Guide wire

Abstract

To provide a guide wire having an excellent bonding strength between a core shaft and a tubular member which suppresses release of the core shaft from the tubular member.SOLUTION: A guide wire 1A includes: a first core shaft 10; a second core shaft 20 positioned on a rear end side of the guide wire from the first core shaft; and a tubular member 30 for connecting the first core shaft and the second core shaft, the tubular member covering a rear end part of the first core shaft and a tip end part of the second core shaft. First projections 50, 60 are formed at the rear end part of the first core shaft that project toward a radially outside. Among side surface parts of the first projections, a first tapered part is formed on a part positioned toward a rear end side of the guide wire from the apex part of the first projection, and the first projection engages with an inner peripheral part of the tubular member.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a guidewire. [Background technology]

[0002] Conventionally, a guidewire formed by joining two core shafts made of different metals has been known. Patent Document 1 describes a technique for fixing the core shafts together by covering the end of the core shaft on the tip side and the end of the core shaft on the rear side with a tubular member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-206174 A [Patent Document 2] Special Publication No. 2011-512938 [Patent Document 3] JP 2003-260140 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a guidewire in which two core shafts are joined by a tubular member, there is a risk that the core shaft may become dislodged from the tubular member during use of the guidewire.

[0005] An object of the present invention is to provide a guidewire which prevents a core shaft from coming off from a tubular member and has excellent bonding strength between the core shaft and the tubular member. [Means for solving the problem]

[0006] The present invention has been made to solve at least part of the above-mentioned problems, and can be realized in the following forms.

[0007] (1) One form of the present invention is a guidewire comprising: a first core shaft; a second core shaft located closer to the rear end of the guidewire than the first core shaft; and a tubular member connecting the first core shaft and the second core shaft, the tubular member covering the rear end of the first core shaft and the tip end of the second core shaft, wherein the rear end of the first core shaft is formed with a first protrusion protruding radially outward, and a first tapered portion is formed on a side portion of the first protrusion located closer to the rear end of the guidewire than the apex of the first protrusion, and the first protrusion engages with an inner peripheral portion of the tubular member.

[0008] According to this configuration, the first protrusion engages with the tubular member, thereby preventing the first core shaft from coming off the tubular member, and improving the joining strength between the first core shaft and the tubular member. Also, the first tapered portion narrows the width of the first protrusion in the axial direction of the first core shaft toward the height direction of the first protrusion, thereby narrowing the apex, making it easier for the apex to engage with the inner periphery of the tubular member. Furthermore, the first tapered portion makes it easier to insert the first core shaft into the tubular member when manufacturing the guidewire.

[0009] (2) In the guidewire of the above embodiment, a second protrusion protruding radially outward is formed on the rear end of the second core shaft, and a second tapered portion is formed on a side portion of the second protrusion that is located closer to the tip of the guidewire than the apex of the second protrusion, and the second protrusion may engage with an inner peripheral portion of the tubular member.

[0010] According to this configuration, the second protrusion engages with the tubular member, thereby preventing the second core shaft from coming off the tubular member, and improving the joining strength between the second core shaft and the tubular member. Also, the second tapered portion narrows the width of the second protrusion in the axial direction of the second core shaft toward the height direction of the second protrusion, thereby narrowing the apex, making it easier for the apex to engage with the inner periphery of the tubular member. Furthermore, the second tapered portion makes it easier to insert the second core shaft into the tubular member when manufacturing the guidewire.

[0011] (3) The first protrusion portion may be provided along a circumferential direction on an outer periphery of the first core shaft, and the first tapered portion of the first core shaft may have an outer diameter that decreases from the tip side toward the rear end side of the first core shaft.

[0012] According to this configuration, since the first protrusion is provided along the circumferential direction, it is possible to more reliably prevent the first core shaft from coming off the tubular member.

[0013] (4) The second protrusion portion may be provided along the circumferential direction on the outer periphery of the second core shaft, and the second tapered portion of the second core shaft may have an outer diameter that decreases from the rear end side to the tip end side of the second core shaft.

