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; a coil 30 formed by winding a wire 31 so as to closely contact an outer surface of a distal end portion of the core member 20; and a resin layer 50 covering an outer surface of the coil 30. The core member 20 includes: a recess 27 located on its outer surface and engageable with at least a part of the wire 31 of the coil 30; and a distal contact portion 28 and a proximal contact portion 29 that are located on at least one end side in the width direction of the recess 27, and are adjacent to the recess 27 and in contact with the wire 31.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] Intravascular treatment is performed to diagnose and treat lesions that have developed in blood vessels by inserting a medical device percutaneously into the blood vessel under X-ray fluoroscopy. In intravascular treatment, a guidewire is first inserted into the blood vessel. Next, the medical device 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 disposed at the tip of the guidewire. This causes the coil to elongate or move in the longitudinal direction of the guidewire, which may damage 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 which achieves the above-mentioned object is a guide wire having a long core member, a coil formed by winding a wire material so as to be in close contact with the outer surface of the tip of the core member, and a resin layer covering the outer surface of the coil, wherein the core member has on its outer surface a recess capable of engaging with at least a portion of the wire material of the coil, and a contact portion adjacent to the recess and in contact with the wire material on at least one end side in the width direction of the recess. Effect of the Invention

[0008] In the guidewire described in (1) above, the core member and the wire of the coil engage with each other, and the outer surface of the core member located at one end or both ends in the width direction of the recess is in reliable contact with the wire of the coil. Therefore, even if a force that would move the coil in the longitudinal direction relative to the core member due to bending or twisting of the tip portion is applied to this guidewire, the extension or movement of the coil is suppressed. As a result, this guidewire can suppress damage or detachment of the resin layer due to the extension or movement of the coil, thereby improving safety.

[0009] (2) In the guidewire described in (1) above, the wire may have a protrusion that is accommodated in the recess of the core member and a protruding portion that is adjacent to the protrusion and that contacts the contact portion of the core member. This increases the contact area between the wire of the coil and the outer surface of the core member, allowing for reliable engagement. This allows the guidewire to further suppress the elongation and movement of the coil.

[0010] (3) In the guidewire described in (1) or (2) above, the recess of the core member may be formed in a spiral shape, and the wire of the coil may be arranged along the recess. This increases the area of ​​engagement between the wire of the coil and the outer surface of the core member, thereby increasing the frictional force between the coil and the core member. As a result, the guidewire can further suppress the elongation and movement of the coil.

[0011] (4) In the guidewire described in (1) or (2) above, the recess of the core member may be formed in a spiral shape, and the wire of the coil may be wound in a direction opposite to the spiral direction of the recess of the core member. As a result, in this guidewire, the wire of the coil and the recess of the core are engaged with a gap along the longitudinal direction of the wire of the coil, so that the wire of the coil can move moderately relative to the core member. Therefore, this guidewire can suppress the elongation and movement of the coil while maintaining the flexibility of the tip portion. In addition, the recess that does not accommodate the wire of the coil can accommodate a resin layer, so that the damage and detachment of the resin layer can be further suppressed.

[0012] (5) In the guidewire according to any one of (1) to (4) above, the material of the wire of the coil may be made of a material that is more easily plastically deformed than the material of the core member. In this way, when winding the wire on the outer surface of the core member, a radially inward force is applied, causing the wire made of the material that is more easily plastically deformed to plastically deform and be accommodated inside the recess. Therefore, in this guidewire, the core member and the wire can be engaged with each other at the same time as the wire is wound.

[0013] (6) In the guidewire according to any one of (1) to (5) above, the coil may be formed of a material that is opaque to radiography, 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 be formed of a strand of a plurality of thin wires, which makes it possible to easily form a spiral recess on the outer surface of the core member of the guidewire.

[0015] (8) A method for manufacturing a guide wire according to the present invention which achieves the above-mentioned object is characterized in that, when winding a wire around the outer surface of the tip of a long core member, the wire is brought into contact with a recess formed on the outer surface of the core member and a contact portion adjacent to the recess at least one end side of the recess in the width direction, thereby plastically deforming the wire, thereby accommodating at least a portion of the wire within the recess, and bringing the wire into contact with the contact portion to engage the core member and the coil.

