Guide wire

Abstract

Provided is a guidewire in which a distal-end-side core and a proximal-end-side core are connected by a tubular connection member, the guidewire being capable of improving the ability to pass through a curved section of a blood vessel and suppressing a load on the blood vessel and damage to the blood vessel. At least one of a base end tapered section (112a) of the first core section (11) and a tip tapered section (122b) of the second core section (12) has a continuous tapered section (13). The continuous tapered portion includes, in the long axis direction, a first connecting tapered portion (13a) disposed closest to the base end of the first core portion or the tip of the second core portion, and a second connecting tapered portion (13b) disposed adjacent to the first connecting tapered portion on the side farther from the base end of the first core portion or the tip of the second core portion and having an inclination angle (theta) different from that of the first connecting tapered portion. In addition, the continuous tapered section has a fitting section (60) in which the outer surface of the first connecting tapered section and the inner surface of the end section of the connecting member (50) are fitted.

Description

[0001] This application is a divisional application of the invention patent application of Chinese Patent Application No. 202180071128.5, entered into the Chinese State stage on April 18, 2023, international application date on November 10, 2021, PCT international application number PCT / JP2021 / 041324, and invention name "Guide wire". TECHNICAL FIELD

[0002] The present application relates to a guide wire. BACKGROUND

[0003] A guide wire is a medical instrument used to guide various catheters for performing treatment of a stenosis portion generated intravascularly to the stenosis portion.

[0004] A guide wire needs to advance in a complicated curved portion and a branch portion of a blood vessel and pass through a stenosis portion. Therefore, it is sought that the guide wire is low in bending rigidity on the side (distal end side) inserted into the blood vessel for improving blood vessel selectivity and safety, and high in bending rigidity on the side (proximal end side) operated by an operator for ensuring pushability and torque transmissibility. Therefore, a guide wire using a core member in which core portions having different outer diameters and material properties are connected to each other so that the distal end side and the proximal end side have different properties is known.

[0005] In the following Patent Literature 1, a guide wire in which a core portion on the distal end side and a core portion on the proximal end side are connected by inserting small diameter portions respectively provided on the core portions into inner cavities of a tubular connection member is disclosed.

[0006] PRIOR ART DOCUMENTS

[0007] PATENT LITERATURE

[0008] Patent Literature 1: WO2006 / 002199 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] When a guide wire passes through a curved portion of a blood vessel, the guide wire is bent in such a manner as to be pressed to an inner wall on the outside of the curved portion of the blood vessel, and moves while contacting the inner surface of the blood vessel. At this time, if the radius of curvature of the bent guide wire is large, the contact area of the guide wire with the inner surface of the blood vessel becomes large. Therefore, the passage of the guide wire at the curved portion of the blood vessel decreases, and the load on the blood vessel increases. Especially, for a guide wire using a core member in which core portions are connected to each other using a tubular connection member, in a case where the end portion of the connection member has a step corresponding to the wall thickness of the connection member, there is a concern that the blood vessel is damaged due to the end portion of the connection member contacting the inner surface of the blood vessel.

[0011] At least one embodiment of the present application was made in view of the above circumstances, and specifically, to provide a guide wire in which passability at a curved portion of a blood vessel is improved and a load on the blood vessel and damage to the blood vessel are suppressed in a guide wire in which a proximal end side core portion and a base end side core portion are connected by a tubular connection member.

[0012] Means for solving the problem

[0013] The guide wire of the present embodiment is a guide wire in which a base end portion of a first core portion and a proximal end portion of a second core portion disposed on a base end side of the first core portion are connected by a tubular connection member, in which the base end portion of the first core portion has a base end taper portion in which an outer diameter gradually decreases toward a base end, the proximal end portion of the second core portion has a proximal end taper portion in which an outer diameter gradually decreases toward a proximal end, and at least one of the base end taper portion and the proximal end taper portion has a continuous taper portion including a first connection taper portion disposed at a position closest to the base end of the first core portion or the proximal end of the second core portion and a second connection taper portion disposed adjacent to a side farther from the base end of the first core portion or the proximal end of the second core portion than the first connection taper portion and having a different inclination angle from the first connection taper portion, in a longitudinal direction of the guide wire, and the continuous taper portion has an engagement portion in which an outer surface of the first connection taper portion and an inner surface of an end portion of the connection member are engaged.

[0014] Effects of the Invention

[0015] According to one embodiment of the present application, rigidity in the longitudinal direction of the guide wire changes at a boundary position of the first connection taper portion and the second connection taper portion forming the continuous taper portion. Thereby, a radius of curvature of the guide wire when passing through the curved portion of the blood vessel becomes small, and thus a contact area of the guide wire with the inner surface of the blood vessel can be reduced. Therefore, the passability of the guide wire at the curved portion of the blood vessel is improved, and a load on the blood vessel is reduced. In addition, the opportunity for the end portion of the connection member of the guide wire to contact the inner surface of the blood vessel is reduced, and thus even in a case where the end portion of the connection member has a step equivalent to the wall thickness of the connection member, damage to the blood vessel can be suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a schematic plan view of the guide wire of the present embodiment.

[0017] Figure 2 is a partial cross-sectional view of the guide wire of the present embodiment in the longitudinal direction as viewed in the thickness direction.

[0018] Figure 3 is a schematic cross-sectional view of the vicinity of the connection member of the guide wire of the present embodiment.

[0019] Figure 4Fig. 10 is a schematic partial cross-sectional view of a connection portion of a first core portion of a guide wire of the present embodiment and a connection member.

[0020] Figure 5 Fig. 11 is a schematic partial cross-sectional view of a connection portion of a second core portion of a guide wire of the present embodiment and a connection member.

[0021] Figure 6 Fig. 12 is a view schematically showing an example of a bent shape of a guide wire when the guide wire is inserted into a passage of a test device.

[0022] BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 10: core member,

[0024] 11: first core portion (11a: first connection portion, 11b: first outer diameter constant portion, 11c: first tapered portion, 11d: second outer diameter constant portion, 11e: second tapered portion, 11f: transition portion, 11g: flat plate portion, 111a: base end connection outer diameter constant portion, 112a: base end tapered portion),

[0025] 12: second core portion (12a: base portion, 12b: second connection portion, 121b: front end connection outer diameter constant portion, 122b: front end tapered portion),

[0026] 13: continuous tapered portion (13a: first connection tapered portion, 13b: second connection tapered portion),

[0027] 14: extension portion,

[0028] 20: lumen,

[0029] 21: first coil,

[0030] 22: second coil,

[0031] 30: fixed portion,

[0032] 31: front end fixed portion,

[0033] 32: intermediate fixed portion,

[0034] 33: base end fixed portion,

[0035] 40: covering layer,

[0036] 41: first covering layer,

[0037] 42: second covering layer,

[0038] 43: third covering layer,

[0039] 50: connection member,

[0040] 51: inner cavity,

[0041] 60: Chimeric part,

[0042] 61: Front fitting part,

[0043] 62: Base end fitting part,

[0044] 70: Connecting and fixing part,

[0045] 71: Front-end connection fixing part,

[0046] 72: Base end connection fixing part (72a: Connection material),

[0047] 100: Guide wire,

[0048] C: Central axis. Detailed Implementation

[0049] The following is a reference to the appendix. Figure 1 The embodiments described herein are illustrated in detail to demonstrate the technical concept of the invention and are not intended to limit the invention. Furthermore, all other methods, embodiments, and techniques that can be implemented by those skilled in the art without departing from the spirit of the invention are included within the scope and spirit of the invention, and are encompassed by the technical solutions described in the claims and their equivalents.

[0050] Furthermore, the accompanying drawings in this specification are intended to facilitate easy illustration and understanding. However, the scale, aspect ratio, shape, etc., may be appropriately modified relative to the actual object and are merely examples, and do not limit the interpretation of the present invention.

[0051] In this specification, for ease of explanation, the orientation of the guidewire 100 in its natural state (extending straight without any external force) is defined. Figure 1 In this context, "major axis direction" refers to the direction in which the guidewire 100 extends, defined as the direction along the central axis C of the guidewire 100 (the left-right direction in the figure). "Radial" is defined as the direction relative to the core member 10 in an axially orthogonal section (cross-section) of the core portion with the major axis direction of the guidewire 100 as the reference axis, moving away from or approaching the core member 10. "Circumferential" is defined as the direction of rotation with the major axis direction of the core member 10 as the reference axis. For "thickness direction," when the guidewire 100 has a flat plate portion 11g at its front end, it is defined as the direction in which the short side of the rectangle of the flat plate portion 11g extends when viewed in cross-section (the near-front / depth direction in the figure). For "width direction," when the guidewire 100 has a flat plate portion 11g at its front end, it is defined as the direction in which the long side of the rectangle of the flat plate portion 11g extends when viewed in cross-section (the up-down direction in the figure).

[0052] Furthermore, the side where the guidewire 100 is inserted into the blood vessel is designated as the "front end side," and the opposite side (the side held by the operator) is designated as the "base end side." Additionally, the portion extending along the long axis from the front end (the very front end) is designated as the "front end portion," and the portion extending along the long axis from the base end (the very base end) is designated as the "base end portion."

[0053] Furthermore, in the following explanations, the use of ordinal numbers such as "the first" and "the second" is for convenience only, unless otherwise specified, and does not indicate any order.

[0054] The guidewire 100 in this embodiment is a medical device inserted into a blood vessel to guide a catheter or stent used for endovascular treatment to a narrowed area. Furthermore, the guidewire 100 can also be inserted into other biological cavities (blood vessels, ureters, bile ducts, fallopian tubes, hepatic ducts, etc.) depending on the treatment purpose.

[0055] [structure]

[0056] like Figure 2 or Figure 3 As shown, the guide wire 100 of this embodiment includes: a long core member 10; a cavity 20 covering the periphery of the front end of the core member 10; a fixing portion 30 fixing the cavity 20 to the core member 10; and a covering layer 40 covering each component including the core member 10. Furthermore, the guide wire 100 includes: a connecting member 50 connecting the first core member 11 and the second core member 12; a fitting portion 60 formed when the first core member 11 or the second core member 12 is connected to the connecting member 50; and a connecting fixing portion 70 for improving the connection strength between the core member 10 and the connecting member 50. Hereinafter, each part of the guide wire 100 will be described in detail.

