Guide wire and method for manufacturing the same

Abstract

To provide a guide wire and a method for manufacturing the same that are capable of suppressing damage to and detachment of a resin layer and improving safety.SOLUTION: A guide wire 10 comprises: an elongated core member 20; an inner tubular member 30 that covers a core outer surface 32 of a distal end portion of the core member 20 and includes a first surface 33 facing radially outward; an outer tubular member 40 having a second surface 43 facing radially inward and covering the first surface 33; and a resin layer 50 disposed to cover the outer tubular member 40. Either the first surface 33 or the second surface 43 has at least one recess and / or projection engageable with the other.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a guidewire for guiding a long medical instrument to be inserted into a living body, and to a method for manufacturing the same. [Background technology]

[0002] In recent years, a procedure has been performed in which a long medical instrument (e.g., a catheter) is inserted through a blood vessel in the lower limb, arm, wrist, or the like to perform treatment. In this procedure, a guidewire is first inserted into the blood vessel. Then, the medical instrument for treatment is inserted along the preceding guidewire to the lesion, and the lesion is treated.

[0003] A guidewire generally comprises a core member, a coil covering the tip of the core member, and a resin layer made of polyurethane or the like that covers the coil (see, for example, Patent Document 1). The coil is formed by winding an X-ray impermeable wire around the outer surface of the core member. The resin layer is formed by disposing a resin on the outer surfaces of the core member and the coil by extrusion or heat shrinkage. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-018574 A Summary of the Invention [Problem to be solved by the invention]

[0005] When the guidewire is inserted into a blood vessel or when it is shaped before insertion, the tip of the guidewire is bent or twisted. At this time, a force along the longitudinal direction of the core member acts on the coil arranged at the tip of the guidewire. This may cause the coil to elongate in the longitudinal direction of the guidewire, damaging the resin layer covering the coil. Furthermore, the damaged resin layer may fall off the guidewire and remain in the blood vessel, causing complications.

[0006] The present invention has been made to solve the above-mentioned problems, and has an object to provide a guidewire and a manufacturing method thereof that can suppress damage and detachment of the resin layer and improve safety. [Means for solving the problem]

[0007] (1) A guide wire according to the present invention that achieves the above-mentioned object is a guide wire comprising: a long core member; an inner tubular member covering the outer surface of the tip of the core member and having a first surface facing radially outward; an outer tubular member having a second surface facing radially inward and covering the first surface; and a resin layer arranged to cover the outer tubular member, wherein either the first surface or the second surface has at least one recess and / or protrusion that can engage with the other. Effect of the Invention

[0008] In the guidewire described in (1) above, the inner tubular member and the outer tubular member can be engaged with each other, so that even if a force acts in the longitudinal direction of the guidewire due to bending or twisting of the distal end of the guidewire, the inner tubular member and the outer tubular member can be prevented from moving in the longitudinal direction. This makes it possible to prevent damage or detachment of the resin layer due to movement of the tubular members, thereby improving safety.

[0009] (2) In the guidewire described in (1) above, the inner tubular member may be an inner coil formed by winding an inner wire, and the outer tubular member may be an outer coil formed by winding an outer wire, and at least one of the first surface formed by the inner wire or the second surface formed by the outer wire may have the recess extending along the outer surface of the inner wire or the outer wire. The inner tubular member and the outer tubular member are formed by coils, thereby improving the flexibility of the distal end of the guidewire. Furthermore, the guidewire can suppress the elongation of the outer coil and / or the inner coil in the longitudinal direction by engaging the outer wire and the inner wire through the recess. Therefore, the guidewire can suppress damage or detachment of the resin layer caused by the elongation of the outer coil and / or the inner coil.

[0010] (3) In the guidewire described in (2) above, the direction in which the recess extends along the outer surface of the inner wire or the outer wire may be inclined with respect to the longitudinal direction of the inner wire or the outer wire in which the recess is formed. This increases the surface area of ​​the inner wire and / or the outer wire in which the recess is formed, thereby improving adhesion between the inner tubular member and / or the outer tubular member and the resin layer. As a result, the guidewire can suppress damage and detachment of the resin layer.

[0011] (4) In the guidewire described in (2) or (3) above, the inner coil and the outer coil may be wound in opposite directions and have the same pitch angle and pitch. This makes it difficult for the guidewire to have anisotropy due to the inner coil and the outer coil. Therefore, the guidewire can suppress a decrease in operability.

