Guidewires

Abstract

To improve torque transmission property while avoiding an excessive increase of rigidity in a proximal end side part of a guide wire.SOLUTION: A guide wire includes: a core shaft; and a coil body wound around a part at least on a proximal end side of the core shaft. The coil body is joined with the core shaft by predetermined joint means at a position of a proximal end of the core shaft and at a first position between the proximal end and a distal end of the core shaft in an axial direction of the guide wire. The coil body is joined with the core shaft by welding at an axially specific position being at least one position within a range from the proximal end of the core shaft to the first position in the axial direction of the guide wire.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology disclosed in this specification relates to a guidewire to be inserted into a blood vessel or the like. [Background technology]

[0002] Methods using catheters are widely used as a method for treating or inspecting stenosis or occlusion (hereinafter referred to as "lesion") in blood vessels, etc. Generally, a guidewire is used to guide the catheter to the lesion in the blood vessel, etc. The guidewire comprises a core shaft and a coil body wound around at least a portion of the core shaft on the base end side. The coil body is provided, for example, to give the base end portion of the guidewire an appropriate thickness without excessively increasing the rigidity of the base end portion of the guidewire.

[0003] In conventional guidewires, the coil body is joined to the core shaft at the proximal and distal ends of the guidewire by, for example, brazing (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Pat. No. 4,003,369 [Patent Document 2] International Publication No. 2010 / 018762 Summary of the Invention [Problem to be solved by the invention]

[0005] In a conventional guidewire in which the coil body is joined to the core shaft at the proximal and distal ends of the guidewire, the torque applied to the proximal portion of the guidewire is transmitted to the core shaft only at the proximal and distal ends, so there is room for improvement in torque transmission from the proximal side to the distal side. On the other hand, in order to improve the torque transmission of the guidewire, it is also possible to continuously join the entire coil body to the core shaft, but this is not preferable because the rigidity of the proximal portion of the guidewire becomes excessively high. Thus, the conventional guidewire has a problem in that it is not possible to improve torque transmission while avoiding the rigidity of the proximal portion of the guidewire becoming excessively high.

[0006] This specification discloses a technique that can solve the above-mentioned problems. [Means for solving the problem]

[0007] The technology disclosed in this specification can be realized, for example, in the following forms.

[0008] (1) The guidewire disclosed in the present specification includes a core shaft and a coil body wound around at least a portion of the core shaft on the base end side. The coil body is joined to the core shaft by a predetermined joining means at the base end position of the core shaft and at a first position between the base end and the tip of the core shaft along the axial direction of the guidewire. The coil body is joined to the core shaft by welding at a specific axial position, which is at least one position within the range from the base end of the core shaft to the first position along the axial direction of the guidewire. According to this guidewire, the coil body and the core shaft are joined at the base end position and the first position, and are also welded to the core shaft at at least one axial specific position, which is at least one position within the range from the base end to the first position. This increases the number of points at which a rotational force applied to the base end portion of the guidewire is transmitted to the core shaft, improving torque transmission from the base end side to the tip side. Furthermore, in this guidewire, the entire coil body is not continuously joined to the core shaft, but the coil body and the core shaft are merely welded to each other at specific axial positions, so the stiffness of the proximal end portion of the guidewire does not become excessively high. Therefore, with this guidewire, it is possible to improve torque transmissibility while preventing the stiffness of the proximal end portion of the guidewire from becoming excessively high.

[0009] (2) In the above-mentioned guidewire, a configuration may be adopted in which a plurality of the specific axial positions are present. By adopting such a configuration, the presence of welded points at the plurality of specific axial positions can effectively improve the torque transmissibility of the guidewire.

[0010] (3) In the above guidewire, the plurality of specific axial positions may be arranged at equal intervals along the axial direction of the guidewire. By adopting such a configuration, the welded portions between the coil body and the core shaft can be arranged in a well-balanced manner along the axial direction, and the torque transmission of the guidewire can be further effectively improved.

[0011] (4) In the above guidewire, the coil body may be joined to the core shaft by welding only at a portion along the circumferential direction of the guidewire at at least one of the specific axial positions. By adopting such a configuration, it is possible to limit an area that is affected by heat during welding, and to suppress changes in the characteristics of the guidewire caused by welding.

[0012] (5) In the above guidewire, in at least one of the specific axial positions, the coil body may be joined to the core shaft by welding at a plurality of different positions along the circumferential direction of the guidewire. By adopting such a configuration, the torque transmission of the guidewire can be effectively improved by the presence of a plurality of welds at each of the specific axial positions.

[0013] (6) In the above guidewire, the plurality of mutually different positions along the circumferential direction of the guidewire may be arranged at equal intervals along the circumferential direction of the guidewire. By adopting such a configuration, the welded portions between the coil body and the core shaft can be arranged in a well-balanced manner along the circumferential direction at each specific axial position, and the torque transmission of the guidewire can be further effectively improved.

[0014] (7) In the above-mentioned guidewire, the number of welded points at one of the specific axial positions may be configured to be different from the number of welded points at the other specific axial positions. By adopting such a configuration, the operator can recognize the rotation angle of the guidewire from the appearance of the guidewire, thereby improving operability and convenience.

[0015] (8) In the above guidewire, a first combination of a plurality of the specific axial positions successive along the axial direction of the guidewire, in which the number of welded points at each of the specific axial positions is a specific pattern, may be arranged along the axial direction of the guidewire. By adopting such a configuration, the appearance of the guidewire can be made regular throughout the entire range from the base end of the core shaft to the first position, and the operator can easily recognize the rotation angle of the guidewire from the appearance of the guidewire, thereby effectively improving operability and convenience.

[0016] (9) In the above-mentioned guidewire, the position of the welded portion along the circumferential direction of the guidewire at one of the specific axial positions may be configured to be different from the position of the welded portion along the circumferential direction of the guidewire at another of the specific axial positions. By adopting such a configuration, the welded portions of the coil body and the core shaft can be arranged in a balanced manner along the circumferential direction, and the torque transmission of the guidewire can be further effectively improved.

[0017] (10) In the above guidewire, a second combination of a plurality of the specific axial positions consecutive along the axial direction of the guidewire, in which the positions of the welded points along the circumferential direction of the guidewire at each of the specific axial positions are in a specific pattern, may be arranged along the axial direction of the guidewire. By adopting such a configuration, the welded points of the coil body and the core shaft can be arranged in a well-balanced manner along the circumferential direction over the entire range from the base end of the core shaft to the first position, and the torque transmission of the guidewire can be further effectively improved. In addition, by adopting such a configuration, it is not necessary to stop the axial movement of the workpiece during welding, so that the time required for welding can be shortened, and the efficiency of manufacturing the guidewire can be improved.

[0018] (11) In the above guidewire, the amount of deviation of the positions of the welded points along the circumferential direction of the guidewire at any two of the axial specific positions adjacent to each other along the axial direction of the guidewire may be equal to each other for the plurality of axial specific positions constituting the second combination. By adopting such a configuration, the welded points of the coil body and the core shaft can be arranged in a highly balanced manner along the circumferential direction over the entire range from the base end of the core shaft to the first position, and the torque transmissibility of the guidewire can be improved very effectively.

[0019] (12) In the above guidewire, the coil body may be joined to the core shaft by welding over the entire circumference of the guidewire in the circumferential direction at at least one of the specific axial positions. By adopting such a configuration, it is possible to increase the welding strength at each position, and effectively improve the torque transmission of the guidewire. In addition, by adopting such a configuration, the operator can easily recognize the insertion length of the guidewire by the appearance and / or touch of the guidewire, and operability and convenience can be improved.

[0020] (13) In the above guidewire, the positions of the welded points along the circumferential direction of the guidewire at each of the specific axial positions may be configured to be the same as each other. By adopting such a configuration, it is possible to generate an intentional flutter every time the guidewire is rotated 360° in the circumferential direction, and the operator can easily perform a specific operation of the guidewire (for example, escape from a false lumen or guidance to a branch vessel), thereby improving operability and convenience. In addition, by adopting such a configuration, it is not necessary to stop the axial movement of the workpiece during welding, so that the time required for welding can be shortened, and the efficiency of manufacturing the guidewire can be improved.

[0021] (14) In the guidewire, the predetermined joining means may be brazing. By adopting such a configuration, melting of the base material can be suppressed by using brazing at the position of the base end of the core shaft and the first position, and high-strength joining can be achieved by using welding at each specific axial position.