[0057] <Core Components>

[0058] The core component 10 has a first core 11, a second core 12 disposed on the base end side of the first core 11, and a tubular connecting member 50 connecting the first core 11 and the second core 12. The first core 11 and the second core 12 are connected by inserting the base end of the first core 11 into the front end of the connecting member 50 and inserting the front end of the second core 12 into the base end of the connecting member 50. A fitting portion 60 is formed at the contact portion between the core component 10 and the connecting member 50.

[0059] The first core portion 11 is an elongated member extending in the long axis direction toward the distal end side of the guide wire 100. The first core portion 11 has, in order from the proximal end of the first core portion 11 toward the distal end side, a first connecting portion 11a, a first outer diameter constant portion 11b, a first taper portion 11c, a second outer diameter constant portion 11d, a second taper portion 11e, a transition portion 11f, and a flat plate portion 11g, each of which is formed integrally.

[0060] The first connecting portion 11a is a site that is connected to the second connecting portion 12b of the second core portion 12 described later via the connecting member 50. The first connecting portion 11a extends from the proximal end of the first core portion 11 to the proximal end of the first outer diameter constant portion 11b by a prescribed length. The outer diameter of the first connecting portion 11a is smaller than the outer diameter of the first outer diameter constant portion 11b in the entire range of the first connecting portion 11a. The first connecting portion 11a has, in order from the proximal end of the first core portion 11 toward the distal end side, a proximal end connecting outer diameter constant portion 111a and a proximal end taper portion 112a as shown in Figs. 1 and 2. Figure 4 and Figure 4 The first connecting portion 11a has, in order from the proximal end of the first core portion 11 toward the distal end side, a proximal end connecting outer diameter constant portion 111a and a proximal end taper portion 112a. In addition, the first connecting portion 11a can have other taper portions and / or outer diameter constant portions on the basis of the proximal end taper portion 112a.

[0061] The proximal end connecting outer diameter constant portion 111a extends from the proximal end of the first core portion 11 to the proximal end of the proximal end taper portion 112a by a prescribed length. The outer diameter d1 of the proximal end connecting outer diameter constant portion 111a is substantially constant and is smaller than the inner diameter of the connecting member 50. The outer diameter d1 of the proximal end connecting outer diameter constant portion 111a is 0.2 mm to 0.6 mm. The proximal end connecting outer diameter constant portion 111a is disposed in the inner cavity 51 of the connecting member 50 as shown in Fig. 1. Figure 4

[0062] The proximal end taper portion 112a extends from the distal end of the proximal end connecting outer diameter constant portion 111a to the proximal end of the first outer diameter constant portion 11b by a prescribed length. In the guide wire 100 of the present embodiment, the proximal end taper portion 112a is a continuous taper portion 13 in which the first connecting taper portion 13a and the second connecting taper portion 13b are disposed adjacent to each other in the long axis direction in order from the distal end of the proximal end connecting outer diameter constant portion 111a toward the distal end side. The second connecting taper portion 13b is disposed adjacent to the first connecting taper portion 13a on the side farther from the proximal end of the first core portion 11 in the long axis direction. The first connecting taper portion 13a and the second connecting taper portion 13b have different inclination angles Θ. In the present specification, the "inclination angle Θ" refers to the angle formed by the center axis C or an imaginary line parallel to the center axis C and the outer surface of each taper portion in a longitudinal cross section passing through the center axis C of the guide wire 100.

[0063] ​The outer diameter of the base end of the base end tapered portion 112a is equal to the outer diameter dl of the base end connecting outer diameter constant portion 111a. The outer diameter of the front end of the base end tapered portion 112a is equal to the outer diameter of the first outer diameter constant portion 11b. Further, the number of tapered portions forming the continuous tapered portion 13 can be two or more. In addition, the base end tapered portion 112a can be a single tapered portion having one inclination angle Θ.

[0064] The continuous tapered portion 13 functioning as the base end tapered portion 112a has a stepped tapered shape in which a plurality of tapered portions having different inclination angles Θ are continuously arranged in the longitudinal direction. The outer surface of the first connecting tapered portion 13a forming the continuous tapered portion 13 has a fitting portion 60 in a portion in contact with the inner surface of the front end portion of the connecting member 50.

[0065] The first connecting tapered portion 13a extends from the front end of the base end connecting outer diameter constant portion 111a to the base end of the second connecting tapered portion 13b by a prescribed length. The first connecting tapered portion 13a has a tapered shape in which the outer diameter gradually increases toward the front end side from the base end connecting outer diameter constant portion 111a. The outer diameter of the base end of the first connecting tapered portion 13a is equal to the outer diameter dl of the base end connecting outer diameter constant portion 111a. The outer diameter d2 of the front end of the first connecting tapered portion 13a is larger than the inner diameter of the connecting member 50. Therefore, only a portion of the first connecting tapered portion 13a is inserted into the inner cavity 51 of the connecting member 50 as shown in FIG. 6. The tapered shape of the first connecting tapered portion 13a can be formed by mechanical polishing based on a grinding wheel or etching based on an acid with respect to the first core portion 11. Figure 3

[0066] The second connecting tapered portion 13b extends from the front end of the first connecting tapered portion 13a to the base end of the first outer diameter constant portion 11b by a prescribed length. The second connecting tapered portion 13b has a tapered shape in which the outer diameter gradually increases toward the front end side from the front end of the first connecting tapered portion 13a. The outer diameter of the base end of the second connecting tapered portion 13b is equal to the outer diameter d2 of the front end of the first connecting tapered portion 13a. Therefore, the second connecting tapered portion 13b is not arranged in the inner cavity 51 of the connecting member 50. The outer diameter d3 of the front end of the second connecting tapered portion 13b is equal to the outer diameter of the first outer diameter constant portion 11b. The tapered shape of the second connecting tapered portion 13b can be formed by mechanical polishing based on a grinding wheel or etching based on an acid with respect to the first core portion 11.

[0067] The first outer diameter constant portion 11b extends from the front end of the first connecting portion 11a to the base end of the first tapered portion 11c by a prescribed length. The outer diameter of the first outer diameter constant portion 11b is substantially constant and is substantially equal to the outer diameter of the base portion 12a of the second core portion 12.

[0068] ​The first tapered portion 11c extends from the front end of the first outer diameter constant portion 11b to the base end of the second outer diameter constant portion 11d by a prescribed length. The first tapered portion 11c has a tapered shape in which the outer diameter gradually decreases toward the front end side from the first outer diameter constant portion 11b. The tapered shape of the first tapered portion 11c can be formed by mechanical polishing based on a grinding wheel or etching based on an acid with respect to the first core portion 11.

[0069] The second outer diameter constant portion 11d extends from the front end of the first tapered portion 11c to the base end of the second tapered portion 11e by a prescribed length. The outer diameter of the second outer diameter constant portion 11d is substantially constant and is smaller than the outer diameter of the first outer diameter constant portion 11b.

[0070] The second tapered portion 11e extends from the front end of the second outer diameter constant portion 11d to the base end of the transition portion 11f by a prescribed length. The second tapered portion 11e has a tapered shape in which the outer diameter gradually decreases toward the transition portion 11f from the second outer diameter constant portion 11d. The tapered shape of the second tapered portion 11e can be formed by mechanical polishing based on a grinding wheel or etching based on an acid with respect to the first core portion 11.

[0071] The transition portion 11f extends from the front end of the second tapered portion 11e to the base end of the flat plate portion 11g by a prescribed length. The transition portion 11f has a wedge shape in which the thickness gradually decreases and the width gradually increases toward the flat plate portion 11g from the second tapered portion 11e. The wedge shape of the transition portion 11f can be formed by press working, which is one of cold working, with respect to the first core portion 11 having a circular cross-sectional shape. The cross-sectional shape of the transition portion 11f when viewed from a surface orthogonal to the long axis direction (when a cross section is observed) is circular at the base end side and has substantially the same outer diameter as the second tapered portion 11e, but gradually deforms from circular to rectangular as it approaches the front end side from the base end side, and is rectangular at the front end side and has substantially the same shape as the flat plate portion 11g. The front end portion of the transition portion 11f has substantially the same thickness and width as the base end portion of the flat plate portion 11g, and forms a surface continuous with the flat plate portion 11g. Further, the "thickness" of the flat plate portion 11g is set as the length of the short side of the rectangular shape when a cross section of the flat plate portion 11g is observed, and the "width" of the flat plate portion 11g is set as the length of the long side of the rectangular shape when a cross section of the flat plate portion 11g is observed.

[0072] The flat plate portion 11g extends from the front end of the transition portion 11f to the front end of the guide wire 100 by a prescribed length. The flat plate portion 11g is formed by press working the first core portion 11 having a circular cross-sectional shape. Therefore, the cross-sectional shape of the flat plate portion 11g is formed into a rectangle. The thickness of the flat plate portion 11g is substantially constant from the front end of the transition portion 11f to the front end of the flat plate portion 11g. The shape of the flat plate portion 11g as viewed in the thickness direction is formed into a rectangle with rounded corners at the front end of the flat plate portion 11g. Therefore, the width of the flat plate portion 11g is substantially constant from the front end of the transition portion 11f toward the front end side, but decreases in the portion with the rounded corners. Further, the width of the flat plate portion 11g can also be constant from the front end of the transition portion 11f to the front end of the flat plate portion 11g. The cross-sectional shape of the flat plate portion 11g is not limited to a rectangle, and can also be a rounded rectangle having an R shape at the corners.

[0073] Further, the configuration of the first core portion 11 is not limited to the above. For example, the first core portion 11 can also have a constant outer shape and a constant outer diameter from the front end to the base end.

[0074] The second core portion 12 is an elongated member that extends from the connecting member 50 toward the base end side of the guide wire 100. The second core portion 12 is provided with, in order from the base end of the second core portion 12 toward the front end side, the extension portion 14, the base portion 12a, and the second connecting portion 12b, each of which is formed integrally. Figure 5 Figure 5 As shown in FIGS. 1 and 2, the second core portion 12 is provided with, in order from the base end of the second core portion 12 toward the front end side, the extension portion 14, the base portion 12a, and the second connecting portion 12b, each of which is formed integrally.