[0016] The method for manufacturing a guide wire described in (8) above can easily achieve an engagement state between the core member and the coil by accommodating the wire in the recess of the core member and contacting the wire of the coil with the contact portion, simultaneously with winding the wire. [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] 2 is an enlarged cross-sectional view showing the distal end portion of the guidewire according to the first embodiment. FIG. [Diagram 3] FIG. 4 is a plan view showing a tip portion of a core member. [Figure 4] 13 is a plan view showing a state in which a coil is disposed at the tip of a core member. FIG. [Diagram 5] 1A and 1B are enlarged cross-sectional views showing the state in which a coil is arranged on the outer surface of a core member, where (A) shows the state in which a wire rod with a circular cross-sectional shape is wound, and (B) shows the state in which a wire rod with a rectangular cross-sectional shape is wound. [Figure 6] 13 is a plan view showing a modified example in which a coil is disposed at the tip of a core member. FIG. [Figure 7] FIG. 11 is an enlarged perspective view showing a distal end portion of a core member of a guidewire according to a second embodiment. [Figure 8] 4 is an enlarged cross-sectional view showing a state in which a coil is disposed on the outer surface of a core member. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that dimensions in the drawings may be exaggerated and may differ from actual dimensions for convenience of explanation. In addition, in this specification and the drawings, components having substantially the same functional configurations are given the same reference numerals to avoid repeated explanation. In this specification, the side of the guidewire that is inserted into a blood vessel is referred to as the "distal side" and the side that is operated is referred to as the "base side".

[0019] First Embodiment The guidewire 10 according to the first embodiment is a medical instrument that is inserted into the lumen of a catheter, an endoscope, or the like. As shown in FIG. 1, the guidewire 10 includes a long core member 20, a coil 30 formed by tightly winding a wire 31 around the distal end of the core member 20, and a resin layer 50 that covers the coil 30. The total length of the guidewire 10 is not particularly limited, but is preferably about 200 mm to 5000 mm. The guidewire 10 also includes an annular member 60 that covers the core member 20 on the proximal side of the resin layer 50, a marker 70 disposed on the outer surface of the proximal end of the core member 20, and a coating layer 80 that covers the outer surface of the proximal end of the core member 20 and the marker 70. The guidewire 10 does not necessarily have to include the annular member 60, the marker 70, and the coating layer 80.

[0020] Core member 20 is formed of a single continuous wire extending over substantially the entire length of guidewire 10. Core member 20 may be formed by joining multiple wires of the same or different materials by welding, brazing, etc. The shape of a cross section perpendicular to the long axis of core member 20 is circular, but does not have to be circular.

[0021] The core member 20 comprises a base end constant outer diameter portion 24, a tapered portion 25 disposed on the tip side of the base end constant outer diameter portion 24, and a tip end constant outer diameter portion 26 disposed on the tip side of the tapered portion 25. The base end constant outer diameter portion 24 has a substantially constant outer diameter along the long axis of the core member 20. The tapered portion 25 has an outer diameter that gradually decreases from the tip of the base end constant outer diameter portion 24 toward the tip. The tip end constant outer diameter portion 26 has a substantially constant outer diameter from the tip of the tapered portion 25 toward the tip.

[0022] 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.

[0023] As shown in Figs. 1 to 3, a recess 27 is formed on the outer surface of the distal end of core member 20, with which at least a portion of coil 30 engages. Recess 27 is formed in tapered portion 25 and distal constant outer diameter portion 26 of core member 20. Recess 27 may be formed only in tapered portion 25 or only in distal constant outer diameter portion 26. Recess 27 is preferably formed in a range of 0 mm to 100 mm from the distal end of core member 20 toward the proximal end. The position at which recess 27 is formed may be within a range in which guidewire 10 can be shaped. Recess 27 may be disposed at a plurality of locations along the longitudinal axis of guidewire 10.