[0022] The techniques disclosed in this specification can be realized in various forms, for example, in the form of a guidewire or a manufacturing method thereof. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is an explanatory diagram illustrating a schematic configuration of a guidewire 100 according to a first embodiment. [Diagram 2] FIG. 1 is an explanatory diagram illustrating a schematic configuration of a guidewire 100 according to a first embodiment. [Diagram 3] FIG. 1 is an explanatory diagram showing the arrangement of welded portions 50 in a guide wire 100 according to a first embodiment. [Figure 4] FIG. 1 is an explanatory diagram showing the arrangement of welded portions 50 in a guide wire 100 according to a first embodiment. [Diagram 5] FIG. 1 is an explanatory diagram showing in detail the external shape of a guidewire 100 according to a first embodiment. [Figure 6] FIG. 11 is an explanatory diagram showing the arrangement of welded portions 50 in a guide wire 100a according to a second embodiment. [Figure 7] FIG. 11 is an explanatory diagram showing the arrangement of welded portions 50 in a guide wire 100a according to a second embodiment. [Figure 8] FIG. 11 is an explanatory diagram showing in detail the shape of a guidewire 100a according to a second embodiment. [Figure 9] FIG. 11 is an explanatory diagram showing the arrangement of welded portions 50 in a guide wire 100b according to a third embodiment. [Figure 10] FIG. 11 is an explanatory diagram showing the arrangement of welded portions 50 in a guide wire 100b according to a third embodiment. [Figure 11] FIG. 11 is an explanatory diagram showing in detail the shape of a guidewire 100b according to a third embodiment. [Figure 12] FIG. 13 is an explanatory diagram showing the arrangement of welded portions 50 in a guide wire 100c according to a fourth embodiment. [Figure 13] FIG. 13 is an explanatory diagram showing the arrangement of welded portions 50 in a guide wire 100c according to a fourth embodiment. [Figure 14] FIG. 13 is an explanatory diagram showing the arrangement of welded portions 50 in a guide wire 100d according to a fifth embodiment. [Figure 15] FIG. 13 is an explanatory diagram showing the arrangement of welded portions 50 in a guide wire 100d according to a fifth embodiment. [Figure 16] FIG. 13 is an explanatory diagram showing the arrangement of welded portions 50 in a guide wire 100e according to a sixth embodiment. [Figure 17] FIG. 13 is an explanatory diagram showing the arrangement of welded portions 50 in a guide wire 100e according to a sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] A. First embodiment: A-1. Basic configuration of guidewire 100: 1 and 2 are explanatory diagrams that show a schematic configuration of the guidewire 100 in the first embodiment. FIG. 1 shows the configuration of a longitudinal section (YZ section) of the guidewire 100, and FIG. 2 shows the configuration of a transverse section (XY section) of the guidewire 100 at the position II-II in FIG. 1. Note that FIG. 1 does not show a part of the guidewire 100. In FIG. 1, the positive Z-axis direction side is the tip end side (distal side) that is inserted into the body, and the negative Z-axis direction side is the base end side (proximal side) that is operated by an operator such as a doctor. FIG. 1 shows a state in which the guidewire 100 as a whole is linear and substantially parallel to the Z-axis direction, but the guidewire 100 has flexibility to the extent that it can be curved.

[0025] For ease of explanation, in this specification, guidewire 100 is assumed to be in the state shown in Fig. 1, the Z-axis direction is referred to as the "axial direction of guidewire 100" or simply the "axial direction", and the rotation direction about the Z-axis is referred to as the "circumferential direction of guidewire 100" or simply the "circumferential direction". Also, as shown in Fig. 2, with respect to the circumferential direction, the positive Y-axis direction is referred to as the upward direction or 0° direction, the negative Y-axis direction is referred to as the downward direction or 180° direction, the negative X-axis direction is referred to as the forward direction or 90° direction, and the positive X-axis direction is referred to as the backward direction or 270° direction.

[0026] The guidewire 100 is a long medical device that is inserted into a blood vessel, etc., in order to guide a catheter to a lesion (a narrowed or blocked area) in the blood vessel, etc. The total length of the guidewire 100 is, for example, about 1500 mm to 2000 mm, and the outer diameter of the guidewire 100 is, for example, about 0.5 to 1.2 mm.

[0027] The guidewire 100 includes a core shaft 10, a proximal coil body 20, a distal coil body 30, a distal joint portion 42, a proximal joint portion 44, and an intermediate joint portion 46.

[0028] The core shaft 10 is an elongated member having a small diameter at the tip end and a large diameter at the base end. More specifically, the core shaft 10 is composed of a rod-shaped small diameter portion 11, a rod-shaped large diameter portion 13 located at the base end side of the small diameter portion 11 and having a larger diameter than the small diameter portion 11, and a tapered portion 12 located between the small diameter portion 11 and the large diameter portion 13 and gradually increasing in diameter from the boundary position with the small diameter portion 11 toward the boundary position with the large diameter portion 13. The shape of the cross section (XY cross section) at each position of the core shaft 10 can be any shape, for example, a circle or a flat plate. The outer diameter of the large diameter portion 13 is, for example, about 0.2 to 0.6 mm.

[0029] The core shaft 10 is made of a known material, for example, a metal material, more specifically, stainless steel (SUS302, SUS304, SUS316, etc.), a superelastic alloy such as a Ni-Ti alloy, a piano wire, a nickel-chromium alloy, a cobalt alloy, tungsten, etc. The core shaft 10 may be made of the same material as a whole, or may be made of different materials in different parts.

[0030] The base-side coil body 20 is a coil-shaped member formed into a hollow cylinder by helically winding a wire. The base-side coil body 20 is wound around a part of the core shaft 10 on the base side (for example, a part that is 700 mm to 1200 mm away from the base end). The part of the guidewire 100 around which the base-side coil body 20 is wound is a part that is not inserted into the body and is held by the operator. In this embodiment, the base-side coil body 20 is configured by densely winding one wire. The tip-side coil body 30 is a coil-shaped member formed into a hollow cylinder by helically winding a wire. The tip-side coil body 30 is wound around a part of the core shaft 10 on the tip side (for example, the remaining part where the base-side coil body 20 is not wound). The part of the guidewire 100 around which the tip-side coil body 30 is wound is a part that is mainly inserted into the body. In this embodiment, the tip side coil body 30 is configured by densely winding a single wire. In this embodiment, the outer diameter of the base side coil body 20 and the outer diameter of the tip side coil body 30 are approximately the same. The diameter of the wire constituting the base side coil body 20 is larger than the diameter of the wire constituting the tip side coil body 30, and is, for example, about 0.1 to 0.3 mm. The base side coil body 20 is an example of a coil body in the claims.

[0031] The base-end coil body 20 and the tip-end coil body 30 are made of known materials, such as metal materials, more specifically, stainless steel (SUS302, SUS304, SUS316, etc.), superelastic alloys such as Ni-Ti alloys, piano wire, nickel-chromium alloys, cobalt alloys, tungsten, etc. The base-end coil body 20 and the tip-end coil body 30 may be made of the same material, or may be made of different materials. The base-end coil body 20 and the tip-end coil body 30 may be made of the same material as a whole, or may be made of different materials in parts.

[0032] The tip-side joint 42 is a member that joins the tip of the core shaft 10 and the tip of the tip-side coil body 30. That is, the tip of the core shaft 10 and the tip of the tip-side coil body 30 are fixed so as to be embedded inside the tip-side joint 42. The outer peripheral surface on the tip side of the tip-side joint 42 is a smooth surface (for example, a substantially hemispherical surface). The base-side joint 44 is a member that joins the base end of the core shaft 10 and the base end of the base-side coil body 20. That is, the base end of the core shaft 10 and the base end of the base-side coil body 20 are fixed so as to be embedded inside the base-side joint 44. The intermediate joint 46 is a member that joins the core shaft 10, the base end of the tip-side coil body 30, and the tip of the base-side coil body 20 at a predetermined position (hereinafter referred to as "intermediate position Z1") between the base end and the tip of the core shaft 10 along the axial direction. That is, the base end of the tip side coil body 30 and the tip of the base side coil body 20 are fixed so as to be embedded inside an intermediate joint portion 46 formed on the outer circumferential surface of the core shaft 10 at the intermediate position Z1. The intermediate position Z1 is an example of the first position in the claims.

[0033] The materials constituting the tip-side joint 42, the base-side joint 44, and the intermediate joint 46 are known materials, such as brazing material (aluminum alloy brazing, silver brazing, gold brazing, etc.), metal solder (Ag-Sn alloy, Au-Sn alloy, etc.), adhesive (epoxy adhesive, etc.). In this embodiment, brazing material is used as the material constituting the tip-side joint 42, the base-side joint 44, and the intermediate joint 46. That is, in this embodiment, the base-side coil body 20 is joined to the core shaft 10 by brazing at the base end position and the intermediate position Z1 of the core shaft 10. Brazing is an example of a predetermined joining means in the claims.

[0034] A part or the whole of guidewire 100 may be coated with a known coating agent.

[0035] A-2. Detailed configuration regarding the joining of the core shaft 10 and the base-end coil body 20: Next, a detailed configuration of the joint between the core shaft 10 and the base-side coil body 20 in the guidewire 100 of this embodiment will be described. As shown in Figs. 1 and 2, in the guidewire 100 of this embodiment, the base-side coil body 20 is joined to the core shaft 10 by welding. In other words, the guidewire 100 of this embodiment has a welded portion 50 that joins the base-side coil body 20 and the core shaft 10. The welded portion 50 is a portion formed by heating and melting the base material, the base material, and the core shaft 10, and then solidifying. For reference, in Figs. 1 and 2, the state of the base material before the welded portion 50 is formed is shown by a broken line near the welded portion 50. The outer diameter of the welded portion 50 is, for example, about 70% to 90% of the outer diameter of the guidewire 100. The penetration depth of the welded portion 50 is, for example, about 25% to 50% of the outer diameter of the guidewire 100. Any known welding means can be used to weld between the base end coil body 20 and the core shaft 10, but it is preferable to use laser welding, which can achieve a deep penetration depth with a small amount of heat input.