[0075] The extension portion 14 is a site for connecting to an extension wire prepared separately in order to lengthen the overall length of the guide wire 100. The extension portion 14 extends from the base end of the base portion 12a toward the base end side of the guide wire 100 by a prescribed length. The extension portion 14 has a shape in which the outer diameter gradually decreases from the base portion 12a toward the base end side and has a plurality of curved portions. Further, the extension portion 14 can also not be provided.

[0076] The base portion 12a extends from the base end of the second connecting portion 12b to the front end of the extension portion 14 by a prescribed length. The outer diameter of the base portion 12a is substantially constant and is substantially equal to the outer diameter of the first outer diameter constant portion 11b of the first core portion 11.

[0077] The second connecting portion 12b is a site that is connected to the first connecting portion 11a of the first core portion 11 via the connecting member 50. The second connecting portion 12b extends from the front end of the second core portion 12 to the front end of the base portion 12a by a prescribed length. The outer diameter of the second connecting portion 12b is smaller than the outer diameter of the base portion 12a in the entire range of the second connecting portion 12b. The second connecting portion 12b is provided with, in order from the front end of the second core portion 12 toward the base end side, the front end connecting outer diameter constant portion 121b and the front end taper portion 122b. Further, the second connecting portion 12b can also have other taper portions and / or outer diameter constant portions on the basis of the front end taper portion 122b. ​

[0078] The front end connection outer diameter constant portion 121b extends from the front end of the second core portion 12 to the front end of the front end taper portion 122b by a prescribed length. The outer diameter of the front end connection outer diameter constant portion 121b is substantially constant and is smaller than the inner diameter of the connection member 50. In addition, the outer diameter of the front end connection outer diameter constant portion 121b is substantially equal to the outer diameter dl of the base end connection outer diameter constant portion 111a of the first core portion 11. The outer diameter of the front end connection outer diameter constant portion 121b is 0.2 mm to 0.6 mm.

[0079] The front end taper portion 122b extends from the base end of the front end connection outer diameter constant portion 121b to the front end of the base portion 12a by a prescribed length. The front end taper portion 122b has a tapered shape in which the outer diameter gradually increases toward the base end side from the front end connection outer diameter constant portion 121b. In the guide wire 100 of the present embodiment, the front end taper portion 122b is a single taper portion. The outer diameter of the front end of the front end taper portion 122b is equal to the outer diameter of the front end connection outer diameter constant portion 121b. The outer diameter of the base end of the front end taper portion 122b is equal to the outer diameter of the base portion 12a. Therefore, as shown in FIG. 1, only a portion of the front end taper portion 122b is inserted into the inner cavity 51 of the connection member 50. In addition, the front end taper portion 122b can also be a continuous taper portion 13. The outer surface of the front end taper portion 122b has a fitting portion 60 in the portion that contacts the inner surface of the base end portion of the connection member 50. Figure 2

[0080] The inclination angle Θ3 of the front end taper portion 122b of the second core portion 12 is greater than the inclination angle Θ1 of the first connection taper portion 13a of the first core portion 11 and is smaller than the inclination angle Θ2 of the second connection taper portion 13b of the first core portion 11. The inclination angle Θ3 of the front end taper portion 122b is 0.10° to 0.17°. In addition, the length of the front end taper portion 122b of the second core portion 12 is shorter than the first connection taper portion 13a of the first core portion 11 and is longer than the second connection taper portion 13b. The length of the front end taper portion 122b is 19 mm to 25 mm.

[0081] Here, specific dimensional examples of the guide wire 100 will be described. The overall length of the guide wire 100 in the long axis direction is 1000 mm to 4500 mm. The length of the first core portion 11 is 150 mm to 1000 mm. The length of the first connection portion 11a and the first outer diameter constant portion 11b taken together is 10 mm to 300 mm. The length of the first taper portion 11c is 10 mm to 100 mm. The length of the second outer diameter constant portion 11d is 10 mm to 300 mm. The length of the second taper portion 11e is 10 mm to 100 mm. The length of the transition portion 11f is 1 mm to 20 mm. The length of the flat plate portion 11g is 1 mm to 20 mm.

[0082] ​The outer diameter of the first connecting portion 11a and the first outer diameter constant portion 11b is 0.2 mm to 1 mm. The outer diameter of the first tapered portion 11c and the second outer diameter constant portion 11d is 0.1 mm to 1 mm. The outer diameter of the second tapered portion 11e is 0.05 mm to 1 mm. The thickness of the transition portion 11f is 0.01 mm to 1 mm, and the width is 0.05 mm to 1 mm. The thickness of the flat plate portion 11g is 0.01 mm to 1 mm, and the width is 0.05 mm to 1 mm.

[0083] The length of the second core portion 12 is 850 mm to 3500 mm. The outer diameter of the second core portion 12 is 0.2 mm to 1 mm.

[0084] The first core portion 11 and the second core portion 12 can be formed of a super-elastic alloy such as a Ni-Ti alloy, stainless steel such as SUS302, SUS304, SUS303, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429, SUS430F, piano wire, a cobalt alloy, and the like. In addition, the first core portion 11 is preferably formed of a material having a lower rigidity than the material of the second core portion 12. As an example, the first core portion 11 is formed of a Ni-Ti alloy, and the second core portion 12 is formed of stainless steel. Furthermore, the material forming the first core portion 11 and the second core portion 12 is not limited to the above examples. In addition, the first core portion 11 and the second core portion 12 can be formed of the same material.

[0085] 〈Tube Body〉

[0086] The tube body 20 is a member formed by winding the wire around the core member 10 in a spiral shape. In the present embodiment, the tube body 20 is formed of a first coil 21 and a second coil 22 disposed on the base end side of the first coil 21. The first coil 21 is disposed from the front end to the intermediate portion of the first core portion 11. The second coil 22 is disposed from the intermediate portion to the base end side of the first core portion 11. Furthermore, the tube body 20 can be formed of one coil. The tube body 20 can also be formed of three or more coils.

[0087] The first coil 21 surrounds the first core portion 11 of the core member 10 and is fixed to the first core portion 11. The first coil 21 is disposed coaxially with the first core portion 11. The length of the first coil 21 is 3 mm to 60 mm.

[0088] The first coil 21 is formed by winding the wire in a spiral shape such that adjacent wires have a gap therebetween. The gap between the adjacent wires of the first coil 21 is 1 μm to 10 μm. The gap between the adjacent wires of the first coil 21 is preferably set to be equal intervals.

[0089] The second coil 22 surrounds the first core portion 11 of the core member 10 and is fixed to the first core portion 11. The second coil 22 is disposed coaxially with the first core portion 11. The length of the second coil 22 is 10 mm to 400 mm.

[0090] The second coil 22 is formed as a tightly wound portion in which the wire is tightly wound in a spiral shape with no gap between adjacent wires. Alternatively, the second coil 22 can have a tightly wound portion and a loosely wound portion in which the wire is loosely wound in a spiral shape with a gap between adjacent wires. In the case of having the loosely wound portion, the tightly wound portion in the second coil 22 is located at the tip end portion and the base end portion of the second coil 22, and the loosely wound portion is located between the tightly wound portion on the tip end side and the tightly wound portion on the base end side.

[0091] The base end portion of the first coil 21 and the tip end portion of the second coil 22 are disposed in contact with each other. Alternatively, the base end portion of the first coil 21 and the tip end portion of the second coil 22 can be partially entangled with each other. In this case, the wire of the base end portion of the first coil 21 and the wire of the tip end portion of the second coil 22 are alternately arranged in the longitudinal direction. Thus, the first coil 21 and the second coil 22 are prevented from being separated from each other. The length of the base end portion of the first coil 21 and the tip end portion of the second coil 22 entangled with each other is 0.1 mm to 2 mm. The first coil 21 and the second coil 22 are wound in the same direction so as to be entangled with each other.

[0092] The outer diameter of the wire of the first coil 21 and the second coil 22 is 20 μm to 90 μm, and preferably 30 μm to 70 μm. In the present embodiment, the outer diameter of the wire forming the first coil 21 is larger than the outer diameter of the wire forming the second coil 22. Alternatively, the wire forming the first coil 21 and the second coil 22 can be a twisted wire formed of two or more wires.

[0093] The wire of the first coil 21 and the second coil 22 is not particularly limited and can be formed of a metal such as stainless steel, super-elastic alloy, cobalt-based alloy, gold, platinum, tungsten, or an alloy containing these metals. As an example, the first coil 21 is a platinum-based alloy which is softer and has higher radiopacity than the second coil 22, and the material of the second coil 22 is formed of stainless steel. The platinum-based alloy is preferably Pt-Ir, Pt-Ni, Pt-W, or the like.

[0094] The outer diameter of the first coil 21 and the second coil 22 is preferably constant from the tip end to the base end. In the present embodiment, the outer diameter of the first coil 21 is substantially equal to the outer diameter of the second coil 22. Thus, the outer diameter of the lumen 20 is substantially constant from the tip end to the base end. The outer diameter of the first coil 21 and the second coil 22 is 0.15 mm to 2 mm.

[0095] The material forming the wire, the outer diameter of the wire, the cross-sectional shape of the wire, the pitch of the wire, and the like of the wire forming the first coil 21 and the second coil 22 can be appropriately selected according to the purpose of the guide wire 100. In addition, the cross-sectional shape of the wire is preferably circular, but can be elliptical, polygonal, or the like. The center of the cross section of the wire having a cross-sectional shape other than circular can be the barycenter of the cross section of the wire.

[0096] 〈Fixed portion〉

[0097] The fixed portion 30 is a portion for fixing the tube cavity 20 to the core member 10. In the guide wire 100 of the present embodiment, the fixed portion 30 has a front end fixing portion 31 for fixing the front end of the tube cavity 20 to the core member 10, an intermediate fixing portion 32 for fixing the intermediate portion of the tube cavity 20 to the core member 10, and a base end fixing portion 33 for fixing the base end of the tube cavity 20 to the core member 10.