[0024] Recess 27 is formed to extend in a spiral shape along the outer surface of core member 20. Note that recess 27 may be, for example, linear extending in the long axis direction of guidewire 10, annular extending in the circumferential direction perpendicular to the long axis of guidewire 10, or mesh-like, so long as at least a portion of coil 30 can be engaged with recess 27. Recess 27 may be formed only in a portion of the circumferential direction of core member 20, such as half the circumference or in a dot shape.

[0025] As shown in FIGS. 2, 3 and 5(A), the core member 20 has a tip side contact portion 28 adjacent to the recess 27 on the outer surface on the tip side of the recess 27. The tip side contact portion 28 comes into contact with the wire 31 of the coil 30 protruding from the recess 27 to the tip side. The tip side contact portion 28 is formed in a spiral shape along the spiral recess 27. The core member 20 also has a base side contact portion 29 adjacent to the recess 27 on the outer surface on the base side of the recess 27. The base side contact portion 29 comes into contact with the wire 31 of the coil 30 protruding from the recess 27 to the base side. The base side contact portion 29 is formed in a spiral shape along the spiral recess 27.

[0026] The core member 20 can be formed from a metal such as a superelastic alloy, such as a nickel-titanium alloy, a nickel-aluminum alloy, or a copper-zinc alloy, stainless steel, or an alloy containing these.

[0027] As shown in Figs. 1, 2, 4 and 5(A), the coil 30 is formed by winding the wire 31 in a spiral shape around the outer surface of the tip of the core member 20. The coil 30 has at least a portion of an openly wound portion having gaps between adjacent wires 31, and the material forming the resin layer 50 fills the gaps. Therefore, the coil 30 can suppress damage and falling off of the resin layer 50. The coil 30 may be a single-strand coil formed of one wire 31, or a multiple-strand coil formed of multiple wires 31.

[0028] As shown in FIG. 4, the winding direction of the coil 30 coincides with the winding direction of the spiral of the recess 27 of the core member 20. The pitch of the coil 30 is equal to the pitch of the recess 27 of the core member 20. Therefore, the wire 31 of the coil 30 is arranged so as to follow the recess 27. At least a portion of the wire 31 is accommodated in the recess 27 and engages with the recess 27. It is preferable that the wire 31 of the coil 30 is accommodated in the recess 27 over its entire length. The pitch of the coil 30 is the center-to-center distance between the material cross sections parallel to the center line of the coil 30 adjacent to each other in a cross section including the center line of the coil 30. The pitch of the recess 27 is the center-to-center distance between the material cross sections parallel to the center line of the recess 27 adjacent to each other in a cross section including the long axis of the core member 20.

[0029] The pitch of the coil 30 may be smaller than the pitch of the recesses 27 of the core member 20. That is, a part of the wire 31 of the coil 30 may be disposed between the recesses 27 adjacent to each other in the longitudinal direction of the core member 20. In this case, the pitch of the recesses 27 is preferably an integer multiple of the pitch of the coil 30.

[0030] 6, the winding direction of the coil 30 may be opposite to the spiral winding direction of the recess 27 of the core member 20. In this case, a part of the wire 31 engages with the recess 27. The recess 27 that does not accommodate the wire 31 of the coil 30 can accommodate the resin layer 50, so that damage or falling off of the resin layer 50 can be suppressed.

[0031] As shown in FIGS. 1 and 2, the base end and tip end of the coil 30 are fixed to the core member 20 by the fixing member 11. The fixing member 11 is formed of solder, brazing material, adhesive, or the like. The coil 30 may also be fixed to the core member 20 by welding. At least a part of the fixing member 11 may be accommodated in the recess 27 of the core member 20. This improves the fixing strength between the core member 20 and the coil 30. In this case, it is preferable that the length of the coil 30 is shorter than the length of the recess 27 at the tip and base ends of the coil 30 so that the fixing material 11 is accommodated in the recess 27. The length of the coil 30 may be longer than the length of the recess 27.

