Medical device

Abstract

A medical device is provided with a long main body and a protruding section that protrudes further toward the distal end side than the distal end of the main body. The maximum value of the width of the profile of the protruding portion as viewed from a first direction orthogonal to the central axis of the main body is larger than the maximum value of the width of the profile as viewed from a second direction orthogonal to the central axis. When viewed from the first direction, the contour has a curved portion, and the width of the contour at the first central axis position is larger than the width of the contour at the second central axis position closer to the base end side than the first central axis position.

Description

Technical Field

[0001] The technology disclosed in this specification relates to medical devices. Background Art

[0002] Catheterization is a widely used method for treating or examining stenosis and occlusion within blood vessels (hereinafter referred to as "lesions"). Guidewires are used to guide the catheter to the lesion within the vessel. To penetrate hard lesions such as chronic total occlusions, the guidewire requires high penetration performance.

[0003] Conventionally, there is known a technique for processing the shape of the most distal end portion of a guide wire into an open lemon shape, a hook shape, a flat paddle shape, or the like (for example, see Patent Documents 1 to 5).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-209152

[0007] Patent Document 2: U.S. Patent Application Publication No. 2018 / 0280051

[0008] Patent Document 3: U.S. Patent Application Publication No. 2018 / 0280052

[0009] Patent Document 4: International Publication No. 2018 / 184017

[0010] Patent Document 5: U.S. Patent Application Publication No. 2021 / 0121199 Summary of the Invention

[0011] Problems to be solved by the invention

[0012] The above-mentioned prior art can improve the penetration performance of the guide wire. However, the penetration performance of the existing guide wire still has room for improvement.

[0013] This specification discloses a technology that can solve the above-mentioned problems.

[0014] Solutions to Problems

[0015] The technology disclosed in this specification can be implemented as follows, for example.

[0016] (1) The medical device disclosed in this specification comprises: a main body having an elongated shape; and a protrusion that protrudes toward the distal end of the main body, wherein the maximum width of the outline of the main body as viewed from a first direction perpendicular to the central axis of the main body is greater than the maximum width of the outline of the main body as viewed from a second direction perpendicular to the central axis. When viewed from the first direction, the outline has a curved portion, and the width of the outline at a first central axis position is greater than the width of the outline at a second central axis position closer to the proximal end than the first central axis position.

[0017] When viewed from the first direction, the protrusion of the medical device has a shape with a curved outline. Furthermore, the maximum width of the protrusion's outline as viewed from the first direction is greater than the maximum width of the protrusion's outline as viewed from a second direction perpendicular to the central axis. In other words, the protrusion has a rotationally asymmetric shape. Therefore, when the protrusion is positioned within a lesion, rotating the medical device about the central axis allows the protrusion to be efficiently perforated by utilizing the curved outline of the protrusion.

[0018] (2) The medical device may be configured such that the first direction and the second direction are orthogonal to each other. According to this medical device, the protrusion can be configured as a flat shape. Therefore, according to this medical device, the resistance when the protrusion enters the lesion and when the protrusion moves toward the distal side within the lesion can be reduced, thereby effectively improving the penetration performance of the medical device.

[0019] (3) The medical device may be configured such that the maximum width of the contour observed from the first direction is equal to the maximum width of the protrusion. In this medical device, the direction in which the contour of the protrusion has a curved portion coincides with the direction in which the protrusion has a maximum width. Therefore, according to this medical device, the width of the portion of the protrusion corresponding to the curved portion can be maximized, effectively improving the perforation performance of the lesion achieved by the rotation of the protrusion. As a result, the penetration performance of the medical device can be more effectively improved.

[0020] (4) In the above-mentioned medical device, the surface of the protrusion may have an edge that serves as a boundary between two surfaces. According to this medical device, by rotating the protrusion about the central axis, the edge of the protrusion can be used to perforate the lesion by incising it, thereby more effectively improving the penetration performance of the medical device.

[0021] (5) In the above-mentioned medical device, the surface of the protrusion may include the edge in its contour as viewed from the first direction. According to this medical device, the edge can be positioned at the outermost periphery of the rotational trajectory of the protrusion when the protrusion is rotated about the central axis. This allows the edge of the rotating protrusion to reliably contact the lesion, effectively improving the perforation performance of the lesion achieved by the rotation of the protrusion. As a result, the penetration performance of the medical device can be significantly improved.

[0022] (6) In the above-mentioned medical device, the width of the profile at the first central axis position of the protrusion, when viewed from the first direction, may be greater than the width of the profile at the third central axis position located closer to the distal end than the first central axis position. According to this medical device, the protrusion has a portion that is temporarily enlarged and then reduced in diameter from the base end toward the distal end. This allows the distal end portion of the protrusion to have a shape that allows for greater penetration into the lesion, and the width of the portion between the base end and the distal end of the protrusion can be made relatively large, thereby improving the perforation performance of the lesion achieved by the rotation of the protrusion. As a result, the penetration performance of the medical device can be more effectively improved.

[0023] (7) In the above-mentioned medical device, it can also be configured so that the main body includes: a core wire, which is composed of a metal wire; and a coil body, which has a structure formed by winding one or more wires around the outer circumference of the core wire and is connected to the core wire. According to the present medical device, since the main body includes the core wire and the coil body, when the medical device is rotated around the central axis, the coil body also rotates around the central axis, and the screwing action of the coil body having a spiral outer peripheral surface can reliably move the protrusion toward the distal side within the lesion, and can more effectively improve the penetration performance of the medical device. According to the present medical device, due to the presence of the coil body, the torque transmission performance of the front end of the medical device can be improved, and the flexibility of the front end of the medical device can be improved. Moreover, even if the protrusion is damaged, it can be suppressed from remaining in the body cavity.

