the second direction corresponds to the third direction. The third direction is perpendicular to the extending direction. Figure 3 The near front side corresponds to the outer side in the third direction. Figure 3 The depth side corresponds to the inner side in the third direction.

[0072] like Figure 3 As shown, the plurality of first wires 30 are respectively referred to as ···first wire 3[n-1], first wire 3[n], first wire 3[n+1]···, and they are collectively referred to as first wire 3. The plurality of second wires 40 are respectively referred to as ···second wire 4[n-1], second wire 4[n], second wire 4[n+1]···, and they are collectively referred to as second wire 4. The plurality of positions where the plurality of first wires 30 and the plurality of second wires 40 intersect are referred to as a plurality of intersection points Q. Figure 3 In FIG. 1 , only the intersection points Q at which the first strand 3[n+2] and the second strand 4[n+4] intersect among the plurality of intersection points Q are denoted by reference numerals, and reference numerals are omitted for the other plurality of intersection points Q.

[0073] exist Figure 3 Among the plurality of intersection points Q shown, at the intersection point Q arranged at a position overlapping with the virtual straight lines L1, L2, L3, L4, and L5 extending in the extension direction, the first wire material 3 is arranged outside the second wire material 4 in the third direction ( Figure 3 near the front side).

[0074] The material of the first wire material 3 is tungsten (W), which has a melting point of 3422°C. The cross-sectional shape of the first wire material 3 is a perfect circle (see Figure 4 The absorption coefficient of the first strand 3 is 0.4 or more. The material of the second strand 4 is stainless steel (SUS304) with a melting point of 1450°C. The cross-sectional shape of the second strand 4 is rectangular (see Figure 4 The absorption coefficient of the second strand 4 is approximately 0.3. The difference in melting point between the first strand 3 and the second strand 4 is approximately 2000°C. The melting point of the first strand 3 is at least 500°C higher than that of the second strand 4. The absorption coefficient of the first strand 3 is greater than that of the second strand 4. Furthermore, to increase the absorption coefficient of the first strand 3 relative to that of the second strand 4, a black yarn is used as the first strand 3.

[0075] Figure 1 The end portion on the front end side of the reinforcement member 2 (hereinafter referred to as "the front end portion 2D of the reinforcement member 2") and the end portion on the base end side (hereinafter referred to as "the base end portion 2P of the reinforcement member 2 (refer to Figure 1 ) ″) are formed by cutting the braid 20 by laser irradiation. In addition, in order to prevent the plurality of first wires 30 and the plurality of second wires 40 of the cut braid 20 from being loosened, a plurality of joints 50 are formed at a portion of the plurality of intersections Q of the plurality of first wires 30 and the plurality of second wires 40 at the distal end portion 2D and the proximal end portion 2P (see Figure 5 ).

[0076] like Figure 3 、 Figure 4 As shown, on both sides of the first direction, the front end portion 2D (refer to Figure 1 ) is referred to as the "first distal end side", and the side closer to the base end 2P (refer to Figure 1 ) is referred to as the "first base end portion". Figure 1 ) is referred to as the "second distal end side", and the side closer to the base end portion 2P (refer to Figure 1 ) is called the "second base end portion".

[0077] Figure 5 This is an enlarged view of a portion of the front end portion 2D of the reinforcing member 2. The plurality of joints 50 are referred to as, respectively, joints 5[n], 5[n+1], etc., and are collectively referred to as the joint 5. The intersections Q that form the joint 5 are referred to as, respectively, joint intersections Qc[n], Qc[n+1], etc. A joint 5[x] (where x is any of n, n+1, n+2, n+3, n+4, and n+5) is formed at the joint intersection Qc[x] between the first wire 3[x] and the second wire 4[x]. The joint 5[x] is formed by alloying the first wire 3[x] and the second wire 4[x] at the joint intersection Qc[x] at the contact portion, thereby joining the first wire 3[x] and the second wire 4[x]. Specifically, the alloy in the joint 5[x] satisfies the following conditions.

[0078] (1) The first strand 3[x] and the second strand 4[x] are melted by laser irradiation.

[0079] (2) The components of the first strand 3[x] and the second strand 4[x] are mixed and diffused, and then melted and solidified.

[0080] (3) The interface between the first wire 3[x] and the second wire 4[x] is not entirely covered with the intermetallic compound layer.

[0081] (4) The first strand 3[x] and the second strand 4[x] are not separated at the boundary of the metal compound layer in (3), but rather form a solid solution and are well mixed with each other.

[0082] The joined intersection points Qc[n] and Qc[n+1], the joined intersection points Qc[n+2] and Qc[n+3], and the joined intersection points Qc[n+4] and Qc[n+5] are arranged in alignment in the extending direction.

[0083] At the junction point Qc[x], the first wire material 3[x] is arranged outside the second wire material [x] in the third direction ( Figure 5 near the front side). Figure 6 、 Figure 7 As shown, the portion of the second wire material 4[x] that is closer to the second front end side in the second direction than the joining intersection Qc[x] is extended outward in the third direction ( Figure 6 、 Figure 7 The first wire 3[x] is bent (on the near-front side) and wound around the first wire 3[x]. The first front end of the first wire 3[x] in the first direction is spaced apart from the junction point Qc[x]. In other words, the first wire 3[x] extends slightly from the junction point Qc[x] toward the first front end in the first direction. The distance in the first direction between the first front end of the first wire 3[x] and the junction point Qc[x] is any value within the range of 0.03 mm to 0.15 mm.