[0032] As shown in Figs. 2, 4 and 5(A), the wire 31 of the coil 30 has a protruding portion 32 accommodated in the recessed portion 27 and an exposed portion 33 that is not accommodated in the recessed portion 27 and is exposed from the core member 20. The protruding portion 32 is formed at a position on the inner surface side of the wire 31 of the coil 30. The exposed portion 33 located on the tip side of the protruding portion 32 has a tip side overhanging portion 34 that contacts the tip side contact portion 28 of the core member 20. The exposed portion 33 located on the base end side of the protruding portion 32 has a base side overhanging portion 35 that contacts the base side contact portion 29 of the core member 20. The tip side overhanging portion 34 faces the tip side contact portion 28 to form a pair, and is formed in a spiral shape together with the tip side contact portion 28. Similarly, the base side overhanging portion 35 faces the base side contact portion 29 to form a pair, and is formed in a spiral shape together with the base side contact portion 29.

[0033] The cross-sectional shape perpendicular to the major axis of the wire 31 before being wound around the core member 20 is circular, but it may be elliptical, rectangular, polygonal, or the like.

[0034] As shown in Figs. 2, 3, 4 and 5(A), the width W1 of the recess 27 (the shortest distance between the tip side contact portion 28 and the base side contact portion 29 sandwiching the recess 27) is smaller than the width W2 of the wire 31 in the width direction of the recess 27. This allows the wire 31 to have a protrusion 32 that engages with the recess 27, as well as a tip side protruding portion 34 that contacts the tip side contact portion 28 and a base side protruding portion 35 that contacts the base side contact portion 29. This increases the engagement force of the coil 30 with the core member 20, and can suppress the extension and movement of the coil 30. The width W1 of the recess 27 is, for example, 10 µm to 90 µm, preferably 20 µm to 60 µm. When the cross-sectional shape perpendicular to the major axis of the wire 31 is circular, the width W2 of the wire 31 is equal to or larger than the outer diameter D of the wire 31 before being wound around the core member 20. The outer diameter D of the wire 31 before being wound around the core member 20 is, for example, 20 μm to 100 μm, and preferably 30 μm to 80 μm. When the shortest distance between the tip-side overhanging portion 34 and the base-side overhanging portion 35 that sandwich the convex portion 32 is equal to or less than the outer diameter D of the wire 31 before being wound around the core member 20, the width W2 of the wire 31 is equal to the outer diameter D of the wire 31 before being wound around the core member 20. When the shortest distance between the tip-side overhanging portion 34 and the base-side overhanging portion 35 that sandwich the convex portion 32 is greater than the outer diameter D of the wire 31 before being wound around the core member 20, the width W2 of the wire 31 is equal to the shortest distance between the tip-side overhanging portion 34 and the base-side overhanging portion 35 that sandwich the convex portion 32.

[0035] The depth H of the recess 27 is preferably smaller than half the outer diameter D of the wire 31 before being wound around the core member 20. This makes it easy for the tip-side overhang 34 of the wire 31 to contact the tip-side contact portion 28 and the base-side overhang 35 to contact the base-side contact portion 29 at the tip and base-side of the recess 27. In addition, the recess 27 may have a gap between it and the protrusion 32 housed in the recess 27. In other words, the protrusion 32 does not have to completely fill the recess 27.

[0036] The coil 30 is preferably disposed in a range of 0 mm to 100 mm from the distal end toward the proximal end of the core member 20. The total length of the coil 30 along the major axis of the guidewire 10 is preferably 10 mm to 100 mm. The pitch of the coil 30 is preferably 20 μm to 200 μm.

[0037] The material of the wire 31 forming the coil 30 is preferably a metal, such as stainless steel, nickel-titanium alloy, gold, platinum, tungsten, or an alloy containing these metals. The wire 31 is preferably made of a radiopaque material, which 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 metals.

[0038] The wire 31 forming the coil 30 is preferably made of a material that is more easily plastically deformed than the material forming the core member 20 in the region that the coil 30 contacts. Thus, by winding the wire 31 with an appropriate tension around the outer surface of the core member 20 on which the recesses 27 are formed, the wire 31 can be plastically deformed into a shape that corresponds to the shape of the outer surface of the core member 20. A part of the wire 31 becomes a protrusion 32 that is accommodated in the recess 27 and engages with the core member 20.

[0039] 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.

[0040] 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).

[0041] 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.