[0098] The material forming the fixed portion 30 is a brazing material or a soldering material. The brazing material has a gold brazing material, a silver brazing material, and the like. The soldering material has a Sn-Ag alloy-based soldering material, a Sn-Pb alloy-based soldering material, and the like. The material forming the fixed portion 30 can also be an adhesive.

[0099] The front end fixing portion 31 fixes the front end portion of the first coil 21 to the flat plate portion 11g of the first core portion 11. The front end fixing portion 31 is located at the foremost end of the guide wire 100, and the outer surface is smoothly formed in a substantially semispherical shape.

[0100] The intermediate fixing portion 32 fixes the base end portion of the first coil 21 and the front end portion of the second coil 22 to the second tapered portion 11e of the first core portion 11. The intermediate fixing portion 32 is provided in the first core portion 11 at a position at which the base end portion of the first coil 21 and the front end portion of the second coil 22 are in contact.

[0101] In a case where the base end portion of the first coil 21 and the front end portion of the second coil 22 are partially wound together and arranged, the base end portion of the first coil 21 and the front end portion of the second coil 22 can also be fixed via a cylindrical member 32a. The cylindrical member 32a is arranged between the inner peripheral surface of the tube cavity 20 and the outer peripheral surface of the core member 10. The cylindrical member 32a fixes the tube cavity 20 and the core member 10 coaxially by reducing the gap between the inner peripheral surface of the tube cavity 20 and the outer peripheral surface of the core member 10. In the guide wire 100 of the present embodiment, the outer diameter of the front end portion of the cylindrical member 32a is smaller than the outer diameter of the base end portion of the cylindrical member 32a. Thus, as shown in FIG. 1, the first coil 21 having a small inner diameter and the second coil 22 having a large inner diameter can be fixed coaxially with respect to the core member 10. The outer diameter of the front end portion of the cylindrical member 32a and the outer diameter of the base end portion of the cylindrical member 32a can be appropriately selected according to the inner diameter of the first coil 21 and the inner diameter of the second coil 22. The cylindrical member 32a can be formed of a metal or a resin material. Figure 6 ​

[0102] The base end fixing portion 33 fixes the base end portion of the second coil 22 to the second outer diameter constant portion 1 Id of the first core portion 11.

[0103] 〈Covering layer〉

[0104] The covering layer 40 includes a first covering layer 41, a second covering layer 42, and a third covering layer 43. The covering layer 40 can be formed of a material that reduces friction between the guide wire 100 and a blood vessel or a catheter. Thus, the covering layer 40 improves the operability and safety of the guide wire 100.

[0105] The first covering layer 41 covers the outer surfaces of the portions (the lumen 20, the fixing portion 30) of the first core portion 11 and a portion (the second outer diameter constant portion 1 Id) of the first core portion 11.

[0106] The second covering layer 42 covers the portion of the first core portion 11 that is located on the base end side compared to the lumen 20. The second covering layer 42 covers the outer surfaces of the base end portion (the first tapered portion 11c, the first outer diameter constant portion 1 Ib) of the first core portion 11.

[0107] The third covering layer 43 covers the outer surface of the base portion 12a of the second core portion 12.

[0108] The first connecting portion 11a of the first core portion 11, the connecting member 50, and the second connecting portion 12b of the second core portion 12 are not covered by the covering layer 40. In addition, the covering layer 40 can be provided at the portions that are not covered by the covering layer 40.

[0109] The first covering layer 41 can be formed of a low-friction material. As the low-friction material, a hydrophilic polymer, a silicone resin can be listed. The hydrophilic polymer that forms the first covering layer 41 can include a cellulose-based high molecular substance, a polyethylene oxide-based high molecular substance, a maleic anhydride-based high molecular substance (for example, a maleic anhydride copolymer such as a methyl vinyl ether-maleic anhydride copolymer), an acrylamide-based high molecular substance (for example, a polyacrylamide, a block copolymer of glycidyl methacrylate-dimethyl acrylamide), a water-soluble nylon, a polyvinyl alcohol, a polyvinylpyrrolidone, and a derivative thereof.

[0110] The second covering layer 42 and the third covering layer 43 can be formed of a low-friction material. As the low-friction material, a polyolefin such as polyethylene or polypropylene, polyvinyl chloride, a polyester (PET, PBT, or the like), a polyamide, a polyimide, a polyurethane, a polystyrene, a polycarbonate, a silicone resin, a fluororesin (PTFE, ETFE, or the like), or a composite material thereof can be listed.

[0111] Further, the materials forming the first covering layer 41, the second covering layer 42, and the third covering layer 43 are not limited to the above. The first covering layer 41, the second covering layer 42, and the third covering layer 43 can also be formed of different materials along the long axis direction of the core member 10, respectively. For example, in the first covering layer 41, the front end portion of the first core portion 11 is formed of silicone, and the base end portion of the first core portion 11 is formed of a hydrophilic polymer. In addition, the number of layers of each of the first covering layer 41, the second covering layer 42, and the third covering layer 43 can also be multiple layers. Further, any one of the first covering layer 41, the second covering layer 42, and the third covering layer 43 can also not be provided.

[0112] <Connection member>

[0113] The connection member 50 is a member that connects the base end portion of the first core portion 11 and the front end portion of the second core portion 12. The connection member 50 is a metal pipe having a prescribed length and an inner cavity 51.

[0114] The first core portion 11 is fitted to the connection member 50 by inserting and pushing the base end side of the base end tapered portion 112a of the first connection portion 11a from the front end of the connection member 50 into the inner cavity 51. The second core portion 12 is fitted to the connection member 50 by inserting and pushing the front end side of the front end tapered portion 122b of the second connection portion 12b from the base end of the connection member 50 into the inner cavity 51. Thus, the connection member 50 is capable of connecting the first core portion 11 and the second core portion 12. In a state in which the first core portion 11 and the second core portion 12 are connected via the connection member 50, the base end (base end connection outer diameter constant portion 111a) of the first core portion 11 and the front end (front end connection outer diameter constant portion 121b) of the second core portion 12 are separated within the inner cavity 51 of the connection member 50.

[0115] Before fitting, the outer diameter of the connection member 50 is substantially constant from the front end to the base end of the connection member 50, and is 0.3 mm to 0.8 mm. The inner diameter of the connection member 50 is substantially constant from the front end to the base end of the connection member 50, and is 0.2 mm to 0.6 mm. The wall thickness t of the connection member 50 is 0.03 mm to 0.10 mm. The length of the connection member 50 is 5 mm to 200 mm.

[0116] The metal forming the connection member 50 can be listed as super-elastic alloys such as stainless steel, Ni-Cr alloy, Ni-Ti alloy, Ni-Al alloy, Cu-Zn alloy, and the like. The metal forming the connection member 50 is preferably a super-elastic alloy, and more preferably a Ni-Ti alloy. Thus, kinking of the guide wire 100 at the position of the connection member 50 is difficult to occur. In addition, the connection member 50 is easily fixed to the core member 10 based on welding by being formed of the same metal as the core member 10.

[0117] <Fit portion>

[0118] The fitting portion 60 is a contact portion of the core member 10 and the connecting member 50. The fitting portion 60 has a front end fitting portion 61 which is a contact portion between the base end portion of the first core portion 11 and the front end portion of the connecting member 50, and a base end fitting portion 62 which is a contact portion between the front end portion of the second core portion 12 and the base end portion of the connecting member 50. The fitting portion 60 is formed when the first core portion 11 and the connecting member 50 are fitted and when the second core portion 12 and the connecting member 50 are fitted, so that the connection of the first core portion 11 and the connecting member 50 and the connection of the second core portion 12 and the connecting member 50 become firm.

[0119] The front end fitting portion 61 is a contact portion of the first core portion 11 and the connecting member 50. After the base end connecting outer diameter constant portion 111a and a portion of the first connecting taper portion 13a of the first core portion 11 are inserted into the inner cavity 51 of the connecting member 50 and the first connecting taper portion 13a contacts the front end portion of the connecting member 50, a prescribed fitting pressure is applied to push the first core portion 11 into the inner cavity 51 of the connecting member 50, whereby the first core portion 11 and the connecting member 50 are fitted. Thus, the front end fitting portion 61 is formed at a portion where the outer surface of the first connecting taper portion 13a of the first core portion 11 contacts the inner surface of the front end portion of the connecting member 50.

[0120] The front end fitting portion 61 preferably has a flared (bell) shape in which the connecting member 50 expands to the radial outside along the outer surface of the first connecting taper portion 13a. When fitting the first core portion 11 with the connecting member 50, by pushing the first core portion 11 into the inner cavity 51 of the connecting member 50, the front end portion of the connecting member 50 becomes a flared shape in which the connecting member 50 expands to the radial outside along the outer surface of the first connecting taper portion 13a. Therefore, the inner diameter and the outer diameter of the connecting member 50 in the front end fitting portion 61 are larger than those of the connecting member 50 before fitting. In the case where the front end portion of the connecting member 50 is not flared, only the inner surface of the front end of the connecting member 50 comes into contact with the outer surface of the first connecting taper portion 13a in the connecting member 50. Therefore, the front end fitting portion 61 is formed only in a small area near the front end of the connecting member 50. In the case where the front end portion of the connecting member 50 is flared, the area of the front end fitting portion 61 becomes larger than in the case where the front end portion of the connecting member 50 is not flared. Therefore, by making the front end fitting portion 61 flared, the first core portion 11 is firmly fitted with the connecting member 50. In addition, by making the front end fitting portion 61 flared, the guide wire 100 can suppress stress concentration at the front end of the connecting member 50 at the time of bending, and therefore it is difficult to generate kinking starting from the front end of the connecting member 50. On the other hand, in the fitting of the first core portion 11 with the connecting member 50, if the first core portion 11 is pushed too far into the inner cavity 51 of the connecting member 50, the front end portion of the connecting member 50 can be deformed and broken. Therefore, the length of the front end fitting portion 61 in the longitudinal direction is preferably 0.1 mm to 3.0 mm.