[0084] Figure 8 : is a cross-sectional view showing a state where the first wire material 3[x] and the second wire material 4[x] are joined at the joining intersection Qc[x] through the joining portion 5[x]. Figure 8 As shown in FIG. 1 , it was confirmed that the first wire 3[x] and the second wire 4[x] were mixed and recrystallized at their respective interfaces due to the solid solution formed. In addition, for example, when the first wire (metal material 1, such as steel) and the second wire (metal material 2, such as aluminum alloy) were joined by a conventional general method, as shown in FIG. Figure 9 As shown, the first and second wires are separated by the intermetallic compound layer formed at their respective interfaces. This result confirms that the joint 5[x] can more firmly join the first wire 3[x] and the second wire 4[x] than in the conventional art.

[0085] <Inner tube 6, outer tube 7, soft tip 8>

[0086] like Figure 2As shown, inner tube 6 has a cylindrical shape centered on centerline C and is positioned within lumen 2L of reinforcement member 2. Inner tube 6 is made of polytetrafluoroethylene (PTFE). The light transmittance of inner tube 6 is greater than 90%. Lumen 6L of inner tube 6 extends in the extension direction, forming lumen 6L of catheter 1. Inner tube 6 is provided to separate lumen 6L of catheter 1 from reinforcement member 2, preventing threads, etc., passing through lumen 6L from becoming caught on reinforcement member 2.

[0087] The outer tube 7 has a cylindrical shape centered on the centerline C and covers the reinforcing member 2 from the outside. The outer tube 7 is made of a pigmented resin material. The light transmittance of the outer tube 7 is less than 90%. The light transmittance of the outer tube 7 is more preferably 10% to 20%. The light transmittance of the inner tube 6 is higher than that of the outer tube 7.

[0088] like Figure 1 As shown, the outer tube 7 includes a first outer tube 71, a second outer tube 72, a third outer tube 73, and a fourth outer tube 74, each having different rigidities. The first outer tube 71, the second outer tube 72, the third outer tube 73, and the fourth outer tube 74 are arranged in this order in the extending direction from the distal end portion 1D toward the proximal end portion 1P of the catheter 1. The rigidity of the outer tube 7 increases gradually in the order of the first outer tube 71, the second outer tube 72, the third outer tube 73, and the fourth outer tube 74.

[0089] The soft tip 8 is provided at the distal end 1D of the catheter 1. The soft tip 8 contacts the side surface of the inner tube 6 near the distal end and the reinforcement member 2 near the distal end 2D. The soft tip 8 is fixed by welding to the inner tube 6 and the reinforcement member 2, with the distal end 1D of the catheter 1 serving as the terminal end.

[0090] A bent portion 2R is provided near the distal end portion 1D of the catheter 1. The bent portion 2R is formed by bending the reinforcing member 2, the inner layer tube 6, and the outer layer tube 7 relative to the extending direction.

[0091] <Method for Manufacturing Catheter 1>

[0092] Reference Figure 10 Next, a method for manufacturing the catheter 1 will be described. In this embodiment, the catheter 1 is manufactured by joining and fusing the two ends of the reinforcement member 2 in its extending direction by laser irradiation, thereby forming the distal end portion 2D and the proximal end portion 2P. This method is based on the following premise: first, the distal end of the reinforcement member 2 is cut by laser irradiation to form the distal end portion 2D, and then the proximal end of the reinforcement member 2 is cut by laser irradiation to form the proximal end portion 2P.

[0093] First, the pre-process (S11) is performed. In the pre-process, the metal wire 100, the inner tube 6 and the reinforcing member 2 are prepared (see Figure 11 ). Details are as follows.

[0094] Pull out the long wire 10 wound on the spool. Figure 11 As shown, the drawn long wire 10 is roughly cut into the required length using scissors or the like. The long wire 10 has a structure in which the inner tube 6 arranged around the cylindrical metal wire 100 is arranged in the inner cavity 2L of the reinforcing member 2. Figure 11 In order to facilitate understanding, the inner tube 6 and the metal wire 100 arranged in the inner cavity 2L of the reinforcing member 2 are visually shown. The metal wire 100 is a soft copper wire. The thermal conductivity of the metal wire 100 is 350 to 450 w / mK. The metal wire 100 can suppress the local temperature rise when irradiated with laser during the manufacturing process by thermal diffusion. The surface of the metal wire 100 is plated into silver to reflect the laser irradiated during the manufacturing process. The inner tube 6 is resin-molded as a coating on the surface of the metal wire 100. The light transmittance of the inner tube 6 is more than 90%, and it can pass through the laser irradiated during the manufacturing process. The reinforcing member 2 is arranged on the outside of the inner tube 6 and is exposed. Furthermore, in the previous process, in order to attach the reinforcing member 2 to the plurality of first wire materials 30 and the plurality of second wire materials 40 (refer to Figure 3 ) is removed, and the long wire 10 is degreased using an organic solvent.

[0095] like Figure 10 As shown, after the preceding step S11, the laser irradiation area is determined to join the first wire 3 and the second wire 4 at the joint 5 at the front end of the long wire 10 and to cut the second wire 4 near the joint 5. Next, the laser light source is positioned to irradiate the determined irradiation area with the laser (S13). This is based on the following premise: at the front end of the reinforcement member 2, corresponding joints 5 [x] are formed sequentially, as x changes in the order of n, n+1, n+2, n+3, etc., and the front end portion 2D is formed.