[0042] 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.

[0043] The markers 70 are members that allow the surgeon to visually recognize the guidewire 10 inside the living body. The markers 70 are arranged in a mesh or spiral pattern on the outer surface of the core member 20 from the tapered portion 25 to the base end.

[0044] The covering layer 80 covers the outer surface of the base end of the core member 20. The covering layer 80 also covers the marker 70 arranged on the outer surface of the core member 20. In this way, the covering layer 80 protects the outer surface of the core member 20 and the marker 70. The covering layer 80 has a transparency that allows the surgeon to visually recognize the marker 70.

[0045] Next, a method for manufacturing the guidewire 10 will be described.

[0046] When manufacturing the guidewire 10, the manufacturer forms a recess 27 on the outer surface of the tip of the core member 20. The recess 27 can be formed by cutting the core member 20, laser processing, or the like. Next, the wire 31 is wound in a spiral shape around the outer surface of the core member 20 on which the recess 27 has been formed so as to be accommodated in the recess 27. At this time, the manufacturer winds the wire 31 while applying an appropriate tension to the wire 31. The wire 31 is made of a material that is more easily plastically deformed than the material forming the core member 20 in the region that contacts the coil 30, and therefore plastically deforms to correspond to the shape of the outer surface of the core member 20. A part of the wire 31 becomes a protrusion 32 due to the plastic deformation, which is accommodated in the recess 27 and engages with the core member 20. Moreover, since the outer diameter D of the wire 31 before being wound around the core member 20 is larger than the width W1 of the recess 27, a part of the wire 31 is exposed from the recess 27, and a tip-side overhang 34 that contacts the tip-side contact portion 28 of the core member 20 and a base-side overhang 35 that contacts the base-side contact portion 29 of the core member 20 are formed. In this way, the manufacturer can form the coil 30 that covers the tip of the core member 20, and at the same time, form the protrusion 32, the tip-side contact portion 28, and the base-side contact portion 29 on the wire 31, thereby engaging the core member 20 with the coil 30. When plastically deforming the wire 31, a method may be used in which, after the coil 30 is formed by winding the wire 31 around the core member 20, the coil 30 is covered with a metal pipe and the metal pipe is crimped to apply a force to the wire 31.

[0047] Furthermore, when forming the coil 30 at the tip of the core member 20, a wire 31 on which a protrusion 32 has been formed in advance may be used. The protrusion 32 can be formed by subjecting the wire 31 to melt extrusion molding, cutting, laser processing, or the like.

[0048] After placing the coil 30 on the core member 20, the manufacturer forms a resin layer 50 that covers the coil 30. The resin layer 50 can be formed on the outer surfaces of the core member 20 and the coil 30 by extruding a material that will form the resin layer 50, or by heat shrinking a tube made of a material that will form the resin layer 50. The resin layer 50 is preferably formed so as to cover the entire coil 30. Note that the resin layer 50 may cover the entire outer surface of the core member 20.

[0049] As described above, the guidewire 10 according to the first embodiment is a guidewire 10 having a long core member 20, a coil 30 formed by winding the wire 31 so as to be in close contact with the outer surface of the tip of the core member 20, and a resin layer 50 covering the outer surface of the coil 30, and the core member 20 has, on its outer surface, a recess 27 capable of engaging with at least a part of the wire 31 of the coil 30, and contact portions (distal contact portion 28, base contact portion 29) adjacent to the recess 27 and in contact with the wire 31 at least one end side in the width direction of the recess 27. As a result, in the guidewire 10, the core member 20 and the wire 31 of the coil 30 engage with each other, and the outer surface of the core member 20 located on one end side or both end sides in the width direction of the recess 27 contacts the wire 31 of the coil 30. Therefore, even if a force that would move the coil 30 in the longitudinal direction relative to the core member 20 due to bending or twisting of the distal end is applied to the guidewire 10, the coil 30 is prevented from elongating or moving. As a result, the guidewire 10 is able to prevent damage or detachment of the resin layer 50 that would be caused by the elongation or movement of the coil 30, thereby improving safety.