[0014] According to this configuration, since the second protrusion is provided along the circumferential direction, it is possible to more reliably prevent the second core shaft from coming off the tubular member.

[0015] (5) A protrusion protruding radially outward from the tubular member may be formed on the outer periphery of the tubular member.

[0016] According to this configuration, the protrusions provided on the outer periphery of the tubular member reduce the contact area between the tubular member and a medical device used in conjunction with the guidewire or the body wall, improving the slidability of the guidewire.

[0017] The present invention can be realized in various aspects, for example, in the form of a guidewire, a method for manufacturing a guidewire, a method for manufacturing a catheter, an endoscope, a dilator, and the like. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is an explanatory diagram illustrating an example of the overall configuration of a guidewire according to a first embodiment. [Diagram 2] FIG. 4 is an explanatory diagram illustrating a vertical cross section of a tubular member. [Diagram 3]FIG. 4 is an explanatory diagram illustrating an enlarged view of a first protrusion portion. [Figure 4] FIG. 3 is an explanatory diagram illustrating a cross section taken along the line AA in FIG. 2. [Diagram 5] FIG. 4 is an explanatory diagram illustrating an enlarged view of a second protrusion portion. [Figure 6] FIG. 3 is an explanatory diagram illustrating a cross section taken along the line BB in FIG. 2; [Figure 7] 5A to 5C are explanatory diagrams illustrating a method for joining a core shaft and a tubular member. [Figure 8] FIG. 1 is an explanatory diagram illustrating a longitudinal section of a tubular member of a conventional guidewire. [Figure 9] 13 is an explanatory view illustrating a vertical cross section of a tubular member of a guidewire according to a second embodiment. FIG. [Figure 10] FIG. 11 is an explanatory view illustrating a vertical cross section of a tubular member of a guidewire according to a third embodiment. [Figure 11] 11 is an explanatory diagram illustrating a cross section taken along the line CC in FIG. 10; [Figure 12] 13 is an explanatory diagram illustrating an enlarged view of a first protrusion portion of the fourth embodiment. FIG. [Figure 13] FIG. 13 is an explanatory diagram illustrating an enlarged view of a first protrusion portion of the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] First Embodiment A guidewire 1A of a first embodiment will be described with reference to Figs. 1 to 7. The sizes of the guidewire 1A and each of the components shown in Figs. 1 to 7 are illustrative and may be expressed on a scale different from the actual size. Hereinafter, the end portion of each component of the guidewire 1A located on the tip side will be referred to as the "tip", and the portion including the "tip" and extending from the tip to the middle toward the rear end will be referred to as the "tip portion". Similarly, the end portion of each component located on the rear end side will be referred to as the "rear end", and the portion including the "rear end" and extending from the rear end to the middle toward the tip side will be referred to as the "rear portion".

[0020] 1 is an explanatory diagram illustrating the overall configuration of a guidewire 1A according to a first embodiment. The guidewire 1A is a medical device used for treating blood vessels, etc. The guidewire 1A has a first core shaft 10, a second core shaft 20, a tubular member 30, and a coil 40.

[0021] The first core shaft 10 is a long member extending from the distal end side to the proximal end side of the guidewire 1 A. The first core shaft 10 will be described in detail later.

[0022] The second core shaft 20 is a long member provided on the rear end side of the first core shaft 10 so as to be coaxial with the first core shaft 10. The second core shaft 20 will be described in detail later.

[0023] The material of the first core shaft 10 and the second core shaft 20 is not particularly limited, but may be, for example, stainless steel (SUS302, SUS304, SUS316, etc.), superelastic alloy such as Ni-Ti alloy, piano wire, nickel-chromium alloy, cobalt alloy, platinum, gold, tungsten, etc. Here, the first core shaft 10 and the second core shaft 20 are made of different materials. Note that the first core shaft 10 and the second core shaft 20 may be made of the same material.

[0024] The tubular member 30 is a hollow member that covers the outer periphery of the rear end portion 11 (FIG. 2) of the first core shaft 10 and the front end portion 21 (FIG. 2) of the second core shaft 20, and is joined to the first core shaft 10 and the second core shaft 20. Details of the tubular member 30 will be described later.