[0036] Figures 3 and 4 are explanatory diagrams showing the arrangement of welded portions 50 in guidewire 100 of the first embodiment. Column A of Figure 3 shows a schematic view of the external configuration of guidewire 100 as viewed from above (0° direction), column B of Figure 3 shows a schematic view of the external configuration of guidewire 100 as viewed from the front (90° direction), column C of Figure 3 shows a schematic view of the external configuration of guidewire 100 as viewed from below (180° direction), and column D of Figure 3 shows a schematic view of the external configuration of guidewire 100 as viewed from the rear (270° direction). Also, section A of Fig. 4 shows a schematic configuration of a cross section (XY cross section) of guidewire 100 at the position IVA-IVA in section B of Fig. 3, section B of Fig. 4 shows a schematic configuration of a cross section (XY cross section) of guidewire 100 at the position IVB-IVB in section B of Fig. 3, and section C of Fig. 4 shows a schematic configuration of a cross section (XY cross section) of guidewire 100 at the position IVC-IVC in section B of Fig. 3. Note that sections A to C of Fig. 4 omit detailed illustration of the configuration of guidewire 100 other than welded portion 50.

[0037] As shown in Figs. 3 and 4, in the guidewire 100 of the first embodiment, a plurality of axial specific positions Pa are set within a range (hereinafter referred to as a "specific range Rx") from the base end (i.e., the position of the base-side joint 44) of the core shaft 10 to the intermediate position Z1 (i.e., the position of the intermediate joint 46) along the axial direction, and one welded portion 50 is formed at each of the axial specific positions Pa. In the guidewire 100 of this embodiment, the base-side coil body 20 is joined to the core shaft 10 by welding only at a portion along the circumferential direction. That is, as shown in Fig. 4, each welded portion 50 is not formed so as to constitute the entire outer periphery of the guidewire 100 in the XY cross section, but is formed so as to constitute only a portion of the outer periphery. Also, in the guidewire 100 of this embodiment, the plurality of axial specific positions Pa are arranged at equal intervals along the axial direction. That is, the distances l1 between two axial specific positions Pa adjacent to each other along the axial direction are all the same, and are, for example, about 10 mm to 50 mm. In this specification, "equal (or identical)" includes "almost equal (or nearly identical)," where "almost equal (or nearly identical)" means that the difference between the two values ​​being compared is 10% or less of the larger value.

[0038] For example, if the length of the base-end coil body 20 is 950 mm, the distance l1 between two adjacent axial specific positions Pa along the axial direction is 30 mm, and the distance from the base end of the guidewire 100 to the nearest welded portion 50 is 10 mm, then 32 axial specific positions Pa will be arranged in the specific range Rx of the guidewire 100.

[0039] In the guide wire 100 of the first embodiment, the position of the welded portion 50 (welded portion) along the circumferential direction at one particular axial position Pa (hereinafter referred to as "circumferential position Pb of the welded portion 50") is different from the circumferential position Pb of the welded portion 50 at another particular axial position Pa. More specifically, the circumferential position Pb1 of the welded portion 50 at the particular axial position Pa whose cross section is shown in column A of FIG. 4 is a position of 0°, the circumferential position Pb2 of the welded portion 50 at the particular axial position Pa whose cross section is shown in column B of FIG. 4 is a position of 120°, and the circumferential position Pb3 of the welded portion 50 at the particular axial position Pa whose cross section is shown in column C of FIG. 4 is a position of 240°. The circumferential position Pb of the welded portion 50 means the position of the center of the outer circumferential surface of the welded portion 50 in a cross section perpendicular to the axial direction (XY cross section). In this manner, in the guide wire 100 of the first embodiment, the circumferential positions Pb of the welded portions 50 at the three specific axial positions Pa aligned in the axial direction are shifted from one another by 120°.

[0040] As shown in Fig. 3, in the guidewire 100 of the first embodiment, a combination of three axially consecutive specific positions Pa (hereinafter referred to as a "unit combination U0"), in which the pattern of the circumferential positions Pb of the welded parts 50 at each specific axial position Pa is the above-mentioned specific pattern (a pattern of the 0° position, the 120° position, and the 240° position), is repeatedly arranged along the axial direction. That is, in order from the position closest to the base end of the guidewire 100, the circumferential positions Pb of the welded parts 50 at each specific axial position Pa are in a regular pattern of the 0° position, the 120° position, the 240° position, the 0° position, the 120° position, the 240° position, and so on. The unit combination U0 in this embodiment is an example of the second combination in the claims.

[0041] The method of forming each welded portion 50 in the guide wire 100 of the first embodiment is, for example, as follows. That is, a workpiece is prepared in which the base end coil body 20 and the core shaft 10 are joined by the base end joint portion 44 and the intermediate joint portion 46. This workpiece is rotated in the circumferential direction at a constant speed while moving in the axial direction at a constant speed, and a laser beam is irradiated to the workpiece at a constant time interval from a laser welder installed at a predetermined position. By irradiating the workpiece with the laser beam, the base end coil body 20 and the core shaft 10 as the base material are heated and melted, and then solidified to become the welded portion 50. Through the above steps, the welded portion 50 at each specific axial position Pa is formed. Note that, when forming the welded portion 50, the outer diameter and penetration depth of the welded portion 50 to be formed can be adjusted by adjusting the outer diameter, peak power, and pulse width of the irradiated laser beam.

[0042] A-3. Advantages of the first embodiment: As described above, the guidewire 100 of the first embodiment includes the core shaft 10 and the base-side coil body 20 wound around a portion of the base-side of the core shaft 10. The base-side coil body 20 is joined to the core shaft 10 at the position of the base end of the core shaft 10 and at an intermediate position Z1 between the base end and the tip of the core shaft 10 along the axial direction. The base-side coil body 20 is joined to the core shaft 10 by welding at a specific axial position Pa, which is at least one position within a specific range Rx from the base end of the core shaft 10 to the intermediate position Z1 along the axial direction (a welded portion 50 is formed to join the base-side coil body 20 and the core shaft 10).

[0043] Thus, in the guidewire 100 of the first embodiment, the base-end coil body 20 and the core shaft 10 are joined by the welded portion 50 formed at the specific axial position Pa in addition to the base-end joint portion 44 and the intermediate joint portion 46. Compared with a configuration without such a welded portion 50, the number of locations where a rotational force applied to the base-end portion of the guidewire 100 is transmitted to the core shaft 10 increases, improving torque transmissibility from the base end side to the tip side. In addition, in the guidewire 100 of the first embodiment, the entire base-end coil body 20 is not continuously joined to the core shaft 10, and the base-end coil body 20 and the core shaft 10 are merely welded to each specific axial position Pa. Therefore, the rigidity of the base-end portion of the guidewire 100 is not excessively high. Therefore, according to the guidewire 100 of the first embodiment, it is possible to improve torque transmissibility while avoiding an excessive increase in the rigidity of the base-end portion of the guidewire 100.

[0044] Furthermore, in the guidewire 100 of the first embodiment, a plurality of specific axial positions Pa exist within the specific range Rx. In other words, a plurality of welds 50 are formed within the specific range Rx of the guidewire 100. Therefore, according to the guidewire 100 of the first embodiment, the presence of the plurality of welds 50 can effectively improve torque transmissibility.

[0045] Furthermore, in the guidewire 100 of the first embodiment, the multiple specific axial positions Pa are arranged at equal intervals along the axial direction. In other words, the multiple welds 50 are formed at the specific axial positions Pa arranged at equal intervals along the axial direction. Therefore, according to the guidewire 100 of the first embodiment, the welded portions between the base end coil body 20 and the core shaft 10 can be arranged in a balanced manner along the axial direction, and torque transmissibility can be further effectively improved.

[0046] Furthermore, in the guidewire 100 of the first embodiment, the base coil body 20 is joined to the core shaft 10 by welding only at a portion along the circumferential direction at each specific axial position Pa. Therefore, according to the guidewire 100 of the first embodiment, the range affected by heat during welding can be limited, and changes in the characteristics of the guidewire 100 due to welding can be suppressed, compared to a configuration in which the base coil body 20 is joined to the core shaft 10 by welding over the entire circumferential circumference.

[0047] Furthermore, in the guidewire 100 of the first embodiment, the circumferential position Pb of the welded portion 50 at one specific axial position Pa is different from the circumferential position Pb of the welded portion 50 at another specific axial position Pa. Therefore, according to the guidewire 100 of the first embodiment, the welded portions of the base-end coil body 20 and the core shaft 10 can be arranged in a well-balanced manner along the circumferential direction, and torque transmissibility can be further effectively improved.