[0050] The wire 31 has a protrusion 32 that is housed in the recess 27 of the core member 20, and protruding portions (distal protruding portion 34, base protruding portion 35) that are provided adjacent to the protrusion 32 and come into contact with the contact portion of the core member 20. This increases the contact area between the wire 31 of the coil 30 and the core member 20, allowing for reliable engagement. Therefore, the guidewire 10 can further suppress the elongation and movement of the coil 30.

[0051] The recess 27 of the core member 20 is formed in a spiral shape, and the wire 31 of the coil 30 is arranged along the recess 27. This increases the area of ​​engagement between the wire 31 of the coil 30 and the outer surface of the core member 20, thereby increasing the frictional force between the coil 30 and the core member 20. Therefore, the guidewire 10 can further suppress the elongation and movement of the coil 30.

[0052] The recess 27 of the core member 20 may be formed in a spiral shape, and the wire 31 of the coil 30 may be wound in a direction opposite to the spiral direction of the recess 27 of the core member 20. As a result, in the present guidewire 10, the wire 31 of the coil 30 and the recess 27 of the core are engaged with a gap along the longitudinal direction of the wire 31 of the coil 30, so that the wire 31 of the coil 30 can move moderately relative to the core member 20. Therefore, the present guidewire 10 can suppress the elongation and movement of the coil 30 while maintaining the flexibility of the distal end. In addition, the recess 27 in which the wire 31 of the coil 30 is not accommodated can accommodate the resin layer 50, so that damage and detachment of the resin layer 50 can be further suppressed.

[0053] The wire 31 of the coil 30 is made of a material that is more easily plastically deformed than the material of the core member 20. As a result, when the wire 31 is wound around the outer surface of the core member 20, by applying a radially inward force, the wire 31 made of a material that is easily plastically deformed is plastically deformed and accommodated inside the recess 27. Therefore, the guidewire 10 is capable of engaging the wire 31 with the core member 20 at the same time as the wire 31 is wound.

[0054] The coil 30 is made of a material that is opaque to X-rays, which allows an operator using the guidewire 10 to confirm the position of the distal end of the guidewire 10 under X-ray fluoroscopy.

[0055] Furthermore, in the manufacturing method of guidewire 10 in this embodiment, when winding wire 31 on the outer surface of the tip of long core member 20, wire 31 is brought into contact with recess 27 formed on the outer surface of core member 20 and contact portions (tip side contact portion 28, base side contact portion 29) adjacent to recess 27 at least one end side in the width direction of recess 27, thereby causing plastic deformation, so that at least a portion of wire 31 is accommodated in recess 27, and wire 31 is brought into contact with the contact portions, thereby engaging core member 20 with coil 30. Thus, in the manufacturing method of guidewire 10, while winding wire 31, an engaged state between core member 20 and coil 30 can be easily achieved by accommodating wire 31 in recess 27 of core member 20 and contacting wire 31 of coil 30 with the contact portions (tip side contact portion 28, base side contact portion 29).

[0056] <Second embodiment> 7 and 8, in the guidewire 10 according to the second embodiment, the core member 20 is formed of a strand of multiple thin wires 40. As a result, a recess 27 is formed in a spiral shape between adjacent thin wires 40. Therefore, in this guidewire 10, the spiral recess 27 can be easily formed in the outer surface of the core member 20.

[0057] The tip side contact portion 28 of the core member 20 is formed on the outer surface of the thin wire 40 on the tip side of the recess 27. The base side contact portion 29 of the core member 20 is formed on the outer surface of the thin wire 40 on the base side of the recess 27.

[0058] The coil 30 is formed by arranging the wire 31 along the spiral recess 27 formed between adjacent fine wires 40 of the core member 20. As a result, at least a portion of the wire 31 is accommodated in the recess 27 and engages with the recess 27. The winding direction of the coil 30 coincides with the extension direction of the spiral recess 27 formed between adjacent fine wires 40. The pitch of the coil 30 is preferably equal to the pitch of the recess 27 of the core member 20.