[0096] Explain the following situation: Let x = n, that is, Figure 5 At the junction point Qc[n] shown in FIG. 1 , the first wire material 3[n] and the second wire material [n] are joined by the joining portion 5[n], and the second wire material 4[n] is cut. Figure 12As shown, at the junction intersection Qc[n], the first wire 3[n] is arranged outside the second wire 4[n] in the third direction. At the intersection Q1[n] where the first wire 3[n+1], which is adjacent to the second proximal end side of the first wire 3[n] in the second direction, and the second wire 4[n] intersect, the first wire 3[n+1] is arranged outside the second wire 4[n] in the third direction. At the intersection Q2[n] where the second wire 4[n+1], which is adjacent to the first proximal end side of the second wire 4[n] in the first direction, and the first wire 3[n] intersect, the second wire 4[n+1] is arranged outside the first wire 3[n] in the third direction.

[0097] The irradiation area of the laser positioned by S13 is referred to as the first irradiation area 51[n]. The first irradiation area 51[n] is specifically defined as the following area. Figure 13 As shown, at the junction intersection Qc[n], a junction region 53[n] is defined where the first wire 3[n] and the second wire 4[n] overlap when the braid 20 is viewed from the outside in the third direction. In this case, the first irradiation region 51[n] includes at least a portion 511 of the junction region 53[n] on the second front end side in the second direction and a portion 512 of the second wire 4[n] that is closer to the second front end side than the junction region 53[n] and does not overlap with the first wire 3[n].

[0098] The laser light source is positioned using an imaging system. This system displays the center and periphery of the laser light path, determined by the position of the light source. The diameter of the circle described by the periphery of the laser light path (the laser spot diameter) is set to be less than or equal to the smaller of the diameter of the first strand 3 or the width of the second strand 4.

[0099] like Figure 10 As shown, after the laser light source is positioned in S13, the first irradiation area 51[n] (see Figure 13 ) is sprayed in a laminar flow state near the inert gas (S15). Specifically, the inert gas is argon gas or helium gas. Then, laser light is output from the light source while the inert gas is being sprayed. As a result, the first irradiation area 51[n] is irradiated with laser light from the outside in the third direction (S17).

[0100] When the laser is irradiated to the first irradiation area 51[n] in S17, Figure 14AAs shown, the laser is first irradiated to the first wire 3[n]. As a result, the energy of the laser is supplied to the first wire 3[n], and the first wire 3[n] is heated and melted. In addition, the energy of the laser is reduced by being supplied to the first wire 3[n]. The laser is then irradiated to the second wire 4[n]. As a result, the energy of the laser is supplied to the second wire 4[n], and the second wire 4[n] is heated and melted, and then cut. As a result, as shown in FIG. Figure 14B As shown, the molten portions of the first wire material 3[n] and the second wire material 4[n] come into contact and alloy with each other, thereby joining. In addition, the second wire material 4[n] is melted at a portion closer to the second front end side in the second direction than the joining portion 5[n], and is bent outward in the third direction and wound around the first wire material 3[n] (see FIG. Figure 6 、 Figure 7 ). After the first strand [n] and the second strand [n] are joined at the joining intersection Qc[n], the irradiation of the laser light from the light source is stopped.

[0101] Furthermore, in S17, the joining of the first wire 3[n] and the second wire 4[n] and the fusing of the second wire [4] are achieved by irradiation with a single pulse of laser light. Therefore, compared to a case where each is performed in separate steps, the position of the joining intersection Qc[n] and the fusing position of the second wire 4[n] are less likely to deviate from each other.

[0102] Furthermore, during the process of joining the first strand 3[n] and the second strand 4[n] by laser irradiation, and the fusing of the second strand 4[n], the laser irradiation may cause the first strand 3 and the second strand 4 to generate heat at locations other than the joining intersection Qc[n]. In this case, the physical properties of the first strand 3 and the second strand 4 may change due to heat, or the strands may fuse, in regions other than the joining intersection Qc[n], which is not desirable. In contrast, in this embodiment, the energy supplied to the braid 20 by laser irradiation is varied over time. This reduces the possibility of the first strand 3 and the second strand 4 generating heat at locations other than the joining intersection Qc[n]. Details are as follows.

[0103] like Figure 15AAs shown, in S17, the laser light of one pulse is divided and irradiated intermittently multiple times. More specifically, the laser light is irradiated while repeatedly switching between a period of relatively high intensity (hereinafter referred to as a "high-level period") and a period of relatively low intensity (hereinafter referred to as a "low-level period"). In this case, the heat generated by the energy of the laser light in the first wire 3 or the second wire 4 of the braid 20 is difficult to diffuse to the surroundings. The reason is that during the low-level period in which the intensity of the irradiated laser light is relatively low, the heat cools down, and the diffusion to the surroundings is suppressed. This effect is generally referred to as a pulse division effect (Cool effect). In this case, as Figure 15B As shown, it is possible to suppress the heat from being diffused to the surroundings (arrow Y1) by continuously irradiating the laser beam corresponding to one pulse at a constant intensity.

[0104] The laser intensity and irradiation duration are adjusted so that the energy required to fuse the first wire 3 is supplied with the energy of a single pulse. Furthermore, the laser intensity during the low-level period can be less than half the laser intensity during the high-level period. In other words, the laser intensity during the low-level period can be set to any value between 0% and 50% of the laser intensity during the high-level period. If the laser intensity during the low-level period is set to zero, laser irradiation ceases during the low-level period. Furthermore, the duration of the low-level period can be set to any value between 10% and 100% of the duration of the high-level period.

[0105] like Figure 10 As shown in FIG. 1 , after the laser irradiation of the first irradiation area 51[n] is completed in S17, the blowing of the inert gas started in S15 is stopped (S19). Next, the irradiation area of the laser irradiation for cutting the first wire material 3[n] near the joint 5[n] is determined. Figure 5 Among the first wire materials 3[n] shown, the first wire material 3[n] is melted at a position spaced apart toward the first front end side in the first direction with respect to the joining intersection point Qc[n].