[0025] The material of the tubular member 30 is not particularly limited, but examples of usable materials include stainless steel (SUS302, SUS304, SUS316, etc.), superelastic alloys such as Ni-Ti alloys, piano wire, nickel-chromium alloys, cobalt alloys, platinum, gold, tungsten, etc.

[0026] The coil 40 is a member that covers the tip end side of the first core shaft 10, and is formed of a metal wire wound in a spiral shape around the outer periphery of the first core shaft 10.

[0027] 2 is an explanatory diagram illustrating a longitudinal cross section of the tubular member 30 of the guidewire 1A of the first embodiment. The rear end portion 11 of the first core shaft 10 and the tip portion 21 of the second core shaft 20 are disposed inside the tubular member 30. The inside of the tubular member 30 is filled with an adhesive 100, and the tubular member 30, the first core shaft 10, and the second core shaft 20 are bonded together with the adhesive 100.

[0028] <Details of the first core shaft 10> The rear end portion 11 of the first core shaft 10 is arranged in the order of the first protrusion portion 50, the straight portion 13, the first protrusion portion 60, the straight portion 14, and the straight portion 15 from the rear end 12 of the first core shaft 10 toward the tip side. The first protrusion portions 50 and 60 are portions that protrude toward the radially outer side of the first core shaft 10 and have a relatively larger outer diameter than the straight portions 13 and 14. The maximum outer diameter of the first protrusion portions 50 and 60 is approximately the same as the maximum outer diameter of the straight portion 15. The straight portions 13, 14, and 15 are portions whose outer diameter is approximately constant in the long axis direction. A part of the straight portion 15 is arranged outside the tubular member 30. Details of the first protrusion portions 50 and 60 will be described later.

[0029] <Details of the second core shaft 20> The tip portion 21 of the second core shaft 20 is arranged in the order of the second protrusion portion 70, the straight portion 23, the second protrusion portion 80, the straight portion 24, and the straight portion 25 from the tip portion 22 of the second core shaft 20 toward the rear end side. The second protrusion portions 70, 80 protrude toward the radially outer side of the second core shaft 20 and are portions having a relatively larger outer diameter than the straight portions 23, 24. The maximum outer diameter of the second protrusion portions 70, 80 is approximately the same as the maximum outer diameter of the straight portion 25. The straight portions 23, 24, 25 are portions having an approximately constant outer diameter in the long axis direction. A part of the straight portion 25 is arranged outside the tubular member 30. The second protrusion portions 70 and the second protrusion portions 80 will be described in detail later.

[0030] <Details of the first protrusions 50, 60> FIG. 3 is an explanatory diagram illustrating an enlarged view of the first protrusions 50, 60 of the guidewire 1A of the first embodiment. FIG. 4 is an explanatory diagram illustrating a cross section of the tubular member 30 taken along line AA in FIG. 2. Each of the two first protrusions (50, 60) has an apex (51, 61), a first tapered portion (52, 62), and a back surface (53, 63). The apex (51, 61) is formed at the end of the first protrusions (50, 60) in the protrusion direction (radial direction of the first core shaft 10) and engages with the inner periphery 31 of the tubular member 30. The first tapered portion (52, 62) is formed at a portion of the side surface of the first protrusions (50, 60) closer to the rear end of the first core shaft 10 than the apex (51, 61). The angle between the first tapered portion (52, 62) and the straight portion (13, 14) is not particularly limited, but may be in the range of 5 degrees to 80 degrees. The first tapered portion (52, 62) extends from the apex (51, 61) toward the rear end side of the first core shaft 10, and has a shape in which the outer diameter decreases from the front end side to the rear end side of the first core shaft 10. The back surface (53, 63) is formed in the first protrusion portion (50, 60) at a position substantially identical to the apex (51, 61) in the axial direction of the first core shaft 10, or at a portion closer to the front end side of the first core shaft 10 than the apex (51, 61). The back surface (53, 63) extends substantially perpendicularly from the outer circumferential surface of the straight portion (13, 14) toward the outside in the radial direction. In other words, the angle between the back surface (53, 63) and the straight portion (13, 14) is substantially 90 degrees. An apex (51, 61) is formed at the intersection of the back surface (53, 63) and the first tapered portion (52, 62). As a result, as shown in FIG. 3, the first protrusion (50, 60) has a triangular shape protruding toward the inner peripheral portion 31 of the tubular member 30. The inner peripheral portion 31 of the tubular member 30 is recessed along the shape of the apex (51, 61), and the tubular member 30 and the first core shaft 10 are engaged with each other by the recess and the apex (51, 61). Hereinafter, the inner peripheral portion 31 of the tubular member 30 recessed along the shape of the apex 51 is referred to as the "engaged portion 33," and the inner peripheral portion 31 of the tubular member 30 recessed along the shape of the apex 61 is referred to as the "engaged portion 34." Furthermore, when the first tapered portion 52 and the first tapered portion 62 are compared, the first tapered portion 62 has a gentler inclination and a smaller taper rate than the first tapered portion 52 .