[0012] (5) In the guidewire according to any one of (1) to (4) above, the inner tubular member and the outer tubular member may be formed of a material that is easily plastically deformed with respect to the other. In this way, when the outer tubular member is disposed on the first surface of the inner tubular member, a radially inward force is applied to plastically deform the inner tubular member or the outer tubular member made of a material that is easily plastically deformed, forming a recess, and at the same time, the inner tubular member and the outer tubular member are engaged with each other. As a result, the guidewire can suppress damage or detachment of the resin layer due to movement of the inner tubular member and the outer tubular member.

[0013] (6) In the guidewire according to any one of (1) to (5) above, at least one of the inner tubular member and the outer tubular member may be formed of an X-ray impermeable material, thereby enabling an operator using the guidewire to confirm the position of the distal end of the guidewire under X-ray fluoroscopy.

[0014] (7) In the guidewire according to any one of (1) to (6) above, the core member may have, on its outer surface, a core recess or a core protrusion engageable with a radially inward surface of the inner tubular member. This further suppresses movement of the inner tubular member in the longitudinal direction relative to the core member, thereby further suppressing damage or detachment of the resin layer due to movement of the inner tubular member.

[0015] (8) A method for manufacturing a guide wire according to the present invention which achieves the above-mentioned object is characterized in that an inner tubular member is placed on the outer surface of the tip of a long core member, a first surface facing radially outward of the inner tubular member is brought into contact with a second surface facing radially inward of the outer tubular member, and at least one of the inner tubular member or the outer tubular member is plastically deformed to form at least one recess in either the first surface or the second surface which is engageable with the other.

[0016] The method for producing a guidewire as described in (8) above makes it easy to form the recesses in the inner tubular member and / or the outer tubular member and to achieve an engaged state. [Brief description of the drawings]

[0017] [Figure 1] 1 is a partial cross-sectional view showing a guidewire according to a first embodiment. [Diagram 2] 1 is a plan view showing a part of the distal end of a guidewire according to a first embodiment, with a resin layer seen through. [Diagram 3] FIG. 2 is a plan view showing the inner wire and the outer wire. [Figure 4] FIG. 3 is a cross-sectional view taken along line AA in FIG. [Diagram 5] FIG. 11 is a plan view showing a part of a distal end portion of a modified example of the guide wire according to the first embodiment, with a resin layer seen through. [Figure 6] FIG. 11 is a plan view showing a part of the distal end of a guidewire according to a second embodiment, with a resin layer seen through. [Figure 7] FIG. 7 is a cross-sectional view taken along line BB in FIG. [Figure 8] FIG. 11 is a plan view showing a part of the distal end of a guidewire according to a third embodiment, with a resin layer seen through. [Figure 9] FIG. 9 is a cross-sectional view taken along line CC in FIG. [Figure 10] FIG. 11 is a plan view showing a part of the distal end of a guidewire according to a fourth embodiment, with a resin layer seen through. [Figure 11] FIG. 11 is a cross-sectional view taken along line DD in FIG. [Figure 12] FIG. 13 is a plan view showing a part of a tip portion of a modified example of a guide wire according to the fourth embodiment, with a resin layer seen through. [Figure 13] FIG. 13 is a cross-sectional view taken along line EE in FIG. [Figure 14] FIG. 13 is a plan view showing a part of the distal end of a guidewire according to a fifth embodiment, with a resin layer seen through. [Figure 15] FIG. 15 is a cross-sectional view taken along the line FF in FIG. [Figure 16] FIG. 13 is a plan view showing a modified example of the core member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. For convenience of explanation, the dimensions in the drawings may be exaggerated and may differ from the actual dimensions. In addition, in this specification and the drawings, components having substantially the same functional configuration are given the same reference numerals to avoid repeated explanation. In this specification, the side of the guidewire that is inserted into the blood vessel is referred to as the "distal side", and the side that is operated is referred to as the "base side". In addition, in this specification, the direction parallel to the long axis of the guidewire is referred to as the "long axis direction", the direction along the circle centered on the long axis of the guidewire is referred to as the "circumferential direction", and the radial direction of the circle centered on the long axis of the guidewire is referred to as the "radial direction".

[0019] First Embodiment A guidewire 10 according to a first embodiment is a medical device used by being inserted into the lumen of a catheter, an endoscope, or the like, as shown in Fig. 1. As shown in Fig. 1, the guidewire 10 includes a long core member 20, an inner tubular member 30 covering the distal end of the core member 20, an outer tubular member 40 covering the inner tubular member 30, a resin layer 50 covering the outer tubular member 40, an annular member 60 covering the core member 20 on the proximal side of the resin layer 50, and a marker 70. The total length of the guidewire 10 is not particularly limited, but is preferably about 200 to 5000 mm.