[0048] In the guidewire 100 of the first embodiment, the unit combinations U0 of the plurality of axial specific positions Pa consecutive along the axial direction, in which the pattern of the circumferential positions Pb of the welded portions 50 at each of the axial specific positions Pa is a specific pattern, are arranged along the axial direction. Therefore, according to the guidewire 100 of the first embodiment, the welded portions of the base end coil body 20 and the core shaft 10 can be arranged in a well-balanced manner along the circumferential direction over the entire specific range Rx of the guidewire 100, and the torque transmissibility can be further effectively improved. Furthermore, according to the guidewire 100 of the first embodiment, there is no need to stop the axial movement of the workpiece during laser welding to form the welded portions 50, so that the time required to form the welded portions 50 can be shortened, and the efficiency of manufacturing the guidewire 100 can be improved.

[0049] Furthermore, in the guidewire 100 of the first embodiment, for the multiple specific axial positions Pa that constitute the unit combination U0, the deviation amounts of the circumferential positions Pb of the welded parts 50 at any two specific axial positions Pa that are adjacent to each other in the axial direction are equal to each other (i.e., 120°). Therefore, according to the guidewire 100 of the first embodiment, the welded parts of the base end coil body 20 and the core shaft 10 can be arranged in an extremely balanced manner in the circumferential direction over the entire specific range Rx of the guidewire 100, and torque transmissibility can be improved extremely effectively.

[0050] In the guidewire 100 of the first embodiment, the joining means between the base end coil body 20 and the core shaft 10 at the base end position and the intermediate position Z1 of the core shaft 10 is brazing. Therefore, according to the guidewire 100 of the first embodiment, by employing brazing joining at the base end position and the intermediate position Z1 of the core shaft 10, melting of the base material can be suppressed, and by employing welding joining at each specific axial position Pa, high-strength joining can be realized.

[0051] A-4. Details of the external appearance of the guidewire 100: The external shape of the guidewire 100 will be described in detail. FIG. 5 is an explanatory diagram showing the external shape of the guidewire 100 of the first embodiment in detail. In column A of FIG. 5, a plan view (viewed from the 0° direction) of the guidewire 100 is shown, in column B of FIG. 5, a front view (viewed from the 90° direction) of the guidewire 100 is shown, in column C of FIG. 5, a bottom view (viewed from the 180° direction) of the guidewire 100 is shown, in column D of FIG. 5, a rear view (viewed from the 270° direction) of the guidewire 100 is shown, and in column E of FIG. 5, a left side view (viewed from the Z-axis positive direction) of the guidewire 100 is shown. Note that the right side view (viewed from the Z-axis negative direction) of the guidewire 100 is omitted because it is the same as the left side view of the guidewire 100 shown in column E of FIG. 5.

[0052] In columns A to C of FIG. 5, of the two omitted portions, the dimension of the right omitted portion on the drawing is 125.8 cm, the dimension of the left omitted portion on the drawing is 133.1 cm, and the dimension of the entire length direction (Z-axis direction) of the guidewire 100 on the drawing is 282.6 cm. In addition, in column D of FIG. 5, of the two omitted portions, the dimension of the left omitted portion on the drawing is 125.8 cm, the dimension of the right omitted portion on the drawing is 133.1 cm, and the dimension of the entire length direction (Z-axis direction) of the guidewire 100 on the drawing is 282.6 cm. In addition, in columns A to E of FIG. 5, the part indicated by a solid line is the base end coil body 20 of the guidewire 100, which is the part for which design registration is sought as a partial design. In addition, in columns A to D of FIG. 5, partial enlarged views of each part are also shown.

[0053] B. Second embodiment: 6 and 7 are explanatory diagrams showing the arrangement of the welded portion 50 in the guidewire 100a of the second embodiment. In the following, among the configurations of the guidewire 100a of the second embodiment, the same configurations as those of the guidewire 100 of the first embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. Column A of FIG. 6 shows a schematic view of the external configuration of the guidewire 100a as viewed from above (0° direction), column B of FIG. 6 shows a schematic view of the external configuration of the guidewire 100a as viewed from the front direction (90° direction), column C of FIG. 6 shows a schematic view of the external configuration of the guidewire 100a as viewed from below (180° direction), and column D of FIG. 6 shows a schematic view of the external configuration of the guidewire 100a as viewed from the rear direction (270° direction). Also, section A of Fig. 7 shows a schematic configuration of a cross section (XY cross section) of guidewire 100a at a position VIIA-VIIA in section B of Fig. 6, section B of Fig. 7 shows a schematic configuration of a cross section (XY cross section) of guidewire 100a at a position VIIB-VIIB in section B of Fig. 6, and section C of Fig. 7 shows a schematic configuration of a cross section (XY cross section) of guidewire 100a at a position VIIC-VIIC in section B of Fig. 6. Note that sections A to C of Fig. 7 omit detailed illustration of the configuration of guidewire 100a other than welded portion 50.

[0054] The guidewire 100a of the second embodiment differs from the guidewire 100 of the first embodiment in the arrangement of the welded portions 50. That is, as shown in Fig. 6 and Fig. 7, in the guidewire 100a of the second embodiment, a plurality of specific axial positions Pa are set within a specific range Rx, which are arranged at equal intervals along the axial direction, similar to the guidewire 100 of the first embodiment. However, in the guidewire 100a of the second embodiment, two welded portions 50 are formed at each specific axial position Pa. As shown in Fig. 7, in each specific axial position Pa, the formation positions of the two welded portions 50 are arranged at equal intervals (180° apart) along the circumferential direction.

[0055] In the guidewire 100a of the second embodiment, the circumferential position Pb of the welded portion 50 at one particular axial position Pa is different from the circumferential position Pb of the welded portion 50 at another particular axial position Pa. More specifically, the circumferential positions Pb11 and Pb12 of the two welded portions 50 at the particular axial position Pa whose cross section is shown in section A of Fig. 7 are 0° and 180°, respectively, the circumferential positions Pb21 and Pb22 of the two welded portions 50 at the particular axial position Pa whose cross section is shown in section B of Fig. 7 are 120° and 300°, respectively, and the circumferential positions Pb31 and Pb32 of the two welded portions 50 at the particular axial position Pa whose cross section is shown in section C of Fig. 7 are 240° and 60°, respectively. Thus, in the guide wire 100a of the second embodiment, the circumferential positions Pb (Pb11, Pb21, Pb31) of one welded portion 50 at each of the three axial specific positions Pa aligned in the axial direction are shifted from each other by 120°, and the circumferential positions Pb (Pb12, Pb22, Pb32) of the other welded portion 50 are also shifted from each other by 120°.

[0056] 6, in the guidewire 100a of the second embodiment, combinations (unit combinations U0) of three axially consecutive specific positions Pa, in which the patterns of the circumferential positions Pb of the one and the other welded portions 50 at each specific axial position Pa are the specific patterns described above (a pattern of 0° position, 120° position, and 240° position, and a pattern of 180° position, 300° position, and 60° position), are repeatedly arranged along the axial direction. That is, when one of the welded portions 50 at each specific axial position Pa is focused on, the circumferential positions Pb of the welded portions 50 at each specific axial position Pa are arranged in a regular pattern, such as 0° position, 120° position, 240° position, 0° position, 120° position, 240° position, . . . in order from the position closest to the base end of the guidewire 100a. Similarly, when attention is paid to the other welded portion 50 at each specific axial position Pa, the circumferential positions Pb of the welded portion 50 at each specific axial position Pa, in order from the position closest to the base end of the guidewire 100a, are in a regular pattern such as a 180° position, a 300° position, a 60° position, a 180° position, a 300° position, a 60° position, ... The unit combination U0 in this embodiment is an example of a second combination in the claims.

[0057] The method of forming each welded portion 50 in the guide wire 100a of the second embodiment is, for example, as follows. That is, a workpiece is prepared in which the base end coil body 20 and the core shaft 10 are joined by the base end joint portion 44 and the intermediate joint portion 46. This workpiece is rotated in the circumferential direction at a constant speed while moving in the axial direction at a constant speed, and a laser beam is irradiated to the workpiece at a constant time interval from a laser welder installed at a predetermined position. By irradiating the workpiece with the laser beam, the base end coil body 20 and the core shaft 10 as the base material are heated and melted, and then solidified to become the welded portion 50. Through the above process, one of the welded portions 50 at each specific axial position Pa is formed. Then, the workpiece is moved in the opposite direction to the axial direction at a constant speed while rotating in the circumferential direction at a constant speed, and a laser beam is irradiated to the workpiece at a constant time interval from a laser welder installed at a predetermined position. By irradiating the workpiece with the laser light, the base material, that is, the base end coil body 20 and the core shaft 10, are heated and melted, and then solidify to become the welded portion 50. Through the above steps, the other welded portion 50 at each specific axial position Pa is formed, and as a result, two welded portions 50 are formed at each specific axial position Pa.

[0058] As described above, in the guidewire 100a of the second embodiment, similarly to the guidewire 100 of the first embodiment, the base-end coil body 20 is joined to the core shaft 10 by welding at a specific axial position Pa, which is at least one position within the specific range Rx (a welded portion 50 is formed to join the base-end coil body 20 and the core shaft 10). Therefore, similarly to the guidewire 100 of the first embodiment, the guidewire 100a of the second embodiment can improve torque transmissibility while preventing the rigidity of the base-end portion of the guidewire 100a from becoming excessively high.