[0106] Next, in order to irradiate the determined irradiation area with laser light, the laser light source is positioned (S21). Figure 12 As shown in FIG. 5 , the irradiation area of the laser positioned by S21 is referred to as the second irradiation area 52[n]. Figure 10 As shown, after the laser light source is positioned in S21, laminar inert gas is blown toward the vicinity of the second irradiation area 52[n] of the braid 20 (S23). Then, while the inert gas is being blown, laser light is output from the light source. Thus, the second irradiation area 52[n] is irradiated with laser light from the outside in the third direction (S25).

[0107] like Figure 16AAs shown, when the laser is irradiated in S25, the laser supplies energy to the second irradiation area 52[n] of the first strand 3[n]. As a result, Figure 16B As shown, the first wire 3[n] is melted at the first front end side in the first direction relative to the bonding portion 5[n]. After the first wire [n] is melted, the irradiation of the laser light from the light source is stopped.

[0108] In addition, the irradiation conditions of the laser beam irradiated to the second irradiation area 52[n] in S23 are the same as the irradiation conditions of the laser beam irradiated to the first irradiation area 51[n] in S17. In other words, the laser beam of one pulse is divided and irradiated multiple times intermittently. Therefore, the heat generated by the energy of the laser beam in the first strand 3[n] is difficult to diffuse to the surroundings. Therefore, as Figure 17A As shown in FIG. 1 , the fused portion 301 melted by the laser irradiation in the first wire 3[n] does not move after the laser irradiation stops, but remains at the position immediately after the laser irradiation. Figure 17B As shown, continuous irradiation of laser light of one pulse at a constant intensity can suppress heat diffusion to the surroundings, and the fuse portion 301 of the first wire 3[n] moves toward the bonding portion 5[n] (arrow Y2).

[0109] As described above, the fusible portion 301 of the first strand 3[n] and the second strand 4[n] remain separated, and the heat of the fusible portion 301 of the first strand 3[n] is not transferred to the second strand 4[n]. Therefore, even when the second irradiation region 52[n] is irradiated with laser light, the composition of the second strand 4[n] does not change at locations other than the junction 5[n]. In other words, the composition of the second strand 4[n] remains constant regardless of the distance from the junction 5[n], except for the junction 5[n].

[0110] like Figure 10 As shown, after the irradiation of the second irradiation region 52[n] with the laser beam is completed in S25, the blowing of the inert gas started in S23 is stopped (S27).

[0111] Next, it is determined whether the joining and fusing of the first wire 3 and the second wire 4 at the front end of the reinforcing member 2 are all completed (S29). If the joining and fusing are not all completed (S29: No), the process returns to S13. x is updated from n to n+1, and the processes of S13 to S27 are repeated. Figure 5As shown, the first wire material 3[n+1] and the second wire material 4[n-+-1] are joined at the junction point Qc[n+1] by the joint portion 5[n+1], and the second wire material 4[n+1] is cut (S13 to S19). Furthermore, the first wire material 3[n+1] is melted at a position separated from the first front end in the first direction relative to the junction point Qc[n+1] (S21 to S27). At this time, the joint portions 5[n] and 5[n+1] are aligned in the extension direction.

[0112] The above process is repeated while updating x in the order of n+2 and n+3. Figure 5 As shown, at the junction point Qc[n+2], the first wire 3[n+2] and the second wire 4[n+2] are joined by the joining portion 5[n+1], and the second wire 4[n+2] is cut (S13 to S19). Furthermore, within the first wire 3[n+2], the first wire 3[n-+-2] is melted at a position spaced apart from the first front end in the first direction relative to the junction point Qc[n+2] (S21 to S27). Furthermore, at the junction point Qc[n+3], the first wire 3[n+3] and the second wire 4[n+3] are joined by the joining portion 5[n+3], and the second wire 4[n+3] is cut (S13 to S19). Furthermore, within the first wire 3[n-+-3], the first wire 3[n+3] is melted at a position spaced apart from the first front end in the first direction relative to the junction intersection Qc[n+3] (S21 to S27). At this point, the junctions 5[n+2] and 5[n+3] are aligned in the extending direction.

[0113] The same process as above is repeated while updating x in the order of n+4, n+5. Figure 5 The illustrated joints 5[n+4] and 5[n+5] are arranged in the extension direction. Furthermore, the joints 5[n], 5[n+2], and 5[n+4], as well as the joints 5[n+1], 5[n+3], and 5[n+5], are arranged in a direction perpendicular to the extension direction. Thus, the reinforcement member 2 is cut at the front end in a direction perpendicular to the extension direction, forming a front end portion 2D.

[0114] like Figure 10As shown, when it is determined that the joining and fusing of the first wire 3 and the second wire 4 at the front end of the reinforcing member 2 are all completed (S29: Yes), proceed to S31. At both the front end and the base end of the reinforcing member 2, it is determined whether the joining and fusing of the first wire 3 and the second wire 4 are all completed (S31). When only the joining and fusing of the front end of the reinforcing member 2 are completed, but the joining and fusing of the base end are not completed (S31: No), return to S13. Then, the same process as the front end is performed on the first wire 3 and the second wire 4 at the base end of the reinforcing member 2 (S13 to S29). Thus, the base end of the reinforcing member 2 is cut off to form the base end 2P (refer to Figure 1 Since both ends of the reinforcing member 2 are cut to form the front end portion 2D and the base end portion 2P ( S31 : Yes), the process proceeds to S33 .