[0059] The wire 31 of the coil 30 may have a protruding portion 32 accommodated in the recess 27, a tip-side overhanging portion 34 formed in the exposed portion 33, and a base-side overhanging portion 35. The protruding portion 35 of the wire 31 is accommodated in the recess 27 of the core member 20. The tip-side overhanging portion 34 of the wire 31 contacts a tip-side contact portion 28 formed on the outer surface of a thin wire 40 located on the tip side among the adjacent thin wires 40 forming the recess 27 of the core member 20. The base-side overhanging portion 35 of the wire 31 contacts a base-side contact portion 29 formed on the outer surface of a thin wire 40 located on the base side among the adjacent thin wires 40 forming the recess 27 of the core member 20. It is preferable that the width W2 of the wire 31 of the coil 30 is equal to or smaller than the diameter of the adjacent thin wires 40 of the core member 20.

[0060] As shown in FIG. 8, the recess 27 of the core member 20 may have a gap 41 between it and the protrusion 32 accommodated in the recess 27. It is preferable that the radially innermost position of the protrusion 32 reaches a depth H1 of 1 / 3 or more of the distance L from the outer surface of the core member 20 (the surface formed by the tops of the adjacent thin wires 40 forming the recess 27 in a cross-sectional view including the long axis of the core member 20) to the bottom 42 of the recess 27. As a result, the wire 31 has the protrusion 32 accommodated in the recess 27, and the tip-side overhang 34 and the base-side overhang 35 provided adjacent to the protrusion 32 contact the tip-side contact portion 28 and the base-side contact portion 29, respectively. Therefore, the coil 30 can be reliably engaged with the core member 20. The protrusion 32 may completely fill the recess 27.

[0061] The winding direction of the coil 30 may be opposite to the winding direction of the spiral of the recesses 27 between the adjacent thin wires 40. In this case, a part of the wire 31 engages with the recesses 27.

[0062] The present invention is not limited to the above-described embodiment, and various modifications can be made by those skilled in the art within the technical concept of the present invention. For example, when the wire 31 before being wound around the core member 20 is a flat wire (the cross section perpendicular to the long axis of the wire 31 is rectangular), the exposed portion 33 of the coil 30 has a substantially rectangular cross section, as shown in FIG. 5(B). In this case, the width W2 of the wire 31 is equal to or greater than the length of the long side of the wire 31 before being wound around the core member 20. [Explanation of symbols]

[0063] 10 Guidewire 20 Core material 27 Recess 28 Tip side contact part (contact part) 29 Base end contact part (contact part) 30 Coil 31 Wire rod W1 Recess width W2 Wire width

Claims

1. A long core member; a coil formed by winding a wire so as to be in close contact with an outer surface of the tip portion of the core member; a resin layer covering an outer surface of the coil, The guide wire is characterized in that the core member has on its outer surface a recess capable of engaging with at least a portion of the wire of the coil, and a contact portion adjacent to the recess and in contact with the wire on at least one end side of the recess in the width direction.

2. 2. The guide wire according to claim 1, wherein the wire has a protrusion that is received in the recess of the core member, and a protruding portion that is provided adjacent to the protrusion and that contacts the contact portion of the core member.

3. 3. The guide wire according to claim 1, wherein the recess of the core member is formed in a spiral shape, and the wire of the coil is arranged along the recess.

4. The guide wire according to claim 1 or 2, characterized in that the recess of the core member is formed in a spiral shape, and the wire of the coil is wound in a direction opposite to the spiral direction of the recess of the core member.

5. 3. The guide wire according to claim 1, wherein the material of the wire of the coil is made of a material that is more easily plastically deformed than the material of the core member.

6. 3. The guide wire according to claim 1, wherein the coil is made of a material that is radiopaque.

7. 3. The guide wire according to claim 1, wherein the core member is formed of a strand of a plurality of fine wires.

8. A method for manufacturing a guide wire, characterized in that when winding a wire around the outer surface of the tip of a long core member, the wire is brought into contact with a recess formed on the outer surface of the core member and a contact portion adjacent to the recess at least one end side of the recess in the width direction, thereby plastically deforming the wire, thereby accommodating at least a portion of the wire within the recess, and contacting the wire with the contact portion to engage the core member and the coil.

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