[0121] In fitting the first core portion 11 with the connecting member 50, the base end connecting constant outer diameter portion 111a of the first core portion 11 and a portion of the first connecting taper portion 13a are disposed in the inner cavity 51 of the connecting member 50. By the first connecting portion 11a of the first core portion 11 having the base end connecting constant outer diameter portion 111a, the length of the first core portion 11 disposed in the inner cavity 51 of the connecting member 50 becomes longer than in the case where the first connecting portion 11a is formed only by the base end taper portion 112a. Thus, since the separation distance of the first core portion 11 from the second core portion 12 in the inner cavity 51 of the connecting member 50 can be shortened, the core member 10 can suppress a decrease in local rigidity at the portion where the first core portion 11 and the second core portion 12 are separated in the inner cavity 51 of the connecting member 50.

[0122] The base end fitting portion 62 is a contact portion of the second core portion 12 and the connecting member 50. After a portion of the front end connection constant diameter portion 121b and the front end taper portion 122b of the second core portion 12 are inserted into the inner cavity 51 of the connecting member 50, and the front end taper portion 122b is brought into contact with the base end of the connecting member 50, a prescribed fitting pressure is applied and the second core portion 12 is pushed into the inner cavity 51 of the connecting member 50, whereby the second core portion 12 is fitted to the connecting member 50. Thus, the base end fitting portion 62 is formed at a portion where the outer surface of the front end taper portion 122b of the second core portion 12 is in contact with the inner surface of the base end portion of the connecting member 50.

[0123] The same effect as the fitting of the first core portion 11 to the connecting member 50 is obtained by providing the base end portion of the connecting member 50 in an open shape in the fitting of the second core portion 12 to the connecting member 50. The length of the base end fitting portion 62 in the long axis direction is 0.1 mm to 3.0 mm.

[0124] When the second core portion 12 is fitted to the connecting member 50, a portion of the front end connection constant diameter portion 121b and the front end taper portion 122b of the second core portion 12 is disposed in the inner cavity 51 of the connecting member 50. The length of the second core portion 12 disposed in the inner cavity 51 of the connecting member 50 is longer than when the second connecting portion 12b is formed only by the front end taper portion 122b, because the second connecting portion 12b of the second core portion 12 has the front end connection constant diameter portion 121b. Thus, the separation distance between the first core portion 11 and the second core portion 12 in the inner cavity 51 of the connecting member 50 can be shortened, and the core member 10 can suppress a decrease in local rigidity at a portion where the first core portion 11 and the second core portion 12 are separated in the inner cavity 51 of the connecting member 50.

[0125] The fitting of the first core portion 11 to the connecting member 50 and the fitting of the second core portion 12 to the connecting member 50 are performed by mechanical fitting using a fitting machine. The fitting can be performed at a fixed fitting pressure (pushing force), or the fitting pressure can be varied stepwise. Alternatively, the fitting of the first core portion 11 to the connecting member 50 and the fitting of the second core portion 12 to the connecting member 50 can be performed by hand, or a combination of hand and machine can be used.

[0126] 〈Connection fixing portion〉

[0127] The core member 10 and the connecting member 50 are fixed by a connection fixing portion 70. The connection fixing portion 70 has a front end connection fixing portion 71 that fixes the front end portion of the connecting member 50 to the first core portion 11, and a base end connection fixing portion 72 that fixes the base end portion of the connecting member 50 to the second core portion 12.

[0128] The front end connecting fixing portion 71 fixes the front end portion of the connecting member 50 to the first connecting taper portion 13a of the first core portion 11. By providing the front end connecting fixing portion 71 in addition to the front end fitting portion 61, the first core portion 11 and the connecting member 50 can be firmly connected. The front end connecting fixing portion 71 is provided at a position separated from the front end fitting portion 61 toward the base end side in the long axis direction. Thus, the fixing portions of the first core portion 11 and the connecting member 50 when viewed in the long axis direction are the front end fitting portion 61 and the front end connecting fixing portion 71, and thus the first core portion 11 and the connecting member 50 can be more firmly connected. The front end connecting fixing portion 71 is preferably provided at two positions opposite each other in the radial direction of the connecting member 50.

[0129] The front end connecting fixing portion 71 is preferably a welded portion formed by laser welding. Laser welding can fix the connecting member 50 to the first connecting taper portion 13a without changing the outer diameter of the connecting member 50, and thus can reduce the influence of the front end connecting fixing portion 71 on the function of the guide wire 100. The welded portion is substantially circular with a radius of 0.05 mm to 0.40 mm centered on the laser irradiation point P.

[0130] The outer surface of the first connecting taper portion 13a and the inner surface of the connecting member 50 are preferably separated in the radial direction at the front end side and the base end side of the front end connecting fixing portion 71. In laser welding, the metals serving as the materials to be welded are connected to each other by irradiating the metals with a prescribed laser to melt and solidify the metals. Thus, if the front end connecting fixing portion 71 is provided at the front end fitting portion 61 of the first core portion 11 and the connecting member 50 or at a position adjacent to the front end fitting portion 61, the radial distance between the first core portion 11 and the connecting member 50 is too short, and thus gas generated when the metal is melted is likely to remain in the front end connecting fixing portion 71, and pores, pits, cracks, and the like are likely to occur. Thus, the front end connecting fixing portion 71 can have a poor appearance due to unevenness on the outer surface, or the fixing strength can be insufficient. Since the first connecting taper portion 13a has an outer diameter that gradually decreases toward the base end side, the radial distance between the first core portion 11 and the connecting member 50 increases as the front end of the connecting member 50 approaches the base end side. Thus, if the front end connecting fixing portion 71 is provided at a position separated from the front end of the connecting member 50 by a distance of more than a prescribed distance, the radial distance between the first core portion 11 and the connecting member 50 becomes too long, and thus the molten metal spreads in the space between the first core portion 11 and the connecting member 50, and the outer surface is likely to be recessed. Thus, the appearance of the front end connecting fixing portion 71 can be poor. In addition, the contact area of the first core portion 11 and the connecting member 50 with the molten metal decreases, and thus the fixing strength of the front end connecting fixing portion 71 can be insufficient.

[0131] In the guide wire 100 of the present embodiment, the tip end connecting fixing portion 71 is provided at a position where the outer surface of the first connecting taper portion 13a and the inner surface of the connecting member 50 are radially separated on the tip end side and the base end side of the tip end connecting fixing portion 71. Therefore, gas generated at the time of melting of the metal also escapes from the tip end side and the base end side of the tip end connecting fixing portion 71, and it is difficult to generate pores, pits, cracks, and the like. In addition, since the molten metal moderately spreads in the space between the first core portion 11 and the connecting member 50, the outer surface of the connecting member 50 becomes smooth, and sufficient connection strength is obtained.

[0132] By forming the tip end connecting fixing portion 71 at a position where the outer surface of the first connecting taper portion 13a and the inner surface of the connecting member 50 are radially separated on the tip end side and the base end side of the tip end connecting fixing portion 71 as described above, the outer surface of the welded portion of the first core portion 11 and the connecting member 50 of the guide wire 100 becomes smooth and the connection strength is high.

[0133] The distance S in the long axis direction from the tip end of the connecting member 50 to the laser irradiation point P is preferably 2.5 mm to 4.0 mm. That is, the center of the welded portion is provided at a position 2.5 mm to 4.0 mm away from the tip end of the connecting member 50 toward the base end side in the long axis direction. Thereby, the tip end connecting fixing portion 71 (welded portion) is formed in a range of 2.0 mm to 4.5 mm from the tip end of the connecting member 50 toward the base end side in the long axis direction. In addition, the distance H in the radial direction of the outer surface of the first connecting taper portion 13a and the inner surface of the connecting member 50 at the laser irradiation point P for forming the tip end connecting fixing portion 71 is preferably 0.0005 mm to 0.0017 mm. Thereby, the tip end connecting fixing portion 71 (welded portion) is formed in a range where the distance in the radial direction of the outer surface of the first connecting taper portion 13a and the inner surface of the connecting member 50 is 0.0001 mm to 0.0021 mm. By forming the tip end connecting fixing portion 71 in the above range, the tip end portion of the connecting member 50 can be firmly connected to the first core portion 11, and can have a smooth outer surface with small irregularities.

[0134] The ratio r (r = H / t) of the distance H in the radial direction of the outer surface of the first connecting taper portion 13a at the laser irradiation point P from the inner surface of the connecting member 50 with respect to the wall thickness t of the connecting member 50 is preferably 0.01 or more and 0.05 or less, and more preferably 0.010 or more and 0.034 or less. That is, the center of the welded portion is preferably provided at a position where the ratio r is 0.01 or more and 0.05 or less, and more preferably at a position where the ratio r is 0.010 or more and 0.034 or less. By making the ratio r be the lower limit value or more, gas generated at the time of melting of the metal can be separated from the front end connecting fixing portion 71, and thus the front end connecting fixing portion 71 is less likely to generate pores, pits, cracks, and the like. In addition, by making the ratio r be the upper limit value or less, the amount of the metal melted due to laser irradiation in the front end connecting fixing portion 71 with respect to the volume of the space between the first core portion 11 and the connecting member 50 becomes sufficient, and the outer surface is less likely to generate depressions. In addition, since the contact area of the first core portion 11 and the connecting member 50 with the molten metal becomes large, the fixing strength of the front end connecting fixing portion 71 is improved. By setting the ratio r to the above range, the front end portion of the connecting member 50 can be firmly connected to the first core portion 11, and can have a smooth outer surface with small irregularities.

[0135] The base end connecting fixing portion 72 fixes the base end portion of the connecting member 50 to the front end taper portion 122b of the second core portion 12. By further providing the base end connecting fixing portion 72 on the basis of the base end fitting portion 62, the second core portion 12 and the connecting member 50 can be more firmly connected. The connecting material 72a forming the base end connecting fixing portion 72 is a brazing material or a solder material. The brazing material is a gold brazing material or a silver brazing material, or the like. The solder material is a Sn-Ag alloy-based solder, a Sn-Pb alloy-based solder, or the like. The connecting material 72a can also be an adhesive.