[0115] Next, a post-process (S33) of arranging the outer layer tube 7 around the reinforcing member 2 is performed. Figure 18 As shown, the metal wire 100, the inner tube 6, and the reinforcing member 2 are sequentially inserted through the inner cavity 74L of the fourth outer tube 74, the inner cavity 73L of the third outer tube 73, and the inner cavity 72L of the second outer tube 72. Figure 18 Although omitted, the metal wire 100, the inner tube 6 and the reinforcing member 2 are also inserted into the inner cavity of the first outer tube 71. The outer tube 7 extends from the front end portion 2D of the reinforcing member 2 toward the base end portion 2P (see FIG. Figure 1 ), according to the first outer tube 71 (refer to Figure 1 ), the second outer layer tube 72, the third outer layer tube 73 and the fourth outer layer tube 74 are arranged in this order.

[0116] like Figure 10 As shown, after the post-process (S33) is completed, the distal end portion 2D of the reinforcing member 2 is subjected to terminal treatment (S35) using the soft tip 8. Finally, the metal wire 100 is removed from the lumen 6L of the inner tube 6 (S37). The above steps complete the manufacturing process of the catheter 1.

[0117] <How to use the catheter 1>

[0118] An example of how to use the catheter 1 is described below. First, the user shapes the front end of the catheter 1 as needed. The user is a physician, etc. Next, the inner lumen 6L of the catheter 1 is connected to the guide wire that has been inserted into the blood vessel in advance. The user applies force to the base end side of the catheter 1 and inserts the catheter 1 into the blood vessel from the front end side in sequence. In addition, the user rotates the catheter 1 as needed so that the front end of the catheter 1 faces the desired direction. In this way, the user makes the front end of the catheter 1 reach the target site in the blood vessel. Thereafter, the user removes the guide wire from the catheter 1. In this state, the user injects a contrast agent from the connector 9 as needed, or inserts an embolic substance.

[0119] <Functions and Effects of the Present Embodiment>

[0120] The catheter 1 alloys the first wire 3[x] and the second wire 4[x] at their respective contact portions, thereby joining the first wire 3[x] and the second wire 4[x] to form a joint 5[x]. Therefore, when the catheter 1 uses a braid 20 composed of a plurality of first wires 30 and a plurality of second wires 40 having different melting points of 500°C or higher as the reinforcement member 2, the ends of the reinforcement member 2 in the extension direction are less likely to come loose.

[0121] The reinforcing member 2 is bent at the bent portion 2R. Even if a force acts on the reinforcing member 2 due to the bending of the reinforcing member 2 at the bent portion 2R, the joining portion 5[x] of the reinforcing member 2 can maintain the state in which the first strand [x] and the second strand [x] are joined to each other.

[0122] The second wire material 4[x] is bent outward in the third direction at a portion closer to the second front end than the junction point Qc[x] and is wound around the first wire material 3[x] (see FIG. Figure 6 、 Figure 7 In this case, the catheter 1 can more firmly join the first strand 3[x] and the second strand 4[x].

[0123] The catheter 1 includes an inner tube 6. The inner tube 6 prevents threads, etc., from becoming caught on the reinforcement member 2 when passing through the inner lumen 2L of the reinforcement member 2. Furthermore, the catheter 1 includes an outer tube 7 that covers the reinforcement member 2 from the outside. The outer tube 7 prevents exposure of the reinforcement member 2. Thus, the catheter 1 can reduce the possibility of the reinforcement member 2 becoming caught on the blood vessel when passing through the blood vessel.

[0124] The inner tube 6 has a higher light transmittance than the outer tube 7. This prevents the inner tube 6 from heating due to absorption of laser light when the first strand 3[x] and the second strand 4[x] are joined by laser irradiation. Consequently, the catheter 1 can reduce the possibility of heat generation in the inner tube 6 during laser irradiation, which could cause deformation of the first strands 30 and the second strands 40 at locations other than the joined portion 5[x]. Furthermore, by using polytetrafluoroethylene as the material for the inner tube, it is easy to achieve an inner tube 6 with high transmittance.

[0125] The first strand 3[x] is positioned outside the second strand 4[x] in the third direction. In this case, during the manufacturing process of the catheter 1, the first strand 3[x] can be appropriately irradiated with laser light from a light source positioned outside in the third direction, thereby appropriately joining the first strand 3[x] and the second strand 4[x]. Furthermore, during laser irradiation, more laser energy is supplied to the first strand 3[x], which has a higher melting point, thereby melting the first strand 3[x]. Furthermore, the supply of laser energy to the second strand 4[x], which has a lower melting point, can be suppressed, thereby melting and fusing the second strand 4[x].

[0126] The cross-sectional shape of the first wire 3 is a true circle, and the cross-sectional shape of the second wire 4 is a rectangle. In this case, a gap can be formed between the first wire 3[x] and the second wire 4[x] before they are joined. Therefore, the gap can be easily melted in the first wire 3[x] and the second wire 4[x], bringing them into contact and alloying. Consequently, the first wire 3[x] and the second wire 4[x] can be easily alloyed at the contacting portion, forming the joint 5[x].

[0127] The absorption coefficient of the plurality of first wires 30 is greater than the absorption coefficient of the plurality of second wires 40. In this case, a single laser irradiation can achieve the following steps: the first wires 3[x] having a relatively high melting point and the second wires 4[x] having a relatively low melting point are simultaneously melted and alloyed, and the second wires [x] are melted.

[0128] The composition of the second strand 4[x], except for the junction 5[x], remains unchanged even when irradiated with laser light to fuse the first strand 4[x]. Therefore, the composition of the second strand 4[x], except for the junction 5[x], remains constant regardless of the distance from the junction 5[x]. Consequently, the catheter 1 can maintain the stable composition of the second strand 4, thereby maintaining the strength of the braid 20.