[0020] The core member 20 includes a single long core wire 21 and a coating layer 22 that covers the entire area of ​​the core wire 21 except for the tip portion. The core member 20 includes a core outer surface 23.

[0021] Core wire 21 extends over substantially the entire length of guidewire 10. Core wire 21 is formed of a single continuous wire, but may be formed by joining a plurality of wires of the same or different materials by, for example, welding or brazing. The shape of a cross section perpendicular to the major axis of core wire 21 is circular, but does not have to be circular.

[0022] Core wire 21 includes a base end constant outer diameter portion 24, a tapered portion 25 disposed on the tip side of base end constant outer diameter portion 24, and a tip end constant outer diameter portion 26 disposed on the tip side of tapered portion 25. Base end constant outer diameter portion 24 has a substantially constant outer diameter along the longitudinal axis of core wire 21. Tapered portion 25 has an outer diameter that gradually decreases from the tip of base end constant outer diameter portion 24 toward the tip. Tip end constant outer diameter portion 26 has a substantially constant outer diameter from the tip of tapered portion 25 toward the tip.

[0023] The base end constant outer diameter portion 24 provides the guidewire 10 with pushability. The tapered portion 25 gradually reduces the rigidity of the guidewire 10 from the base end constant outer diameter portion 24 toward the tip to the tip constant outer diameter portion 26. This enables the guidewire 10 to be prevented from localized bending or damage such as kinking. The tip constant outer diameter portion 26 provides the guidewire 10 with high flexibility, improving operability and safety when inserted into a living body. At least a portion of the tip constant outer diameter portion 26 may be shaped.

[0024] The core wire 21 can be made of a metal such as a superelastic alloy, such as a Ni-Ti based alloy, a Ni-Al based alloy, or a Cu-Zn based alloy, stainless steel, or an alloy containing these.

[0025] The marker 70 is a portion that allows the surgeon to visually recognize the guide wire 10 inside the living body. The marker 70 is disposed on the outer surface of the core wire 21 from the middle of the tapered portion 25 of the core wire 21 toward the proximal end.

[0026] The covering layer 22 covers the entire area of ​​the core wire 21 except for the tip portion. The covering layer 22 also covers the markers 70 arranged on the outer surface of the core wire 21. In this way, the covering layer 22 protects the outer surface of the core wire 21 and the markers 70. The covering layer 22 has a transparency that allows the surgeon to visually recognize the markers 70.

[0027] As shown in Figs. 1 to 4, the inner tubular member 30 is formed by an inner coil 32 in which an inner wire 31 is spirally wound around the core outer surface 23 at the tip of the core member 20 so as to cover the core outer surface 23. The inner tubular member 30 has a first surface 33 facing radially outward. The inner coil 32 has at least a part of an openly wound portion having a gap between adjacent inner wires 31, and the material forming the resin layer 50 is inserted between the adjacent inner wires 31. Therefore, the inner coil 32 can suppress damage or falling off of the resin layer 50.

[0028] 2 to 4, the inner wire 31 forming the inner coil 32 has, on its outer surface, inner recesses 34 extending spirally along the outer surface of the inner wire 31, and spiral inner protrusions 35 formed between the inner recesses 34. The inner coil 32 may be a single-strand coil formed from one inner wire 31, or a multi-strand coil formed from a plurality of inner wires 31. Each of the inner recesses 34 and the inner protrusions 35 arranged on the inner wire 31 may be single-strand or multi-strand.

[0029] The outer tubular member 40 is formed by an outer coil 42 in which an outer wire 41 is wound in a spiral shape so as to cover the inner tubular member 30. The outer tubular member 40 has a second surface 43 that faces inward in the radial direction and contacts the first surface 33 of the inner tubular member 30. The outer coil 42 has a loosely wound portion having a gap between at least a part of the adjacent outer wires 41, and the material forming the resin layer 50 is inserted between the adjacent outer wires 41. Therefore, the outer coil 42 can suppress damage or detachment of the resin layer 50. The outer coil 42 is preferably wound in the opposite direction to the inner coil 32. This allows the outer wire 41 and the inner wire 31 to cross and come into contact with each other. Note that the outer wire 41 and the inner wire 31 may be wound in the same direction as long as the outer wire 41 and the inner wire 31 can come into contact with each other.