[0136] The base end connecting fixing portion 72 is disposed adjacent to the base end side of the base end fitting portion 62 of the second core portion 12 and the connecting member 50, and has a tapered shape in which the outer diameter gradually decreases from the base end of the connecting member 50 toward the base end side. Thus, the step in the base end of the connecting member 50, which corresponds to the wall thickness t of the connecting member 50, is small, and thus damage to the front end of the catheter when the catheter is inserted from the base end side of the guide wire 100 can be suppressed. The tapered shape of the base end connecting fixing portion 72 can be formed by mechanically polishing the outer surface of the connecting material 72a.

[0137] The guide wire 100 of the present embodiment has the continuous taper portion 13 at the base end taper portion 112a of the first core portion 11, and the continuous taper portion 13 is composed of the first connecting taper portion 13a and the second connecting taper portion 13b disposed adjacent to the first connecting taper portion 13a on the distal end side thereof and having a different inclination angle Θ from the first connecting taper portion 13a. Thus, at the boundary position between the first connecting taper portion 13a and the second connecting taper portion 13b that form the continuous taper portion 13, a rigidity change point is formed at which the rigidity of the guide wire 100 changes in the longitudinal direction thereof. In the guide wire 100, a part of the first connecting taper portion 13a on the base end side thereof in the continuous taper portion 13 is disposed in the lumen 51 of the connecting member 50, and the second connecting taper portion 13b is not disposed in the lumen 51 of the connecting member 50. Therefore, the rigidity change point is disposed on the distal end side of the guide wire 100 as compared with the distal end of the connecting member 50.

[0138] The guide wire 100 thus configured has a smaller radius of curvature from the rigidity change point based on the continuous taper portion 13 to the distal end of the connecting member 50 when bent. Therefore, the guide wire 100 having the rigidity change point on the distal end side of the distal end of the connecting member 50 due to the continuous taper portion 13 can reduce the contact area with the inner surface of the blood vessel when passing through the curved portion of the blood vessel as compared with the guide wire 100 not having the continuous taper portion 13. Therefore, the guide wire 100 improves the passability at the curved portion of the blood vessel, and reduces the load on the blood vessel. The guide wire 100 can suppress the damage to the blood vessel even in the case where the end portion of the connecting member 50 has a step corresponding to the wall thickness t of the connecting member 50, because the opportunity of the end portion of the connecting member 50 contacting the inner surface of the blood vessel is reduced.

[0139] The first core portion 11 of the guide wire 100 is formed of a super-elastic alloy, and the continuous taper portion 13 is disposed at the base end taper portion 112a of the first core portion 11. The super-elastic alloy is difficult to plastically deform. By disposing the continuous taper portion 13 at the first core portion 11 composed of a super-elastic alloy, the guide wire 100 is difficult to kink even in the case where the radius of curvature from the rigidity change point based on the continuous taper portion 13 to the distal end of the connecting member 50 is small.

[0140] In the first core portion 11, the inclination angle θ1 of the first connecting taper portion 13a that is fitted to the connecting member 50 is preferably 0.01° < θ1 < 0.05°. A part of the first connecting taper portion 13a on the proximal end side is disposed in the inner cavity 51 of the connecting member 50. As the inclination angle θ1 of the first connecting taper portion 13a decreases, the length of the first connecting taper portion 13a that is disposed in the inner cavity 51 of the connecting member 50 increases. Therefore, the first connecting taper portion 13a can shorten the separation distance between the first core portion 11 and the second core portion 12 in the inner cavity 51 of the connecting member 50 by making the inclination angle θ1 smaller than a predetermined angle. Thus, the guide wire 100 can suppress a decrease in local rigidity at the portion where the first core portion 11 and the second core portion 12 are separated in the inner cavity 51 of the connecting member 50.

[0141] When the first core portion 11 is fitted to the connecting member 50, the part of the first connecting portion 11a that is disposed in the inner cavity 51 of the connecting member 50 has a function of supporting the connecting member 50. Therefore, by making the length of the first connecting taper portion 13a that is disposed in the inner cavity 51 of the connecting member 50 longer, the connecting member 50 is less likely to be deflected by fitting pressure, and plastic deformation can be suppressed. As a result, the straightness of the guide wire 100 is improved, and the torque transmission property is improved. In addition, since the first core portion 11 and the connecting member 50 can be fitted at a high fitting pressure, the first core portion 11 and the connecting member 50 can be more firmly fitted.

[0142] Furthermore, the first connecting taper portion 13a can shorten the distance between the outer surface of the first connecting taper portion 13a at the proximal end portion of the connecting member 50 and the inner surface of the connecting member 50 by making the inclination angle θ1 smaller than the upper limit value. Thus, the proximal end portion of the connecting member 50 is effectively supported by the first connecting taper portion 13a, and damage to the connecting member 50 during fitting is suppressed. In addition, if the inclination angle θ1 of the first connecting taper portion 13a is smaller than the upper limit value, the proximal end portion of the connecting member 50 is easily deformed into the shape of the outer surface of the first connecting taper portion 13a during fitting, and thus the proximal end fitting portion 61 in the shape of a split is easily formed. On the other hand, if the inclination angle θ1 of the first connecting taper portion 13a is equal to or greater than the upper limit value, the rate of change in the outer diameter at the first connecting taper portion 13a increases. Therefore, the guide wire 100 is easily kinked because the rigidity sharply changes in the long axis direction near the boundary between the proximal end constant diameter portion 111a and the first connecting taper portion 13a. In addition, if the inclination angle θ1 of the first connecting taper portion 13a is equal to or smaller than the lower limit value, the position of the first connecting taper portion 13a and the connecting member 50 during fitting is difficult to determine, and it is difficult to form the proximal end fitting portion 61 at a desired position.

[0143] As described above, the inclination angle θ of the tapered portion fitting into the connecting member 50 (the inclination angle θ1 of the first connecting tapered portion 13a) is preferably smaller than a predetermined angle. However, if the proximal tapered portion 112a is provided as a single tapered portion with a small inclination angle θ, the guide wire 100 has a portion with a smaller outer diameter than the first outer diameter constant portion 11b existing longer on the distal end side of the connecting member 50. For the portion of the guide wire 100 with a small outer diameter, the difference between the outer diameter of the guide wire 100 and the inner diameter of the catheter becomes large, so the supportability of the guide wire 100 to the catheter decreases. In addition, the rigidity of the portion of the guide wire 100 with a small outer diameter also decreases, so the pushability of the guide wire 100 decreases.

[0144] By providing the proximal tapered portion 112a as a continuous tapered portion 13, the guide wire 100 has a portion with a small outer diameter from the distal end of the connecting member 50 to the first outer diameter constant portion 11b shorter than in the case where the proximal tapered portion 112a is provided as a single tapered portion. Thus, the guide wire 100 can suppress the decrease in supportability and pushability to the catheter. In addition, the guide wire 100 can shorten the distance between the first core portion 11 and the connecting member 50 when fitting the first outer diameter constant portion 11b holding the first core portion 11. Thus, for the first core portion 11, the insertion of the first core portion 11 into the connecting member 50 at the time of fitting becomes easy, and the possibility of breakage of the first core portion 11 and the connecting member 50 decreases. Thus, the straightness of the guide wire 100 becomes high, and the torque transmission property improves. Moreover, the first core portion 11 can increase the length of the portion covered by the second covering layer 42. Thus, the frictional resistance between the guide wire 100 and the blood vessel decreases, and the passability in the blood vessel improves.

[0145] In the continuous tapered portion 13, the inclination angle θ2 of the second connecting tapered portion 13b is larger than the inclination angle θ1 of the first connecting tapered portion 13a. Thus, the first core portion 11 can provide a rigidity change point based on the continuous tapered portion 13 while reducing the change in rigidity in the long axis direction of the first connecting portion 11a. In the case where the inclination angle θ2 of the second connecting tapered portion 13b is smaller than the inclination angle θ1 of the first connecting tapered portion 13a, the effect of shortening the length of the portion with a small outer diameter from the distal end of the connecting member 50 to the first outer diameter constant portion 11b decreases, so it is difficult to obtain the effect based on the provision of the proximal tapered portion 112a as a continuous tapered portion 13.

[0146] The inclination angle θ2 of the second connecting tapered portion 13b is preferably 0.1° < θ2 < 2.5°. Thus, since the rigidity in the long axis direction gently changes around the boundary between the first connecting tapered portion 13a and the second connecting tapered portion 13b, the guide wire 100 can suppress kinking at the proximal tapered portion 112a.

[0147] The first connecting taper portion 13a and the second connecting taper portion 13b have different lengths. The length L2 of the first connecting taper portion 13a is preferably longer than the length L3 of the second connecting taper portion 13b. The length L2 of the first connecting taper portion 13a is 25 mm to 33 mm. The length L3 of the second connecting taper portion 13b is 1 mm to 7 mm.

[0148] By setting the length L2 of the first connecting taper portion 13a to be longer than the length L3 of the second connecting taper portion 13b, the first core portion 11 can increase the length of the first connecting taper portion 13a disposed in the inner cavity 51 of the connecting member 50 and shorten the length from the front end of the connecting member 50 to the first outer diameter constant portion lib. If the length of the first connecting taper portion 13a disposed in the inner cavity 51 of the connecting member 50 is increased, the separation distance between the first core portion 11 and the second core portion 12 in the inner cavity 51 of the connecting member 50 is shortened, and thus the guide wire 100 can suppress a decrease in local rigidity at the portion where the first core portion 11 and the second core portion 12 are separated in the inner cavity 51 of the connecting member 50. In addition, since the length of the portion with a small outer diameter from the front end of the connecting member 50 to the first outer diameter constant portion lib is shortened, the guide wire 100 suppresses a decrease in supportability and pushability to the catheter.

[0149] When the first core portion 11 is fitted to the connecting member 50, the portion of the first connecting portion 11a disposed in the inner cavity 51 of the connecting member 50 has a function of supporting the connecting member 50. Therefore, by increasing the length of the first connecting taper portion 13a disposed in the inner cavity 51 of the connecting member 50, it is difficult to cause the connecting member 50 to be deflected by fitting pressure, and plastic deformation of the connecting member 50 can be suppressed. In addition, the guide wire 100 can shorten the distance between the first core portion 11 and the connecting member 50 when fitting the first outer diameter constant portion lib of the first core portion 11. Therefore, for the first core portion 11, the first core portion 11 is easily inserted into the connecting member 50 at the time of fitting, and the possibility of breakage of the first core portion 11 and the connecting member 50 is reduced. As a result, the straightness of the guide wire 100 is increased, and the torque transmission property is improved.