[0031] As shown in Fig. 4, the first protrusion 50 is formed along the circumferential direction on the outer periphery of the first core shaft 10. That is, the first protrusion 50 has a substantially ring shape in cross section. As a result, the annular apex 51 fits into and engages with the inner periphery 31 of the tubular member 30 along the circumferential direction. Although not shown, the first protrusion 60 is also formed along the circumferential direction on the outer periphery of the first core shaft 10.

[0032] <Details of the tubular member 30> As shown in Figs. 2 and 3, the outer peripheral portion 32 of the tubular member 30 is formed with two protrusions 35 and 36 that protrude radially outward from the tubular member 30. The protrusions (35, 36) have a larger outer diameter than the portions of the tubular member 30 other than the protrusions (35, 36). The protrusions (35, 36) protrude in a mountain shape from the outer peripheral portion 32 of the tubular member 30, and their surfaces are formed by curved surfaces. The protrusions (35, 36) are formed by the inner peripheral portion 31 of the tubular member 30 being pressed by the first protrusions (50, 60) of the first core shaft 10, thereby causing the outer peripheral portion 32 to protrude, by a manufacturing method described later. For this reason, the positions of the protrusions (35, 36) of the tubular member 30 and the first protrusions (50, 60) of the first core shaft 10 are substantially the same in the long axis direction.

[0033] 4, the protrusion 35 of the tubular member 30 is formed along the circumferential direction on the outer periphery of the tubular member 30. Although not shown, the protrusion 36 is also formed along the circumferential direction on the outer periphery of the tubular member 30 in a similar manner.

[0034] <Details of second protrusions 70, 80> FIG. 5 is an explanatory diagram illustrating an enlarged view of the second protrusions 70, 80 of the guidewire 1A of the first embodiment. FIG. 6 is a cross section taken along line BB in FIG. 2, and is an explanatory diagram illustrating a transverse section of the tubular member 30. The two second protrusions (70, 80) each have an apex (71, 81), a second tapered portion (72, 82), and a back surface (73, 83). The apex (71, 81) is formed at the end of the second protrusions (70, 80) in the protrusion direction (radial direction of the second core shaft 20) and engages with the inner periphery 31 of the tubular member 30. The second tapered portion (72, 82) is formed at a portion of the side surface of the second protrusions (70, 80) closer to the tip end of the second core shaft 20 than the apex (71, 81). The angle between the second tapered portion (72, 82) and the straight portion (23, 24) is not particularly limited, but may be in the range of 5 degrees to 80 degrees. The second tapered portion (72, 82) extends from the apex (71, 81) toward the tip side of the second core shaft 20, and has a shape in which the outer diameter decreases from the rear end side of the second core shaft 20 toward the tip side. The back surface (73, 83) is formed in the second protrusion portion (70, 80) at a position substantially identical to the apex (71, 81) in the axial direction of the second core shaft 20, or at a portion closer to the rear end side of the second core shaft 20 than the apex (71, 81). The back surface (73, 83) extends substantially perpendicularly from the outer circumferential surface of the straight portion (23, 24) toward the outside in the radial direction. In other words, the angle between the back surface (73, 83) and the straight portion (23, 24) is substantially 90 degrees. Apexes (71, 81) are formed at the intersection of the back surface (73, 83) and the second tapered portion (72, 82). As a result, as shown in FIG. 5, the second protrusions (70, 80) have a triangular shape protruding toward the inner peripheral portion 31 of the tubular member 30. The inner peripheral portion 31 of the tubular member 30 is recessed along the shape of the apexes (71, 81), and the tubular member 30 and the second core shaft 20 are engaged with each other by the recess and the apex (71, 81). Hereinafter, the inner peripheral portion 31 of the tubular member 30 recessed along the shape of the apex 71 is referred to as the "engaged portion 93," and the inner peripheral portion 31 of the tubular member 30 recessed along the shape of the apex 81 is referred to as the "engaged portion 94." Furthermore, when the second tapered portion 72 and the second tapered portion 82 are compared, the second tapered portion 82 has a gentler inclination and a smaller taper rate than the second tapered portion 72.