[0059] Furthermore, in the guidewire 100a of the second embodiment, similarly to the guidewire 100 of the first embodiment, a plurality of specific axial positions Pa are present within the specific range Rx, and therefore the presence of a plurality of welds 50 can effectively improve torque transmissibility. Furthermore, in the guidewire 100a of the second embodiment, similarly to the guidewire 100 of the first embodiment, a plurality of specific axial positions Pa are arranged at equal intervals along the axial direction of the core shaft 10, and therefore the welded portions between the base-end coil body 20 and the core shaft 10 can be arranged in a balanced manner along the axial direction, and torque transmissibility can be further effectively improved.

[0060] Moreover, in the guidewire 100a of the second embodiment, at each specific axial position Pa, the base coil body 20 is joined to the core shaft 10 by welding at a plurality of mutually different positions along the circumferential direction. Therefore, according to the guidewire 100a of the second embodiment, the presence of a plurality of welded parts 50 at each specific axial position Pa can effectively improve torque transmissibility. Furthermore, in the guidewire 100a of the second embodiment, the circumferential positions Pb of the welded parts 50 at each specific axial position Pa are arranged at equal intervals along the circumferential direction. Therefore, according to the guidewire 100a of the second embodiment, the welded parts between the base coil body 20 and the core shaft 10 can be arranged in a well-balanced manner along the circumferential direction at each specific axial position Pa, and torque transmissibility can be further effectively improved.

[0061] As described below, the guidewire 100a of the second embodiment has a similar configuration to the guidewire 100 of the first embodiment, and therefore provides the same effects as those provided by the guidewire 100 of the first embodiment. That is, in the guidewire 100a of the second embodiment, the circumferential position Pb of the welded portion 50 at one specific axial position Pa is different from the circumferential position Pb of the welded portion 50 at another specific axial position Pa, so that the welded portions of the base-end coil body 20 and the core shaft 10 can be arranged in a well-balanced manner along the circumferential direction, and torque transmissibility can be further effectively improved. Furthermore, in the guidewire 100a of the second embodiment, a plurality of unit combinations U0 of a plurality of specific axial positions Pa that are successive along the axial direction, where the pattern of the circumferential positions Pb of the welds 50 at each of the specific axial positions Pa is a specific pattern, are lined up along the axial direction. Therefore, the welds between the base-end coil body 20 and the core shaft 10 can be arranged in a balanced manner along the circumferential direction over the entire specific range Rx of the guidewire 100a, and torque transmissibility can be further effectively improved. Furthermore, for each of the two welds 50 at each of the specific axial positions Pa, there is no need to stop the axial movement of the workpiece during laser welding to form the welds 50. This shortens the time required to form the welds 50, and makes it possible to efficiently manufacture the guidewire 100a. Furthermore, in the guidewire 100a of the second embodiment, for the multiple axial specific positions Pa that constitute the unit combination U0, the amount of positional deviation of one and the other welded portions 50 at any two adjacent axial specific positions Pa along the axial direction is equal to each other (i.e., 120°). Therefore, the welded points between the base end coil body 20 and the core shaft 10 can be arranged in an extremely balanced manner along the circumferential direction over the entire specific range Rx of the guidewire 100a, and torque transmissibility can be improved extremely effectively.In addition, in the guide wire 100a of the second embodiment, the joining means between the base end coil body 20 and the core shaft 10 at the base end position of the core shaft 10 and the intermediate position Z1 is brazing, so that by adopting brazing joining at the base end position of the core shaft 10 and the intermediate position Z1, melting of the base material can be suppressed, and at each specific axial position Pa, by adopting welding joining, a high-strength joint can be realized.

[0062] FIG. 8 is an explanatory diagram showing the shape of the guidewire 100a of the second embodiment in detail. In column A of FIG. 8, a plan view (viewed from the 0° direction) of the guidewire 100a is shown, in column B of FIG. 8, a front view (viewed from the 90° direction) of the guidewire 100a is shown, in column C of FIG. 8, a bottom view (viewed from the 180° direction) of the guidewire 100a is shown, in column D of FIG. 8, a rear view (viewed from the 270° direction) of the guidewire 100a is shown, and in column E of FIG. 8, a left side view (viewed from the Z-axis positive direction) of the guidewire 100a is shown. Note that the right side view (viewed from the Z-axis negative direction) of the guidewire 100a is omitted because it is the same as the left side view of the guidewire 100a shown in column E of FIG. 8.

[0063] In columns A to C of FIG. 8, of the two omitted portions, the dimension of the omitted portion on the right side is 125.8 cm, the dimension of the omitted portion on the left side is 133.1 cm, and the dimension of the entire length direction (Z-axis direction) of the guidewire 100a is 282.6 cm. In column D of FIG. 8, of the two omitted portions, the dimension of the omitted portion on the left side is 125.8 cm, the dimension of the omitted portion on the right side is 133.1 cm, and the dimension of the entire length direction (Z-axis direction) of the guidewire 100 is 282.6 cm. In columns A to E of FIG. 8, the part indicated by a solid line is the base end coil body 20 of the guidewire 100a, which is the part for which design registration is sought as a partial design. In columns A to D of FIG. 8, partial enlarged views of each part are also shown.

[0064] C. Third embodiment: 9 and 10 are explanatory diagrams showing the arrangement of the welded portion 50 in the guidewire 100b of the third embodiment. In the following, among the configuration of the guidewire 100b of the third embodiment, the same configuration as that of the guidewire 100 of the first embodiment described above is denoted by the same reference numerals, and the description thereof will be omitted as appropriate. Column A of FIG. 9 shows the outline of the external configuration of the guidewire 100b as viewed from above (0° direction), column B of FIG. 9 shows the outline of the external configuration of the guidewire 100b as viewed from the front direction (90° direction), column C of FIG. 9 shows the outline of the external configuration of the guidewire 100b as viewed from below (180° direction), and column D of FIG. 9 shows the outline of the external configuration of the guidewire 100b as viewed from the rear direction (270° direction). Column A of Fig. 10 typically shows the configuration of a cross section (XY cross section) of guidewire 100b at a position XA-XA in column B of Fig. 9, column B of Fig. 10 typically shows the configuration of a cross section (XY cross section) of guidewire 100b at a position XB-XB in column B of Fig. 9, and column C of Fig. 10 typically shows the configuration of a cross section (XY cross section) of guidewire 100b at a position XC-XC in column B of Fig. 9. Note that in columns A to C of Fig. 10, detailed illustrations of the configuration of guidewire 100b other than welded portion 50 are omitted.

[0065] The guidewire 100b of the third embodiment differs from the guidewire 100 of the first embodiment in the arrangement of the welded portions 50. That is, as shown in Fig. 9 and Fig. 10, in the guidewire 100b of the third embodiment, a plurality of specific axial positions Pa are set in the specific range Rx and are arranged at equal intervals along the axial direction, similar to the guidewire 100 of the first embodiment. However, in the guidewire 100b of the third embodiment, the number of welded portions 50 formed at the specific axial positions Pa differs for each specific axial position Pa. More specifically, at the specific axial position Pa whose cross section is shown in column A of Figure 10, three welds 50 are formed whose circumferential positions Pb (Pb1, Pb2, Pb3) are 0°, 120°, and 240°, respectively, at the specific axial position Pa whose cross section is shown in column B of Figure 10, two welds 50 are formed whose circumferential positions Pb (Pb2, Pb3) are 120° and 240°, respectively, and at the specific axial position Pa whose cross section is shown in column C of Figure 10, one weld 50 is formed whose circumferential position Pb (Pb3) is 240°.

[0066] 9, in the guidewire 100b of the third embodiment, a combination of three consecutive axial specific positions Pa (hereinafter referred to as a "unit combination U0"), in which the number of welds 50 at each axial specific position Pa is the above-mentioned specific pattern (3, 2, 1 pattern), is repeatedly arranged along the axial direction. That is, starting from the position closest to the base end of the guidewire 100b, the number of welds 50 at each axial specific position Pa is a regular pattern of 3, 2, 1, 3, 2, 1, . . . The unit combination U0 in this embodiment is an example of the first combination in the claims.

[0067] The method of forming each welded portion 50 in the guide wire 100b of the third embodiment is, for example, as follows. That is, a workpiece is prepared in which the base-end coil body 20 and the core shaft 10 are joined by the base-end joint portion 44 and the intermediate joint portion 46. This workpiece is rotated in the circumferential direction at a constant speed while moving in the axial direction at a constant speed, and a laser beam is irradiated from a laser welder installed at a predetermined position to the workpiece at a time interval determined according to the number and positions of the welded portions 50 to be formed. When there are a plurality of welded portions 50 to be formed at a certain axial specific position Pa, the axial movement of the workpiece may be stopped until the irradiation of the laser beam at the axial specific position Pa is completed. By irradiating the workpiece with the laser beam, the base-end coil body 20 and the core shaft 10 as the base material are heated and melted, and then solidified to become the welded portion 50. Through the above steps, the welded portion 50 at each axial specific position Pa is formed.