[0150] Furthermore, by shortening the length from the front end of the connecting member 50 to the first outer diameter constant portion lib, the first core portion 11 can increase the length of the portion covered by the second covering layer 42. Thus, the guide wire 100 has a smaller frictional resistance, and the passability in a blood vessel is improved.

[0151] [Manufacturing Method]

[0152] Next, a manufacturing method of the guide wire 100 of the present embodiment will be described. Furthermore, the following description is directed to a process of connecting the first core portion 11 and the second core portion 12 to the connecting member 50, and a description of other processes for manufacturing the guide wire 100 is omitted.

[0153] (Step 1)

[0154] Step 1 is a step of inserting the base end connecting constant outer diameter portion 111a of the first core portion 11 and a portion of the first connecting taper portion 13a of the first core portion 11 from the front end side of the connecting member 50 into the inner cavity 51 of the connecting member 50. By inserting the portion of the first connecting taper portion 13a of the first core portion 11 into the inner cavity 51 of the connecting member 50, the outer surface of the first connecting taper portion 13a of the first core portion 11 comes into contact with the inner surface of the front end portion of the connecting member 50.

[0155] (Step 2)

[0156] Step 2 is a step of fitting the first core portion 11 and the connecting member 50. In Step 2, the first core portion 11 and the connecting member 50 are moved relatively close to each other in a state where the base end connecting constant outer diameter portion 111a of the first core portion 11 and the portion of the first connecting taper portion 13a of the first core portion 11 are inserted into the inner cavity 51 of the connecting member 50 and the outer surface of the first connecting taper portion 13a of the first core portion 11 is in contact with the inner surface of the front end portion of the connecting member 50. By the relative movement of the first core portion 11 and the connecting member 50, the base end connecting constant outer diameter portion 111a of the first core portion 11 and the portion of the first connecting taper portion 13a of the first core portion 11 are pushed toward the base end side of the inner cavity 51 of the connecting member 50. In addition, when the base end connecting constant outer diameter portion 111a of the first core portion 11 and the portion of the first connecting taper portion 13a of the first core portion 11 are pushed toward the base end side of the connecting member 50, the front end portion of the connecting member 50 becomes an open shape that expands to the radial outer side in a manner along the outer surface of the first connecting taper portion 13a of the first core portion 11 by applying a prescribed fitting pressure. Thus, the front end fitting portion 61 in which the outer surface of the first connecting taper portion 13a of the first core portion 11 is fitted with the inner surface of the front end portion of the connecting member 50 can be formed at the portion where the outer surface of the first connecting taper portion 13a of the first core portion 11 is in contact with the inner surface of the front end portion of the connecting member 50. Furthermore, the work of pushing the first core portion 11 toward the connecting member 50 can be performed using a known fitting machine 200.

[0157] (Step 3)

[0158] Process 3 is a process of forming a front end connection fixing portion 71 (welding portion) that fixes the connection member 50 and the first connection taper portion 13a of the first core portion 11 by irradiating laser light to the outer surface of the connection member 50 from the radial outer side of the connection member 50. At this time, the laser light irradiation point P is set to a position that is separated by a prescribed distance from a position where the outer surface of the first connection taper portion 13a of the first core portion 11 contacts the inner surface of the front end portion of the connection member 50 toward the base end side of the connection member 50. By irradiating laser light to a position that is separated by a prescribed distance from a position where the outer surface of the first connection taper portion 13a of the first core portion 11 contacts the inner surface of the front end portion of the connection member 50 toward the base end side of the connection member 50, the front end connection fixing portion 71 can be formed at a position that is separated by a prescribed distance from the front end of the connection member 50. Further, by irradiating laser light to two positions that are diametrically opposed with respect to the connection member 50, the front end connection fixing portion 71 can be provided at the two positions. The work of irradiating laser light to the connection member 50 can be performed using a publicly known laser light irradiation device.

[0159] (Step 4)

[0160] Process 4 is a process of inserting the front end connection outer diameter constant portion 121b of the second core portion 12 and a portion of the front end taper portion 122b of the second core portion 12 into the inner cavity 51 of the connection member 50 from the base end side of the connection member 50. By inserting a portion of the front end taper portion 122b of the second core portion 12 into the inner cavity 51 of the connection member 50, the outer surface of the front end taper portion 122b of the second core portion 12 contacts the inner surface of the front end portion of the connection member 50.

[0161] (Step 5)

[0162] Step 5 is a step of fitting the second core portion 12 to the connecting member 50. In step 5, the second core portion 12 is moved relatively close to the connecting member 50 in a state where the front end connecting constant outer diameter portion 121b of the second core portion 12 and a part of the front end tapered portion 122b of the second core portion 12 are inserted into the inner cavity 51 of the connecting member 50 and the outer surface of the front end tapered portion 122b of the second core portion 12 is in contact with the inner surface of the base end portion of the connecting member 50. By relatively moving the second core portion 12 and the connecting member 50, the front end connecting constant outer diameter portion 121b of the second core portion 12 and a part of the front end tapered portion 122b of the second core portion 12 are pushed toward the front end side of the inner cavity 51 of the connecting member 50. In addition, when the front end connecting constant outer diameter portion 121b of the second core portion 12 and a part of the front end tapered portion 122b of the second core portion 12 are pushed toward the front end side of the connecting member 50, the base end portion of the connecting member 50 becomes an open shape that expands to the radial outer side in a manner along the outer surface of the front end tapered portion 122b of the second core portion 12 by applying a prescribed fitting pressure. Thus, the outer surface of the front end tapered portion 122b of the second core portion 12 and the inner surface of the base end portion of the connecting member 50 are fitted at the portion where the outer surface of the front end tapered portion 122b of the second core portion 12 is in contact with the inner surface of the base end portion of the connecting member 50, and a base end fitting portion 62 is formed. Furthermore, the operation of pushing the second core portion 12 toward the connecting member 50 can be performed using a known fitting machine 200.

[0163] (Step 6)

[0164] Step 6 is a step of forming a base end connecting fixing portion 72 that fixes the base end portion of the connecting member 50 to the front end tapered portion 122b of the second core portion 12. The base end connecting fixing portion 72 can be formed by applying a connecting material 72a to the outer surface of the front end tapered portion 122b of the second core portion 12 near the base end of the connecting member 50.

[0165] (Step 7)

[0166] Step 7 is a step of mechanically polishing the outer surface of the connecting material 72a that forms the base end connecting fixing portion 72 to a tapered shape in which the outer diameter gradually decreases from the base end of the connecting member 50 toward the base end side. Furthermore, the operation of mechanically polishing the outer surface of the connecting material 72a can be performed using a known polishing machine.

[0167] Furthermore, the guide wire 100 can be manufactured by replacing the order of steps 1 to 3 and steps 4 to 7. That is, the first core portion 11 can be connected to the connecting member 50 after the second core portion 12 is connected to the connecting member 50.

[0168] [Effects]

[0169] As explained above, the guide wire 100 of the present embodiment is a guide wire 100 in which the base end portion of the first core portion 11 having the base end taper portion 112a in which the outer diameter gradually decreases toward the base end and the front end portion of the second core portion 12 having the front end taper portion 122b in which the outer diameter gradually decreases toward the front end are connected by the tubular connecting member 50 disposed on the base end side of the first core portion 11, at least one of the base end taper portion 112a and the front end taper portion 122b has the continuous taper portion 13 in the longitudinal direction of the guide wire 100, the continuous taper portion 13 includes the first connecting taper portion 13a disposed at a position closest to the base end of the first core portion 11 or the front end of the second core portion 12 and the second connecting taper portion 13b adjacently disposed on the side farther from the base end of the first core portion 11 or the front end of the second core portion 12 than the first connecting taper portion 13a and having a different inclination angle Θ from the first connecting taper portion 13a, and the continuous taper portion 13 has the fitting portion 60 in which the outer surface of the first connecting taper portion 13a and the inner surface of the end portion of the connecting member 50 are fitted.

[0170] With such a structure, the rigidity of the guide wire 100 changes at the boundary position of the first connecting taper portion 13a and the second connecting taper portion 13b forming the continuous taper portion 13 in the longitudinal direction of the guide wire 100. Thus, the radius of curvature of the guide wire 100 when passing through the curved portion of the blood vessel becomes small, and thus the contact area of the guide wire 100 with the inner surface of the blood vessel can be reduced. Therefore, the passability of the guide wire 100 at the curved portion of the blood vessel is improved, and the load on the blood vessel is reduced. In addition, since the opportunity for the end portion of the connecting member 50 to contact the inner surface of the blood vessel is reduced, even in the case where the end portion of the connecting member 50 has a step corresponding to the wall thickness t of the connecting member 50, the damage to the blood vessel can be suppressed.

[0171] In addition, it can also be that the continuous taper portion 13 of the guide wire 100 of the present embodiment is disposed at the base end taper portion 112a of the first core portion 11, and the first core portion 11 is formed of a super-elastic alloy.

[0172] With such a structure, even in the case where the radius of curvature from the rigidity change point based on the continuous taper portion 13 to the front end of the connecting member 50 becomes small, the guide wire 100 is less likely to kink.

[0173] In addition, the guide wire 100 of the present embodiment can also be such that, in the continuous taper portion 13, the inclination angle Θ2 of the second connecting taper portion 13b is larger than the inclination angle Θ1 of the first connecting taper portion 13a.

[0174] With such a structure, the guide wire 100 can set the rigidity change point based on the continuous taper portion 13 while reducing the change in the rigidity in the longitudinal direction of the first connecting portion 11a.

[0175] In addition, the guide wire 100 of the present embodiment can also be such that the length in the long axis direction of the first connecting taper portion 13a is longer than the length in the long axis direction of the second connecting taper portion 13b in the continuous taper portion 13.