[0035] 6, the second protrusion 70 is formed along the circumferential direction on the outer periphery of the second core shaft 20. That is, the second protrusion 70 has a substantially ring shape in cross section. As a result, the annular apex 71 fits into and engages with the inner periphery 31 of the tubular member 30 along the circumferential direction. Although not shown, the second protrusion 80 is also formed along the circumferential direction on the outer periphery of the second core shaft 20.

[0036] <Details of the tubular member 30> As shown in Figs. 2 and 5, the outer circumferential portion 32 of the tubular member 30 is formed with two protrusions 95 and 96 that protrude radially outward from the tubular member 30. The protrusions (95, 96) have a larger outer diameter than the portions of the tubular member 30 other than the protrusions (95, 96). The protrusions (95, 96) protrude in a mountain shape from the outer circumferential portion 32 of the tubular member 30, and their surfaces are formed by curved surfaces. The protrusions (95, 96) are formed by the inner circumferential portion 31 of the tubular member 30 being pressed by the second protrusions (70, 80) of the second core shaft 20, thereby causing the outer circumferential portion 32 to protrude, by a manufacturing method described later. For this reason, the positions of the protrusions (95, 96) of the tubular member 30 and the second protrusions (70, 80) of the second core shaft 20 in the long axis direction are substantially the same.

[0037] 6, the protrusion 95 of the tubular member 30 is formed along the circumferential direction on the outer periphery of the tubular member 30. Although not shown, the protrusion 96 is also formed along the circumferential direction on the outer periphery of the tubular member 30 in a similar manner.

[0038] <Joining method> FIG. 7 is an explanatory diagram illustrating a method of joining the first core shaft 10, the second core shaft 20, and the tubular member 30. First, as shown in FIG. 7(A), a tubular member 30 having an inner diameter smaller than the outer diameter of the rear end portion 11 of the first core shaft 10 and the outer diameter of the tip portion 21 of the second core shaft 20 at room temperature is prepared. Next, as shown in FIG. 7(B), the tubular member 30 is heated, and the inner diameter of the tubular member 30 is made larger than the outer diameter of the rear end portion 11 of the first core shaft 10 and the outer diameter of the tip portion 21 of the second core shaft 20 by utilizing thermal expansion. Thereafter, the rear end 12 of the first core shaft 10 is inserted from one side of the tubular member 30, and the tip 22 of the second core shaft 20 is inserted from the other side of the tubular member 30. At this time, the inside of the tubular member 30 is filled with an adhesive 100. Next, as shown in (C) of FIG. 5, the tubular member 30 is cooled to return the tubular member 30 to its shape before heating, so that the first protrusions (50, 60) of the first core shaft 10 and the second protrusions (70, 80) of the second core shaft 20 enter and engage with the inner peripheral portion 31 of the tubular member 30.