[0068] As described above, in the guidewire 100b of the third embodiment, similarly to the guidewire 100 of the first embodiment, the base-side coil body 20 is joined to the core shaft 10 by welding at a specific axial position Pa, which is at least one position within the specific range Rx (a welded portion 50 is formed to join the base-side coil body 20 and the core shaft 10). Therefore, similarly to the guidewire 100 of the first embodiment, the guidewire 100b of the third embodiment can improve torque transmissibility while preventing the rigidity of the base-side portion of the guidewire 100b from becoming excessively high.

[0069] Furthermore, in the guidewire 100b of the third embodiment, similarly to the guidewire 100 of the first embodiment, a plurality of specific axial positions Pa are present within the specific range Rx, and therefore the presence of a plurality of welds 50 can effectively improve torque transmissibility. In addition, in the guidewire 100b of the third embodiment, similarly to the guidewire 100 of the first embodiment, the plurality of specific axial positions Pa are arranged at equal intervals along the axial direction of the core shaft 10, and therefore the welded portions between the base-end coil body 20 and the core shaft 10 can be arranged in a balanced manner along the axial direction, and torque transmissibility can be further effectively improved.

[0070] Furthermore, in guidewire 100b of the third embodiment, the number of welded portions 50 at one specific axial position Pa is different from the number of welded portions 50 at another specific axial position Pa. Therefore, according to guidewire 100b of the third embodiment, the operator can recognize the rotation angle of guidewire 100b from the appearance of guidewire 100b, thereby improving operability and convenience.

[0071] Furthermore, in guidewire 100b of the third embodiment, a plurality of unit combinations U0 of a plurality of specific axial positions Pa successive along the axial direction, where the pattern of the number of welds 50 at each specific axial position Pa is a specific pattern, are lined up along the axial direction. Therefore, according to guidewire 100b of the third embodiment, it is possible to make the appearance of guidewire 100b regular over the entire specific range Rx, and the operator can easily recognize the rotation angle of guidewire 100b from the appearance of guidewire 100b, thereby effectively improving operability and convenience.

[0072] As described below, the guidewire 100b of the third embodiment has a configuration similar to that of the guidewire 100 of the first and second embodiments, and therefore has the same effects as those of the guidewire 100 of the first and second embodiments. That is, in the guidewire 100b of the third embodiment, the base end coil body 20 is joined to the core shaft 10 by welding at a plurality of different positions along the circumferential direction at at least one specific axial position Pa, and the presence of the plurality of welded parts 50 can effectively improve torque transmissibility. In addition, in the guidewire 100b of the third embodiment, the joining means between the base end coil body 20 and the core shaft 10 at the base end position and the intermediate position Z1 of the core shaft 10 is brazing, so that melting of the base material can be suppressed by adopting brazing joint at the base end position and the intermediate position Z1 of the core shaft 10, and high-strength joints can be realized by adopting welding joints at each specific axial position Pa.

[0073] FIG. 11 is an explanatory diagram showing the shape of the guidewire 100b of the third embodiment in detail. In section A of FIG. 11, a plan view (viewed from the 0° direction) of the guidewire 100b is shown, in section B of FIG. 11, a front view (viewed from the 90° direction) of the guidewire 100b is shown, in section C of FIG. 11, a bottom view (viewed from the 180° direction) of the guidewire 100b is shown, in section D of FIG. 11, a rear view (viewed from the 270° direction) of the guidewire 100b is shown, and in section E of FIG. 11, a left side view (viewed from the Z-axis positive direction) of the guidewire 100b is shown. Note that the right side view (viewed from the Z-axis negative direction) of the guidewire 100b is omitted because it is the same as the left side view of the guidewire 100b shown in section E of FIG. 11.

[0074] In columns A to C of FIG. 11, of the two omitted parts, the dimension of the right omitted part on the drawing is 125.8 cm, the dimension of the left omitted part on the drawing is 133.1 cm, and the dimension of the entire length direction (Z-axis direction) of the guidewire 100b on the drawing is 282.6 cm. In addition, in column D of FIG. 11, of the two omitted parts, the dimension of the left omitted part on the drawing is 125.8 cm, the dimension of the right omitted part on the drawing is 133.1 cm, and the dimension of the entire length direction (Z-axis direction) of the guidewire 100 on the drawing is 282.6 cm. In addition, in columns A to E of FIG. 11, the part indicated by a solid line is the base end coil body 20 of the guidewire 100b, which is the part for which design registration is sought as a partial design. In addition, in columns A to D of FIG. 11, partial enlarged views of each part are also shown.

[0075] D. Fourth embodiment: 12 and 13 are explanatory diagrams showing the arrangement of the welded portion 50 in the guidewire 100c of the fourth embodiment. In the following, among the configurations of the guidewire 100c of the fourth embodiment, the same configurations as those of the guidewire 100 of the first embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. Column A of FIG. 12 shows a schematic view of the external configuration of the guidewire 100c as viewed from above (0° direction), column B of FIG. 12 shows a schematic view of the external configuration of the guidewire 100c as viewed from the front direction (90° direction), column C of FIG. 12 shows a schematic view of the external configuration of the guidewire 100c as viewed from below (180° direction), and column D of FIG. 12 shows a schematic view of the external configuration of the guidewire 100c as viewed from the rear direction (270° direction). Column A of Fig. 13 typically shows the configuration of the cross section (XY cross section) of guidewire 100c at the position XIIIA-XIIIA in column B of Fig. 12, column B of Fig. 13 typically shows the configuration of the cross section (XY cross section) of guidewire 100c at the position XIIIB-XIIIB in column B of Fig. 12, and column C of Fig. 13 typically shows the configuration of the cross section (XY cross section) of guidewire 100c at the position XIIIC-XIIIC in column B of Fig. 12. Note that in columns A to C of Fig. 13, detailed illustrations of the configuration of guidewire 100c other than welded portion 50 are omitted.

[0076] The guidewire 100c of the fourth embodiment is different from the guidewire 100 of the first embodiment in the arrangement of the welded portion 50. That is, as shown in Figs. 12 and 13, in the guidewire 100c of the fourth embodiment, a plurality of axial specific positions Pa are set in a specific range Rx at equal intervals along the axial direction, and one welded portion 50 is formed at each axial specific position Pa, as in the guidewire 100 of the first embodiment. However, in the guidewire 100c of the fourth embodiment, the circumferential positions Pb (Pb1) of the welded portions 50 at each axial specific position Pa are the same as each other (all at 0°). That is, in the guidewire 100c of the fourth embodiment, the base end coil body 20 is joined to the core shaft 10 by welding at each axial specific position Pa at the same position along the circumferential direction.

[0077] The method of forming each welded portion 50 in the guidewire 100c of the fourth embodiment is, for example, as follows. That is, a workpiece is prepared in which the base-end coil body 20 and the core shaft 10 are joined by the base-end joint portion 44 and the intermediate joint portion 46. This workpiece is moved in the axial direction at a constant speed without rotating in the circumferential direction, and a laser beam is irradiated onto the workpiece at constant time intervals from a laser welder installed at a predetermined position. By irradiating the workpiece with the laser beam, the base-end coil body 20 and the core shaft 10 as base materials are heated and melted, and then solidified to become the welded portion 50. Through the above steps, the welded portion 50 is formed at each specific axial position Pa.

[0078] As described above, in the guidewire 100c of the fourth embodiment, similarly to the guidewire 100 of the first embodiment, the base-side coil body 20 is joined to the core shaft 10 by welding at a specific axial position Pa, which is at least one position within the specific range Rx (a welded portion 50 is formed to join the base-side coil body 20 and the core shaft 10). Therefore, similarly to the guidewire 100 of the first embodiment, the guidewire 100c of the fourth embodiment can improve torque transmissibility while preventing the rigidity of the base-side portion of the guidewire 100c from becoming excessively high.

[0079] Furthermore, in the guidewire 100c of the fourth embodiment, similarly to the guidewire 100 of the first embodiment, a plurality of specific axial positions Pa are present within the specific range Rx, and therefore the presence of a plurality of welds 50 can effectively improve torque transmissibility. In addition, in the guidewire 100c of the fourth embodiment, similarly to the guidewire 100 of the first embodiment, a plurality of specific axial positions Pa are arranged at equal intervals along the axial direction of the core shaft 10, and therefore the welded portions between the base-end coil body 20 and the core shaft 10 can be arranged in a balanced manner along the axial direction, and torque transmissibility can be further effectively improved.

[0080] In the guidewire 100c of the fourth embodiment, the circumferential positions Pb of the welded portion 50 at each specific axial position Pa are the same position. Therefore, according to the guidewire 100c of the fourth embodiment, it is possible to intentionally generate a flutter every time the guidewire 100c is rotated 360° in the circumferential direction, and the operator can easily perform a specific operation of the guidewire 100c (for example, escape from a false lumen or guidance to a branch tube), thereby improving operability and convenience. In addition, since it is not necessary to stop the axial movement of the workpiece during laser welding for forming the welded portion 50 at each specific axial position Pa, it is possible to shorten the time required to form the welded portion 50, and it is possible to realize efficient manufacturing of the guidewire 100c.