[0176] With this structure, the guide wire 100 can increase the length of the first connecting taper portion 13a disposed in the lumen 51 of the connecting member 50 and decrease the length from the front end of the connecting member 50 to the first outer diameter constant portion 1 lb. Thus, the guide wire 100 can suppress a decrease in local rigidity, a decrease in supportability for a catheter, and a decrease in pushability. In addition, the guide wire 100 has a higher straightness and improved torque transmission because the possibility of plastic deformation and breakage of the connecting member 50 when the first core portion 11 is fitted to the connecting member 50 is reduced. Moreover, the guide wire 100 has an increased length of the portion of the first core portion 11 covered by the second covering layer 42, and thus has improved passability in a blood vessel.

[0177] In addition, the connecting fixing portion 70 of the present embodiment that fixes the continuous taper portion 13 of the guide wire 100 to the connecting member 50 can be provided at the first connecting taper portion 13a and at a position separated from the fitting portion 60 in the long axis direction.

[0178] With this structure, the fixing portions of the first core portion 11 and the connecting member 50 of the guide wire 100 when viewed in the long axis direction are the fitting portion 60 and the front end connecting fixing portion 71, and thus the first core portion 11 and the connecting member 50 can be more firmly connected.

[0179] In addition, the outer surface of the first connecting taper portion 13a of the guide wire 100 of the present embodiment and the inner surface of the connecting member 50 can be separated in the radial direction on the front end side and the base end side of the connecting fixing portion 70.

[0180] With this structure, the outer surface of the connecting member 50 of the guide wire 100 including the connecting fixing portion 70 is smooth, and the connection strength of the first core portion 11 and the connecting member 50 is high.

[0181] In addition, the fitting portion 60 of the guide wire 100 of the present embodiment can have a flared shape in which the connecting member 50 expands to the radial outside along the outer surface of the first connecting taper portion 13a.

[0182] With this structure, the guide wire 100 can increase the area of the fitting portion 60, and thus the first core portion 11 and the connecting member 50 are firmly fitted. In addition, stress can be suppressed from concentrating on the front end of the connecting member 50 when bent, and thus the guide wire 100 is less likely to have a kink starting from the front end of the connecting member 50.

[0183]

EMBODIMENT

[0184] Hereinafter, the present application will be specifically described using examples, but the scope of the present application is not limited to the following examples.

[0185] [Manufacture of guide wire]

[0186] The guide wire 100 of Example 1 was manufactured as follows. Further, for the manufacturing process, the process 1, the process 3, the process 4, the process 6, and the process 7 in the manufacturing method of the guide wire 100 described above were implemented.

[0187] The first core portion 11 of the guide wire 100 was formed by processing a metal wire made of Ni-Ti alloy. The first connecting portion 11a of the first core portion 11 was formed to have a base end connecting outer diameter constant portion 111a and a base end taper portion 112a. The base end taper portion 112a was formed as a continuous taper portion 13 in which the first connecting taper portion 13a and the second connecting taper portion 13b were arranged adjacent to each other in the longitudinal direction. The outer diameter dl of the base end connecting outer diameter constant portion 111a was 0.235 mm, the outer diameter d2 of the tip end of the first connecting taper portion 13a was 0.279 mm, and the outer diameter d3 of the tip end of the second connecting taper portion 13b was 0.340 mm. The length LI of the base end connecting outer diameter constant portion 111a was 4 mm, the length L2 of the first connecting taper portion 13a was 29 mm, and the length L3 of the second connecting taper portion 13b was 4 mm. The inclination angle Θ1 of the first connecting taper portion 13a was 0.04°, and the inclination angle Θ2 of the second connecting taper portion 13b was 0.44°.

[0188] The second core portion 12 of the guide wire 100 was formed by processing a metal wire made of stainless steel. The second connecting portion 12b of the second core portion 12 was formed to have a tip end connecting outer diameter constant portion 121b and a tip end taper portion 122b. The tip end taper portion 122b was formed as a single taper portion. The outer diameter of the tip end connecting outer diameter constant portion 121b was 0.235 mm, and the outer diameter of the base end of the tip end taper portion 122b was 0.340 mm. The length of the tip end connecting outer diameter constant portion 121b was 5 mm, and the length of the tip end taper portion 122b was 25 mm. The inclination angle Θ3 of the tip end taper portion 122b was 0.14.

[0189] The connecting member 50 used a tube made of Ni-Ti alloy having an outer diameter of 0.350 mm, an inner diameter of 0.255 mm, a wall thickness t of 0.048 mm, and a length of 35 mm.

[0190] In the process 1, the tester held the first core portion 11 and the connecting member 50, inserted and forcibly pushed the base end connecting outer diameter constant portion 111a of the first core portion 11 and a part of the first connecting taper portion 13a of the first core portion 11 from the tip end side of the connecting member 50, and thereby the first core portion 11 and the connecting member 50 were fitted.

[0191] In Step 3, the tester set the laser irradiation point P at a position 2.5 mm from the front end of the connecting member 50 in the long axis direction to the laser irradiation point P and performed laser irradiation. Next, the tester set the laser irradiation point P at a position 180° in the circumferential direction of the first core portion 11 from the first laser irradiation point P and performed laser irradiation. The voltage value at the time of laser irradiation was 280 V, and the pulse width was 1.0 ms.

[0192] In Step 4, the tester inserted a portion of the front end tapered portion 122b of the second core portion 12 into the base end side of the connecting member 50 and forcibly pushed it in, thereby fitting the second core portion 12 to the connecting member 50.

[0193] In Step 6, the formation of the base end connecting fixing portion 72 that fixes the base end portion of the connecting member 50 to the front end tapered portion 122b of the second core portion 12 was performed by soldering using solder as the connecting material 72a.

[0194] In Step 7, the tester ground the surface of the base end connecting fixing portion 72 composed of the connecting material 72a obtained by soldering in Step 6 using a grinder to shape it into a tapered shape in which the outer diameter gradually decreases toward the base end side.

[0195] The guide wire 500 of Comparative Example 1 was manufactured according to the manufacturing procedure of the guide wire 100 described above. In Comparative Example 1, the first connecting portion 11a of the first core portion 11 was formed to have a base end connecting outer diameter constant portion 111a and a base end tapered portion 112a. The base end tapered portion 112a was formed as a single tapered portion. The outer diameter dl of the base end connecting outer diameter constant portion 111a was 0.220 mm, and the outer diameter of the front end of the base end tapered portion 112a was 0.340 mm. The length of the base end connecting outer diameter constant portion 111a was 15 mm, and the length of the base end tapered portion 112a was 80 mm. The inclination angle Θ of the base end tapered portion 112a was 0.04°.

[0196] [Experiment 1]

[0197] Experiment 1 is an experiment for evaluating the behavior of the guide wire when passing through a curved portion. The guide wire 100 of Example 1 and the guide wire 500 of Comparative Example 1 were inserted into the test tool 400 having a passage 410 (a tube with a diameter of 6 mm and a radius of curvature of 30 mm) including a U-shaped curved portion, and the behavior of the guide wire 100, including the fitting portion of the first core portion and the connecting member, when passing through the curved portion was observed by visual inspection.

[0198] [Results of Experiment 1]

[0199] Figure 6is a drawing schematically showing an example of a bent shape of the guide wire when the guide wire 100 of Example 1 and the guide wire 500 of Comparative Example 1 are inserted into the passage 410 of the test jig 400. In Figure 6 the solid line represents the guide wire 100 of Example 1, and the broken line represents the guide wire 500 of Comparative Example 1.

[0200] As shown in Figure 6 , the guide wire 100 of Example 1 passes through from a position close to the inner side of the bend of the passage 410 with a small radius of curvature of the guide wire 100. On the other hand, as shown in ​ , the guide wire 500 of Comparative Example 1 passes through from a position close to the outer side of the bend of the passage 410 with a large radius of curvature of the guide wire 100. The guide wire 100 of Example 1 having the continuous taper portion 13 has a smaller contact area with the inner surface of the blood vessel when passing through the bend of the blood vessel than the guide wire 500 of Comparative Example 1 not having the continuous taper portion 13. It is inferred that, since the rigidity of the guide wire 100 along the longitudinal direction of the guide wire 100 changes at the boundary position between the first connecting taper portion 13a and the second connecting taper portion 13b forming the continuous taper portion 13, the radius of curvature from the point of rigidity change based on the continuous taper portion 13 to the front end of the connecting member 50 becomes small when bent.

[0201] This application is based on Japanese Patent Application No. 2020-188863 filed on November 12, 2020, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A guide wire which connects a base end portion of a first core portion with a front end portion of a second core portion disposed on a base end side of the first core portion, using a tubular connecting member, wherein the base end portion of the first core portion has a base end taper portion which has an outer diameter that decreases toward the base end, the base end taper portion has a first connecting taper portion which is disposed at a position closest to the base end of the first core portion in a long axis direction of the guide wire, an inclination angle θ1 of the first connecting taper portion is 0.01° < θ1 < 0.05°.

2. The guide wire according to claim 1, wherein the first core portion has an engagement portion in which an outer surface of the first connecting taper portion engages with an inner surface of an end portion of the connecting member, the engagement portion has a flared shape in which the connecting member expands to the radially outer side along the outer surface of the first connecting taper portion.

3. The guide wire according to claim 2, wherein a connecting fixing portion which fixes the base end taper portion and the connecting member is provided at a position separated from the engagement portion in the long axis direction.

4. The guide wire according to any one of claims 1 to 3, wherein the base end taper portion has a continuous taper portion which includes the first connecting taper portion and a second connecting taper portion which is disposed adjacent to a front end side of the first connecting taper portion and has an inclination angle different from that of the first connecting taper portion.

5. The guide wire according to claim 4, wherein in the continuous taper portion, the inclination angle of the second connecting taper portion is larger than the inclination angle of the first connecting taper portion.

6. The guide wire according to claim 4, wherein in the continuous taper portion, a length in the long axis direction of the first connecting taper portion is longer than a length in the long axis direction of the second connecting taper portion.

7. The guide wire according to claim 5, wherein in the continuous taper portion, a length in the long axis direction of the first connecting taper portion is longer than a length in the long axis direction of the second connecting taper portion. ​

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