[0039] According to the guidewire 1A of the first embodiment described above, the first protrusions (50, 60) engage with the tubular member 30, thereby preventing the first core shaft 10 from coming off from the tubular member 30, and improving the joining strength between the first core shaft 10 and the tubular member 30. Furthermore, when a force is applied to the first core shaft 10 in a direction to pull it out toward the distal end, the back surface (53, 63) engages with the wall surface of the engaged portion (33, 34) to generate resistance, so that the first core shaft 10 can be more reliably prevented from coming off. In addition, the first tapered portion (52, 62) narrows the axial width of the first protrusions (50, 60) toward the height direction, thereby narrowing the shape of the apex (51, 61), and thus making it easier for the apex (51, 61) to engage with the inner peripheral portion 31 of the tubular member 30. Furthermore, the first tapered portion (52, 62) makes it easier to insert the first core shaft 10 into the tubular member 30 during manufacturing.

[0040] In addition, the second protrusions (70, 80) engage with the tubular member 30, thereby preventing the second core shaft 20 from coming off from the tubular member 30, and improving the joining strength between the second core shaft 20 and the tubular member 30. Furthermore, when a force is applied to the second core shaft 20 in a direction to pull it off toward the base end, the back surface (73, 83) engages with the wall surface of the engaged portion (93, 94) to generate resistance, so that the second core shaft 20 can be more reliably prevented from coming off. In addition, the second tapered portion (72, 82) narrows the axial width of the second protrusions (70, 80) toward the height direction, thereby narrowing the shape of the top portion (71, 81), and the top portion (71, 81) can be easily engaged with the inner peripheral portion 31 of the tubular member 30. Furthermore, the second tapered portion (72, 82) makes it easy to insert the second core shaft 20 into the tubular member 30 during manufacturing.

[0041] The first protrusions (50, 60) and the second protrusions (70, 80) are provided along the circumferential direction of the inner peripheral portion 31 of the tubular member 30. This allows the apexes (51, 61) and the apexes (71, 81) to engage with each other along the entire circumferential direction, making it possible to more reliably prevent the first core shaft 10 and the second core shaft 20 from coming loose.

[0042] The tubular member 30 has protrusions (35, 36, 95, 96) on the outer circumferential portion 32. This reduces the contact area between the guidewire 1A, a medical device (not shown) used in combination with the guidewire 1A, and the inner wall of the body and the tubular member 30, improving the slidability of the guidewire 1A.

[0043] 8 is an explanatory diagram illustrating a longitudinal section of a tubular member 30Z of a conventional guidewire 1Z. Although the conventional guidewire 1Z and the guidewire 1A of the first embodiment share a part of their configurations in common, the guidewire 1Z is different from the guidewire 1A in that the guidewire 1Z does not have a first protrusion (50, 60) at the rear end 11Z of the first core shaft 10Z and does not have a second protrusion (70, 80) at the front end 21Z of the second core shaft 20Z. In addition, the inner diameter of the tubular member 30Z at room temperature is larger than the outer diameter of the rear end 11Z of the first core shaft 10Z and the outer diameter of the front end 21Z of the second core shaft 20Z. The first core shaft 10Z and the tubular member 30Z, and the second core shaft 20Z and the tubular member 30Z are connected to each other only by the adhesive force of the adhesive 100. That is, in the guidewire 1Z, the first core shaft 10Z and the second core shaft 20Z are not engaged with the tubular member 30Z, so there is a high possibility that the first core shaft 10Z and the second core shaft 20Z will come off the tubular member 30Z. On the other hand, according to the guidewire 1A of the present embodiment, the first core shaft 10 and the second core shaft 20 are engaged with the inner periphery of the tubular member 30 via the first and second protrusions (50, 60, 70, 80), so the possibility that the first core shaft 10 and the second core shaft 20 will come off the tubular member 30 can be reduced. Also, according to the conventional guidewire 1Z, the outer periphery 32Z of the tubular member 30Z is flat in the axial direction, so that the slidability with other medical devices and the body wall can be reduced. On the other hand, according to the guidewire 1A of the present embodiment, the protrusions (35, 36, 95, 96) are formed on the outer periphery 32 of the tubular member 30, so that the reduction in slidability can be suppressed.