[0081] As described below, the guidewire 100c of the fourth embodiment has a configuration similar to that of the guidewire 100 of the first to third embodiments, and therefore provides the same effects as those provided by the guidewire 100 of the first to third embodiments. That is, in the guidewire 100c of the fourth embodiment, the joining means between the base end coil body 20 and the core shaft 10 at the base end position of the core shaft 10 and the intermediate position Z1 is brazing, so that by employing brazing joining at the base end position of the core shaft 10 and the intermediate position Z1, melting of the base material can be suppressed, and at each specific axial position Pa, by employing welding joining, a high-strength joining can be achieved.

[0082] E. Fifth embodiment: 14 and 15 are explanatory diagrams showing the arrangement of the welded portion 50 in the guidewire 100d of the fifth embodiment. In the following, among the configuration of the guidewire 100d of the fifth embodiment, the same configuration as that of the guidewire 100 of the first embodiment described above is denoted by the same reference numerals, and the description thereof will be omitted as appropriate. Column A of FIG. 14 shows a schematic external configuration of the guidewire 100d as viewed from above (0° direction), column B of FIG. 14 shows a schematic external configuration of the guidewire 100d as viewed from the front direction (90° direction), column C of FIG. 14 shows a schematic external configuration of the guidewire 100d as viewed from below (180° direction), and column D of FIG. 14 shows a schematic external configuration of the guidewire 100d as viewed from the rear direction (270° direction). Also, section A of Fig. 15 typically shows the configuration of a cross section (XY cross section) of guidewire 100d at a position XVA-XVA in section B of Fig. 14, section B of Fig. 15 typically shows the configuration of a cross section (XY cross section) of guidewire 100d at a position XVB-XVB in section B of Fig. 14, and section C of Fig. 15 typically shows the configuration of a cross section (XY cross section) of guidewire 100d at a position XVC-XVC in section B of Fig. 14. Note that sections A to C of Fig. 15 do not show detailed configurations of guidewire 100d other than welded portion 50.

[0083] The guidewire 100d of the fifth embodiment is different from the guidewire 100 of the first embodiment in the arrangement of the welded parts 50. That is, as shown in FIG. 14 and FIG. 15, in the guidewire 100d of the fifth embodiment, a plurality of axial specific positions Pa are set in the specific range Rx, which are arranged at equal intervals along the axial direction, as in the guidewire 100 of the first embodiment. However, in the guidewire 100d of the fifth embodiment, two welded parts 50 are formed at each axial specific position Pa. In addition, in the guidewire 100d of the fifth embodiment, the combinations of the circumferential positions Pb (Pb1, Pb2) of the two welded parts 50 at each axial specific position Pa are the same as each other (all are combinations of the 0° position and the 180° position). In addition, in the guidewire 100d of the fifth embodiment, the circumferential positions Pb (Pb1, Pb2) of the welded parts 50 at each axial specific position Pa are arranged at equal intervals (180° intervals) along the circumferential direction.

[0084] The method of forming each welded portion 50 in the guide wire 100d of the fifth embodiment is, for example, as follows. That is, a workpiece is prepared in which the base end coil body 20 and the core shaft 10 are joined by the base end joint portion 44 and the intermediate joint portion 46. The workpiece is moved in the axial direction at a constant speed while the circumferential rotation is restricted, and a laser beam is irradiated from a laser welder installed at a predetermined position to the workpiece at a constant time interval. By irradiating the workpiece with the laser beam, the base end coil body 20 and the core shaft 10 as the base material are heated and melted, and then solidified to become the welded portion 50. Through the above process, one of the welded portions 50 at each specific axial position Pa is formed. After that, the workpiece is rotated 180° in the circumferential direction, and the circumferential rotation is restricted, and the workpiece is moved in the opposite direction to the axial direction at a constant speed, and the laser beam is irradiated from a laser welder installed at a predetermined position to the workpiece at a constant time interval. By irradiating the workpiece with the laser light, the base end coil body 20 and the core shaft 10 as the base material are heated and melted, and then solidified to become the welded portion 50. Through the above steps, the other welded portion 50 is formed at each axial specific position Pa, and as a result, two welded portions 50 are formed at each axial specific position Pa. Note that instead of the above method, the welded portions 50 in the guidewire 100d of the fifth embodiment may be formed by repeatedly performing, for each axial specific position Pa, the formation of two welded portions 50 at one axial specific position Pa by moving the workpiece a predetermined distance in the axial direction, irradiating the laser light a first time, rotating the workpiece 180°, and irradiating the laser light a second time.

[0085] As described above, in the guidewire 100d of the fifth embodiment, similarly to the guidewire 100 of the first embodiment, the base-side coil body 20 is joined to the core shaft 10 by welding at a specific axial position Pa, which is at least one position within the specific range Rx (a welded portion 50 is formed to join the base-side coil body 20 and the core shaft 10). Therefore, similarly to the guidewire 100 of the first embodiment, the guidewire 100d of the fifth embodiment can improve torque transmissibility while preventing the rigidity of the base-side portion of the guidewire 100d from becoming excessively high.

[0086] Furthermore, in the guidewire 100d of the fifth embodiment, similarly to the guidewire 100 of the first embodiment, a plurality of specific axial positions Pa are present within the specific range Rx, and therefore the presence of a plurality of welds 50 can effectively improve torque transmissibility. Furthermore, in the guidewire 100d of the fifth embodiment, similarly to the guidewire 100 of the first embodiment, the plurality of specific axial positions Pa are arranged at equal intervals along the axial direction of the core shaft 10, and therefore the welded portions between the base-end coil body 20 and the core shaft 10 can be arranged in a balanced manner along the axial direction, and torque transmissibility can be further effectively improved.

[0087] As described below, the guidewire 100d of the fifth embodiment has a similar configuration to the guidewire 100 of the first to fourth embodiments, and therefore has the same effects as those of the guidewire 100 of the first to fourth embodiments. That is, in the guidewire 100d of the fifth embodiment, the base coil body 20 is joined to the core shaft 10 by welding at a plurality of different positions along the circumferential direction at each specific axial position Pa, and therefore the presence of a plurality of welded parts 50 at each specific axial position Pa can effectively improve torque transmissibility. In addition, in the guidewire 100d of the fifth embodiment, the circumferential positions Pb of the welded parts 50 at each specific axial position Pa are arranged at equal intervals along the circumferential direction, and therefore the welded parts between the base coil body 20 and the core shaft 10 can be arranged in a well-balanced manner along the circumferential direction at each specific axial position Pa, and therefore the torque transmissibility can be further effectively improved. In addition, in the guidewire 100d of the fifth embodiment, the joining means between the base end coil body 20 and the core shaft 10 at the base end position of the core shaft 10 and the intermediate position Z1 is brazing, so that by adopting brazing joining at the base end position of the core shaft 10 and the intermediate position Z1, melting of the base material can be suppressed, and at each specific axial position Pa, by adopting welding joining, a high-strength joint can be realized.

[0088] F. Sixth embodiment: 16 and 17 are explanatory diagrams showing the arrangement of the welded portion 50 in the guidewire 100e of the sixth embodiment. In the following, among the configuration of the guidewire 100e of the sixth embodiment, the same configuration as that of the guidewire 100 of the first embodiment described above is denoted by the same reference numerals, and the description thereof will be omitted as appropriate. Column A of FIG. 16 shows a schematic external configuration of the guidewire 100e as viewed from above (0° direction), column B of FIG. 16 shows a schematic external configuration of the guidewire 100e as viewed from the front direction (90° direction), column C of FIG. 16 shows a schematic external configuration of the guidewire 100e as viewed from below (180° direction), and column D of FIG. 16 shows a schematic external configuration of the guidewire 100e as viewed from the rear direction (270° direction). Column A of Fig. 17 typically shows the configuration of a cross section (XY cross section) of guidewire 100e at a position XVIIA-XVIIA in column B of Fig. 16, column B of Fig. 17 typically shows the configuration of a cross section (XY cross section) of guidewire 100e at a position XVIIB-XVIIB in column B of Fig. 16, and column C of Fig. 17 typically shows the configuration of a cross section (XY cross section) of guidewire 100e at a position XVIIC-XVIIC in column B of Fig. 16. Note that in columns A to C of Fig. 17, detailed illustrations of the configuration of guidewire 100e other than welded portion 50 are omitted.

[0089] The guidewire 100e of the sixth embodiment is different from the guidewire 100 of the first embodiment in the arrangement of the welded portion 50. That is, as shown in Figs. 16 and 17, in the guidewire 100e of the sixth embodiment, a plurality of axial specific positions Pa are set in the specific range Rx at equal intervals along the axial direction, and one welded portion 50 is formed at each axial specific position Pa, as in the guidewire 100 of the first embodiment. However, in the guidewire 100e of the sixth embodiment, the base end coil body 20 is joined to the core shaft 10 by welding over the entire circumference along the circumferential direction at each axial specific position Pa. That is, each welded portion 50 is formed so as to constitute the entire outer circumference of the guidewire 100e in the XY cross section.