[0129] The first wires 30 are made of tungsten, and the second wires 40 are made of stainless steel (SUS). In this case, the catheter 1 can be inserted easily due to the high hardness of tungsten. Furthermore, since tungsten has excellent radiation shielding capabilities, the position of the catheter 1 within the body can be easily confirmed by irradiation with radiation.

[0130] When any portion of the long wire 10 is cut to produce the catheter 1, the end may become loose due to the elasticity of the first wire 3 and the second wire 4. Furthermore, when tungsten is used as the first wire 3, although its high hardness improves the insertion characteristics of the catheter 1, it cannot be easily cut with a conventional cutter.

[0131] In contrast, in Figure 10 In the illustrated method for manufacturing the catheter 1, in step S13, the laser beam irradiated into the first irradiation region 51[x] first applies energy to a portion of the first wire 3[x], melting the first wire 3[x]. Simultaneously, the laser beam applies energy to the second wire 4[x], melting and fusing the second wire 4[x]. The melted first wire 3[x] and the second wire 4[x] are then alloyed and joined. In step S25, the laser beam irradiated into the second irradiation region 52[x] applies energy to the first wire 3[x], fusing the first wire 3[x]. The above steps are repeated until both ends of the reinforcement member 2 are cut, forming the distal end 2D and the proximal end 2P. This prevents the distal end 2D and proximal end 2P of the reinforcement member 2 from coming loose due to the joint 5[x].

[0132] When the joining of the first wire 3[x] and the second wire 4[x] and the cutting of the second wire 4[x] are achieved by irradiating different laser beams, the position of the second wire 4[x] may shift due to the initial laser irradiation, and the position of the melting portion of the second wire 4[n] may shift from the intended position. In this case, there is a possibility that the positions of the joining portion 5[n] and the melting portion of the second wire 4[n] may shift. In contrast, in this embodiment, a single laser irradiation in S13 simultaneously performs the joining of the first wire 3[x] and the second wire 4[x] by alloying and the cutting of the second wire 4[x]. This reduces the possibility of the melting position of the joining portion 5[x] and the second wire 4[x] shifting, and thus maintains good accuracy in the positional relationship between the melting positions of the joining portion 5[x] and the second wire 4[x].

[0133] The energy of the laser beam irradiated in S13 is initially supplied to the first wire 3[x], and the remaining energy is supplied to the second wire 4[x]. Therefore, even if the melting point of the first wire 3 is higher than that of the second wire 4 by 500°C or more, the first wire 3[x] and the second wire 4[x] can be efficiently joined and the second wire 4[x] can be melted by a single irradiation of the laser beam.

[0134] For example, if the first wire 3[x] and the second wire 4[x] are joined after the first wire 3[x] has been melted, the first wire 3[x] may move during melting, potentially shifting the positional relationship between the first and second wires 3[x] and 4[x]. In this case, the first and second wires 3[x] and 4[x] may not be joined with high precision. In contrast, in this embodiment, the first wire 3[x] is melted after the first and second wires 3[x] have been joined. In this case, the position of the first wire 3[x] relative to the second wire 4[x] is less likely to shift due to the joining of the first and second wires 3[x] and 4[x]. Therefore, the first and second wires 3[x] and severing of the first wire 3[x] can be joined and the first wire 3[x] can be cut with high precision.

[0135] In this embodiment, the energy supplied to the braid 20 by the laser irradiation in S13 and S25 is varied over time. More specifically, the laser irradiation in S13 and S25 is performed intermittently and multiple times. This prevents heat transfer from the laser irradiation area to the surrounding area in the first and second strands 3 and 4. This prevents the first and second strands 3 and 4 located near the laser irradiation area from melting, evaporating, or disappearing. Furthermore, the laser irradiation conditions in S13 and S25 are identical. In other words, since the laser irradiation conditions in different steps can be standardized, the manufacturing process of the catheter 1 can be made more efficient.

[0136] At the joining intersection Qc[x], the first strand 3[x] is positioned outwardly in the third direction relative to the second strand 4[x]. At the intersection Q1[x] where the first strand 3[x+1] adjacent to the first strand 3[x] intersects the second strand 4[x], the first strand 3[x+1] is positioned outwardly in the third direction relative to the second strand 4[x]. In this case, when the first strand 3[x] and the second strand 4[x] are joined at the joining intersection Qc[x] by laser irradiation in S13, the first strand 3[x+1] is pressed from the outside in the third direction, thereby suppressing the second strand 4[x] from moving outwardly in the third direction. Furthermore, at the intersection Q2[x] where the second strand 4[x+1], which is adjacent to the second strand 4[x], intersects the first strand 3[x], the second strand 4[x+1] is positioned outward in the third direction relative to the first strand 3[x]. In this case, when the first strand 3[x] and the second strand 4[x] are joined at the joining intersection Qc[x] by laser irradiation in S13, the second strand 4[x+1] is pressed from the outside in the third direction, thereby suppressing the first strand 3[x] from moving outward in the third direction. Therefore, since the respective positions of the first strand 3[x] and the second strand 4[x] during joining can be stabilized, the first strand 3[x] and the second strand 4[x] can be stably joined via the joining portion 5[x].

[0137] The joints 5[n] and 5[n+1] are arranged in the extension direction. The joints 5[n+2] and 5[n+3] are arranged in the extension direction. The joints 5[n+4] and 5[n+5] are arranged in the extension direction. Furthermore, the joints 5[n], 5[n+2], and 5[n+4] are arranged in a direction perpendicular to the extension direction. The joints 5[n+1], 5[n+3], and 5[n+5] are arranged in a direction perpendicular to the extension direction. By arranging the joints 5 in this manner, the reinforcement member 2 can be cut in a direction perpendicular to the extension direction to form the distal end portion 2D and the proximal end portion 2P.