[0044] <Second embodiment> 9 is an explanatory diagram illustrating a longitudinal cross section of a tubular member 30 of a guidewire 1B of the second embodiment. The guidewire 1B of the second embodiment differs from the guidewire 1A of the first embodiment in that the second core shaft 20B does not have second protrusions (70, 80). Of the configuration of the guidewire 1B, a description of the configuration common to the guidewire 1A will be omitted.

[0045] In the guide wire 1B of this embodiment, the first core shaft 10 has the first protrusion portion (50, 60), which prevents the first core shaft 10 from coming out of the tubular member 30 and improves the bonding strength between the first core shaft 10 and the tubular member 30.

[0046] <Third embodiment> 10 is an explanatory diagram illustrating a longitudinal cross section of a tubular member 30 of a guidewire 1C of the third embodiment. The guidewire 1C of the third embodiment differs from the guidewire 1A of the first embodiment in that the first protrusions (50C, 60C) and the second protrusions (70C, 80C) are not provided along the circumferential direction. A description of the configuration of the guidewire 1C that is common to the guidewire 1A will be omitted.

[0047] FIG. 11 is a cross section taken along the CC line in FIG. 10, and is an explanatory diagram illustrating a cross section of the tubular member 30. The first protrusion 50C is provided on a part of the outer periphery of the first core shaft 10C in the circumferential direction. In this embodiment, two first protrusions 50C are provided in the circumferential direction, and each first protrusion 50C is provided so as to be 180° opposite in the circumferential direction. The top 51C engages with a part of the inner periphery 31 of the tubular member 30 in the circumferential direction. Although not shown, the first protrusion 60C is also provided on a part of the outer periphery of the first core shaft 10C in the circumferential direction. In this embodiment, two first protrusions (50C, 60C) are provided in the circumferential direction, but three or more first protrusions (50C, 60C) may be provided in the circumferential direction.

[0048] Also, although the cross-section of the second protrusion portions (70C, 80C) is not shown, in this embodiment, the second protrusion portions (70C, 80C), like the first protrusion portions (50C, 60C), are provided on a portion of the circumferential outer periphery of the second core shaft 20C.

[0049] In the guide wire 1C of this embodiment described above, the first core shaft 10C has the first protrusion portion (50C, 60C) and the second core shaft 20C has the second protrusion portion (70C, 80C), thereby preventing the first core shaft 10C and the second core shaft 20C from coming loose from the tubular member 30 and improving the joining strength between the first core shaft 10C, the second core shaft 20C, and the tubular member 30.

[0050] <Fourth embodiment> FIG. 12 is an explanatory diagram illustrating an enlarged view of the first protrusion portions (50D, 60D) of a guidewire 1D of the fourth embodiment. The guidewire 1D of the fourth embodiment differs from the guidewire 1A of the first embodiment in that the back surface (53D, 63D) is inclined toward the tip side with respect to the outer peripheral surface of the first core shaft 10D. That is, here, the angle formed between the back surface (53D, 63D) and the straight portions (13, 14) is 90 degrees or more. Description of the configuration of the guidewire 1D that is common to the guidewire 1A will be omitted.

[0051] In the guide wire 1D of this embodiment, the first core shaft 10D has a first protrusion portion (50D, 60D), which prevents the first core shaft 10D from coming out of the tubular member 30, thereby improving the bonding strength between the first core shaft 10D and the tubular member 30.

[0052] <Fifth embodiment> 13 is an explanatory diagram illustrating an enlarged view of the first protrusion portions (50E, 60E) of the guidewire 1E of the fifth embodiment. The guidewire 1E of the fifth embodiment differs from the guidewire 1A of the first embodiment in that the back surface (53E, 63E) is inclined toward the rear end side with respect to the outer peripheral surface of the first core shaft 10. That is, here, the angle formed between the back surface (53E, 63E) and the straight portions (13, 14) is smaller than 90 degrees. Description of the configuration of the guidewire 1E that is common to the guidewire 1A will be omitted.

[0053] In the guide wire 1E of this embodiment, the first core shaft 10E has a first protrusion portion (50E, 60E), which prevents the first core shaft 10E from coming out of the tubular member 30, thereby improving the bonding strength between the first core shaft 10E and the tubular member 30.