[0030] The outer wire 41 forming the outer coil 42 has, on its outer surface, an outer recess 44 that extends helically along the outer surface of the outer wire 41, and an outer protrusion 45 that extends helically along the outer surface of the outer wire 41 between the outer recess 44. In the area where the outer coil 42 and the inner coil 32 contact each other, the outer recess 44 and / or the outer protrusion 45 engage with the inner protrusion 35 and / or the inner recess 34. That is, the outer protrusion 45 fits into the inner recess 34, and the inner protrusion 35 fits into the outer recess 44. The outer coil 42 may be a single-strand coil formed by one outer wire 41, or may be a multiple-strand coil formed by multiple outer wires 41. In addition, each of the outer recess 44 and the outer protrusion 45 arranged on the outer wire 41 may be single-strand or multiple-strand.

[0031] As shown in FIG. 3, the acute inclination angle of the inner recess 34 with respect to the long axis of the inner wire 31 is α, and the acute inclination angle of the outer recess 44 with respect to the long axis of the outer wire 41 is β. In addition, the winding angle, which is the angle between the long axis of the inner coil 32 and the long axis of the inner wire 31, is γ1, and the winding angle, which is the angle between the long axis of the outer coil 42 and the long axis of the outer wire 41, is γ2. When the inner coil 32 and the outer coil 42 are wound in opposite directions and are formed with the same pitch and pitch angle, the winding angle γ1 is equal to the winding angle γ2, and the winding angle γ=γ1=γ2 can be defined. In this case, it is preferable that the following formula (1) is satisfied for the inclination angle α, the inclination angle β, and the winding angle γ.

[0032] α+β+2γ=180° Equation (1)

[0033] 2 and 4, the direction in which the inner convex portion 35 on the first surface 33 extends coincides with the direction in which the outer concave portion 44 on the second surface 43 extends, and the inner convex portion 35 and the outer concave portion 44 engage with each other. This prevents the inner coil 32 and the outer coil 42 from elongating. The coil pitch is the center-to-center distance between the cross sections of the wire parallel to the long axis of adjacent coils in a cross section including the long axis of the coil. The coil pitch angle is the angle between the long axis of the wire of the coil and a plane perpendicular to the long axis of the coil. Therefore, the coil winding angle γ is 90° minus the pitch angle.

[0034] When β>α, γ can be calculated by the following formula (2).

[0035] γ = β - α Equation (2)

[0036] When α=β, the inner convex portion 35 on the first surface 33 and the outer concave portion 44 on the second surface 43 are perpendicular to the long axis of the coil, as in the modified example shown in Fig. 5. In this case, the engagement force between the inner coil 32 and the outer coil 42 in the direction along the long axis of the guidewire 10 is maximized, and therefore the effect of suppressing elongation of the outer coil 42 and the inner coil 32 is maximized.

[0037] The pitch of the inner coil 32 and the pitch of the outer coil 42 may be different. For example, the pitch of one coil may be an integer multiple of the pitch of the other coil.

[0038] The portion of the inner recess 34 that does not engage with the outer wire 41 and the portion of the outer recess 44 that does not engage with the inner wire 31 increase the contact area between the inner tubular member 30 and the outer tubular member 40 and the resin layer 50, thereby effectively suppressing damage or detachment of the resin layer 50.

[0039] 1, the base end and tip end of the inner coil 32 and the outer coil 42 are respectively fixed (bonded) to the core member 20 by a fixing member 11. The fixing member 11 is formed of solder, (brazing material), adhesive, or the like. Note that the fixing member 11 is not limited to solder, and may be, for example, an adhesive. Also, the inner coil 32 and the outer coil 42 may be fixed to the core member 20 by welding.

[0040] The material forming the inner coil 32 and the outer coil 42 (the material of the inner wire 31 and the outer wire 41) is preferably a metal, and for example, stainless steel, Ni-Ti alloy, gold, platinum, tungsten, or an alloy containing these can be used. At least one of the inner coil 32 and the outer coil 42 is preferably formed from a radiopaque material. This allows the surgeon to grasp the position of the tip of the guidewire 10 in the living body under X-ray fluoroscopy. The radiopaque material is, for example, gold, platinum, tungsten, or an alloy containing these.

[0041] The outer wire 41 forming the outer coil 42 may be made of a material that is more easily plastically deformed than the inner wire 31 forming the inner coil 32. For example, the inner coil 32 is made of stainless steel, and the outer coil 42 is made of gold. In this case, the outer wire 41 forming the outer coil 42 is wound around the inner wire 31 forming the inner coil 32 while applying an appropriate tension, so that the portion of the outer wire 41 that comes into contact with the inner wire 31 is plastically deformed into a shape that conforms to the inner wire 31. This allows the outer recess 44 to be formed on the second surface 43 of the outer wire 41 and simultaneously engage with the first surface 33 of the inner wire 31.