[0090] The method of forming each welded portion 50 in the guide wire 100e of the sixth embodiment is, for example, as follows. That is, a workpiece is prepared in which the base-end coil body 20 and the core shaft 10 are joined by the base-end joint portion 44 and the intermediate joint portion 46. The workpiece is moved a predetermined distance in the axial direction, and while rotating the workpiece 360° in the circumferential direction, a laser beam is irradiated onto the workpiece from a laser welder installed at a predetermined position. Thereafter, the workpiece is moved a predetermined distance in the axial direction, and while rotating the workpiece 360° in the circumferential direction, a laser beam is irradiated onto the workpiece from a laser welder installed at a predetermined position. By repeatedly performing such a process as many times as the number of specific axial positions Pa, the welded portion 50 at each specific axial position Pa is formed.

[0091] As described above, in the guidewire 100e of the sixth embodiment, similarly to the guidewire 100 of the first embodiment, the base-side coil body 20 is joined to the core shaft 10 by welding at a specific axial position Pa, which is at least one position within the specific range Rx (a welded portion 50 is formed to join the base-side coil body 20 and the core shaft 10). Therefore, similarly to the guidewire 100 of the first embodiment, the guidewire 100e of the sixth embodiment can improve torque transmissibility while preventing the rigidity of the base-side portion of the guidewire 100e from becoming excessively high.

[0092] Furthermore, in the guidewire 100e of the sixth embodiment, similarly to the guidewire 100 of the first embodiment, a plurality of specific axial positions Pa are present within the specific range Rx, and therefore the presence of a plurality of welds 50 can effectively improve torque transmissibility. Furthermore, in the guidewire 100e of the sixth embodiment, similarly to the guidewire 100 of the first embodiment, a plurality of specific axial positions Pa are arranged at equal intervals along the axial direction of the core shaft 10, and therefore the welded portions between the base-end coil body 20 and the core shaft 10 can be arranged in a balanced manner along the axial direction, and torque transmissibility can be further effectively improved.

[0093] Moreover, in the guidewire 100e of the sixth embodiment, the base-end coil body 20 is joined to the core shaft 10 by welding over the entire circumference in the circumferential direction at each specific axial position Pa. Therefore, according to the guidewire 100e of the sixth embodiment, it is possible to increase the welding strength at each location, and effectively improve torque transmissibility. Also, the operator can easily recognize the insertion length of the guidewire 100e by the appearance and / or touch of the guidewire 100e, and operability and convenience can be improved.

[0094] As described below, the guidewire 100e of the sixth embodiment has a configuration similar to that of the guidewire 100 of the first to fifth embodiments, and therefore provides the same effects as those provided by the guidewire 100 of the first to fifth embodiments. That is, in the guidewire 100e of the sixth embodiment, the joining means between the base end coil body 20 and the core shaft 10 at the base end position of the core shaft 10 and the intermediate position Z1 is brazing, so that by employing brazing joining at the base end position of the core shaft 10 and the intermediate position Z1, melting of the base material can be suppressed, and at each specific axial position Pa, by employing welding joining, a high-strength joining can be achieved.

[0095] G. Variations: The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0096] The configuration of the guidewire in each of the above embodiments is merely an example, and various modifications are possible. For example, in each of the above embodiments, the multiple axial specific positions Pa are arranged at equal intervals along the axial direction, but the multiple axial specific positions Pa may be arranged at non-equidistant intervals along the axial direction. For example, the distance between two axial specific positions Pa adjacent to each other in the axial direction may be gradually increased from the base end side to 20 mm, 30 mm, 40 mm, etc., or may be gradually decreased from the base end side to 300 mm, 290 mm, 280 mm, etc. Alternatively, the distance between two axial specific positions Pa adjacent to each other in the axial direction may be configured to repeat a specific pattern such as 20 mm, 30 mm, 40 mm, 20 mm, 30 mm, 40 mm, etc., from the base end side.

[0097] In addition, in each of the above embodiments, multiple specific axial positions Pa (i.e., positions where the welded portion 50 is formed) are set on the guidewire 100, but only one specific axial position Pa may be set on the guidewire 100.

[0098] In each of the above embodiments, the base-end coil body 20 and the tip-end coil body 30 may be configured as an integrated coil body. In this case, for example, the welded portion 50 may be formed in a portion of the coil body on the base end side (a portion corresponding to the base-end coil body 20).

[0099] In addition, in each of the above embodiments, a welded portion 50 is formed by welding to join the base-end coil body 20 and the core shaft 10. In addition, a laser beam may be irradiated to melt only the base-end coil body 20, forming a molten portion for marking to facilitate the operator's understanding of the rotation angle and insertion length.

[0100] Furthermore, in each of the above embodiments, the base-end coil body 20 and the tip-side coil body 30 are configured with densely wound strands of wire, but the base-end coil body 20 and / or the tip-side coil body 30 may be configured with loosely wound strands of wire. Furthermore, in each of the above embodiments, the base-end coil body 20 and the tip-side coil body 30 are configured with a hollow cylindrical shape formed by spirally winding a single strand of wire, but the base-end coil body 20 and / or the tip-side coil body 30 may be configured with a hollow cylindrical shape formed by spirally winding a plurality of strands of wire, a hollow cylindrical shape formed by spirally winding a single stranded wire formed by twisting a plurality of strands of wire, or a hollow cylindrical shape formed by spirally winding a plurality of stranded wires formed by twisting a plurality of strands of wire.

[0101] In addition, in each of the above embodiments, the core shaft 10 is composed of a thin diameter portion 11, a tapered portion 12, and a thick diameter portion 13, but the core shaft 10 may not have at least one of these three portions, or may have other portions in addition to the three portions.

[0102] Moreover, the materials of the members in each of the above-mentioned embodiments are merely examples and can be modified in various ways. Moreover, the manufacturing method of the guidewire in each of the above-mentioned embodiments is merely examples and can be modified in various ways. For example, in each of the above-mentioned embodiments, the base-end coil body 20 and the core shaft 10 are joined at the base-end joint 44 and the intermediate joint 46, and then the base-end coil body 20 and the core shaft 10 are welded together. However, the base-end joint 44 and the intermediate joint 46 may be formed after the base-end coil body 20 and the core shaft 10 are welded together. Alternatively, the base-end coil body 20 and the core shaft 10 may be welded together while the base-end coil body 20 is being wound around the core shaft 10. [Explanation of symbols]

[0103] 10: Core shaft 11: Small diameter section 12: Tapered section 13: Large diameter section 20: Base end coil body 30: Distal end coil body 42: Distal end joint 44: Base end joint 46: Intermediate joint 50: Welded section 100: Guide wire Pa: Specific axial position Pb: Circumferential position Rx: Specific range U0: Unit combination Z1: Intermediate position

Claims

1. A guidewire comprising: A core shaft; a coil body wound around at least a portion of the core shaft on the base end side; Equipped with At a specific axial position, which is at least one position within a range from a base end of the coil body to a tip end of the coil body along an axial direction of the guide wire, the coil body is joined to the core shaft at only a single portion or at multiple portions along a circumferential direction of the guide wire, There are a plurality of specific axial positions, The coil body is joined to the core shaft by welding at at least one specific axial position, A guidewire, wherein a position of a welded point along a circumferential direction of the guidewire at one of the specific axial positions is different from a position of a welded point along a circumferential direction of the guidewire at another of the specific axial positions.

2. 2. The guidewire of claim 1, A guidewire, wherein the plurality of specific axial positions are arranged at equal intervals along the axial direction of the guidewire.

3. The guidewire according to claim 1 or 2, A guidewire, wherein, at at least one of the specific axial positions, the coil body is joined to the core shaft by welding at a plurality of portions along a circumferential direction of the guidewire.

4. 4. The guidewire of claim 3, The multiple circumferential portions of the guidewire are arranged at equal intervals along the circumferential direction of the guidewire.

5. The guidewire according to claim 3 or 4, A guidewire, wherein the number of welded points at one of the specific axial positions is different from the number of welded points at other specific axial positions.

6. 6. The guidewire of claim 5, A guidewire comprising a first combination of a plurality of the specific axial positions that are consecutive along the axial direction of the guidewire, wherein a plurality of combinations, each of which has a specific pattern of the number of welding points at the specific axial positions, are arranged along the axial direction of the guidewire.

7. A guidewire according to any one of claims 1 to 6, A guidewire comprising a second combination of a plurality of the specific axial positions that are consecutive along the axial direction of the guidewire, wherein a plurality of combinations, each of which has a specific pattern of positions of welding points along the circumferential direction of the guidewire at each of the specific axial positions, are arranged along the axial direction of the guidewire.

8. 8. The guidewire of claim 7, A guidewire, wherein for the multiple axial specific positions that make up the second combination, the amount of shift in the position of the welded point along the circumferential direction of the guidewire at any two of the axial specific positions that are adjacent along the axial direction of the guidewire are equal to each other.

9. A guidewire according to any one of claims 1 to 8, A guidewire, wherein a tip of the coil body is joined to the core shaft by a predetermined joining means at a position between the base end and tip end of the core shaft.

10. A guidewire according to any one of claims 1 to 9, A guidewire, wherein a base end of the coil body is joined to the core shaft at a base end position of the core shaft by a predetermined joining means.

11. The guidewire according to claim 9 or 10, A guidewire, wherein the predetermined joining means is brazing.

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