[0054] <Modification> The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit and scope of the invention. For example, the following modifications are also possible.

[0055] <Variation 1> In the guidewires (1A, 1B, 1C, 1D, 1E), the apexes (51, 61, 71, 81) are triangular, but they do not have to be triangular. For example, they may be square, rectangular, circular, or the like.

[0056] <Variation 2> In the guidewire (1A, 1B, 1C, 1D, 1E), the first tapered portion (52, 62) and the second tapered portion (72, 82) are formed at a constant taper rate in the longitudinal direction of the guidewire (1A, 1B, 1C, 1D, 1E), but they do not have to be formed at a constant taper rate. For example, the taper rate of the first tapered portion (52, 62) and the second tapered portion (72, 82) may vary in the longitudinal direction, or may be formed in a stepped shape.

[0057] <Variation 3> In the guidewires (1A, 1C, 1D, 1E), the protrusions (35, 36, 95, 96) of the tubular member 30 are formed along the circumferential direction on the outer periphery of the tubular member 30, but they do not have to be formed along the circumferential direction on the outer periphery of the tubular member 30. For example, they may be formed on a part of the outer periphery of the tubular member 30 in the circumferential direction, or a plurality of hemispherical protrusions (35, 36, 95, 96) may be formed on the outer periphery of the tubular member 30. [Explanation of symbols]

[0058] 1A…Guidewire 10…First core shaft 20…Second core shaft 11...Rear end of first core shaft 21…Tip of second core shaft 12…Rear end of first core shaft 22…Second core shaft tip 13, 14, 15, 23, 24, 25...Straight section 30...Tubular member 31...Inner circumference 32…Outer periphery 33, 34, 93, 94...Engaged parts 35, 36, 95, 96...protrusion 40…Coil 50, 60...1st protrusion 70, 80...Second protrusion 51, 61, 71, 81...Top 52, 62...First tapered section 72, 82...Second taper section 53, 63, 73, 83...back

Claims

1. A guidewire, a first core shaft; a second core shaft located closer to the rear end of the guide wire than the first core shaft; a tubular member connecting the first core shaft and the second core shaft, the tubular member covering a rear end portion of the first core shaft and a front end portion of the second core shaft, a first protrusion protruding radially outward is formed at a rear end of the first core shaft; a first tapered portion is formed in a portion of a side surface of the first protrusion that is located closer to the rear end of the guidewire than the top of the first protrusion, The first protrusion engages with an inner periphery of the tubular member.

2. 2. The guidewire of claim 1, A second protrusion protruding radially outward is formed at a tip end of the second core shaft, a second tapered portion is formed in a portion of the side surface of the second protrusion that is located closer to the distal end of the guidewire than the top of the second protrusion, The second protrusion engages with an inner periphery of the tubular member.

3. The guidewire according to claim 1 or 2, the first protrusion is provided along a circumferential direction on an outer periphery of the first core shaft, The guidewire, wherein the first tapered portion of the first core shaft has an outer diameter that decreases from the distal end side toward the proximal end side of the first core shaft.

4. 3. The guidewire according to claim 2, the second protrusion is provided along a circumferential direction on an outer periphery of the second core shaft, The second tapered portion of the second core shaft has an outer diameter that decreases from the rear end side to the tip end side of the second core shaft.

5. The guide wire according to claim 1 or 2, A guide wire, wherein a protrusion protruding radially outward from the tubular member is formed on the outer periphery of the tubular member.

6. A guide wire according to claim 1 or claim 2, A guidewire, wherein a portion of a rear end portion of the first core shaft overlaps a portion of a tip portion of the second core shaft in the axial direction of the guidewire.

7. A guide wire according to claim 1 or claim 2, The guidewire, wherein the first core shaft and the second core shaft are each bonded to the tubular member by an adhesive.

8. A guide wire according to claim 1 or claim 2, The first tapered portion is a tip-side tapered portion located relatively toward the tip of the first core shaft; a proximal end tapered portion located relatively closer to the proximal end of the first core shaft, The guidewire, wherein the inclination of the distal tapered portion is smaller than the inclination of the proximal tapered portion.

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