[0042] The cross-sectional shape perpendicular to the major axis of the inner wire 31 and the outer wire 41 is circular except for the recessed and protruding portions, but may be elliptical, rectangular, polygonal, or the like.

[0043] The inner coil 32 and the outer coil 42 are preferably disposed in a range of 0 mm to 100 mm from the tip toward the base end of the core member 20. The wire diameters of the inner wire 31 forming the inner coil 32 and the outer wire 41 forming the outer coil 42 are, for example, 20 μm to 100 μm, and preferably 30 μm to 80 μm. The overall length of the inner coil 32 and the outer coil 42 along the major axis of the guidewire 10 is preferably 10 mm to 100 mm. The pitch of the inner coil 32 and the outer coil 42 is preferably 0.09 mm to 0.3 mm.

[0044] The resin layer 50 is a member that forms the tip portion of the guidewire 10. The resin layer 50 is formed of a highly flexible resin, for example, polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polyesters (PET, PBT, etc.), polyamide, polyimide, polystyrene, silicone resin, thermoplastic elastomers such as polyurethane elastomer, polyester elastomer, and polyamide elastomer, various rubber materials such as latex rubber and silicone rubber, or composite materials combining two or more of these. The resin layer 50 is preferably formed of polyurethane.

[0045] Furthermore, particles (fillers) made of a radiopaque material may be dispersed in the resin layer 50. This allows the surgeon to grasp the position of the tip of the guidewire 10 in the living body under X-ray fluoroscopy. The radiopaque material is, for example, a precious metal such as gold, platinum, or tungsten, or an alloy containing these (for example, a platinum-iridium alloy).

[0046] The resin layer 50 may be covered with a lubricating layer 51. The lubricating layer 51 is formed of a hydrophilic polymer that reduces friction. Examples of the hydrophilic polymer that forms the lubricating layer 51 include cellulose-based polymers, polyethylene oxide-based polymers, maleic anhydride-based polymers (e.g., maleic anhydride copolymers such as methyl vinyl ether-maleic anhydride copolymers), acrylamide-based polymers (e.g., polyacrylamide, glycidyl methacrylate-dimethylacrylamide block copolymers), water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone, and derivatives thereof.

[0047] The annular member 60 is a member disposed to eliminate a step between the base end of the resin layer 50 and the core member 20. The material forming the annular member 60 is preferably a metal or a hard resin.

[0048] As described above, the guidewire 10 according to the first embodiment includes a long core member 20, an inner tubular member 30 covering the outer surface (core outer surface 32) of the tip of the core member 20 and having a first surface 33 facing radially outward, an outer tubular member 40 having a second surface 43 facing radially inward and covering the first surface 33, and a resin layer 50 arranged to cover the outer tubular member 40, and either the first surface 33 or the second surface 43 has at least one recess (inner recess 34, outer recess 44) and / or protrusion (outer protrusion 45, inner protrusion 35) that can be engaged with the other. As a result, the guidewire 10 is capable of engaging with the inner tubular member 30 and the outer tubular member 40, so that even if a force in the longitudinal direction of the guidewire 10 due to bending or twisting of the tip of the guidewire 10 acts, movement of the inner tubular member 30 and the outer tubular member 40 in the longitudinal direction can be suppressed. As a result, the guidewire 10 can suppress damage and detachment of the resin layer 50 that occurs when the inner tubular member 30 and the outer tubular member 40 move, thereby improving safety.

[0049] The inner tubular member 30 is an inner coil 32 formed by winding an inner wire 31, and the outer tubular member 40 is an outer coil 42 formed by winding an outer wire 41. At least one of the first surface 33 formed by the inner wire 31 and the second surface 43 formed by the outer wire 41 has a recess (inner recess 34, outer recess 44) extending along the outer surface of the inner wire 31 or the outer wire 41. The inner tubular member 30 and the outer tubular member 40 are formed by coils, thereby improving the flexibility of the distal end of the guidewire 10. Furthermore, the guidewire 10 can suppress the elongation of the outer coil 42 and / or the inner coil 32 in the longitudinal direction by engaging the outer wire 41 and the inner wire 31 through the recess. Therefore, the guidewire 10 can suppress the breakage and detachment of the resin layer 50 caused by the elongation of the outer coil 42 and / or the inner coil 32.