[0138] In S17 and S25, laser irradiation is performed while laminar inert gas is blown toward the reinforcing member 2. In this case, when the first strand 3 and the second strand 4 generate heat due to laser irradiation, the surrounding air is prevented from coming into contact with the first strand 3 and the second strand 4. Therefore, the occurrence of oil bathing and oxidation of the first strand 3 and the second strand 4 due to laser irradiation can be suppressed.

[0139] In the long wire 10 prepared in the pre-process shown in S11, the inner tube 6 is arranged around the metal wire 100, and the metal wire 100 and the inner tube 6 are arranged in the inner lumen 2L of the reinforcement member 2. Furthermore, after the ends of the reinforcement member 2 in the extending direction are cut, the outer tube 7 is arranged around the reinforcement member 2 in the post-process shown in S33. This allows the manufacture of a catheter 1 comprising the reinforcement member 2, the inner tube 6, and the outer tube 7. In particular, the use of the metal wire 100 facilitates the manufacture of a catheter 1 comprising a thin inner tube 6. Furthermore, the surface of the metal wire 100 is plated in silver to reflect the laser light irradiated during the manufacturing process. This prevents the irradiated laser light from passing through the inner lumen 6L of the inner tube 6 and reaching the opposite side. Consequently, the possibility of the reinforcement member 2 on the opposite side being melted by the laser light is reduced.

[0140] Since the light transmittance of the inner tube 6 is higher than that of the outer tube 7, the heat generated by the absorption of laser light by the inner tube 6 can be suppressed. Therefore, the possibility of the inner tube 6 being melted or damaged by heat due to irradiation with laser light can be reduced.

[0141] The thermal conductivity of the metal wire 100 is set to 350 to 450 W / mK. In this embodiment, using a material with high thermal conductivity for the metal wire 100 promotes heat diffusion. By also using a material with high thermal conductivity for the metal wire 100, local temperature increases in the metal wire 100 can be suppressed through thermal diffusion. Consequently, the possibility of melting the inner tube 6 due to the temperature increase of the metal wire 100 can be reduced.

[0142] <Modification>

[0143] The present invention is not limited to the above-described embodiment and can be modified in various ways. The joint 5[x] joining the first wire 3[x] and the second wire 4[x] can be formed only on the distal end side of the reinforcement member 2, not on the proximal end side. Alternatively, the joint 5[x] joining the first wire 3[x] and the second wire 4[x] can be formed only on the proximal end side of the reinforcement member 2, not on the distal end side. The difference in melting point between the plurality of first wires 30 and the plurality of second wires 40 is approximately 2000°C. In contrast, the melting point of the plurality of first wires 30 can be approximately 500°C higher than the melting point of the plurality of second wires 40. In this case, copper can be used as the material for the plurality of first wires 30, and SUS can be used as the material for the plurality of second wires 40. Alternatively, the melting point of the plurality of first wires 30 can be approximately 700°C higher than the melting point of the plurality of second wires 40. In this case, aluminum can be used as the material for the plurality of first wire materials 30, and SUS can be used as the material for the plurality of second wire materials 40. Furthermore, the melting point of the plurality of first wire materials 30 can be approximately 1000°C higher than the melting point of the plurality of second wire materials 40. In this case, aluminum can be used as the material for the plurality of first wire materials 30, and titanium can be used as the material for the plurality of second wire materials 40. In the above embodiment, although the melting point of the plurality of first wire materials 30 is set to be 500°C or higher than the melting point of the plurality of second wire materials 40, it can be more preferably 700°C or higher, and even more preferably 1000°C or higher.

[0144] The curved portion 2R of the catheter 1 can be provided near the proximal end portion 2P, or can be provided at both the distal end portion 2D and the proximal end portion 2P. The curved portion 2R of the catheter 1 can be formed by the user. In this case, the catheter 1 can be shipped in a state extending linearly in the extension direction. The catheter 1 can be used after the user forms the curved portion 2R at the distal end portion 2D.

[0145] The portion of the second wire material 4[x] that is closer to the second distal end than the junction point Qc[x] may extend straight without bending. In the above description, the first distal end of the first wire material 3[x], i.e., the end that is melted by laser irradiation, is separated from the junction point Qc[x] by 0.03 mm to 0.15 mm in the first direction. However, this distance can be appropriately varied.

[0146] The catheter 1 may comprise only the inner tube 6 and the reinforcement member 2, without the outer tube 7. Alternatively, the catheter 1 may comprise only the reinforcement member 2 and the outer tube 7, without the inner tube 6. The hardness of the outer tube 7 may be uniform throughout the entire extension direction. The inner tube 6 may have portions with varying hardness. The portions of the inner tube 6 with varying hardness may be arranged in the extension direction. The thickness of the outer tube 7 does not need to be uniform in the extension direction; multiple portions with varying thicknesses may be arranged in the extension direction. The catheter 1 may consist solely of the reinforcement member 2.

[0147] The light transmittance of the inner tube 6 is not limited to that of the above embodiment and may be other values. The light transmittance of the inner tube 6 may be the same as or lower than that of the outer tube 7. The material of the inner tube 6 is not limited to PTFE and may be other materials. The absorption coefficient of the plurality of first strands 30 may be the same as or lower than that of the plurality of second strands 40.

[0148] The cross-sectional shape of the plurality of first strands 30 is not limited to a perfect circle and may be an ellipse. Alternatively, the cross-sectional shape of the plurality of first strands 30 may be a rectangle, while the cross-sectional shape of the plurality of second strands 40 may be a circle. The cross-sectional shape of either the plurality of first strands 30 or the plurality of second strands 40 may be either a circle or a rectangle.