[0050] The direction in which the recesses (inner recesses 34, outer recesses 44) extend along the outer surface of the inner wire 31 or outer wire 41 is inclined with respect to the longitudinal direction of the inner wire 31 or outer wire 41 in which the recesses are formed. This increases the surface area of ​​the inner wire 31 and / or outer wire 41 in which the helical recesses are formed, thereby improving adhesion between the inner tubular member 30 and / or outer tubular member 40 and the resin layer 50. As a result, the guidewire 10 can suppress damage or detachment of the resin layer 50.

[0051] The inner coil 32 and the outer coil 42 are wound in opposite directions and are formed with the same pitch angle and pitch. This makes it difficult for the guidewire 10 to suffer from anisotropy due to the presence of the inner coil 32 and the outer coil 42. This makes it possible to suppress deterioration in operability of the guidewire 10.

[0052] At least one of the inner tubular member 30 and the outer tubular member 40 is formed of an X-ray impermeable material, which allows an operator using the guidewire 10 to confirm the position of the distal end of the guidewire 10 under X-ray fluoroscopy.

[0053] <Second Embodiment> As shown in FIGS. 6 and 7, in the guide wire 10 according to the second embodiment, the inclination angle α of the inner concave portion 34 of the inner coil 32 and the inclination angle β of the outer concave portion 44 of the outer coil 42 are different from those of the first embodiment.

[0054] In the second embodiment, the inner concave portion 34 and the outer convex portion 35 of the inner wire 31 extend parallel to the long axis of the inner wire 31. The outer concave portion 44 and the outer convex portion 45 of the outer wire 41 extend perpendicular to the long axis of the outer wire 41 and are formed in an annular shape in the circumferential direction of the outer wire 41. Therefore, the inclination angle α of the inner concave portion 34 in the inner coil 32 is 0°, and the inclination angle β of the outer concave portion 44 in the outer coil 42 is 90°.

[0055] When the above-described formula (1) is satisfied, the winding angle γ of the inner coil 32 and the outer coil 42 is 90°. As a result, the extending direction of the inner convex portion 35 on the first surface 33 coincides with the extending direction of the outer concave portion 44 on the second surface 43, the inner concave portion 34 and the outer convex portion 45 mesh with each other, and the inner convex portion 35 and the outer concave portion 44 mesh with each other and engage. For this reason, the elongation of the inner coil 32 and the outer coil 42 is suppressed. As a result, the guide wire 10 can suppress damage and peeling of the resin layer 50 accompanying the elongation of the inner tubular member 30 and the outer tubular member 40, and can improve safety.

[0056] <Third Embodiment> As shown in FIGS. 8 and 9, the guide wire 10 according to the third embodiment is different from the first embodiment in that a plurality of dot-shaped convex portions are formed on the outer surfaces of the inner wire 31 forming the inner coil 32 and the outer wire 41 forming the outer coil 42, instead of spiral convex portions or concave portions.

[0057] In the third embodiment, the inner coil 32 is formed with a plurality of dot-shaped inner convexities 36, instead of concaves or convexities extending along the outer surface of the inner wire 31. The portion of the outer surface of the inner wire 31 other than the inner convexities 36 may be defined as a concave portion. The outer coil 42 is formed with a plurality of dot-shaped outer convexities 46, instead of concaves or convexities extending spirally along the outer surface of the outer wire 41. The portion of the outer surface of the outer wire 41 other than the outer convexities 46 may be defined as a concave portion. The inner wire 31 and the outer wire 41 may be formed with dot-shaped concave portions, instead of dot-shaped convex portions. In this case, the portion of the outer surface of the inner wire 31 and the outer wire 41 other than the dot-shaped concave portions may be defined as a convex portion. Alternatively, the inner wire 31 and the outer wire 41 may be formed with both dot-shaped convexities and dot-shaped concave portions.

[0058] When the first surface 33 of the inner coil 32 and the second surface 43 of the outer coil 42 come into contact with each other, the inner convex portion 36 of the first surface 33 engages with the concave portion of the second surface 43 other than the outer convex portion 46. This prevents the inner coil 32 and the outer coil 42 from elongating. As a result, the guidewire 10 prevents damage or detachment of the resin layer 50 caused by movement of the inner tubular member 30 and the outer tubular member 40, improving safety.

[0059] <Fourth embodiment> As shown in FIGS. 10 and 11, the guidewire 10 according to the fourth embodiment differs from the first embodiment in the configurations of the inner tubular member 30 and the outer tubular member 40.

[0060] In the fourth embodiment, the inner tubular member 30 is a cylindrical member different from a coil, and an inner protrusion 37, which is a protrusion extending in a spiral shape along the outer surface of the cylindrical member, is formed on a first surface 33 facing radially outward of the cylindrical member. The outer tubular member 40 is formed by an outer coil 42 in which an outer wire 41 is wound in a spiral shape. The winding direction of the outer coil 42 is opposite to the winding direction of the spiral inner protrusion 37 of the inner tubular member 30. Therefore, the outer wire 41 of the outer coil 42 crosses and contacts the inner protrusion 37. The outer coil 42 has an outer recess 47 formed at a position where it contacts the inner protrusion 37 on a second surface 43 facing radially inward. Note that if the pitch of the outer coil 42 is different from the pitch of the spiral inner protrusion 37, the outer coil 42 can cross and contact even if the winding direction of the outer coil 42 is the same as the winding direction of the spiral inner protrusion 37.

[0061] The outer wire 41 forming the outer coil 42 is preferably made of a material that is more easily plastically deformed than the material forming the inner tubular member 30. In this case, by winding the outer wire 41, which does not have an outer recess 47, around the first surface 33 of the inner tubular member 30 while applying an appropriate tension, the portion of the outer wire 41 that comes into contact with the inner protrusion 37 is plastically deformed, and the outer recess 47 into which the inner protrusion 37 fits is formed.

[0062] As a modification of the fourth embodiment, as shown in Figs. 12 and 13, the inner tubular member 30 is a cylindrical member different from a coil, and an inner recess 38, which is a recess extending in a spiral shape along the outer surface of the cylindrical member, is formed on a first surface 33 facing radially outward of the cylindrical member. The outer tubular member 40 is formed by an outer coil 42 in which an outer wire 41 is wound in a spiral shape. The winding direction of the outer coil 42 is the same as the winding direction of the spiral inner recess 38 of the inner tubular member 30. The pitch and pitch angle of the inner recess 38 are the same as the pitch and pitch angle of the outer coil 42. The outer wire 41 forming the outer coil 42 enters the inner recess 38 of the inner tubular member.

[0063] In the modified example, the inner tubular member 30 is preferably made of a material that is more easily plastically deformed than the outer wire 41 that forms the outer coil 42. In this case, by winding the outer wire 41 with an appropriate tension around the first surface 33 of the inner tubular member 30 on which no recesses or protrusions are formed, the first surface 33 of the inner tubular member 30 that comes into contact with the outer wire 41 is plastically deformed, and an inner recess 38 into which the outer coil 42 fits is formed.

[0064] As described above, in the guidewire 10 according to the fourth embodiment, the inner tubular member 30 and the outer tubular member 40 are formed of a material that is easily plastically deformed relative to the other. As a result, when the outer tubular member 40 is disposed on the first surface 33 of the inner and outer tubular members 40, a radially inward force is applied to plastically deform the inner tubular member 30 or the outer tubular member 40, which are formed of a material that is easily plastically deformed, and a recess (the inner recess 38, the outer recess 47) is formed, and at the same time, the inner tubular member 30 and the outer tubular member 40 are engaged with each other. As a result, the guidewire 10 can suppress damage or detachment of the resin layer due to movement of the inner tubular member 30 and the outer tubular member 40.

[0065] Furthermore, the manufacturing method of guidewire 10 according to the fourth embodiment involves disposing inner tubular member 30 on the outer surface of the tip portion of long core member 20, and bringing a second surface 43 of outer tubular member 40 facing radially inward into contact with a first surface 33 facing radially outward of inner tubular member 30 to cause plastic deformation, thereby forming at least one recess in either first surface 33 or second surface 43 that is engageable with the other. This manufacturing method of guidewire 10 makes it easy to form recesses in inner tubular member 30 and / or outer tubular member 40 and to achieve an engaged state.

[0066] <Fifth embodiment> As shown in FIGS. 14 and 15, the guidewire according to the fifth embodiment differs from the first embodiment in the configurations of the inner tubular member 30 and the outer tubular member 40. As shown in FIG.

[0067] In the fifth embodiment, the outer tubular member 40 is a cylindrical member different from a coil, and an outer recess 49 is formed on a second surface 43 facing radially inward of the cylindrical member, the outer recess 49 extending in a spiral shape along the outer surface of the cylindrical member. The inner tubular member 30 is formed by an inner coil 32 in which an inner wire 31 is wound in a spiral shape. The winding direction of the inner coil 32 is the same as the winding direction of the spiral outer recess 49 of the outer tubular member 40. The pitch and pitch angle of the outer recess 49 are the same as the pitch and pitch angle of the outer coil 42. The inner wire 31 of the inner coil 32 is inserted into the outer recess 49.