[0149] The material of the plurality of first wires 30 is not limited to tungsten. The material of the plurality of second wires 40 is not limited to SUS. Any material can be used for the plurality of first wires 30 and the plurality of second wires 40, as long as the melting point of the plurality of first wires 30 is at least 500°C higher than the melting point of the plurality of second wires 40. For example, molybdenum, platinum, or gold can be used for the plurality of first wires 30, while nickel alloys, titanium alloys, or aluminum alloys can be used for the plurality of second wires 40. Furthermore, SUS with different compositions can be used for the first wires 30 and the second wires 40.

[0150] The irradiation mode when irradiating laser light in S13 and S25 is not limited to the above-mentioned embodiment. Figure 19A As shown, in S13 and S25, a laser with relatively low intensity is first irradiated, and then, as shown in Figure 19B As shown, relatively high-intensity laser irradiation is possible. Furthermore, in this case, by initially irradiating with relatively low-intensity laser light, the area of the first and second strands 3 and 4 that is heated by the laser light can be limited. This effect is generally referred to as a slow-up effect. Therefore, even when irradiating with relatively high-intensity laser light, sufficient energy can be supplied to the first and second strands 3 and 4, even if the laser light intensity is suppressed. In other words, because the energy supplied to the first and second strands 3 and 4 can be localized, melting, evaporation, or disappearance of the first and second strands 3 and 4 near the laser irradiation area can be prevented.

[0151] The output mode of the laser in S13 and S25 is not limited to the above. For example, the action of intermittently irradiating the laser and the action of gradually increasing the intensity of the laser can be used at the same time. The number of times the laser is irradiated intermittently is not limited to the above embodiment. It is also possible to first irradiate a laser with a relatively high intensity and then irradiate a laser with a relatively low intensity. The change in the irradiation form of the laser can be performed only in S13 and not in S25. Conversely, the change in the irradiation form of the laser can also be performed only in S25 and not in S13. The laser irradiated by S13 and S25 can be irradiated continuously with a uniform intensity. That is, the energy supplied to the braid 20 by the irradiation of the laser can remain unchanged over time.

[0152] The braid 20 can be a metal mesh formed by alternating a plurality of first strands 30 and a plurality of second strands 40, each interlaced one at a time, a so-called plain weave. Furthermore, the interweaving of the plurality of first strands 30 and the plurality of second strands 40 is not limited to a plain weave or a twill weave; other forms are also possible. In this case, at the intersection Q1[x], the first strand 3[x+1] can be positioned inwardly of the second strand 4[x] in the third direction. At the intersection Q2[x], the second strand 4[x+1] can be positioned inwardly of the first strand 3[x] in the third direction.

[0153] Instead of blowing the laminar inert gas starting in S15 and S23, the inert gas may be injected and filled as the atmosphere around the reinforcing member 2 before laser irradiation. The material and conductivity of the metal wire 100 used in the manufacturing process of the catheter 1 are not limited to those in the above embodiment. The metal wire 100 may not be used in the manufacturing process of the catheter 1.

Claims

1. A catheter, characterized in that: The invention comprises at least: a reinforcing member comprising a braided body formed by weaving a plurality of first wires extending in a first direction and a plurality of second wires extending in a second direction intersecting the first direction into a mesh shape, and a reinforcing member being a tubular member extending in the extending direction; The melting point of the plurality of first strands is higher than the melting point of the plurality of second strands by 500° C. or more. The absorption coefficient of the plurality of first strands is greater than the absorption coefficient of the plurality of second strands, At least one of the two ends of the reinforcing member in the extending direction forms a plurality of joints arranged in the extending direction and in a direction perpendicular to the extending direction at a portion of a plurality of intersections where the plurality of first strands and the plurality of second strands intersect. The joining portion joins the plurality of first wires and the plurality of second wires that intersect each other at a portion of the plurality of intersections, i.e., a first crossing wire and a second crossing wire, and performs joining by alloying at respective contact portions of the first crossing wire and the second crossing wire. The first cross wire is arranged on one side of the second cross wire in a third direction perpendicular to the first direction and the second direction. The one side in the third direction is the outer side of the reinforcing member.

2. The catheter according to claim 1, wherein In each of the plurality of first wire materials and the plurality of second wire materials, at least one of both end portions in the extending direction has a bent portion that is bent with respect to the extending direction.

3. The catheter according to claim 1 or 2, wherein A second front end portion of the second intersecting wire, which is located on a front end side of the joining portion, is wound around the first intersecting wire.

4. The catheter according to claim 1 or 2, wherein: The catheter comprises: an inner tube having a cylindrical shape centered on the central axis of the reinforcing member and disposed in the inner cavity of the reinforcing member; and The outer layer tube has a cylindrical shape centered on the central axis and covers the reinforcing member from the outside.

5. The catheter according to claim 4, wherein The light transmittance of the inner tube is higher than that of the outer tube.

6. The catheter according to claim 4, wherein The material of the inner tube is polytetrafluoroethylene.

7. The catheter according to claim 1 or 2, wherein: One of the plurality of first strands and the plurality of second strands has a circular cross-sectional shape, and the other of the plurality of first strands and the plurality of second strands has a rectangular cross-sectional shape.

8. The catheter according to claim 7, wherein The cross-sectional shape of the plurality of first strands is circular, The plurality of second strands have a rectangular cross-sectional shape.

9. The catheter according to claim 1 or 2, wherein: The composition of the portion of the second intersecting wire other than the joining portion is equal regardless of the distance from the joining portion.

10. The catheter according to claim 1 or 2, wherein The material of the plurality of first wires is tungsten, and the material of the plurality of second wires is stainless steel.

Images