[0068] The outer tubular member 40 is preferably made of a material that is more easily plastically deformed than the inner wire 31 that forms the inner coil 32. In this case, by placing a circular tube without an outer recess 49 against the first surface 33 of the inner coil 32, which is the inner tubular member 30, while applying a radially inward force, a portion of the second surface 43 of the outer tubular member 40 that comes into contact with the inner wire 31 of the inner coil 32 is plastically deformed, and an outer recess 49 into which the inner wire 31 fits is formed.

[0069] In the guidewire 10 according to the fifth embodiment, the inner wire 31 of the inner coil 32, which is the inner tubular member 30, enters the outer recess 49 of the second surface 43 of the outer tubular member 40, thereby engaging the inner tubular member 30 and the outer tubular member 40 with each other. This makes it possible for the guidewire 10 to suppress damage or detachment of the resin layer due to movement of the inner tubular member 30 and the outer tubular member 40.

[0070] The present invention is not limited to the above-described embodiment, and various modifications may be made by those skilled in the art within the technical spirit of the present invention. For example, the recesses and / or protrusions of the inner tubular member 30 and the outer tubular member 40 may be provided on at least the first surface 33 or the second surface 43, and may be provided only on a portion of the circumferential direction.

[0071] 16, the core member 20 may have a core recess 27 or a core protrusion on the core outer surface 23 that can engage with a surface of the inner tubular member 30 facing radially inward. The core recess 27 can accommodate a part of the inner tubular member 30. The portion of the core outer surface 23 other than the core recess 27 can be defined as a core protrusion. The core protrusion can contact the inner tubular member 30 to support the inner tubular member. This further suppresses movement of the inner tubular member 30 in the longitudinal direction relative to the core member 20 in the guidewire 10, thereby further suppressing damage and detachment of the resin layer 50 associated with movement of the inner tubular member 30. [Explanation of symbols]

[0072] 10 Guidewire 20 Core material 23 Core outer surface 27 Core recess 30 Inner tubular member 31 Inner wire rod 32 Inner coil 33 Page 1 34, 38 Inner recess (recess) 35, 36, 37 Inner convex part (convex part) 40 Outer tubular member 41 Outer wire 42 Outer coil 43 2nd page 44, 47, 49 Outer recess (recess) 45, 46 Outer convex part (convex part) 50 Resin layer

Claims

1. A long core member; an inner tubular member covering an outer surface of the tip end of the core member and having a first surface facing radially outward; an outer tubular member having a second surface facing radially inwardly and covering the first surface; a resin layer disposed to cover the outer tubular member, A guidewire, characterized in that either the first surface or the second surface has at least one recess and / or protrusion engageable with the other surface.

2. the inner tubular member is an inner coil formed by winding an inner wire, the outer tubular member is an outer coil formed by winding an outer wire, 2. The guidewire of claim 1, wherein at least one of the first surface formed by the inner wire or the second surface formed by the outer wire has the recess extending along an outer surface of the inner wire or the outer wire.

3. The guide wire according to claim 2, characterized in that the direction in which the recess extends along the outer surface of the inner wire or the outer wire is inclined with respect to the longitudinal direction of the inner wire or the outer wire in which the recess is formed.

4. 4. The guidewire according to claim 2, wherein the inner coil and the outer coil are wound in opposite directions and have the same pitch angle and pitch.

5. 4. The guidewire according to claim 1, wherein one of the inner tubular member and the outer tubular member is formed from a material which is more easily plastically deformed than the other.

6. 4. The guide wire according to claim 1, wherein at least one of the inner tubular member and the outer tubular member is formed of a radiopaque material.

7. The guide wire according to any one of claims 1 to 3, characterized in that the core member has, on its outer surface, a core recess or a core protrusion that is engageable with a radially inward facing surface of the inner tubular member.

8. A method for manufacturing a guidewire, characterized in that an inner tubular member is placed on the outer surface of the tip of a long core member, and a first surface facing radially outward of the inner tubular member is contacted with a second surface facing radially inward of the outer tubular member, thereby plastically deforming at least one of the inner tubular member or the outer tubular member, thereby forming at least one recess in either the first surface or the second surface that is engageable with the other.

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