[0024] (8) In the above-mentioned medical device, the protrusion may include a ring portion. According to this medical device, the protrusion can be shaped to have a wide portion and a thin linear portion, and the rotating protrusion can effectively perforate the lesion, thereby significantly improving the penetration performance of the medical device.

[0025] (9) In the above-mentioned medical device, the protrusion may include a loop portion, the metal wire constituting the core wire may include a front end portion, a base end portion, and an intermediate portion located between the front end portion and the base end portion, the front end portion and the base end portion of the metal wire being joined to each other at a position covered by the coil body, and the intermediate portion of the metal wire constituting the loop portion. According to this medical device, a core wire having a loop-shaped protrusion can be formed using a single metal wire, and as a result, the protrusion can be prevented from detaching compared to a structure in which the protrusion is formed as a separate body.

[0026] (10) In the above-mentioned medical device, the base end portion of the metal wire material constituting the core wire may include: a first portion; and a second portion adjacent to the first portion on the front end side, the second portion being joined to the front end portion of the metal wire material and having a cross-sectional area smaller than the cross-sectional area of ​​the first portion. According to this medical device, in the core wire, it is possible to suppress the width of the portion formed by joining the second portion of the base end portion of the metal wire material to the front end portion of the metal wire material from becoming too large, and to suppress the rigid gap between the portion of the base end portion of the metal wire material constituted by the first portion from becoming too large. Therefore, according to this medical device, the rigid gap of the core wire can be reduced, and the durability and operability of the medical device can be improved.

[0027] (11) In the above-mentioned medical device, the second portion of the base end portion of the metal wire material constituting the core wire may have a tapered shape in which the width gradually decreases from the boundary position with the first portion toward the distal end. According to this medical device, compared with a structure in which a step is provided at the boundary position between the second portion and the first portion of the base end portion of the metal wire material, it is possible to suppress the rigid gap of the metal wire material constituting the core wire from becoming excessively large, thereby effectively improving the durability and operability of the medical device.

[0028] (12) In the above-mentioned medical device, the coil body may be composed of a plurality of coils formed by winding a plurality of the wires around the outer periphery of the core wire. According to this medical device, the torque transmission performance and flexibility of the front end portion of the medical device can be effectively improved.

[0029] (13) In the above-mentioned medical device, the first central axis position may be located closer to the distal end than the center of the central axis position of the protruding portion. According to this medical device, the penetration performance can be effectively improved.

[0030] The technology disclosed in this specification can be implemented in various forms, for example, in the form of a medical device, a method for manufacturing the same, and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1It is an explanatory diagram schematically showing the structure of the guide wire according to the first embodiment.

[0032] Figure 2 It is an explanatory diagram showing the detailed structure of the core wire constituting the guide wire according to the first embodiment.

[0033] Figure 3 It is an explanatory diagram showing the detailed structure of the core wire constituting the guide wire according to the first embodiment.

[0034] Figure 4 It is an explanatory diagram showing an example of the method for producing the core wire according to the first embodiment.

[0035] Figure 5 This is an explanatory diagram showing an example of a method of using the guide wire according to the first embodiment.

[0036] Figure 6 It is an explanatory diagram showing the detailed structure of the core wire constituting the guide wire according to the second embodiment.

[0037] Figure 7 This is an explanatory diagram showing an example of a method for producing a core wire constituting the guide wire of the second embodiment.

[0038] Figure 8 It is an explanatory diagram showing the detailed structure of a core wire constituting the guide wire according to the third embodiment.

[0039] Figure 9 It is an explanatory diagram showing the detailed structure of a core wire constituting the guide wire according to the fourth embodiment.

[0040] Figure 10 This is an explanatory diagram showing an example of a method for producing a core wire constituting the guide wire of the fourth embodiment.

[0041] Figure 11 It is an explanatory diagram showing the detailed structure of a core wire constituting the guide wire according to the fifth embodiment.

[0042] Figure 12 It is an explanatory diagram showing the detailed structure of a core wire constituting the guide wire according to the sixth embodiment. DETAILED DESCRIPTION

[0043] A. First embodiment:

[0044] A-1. Structure of guidewire 100:

[0045] Figure 1 It is an explanatory diagram schematically showing the structure of the guide wire 100 according to the first embodiment. Figure 1 The structure of the side surface of the guide wire 100 (the side surface viewed from the X-axis direction) is shown. Figure 1In the Z axis, the positive direction side is the front end side (distal side) inserted into the body, and the negative direction side is the base end side (proximal side) operated by doctors and other operators. Figure 1 In FIG, a portion of the guide wire 100 is omitted. Figure 1 , the central axis AX of the guide wire 100 is shown to be a straight line parallel to the Z-axis direction. The guide wire 100 has a degree of flexibility that allows it to bend. These points also apply to the following figures.

[0046] In this specification, with respect to the guidewire 100 and its components, the distal end is referred to as the "tip end," the distal end and its vicinity as the "tip end," the proximal end is referred to as the "proximal end," and the proximal end and its vicinity as the "proximal end." The outer diameter of the guidewire 100 and its components refers to either the size or the width along a direction perpendicular to the central axis AX. A longitudinal cross-section of the guidewire 100 and its components refers to a cross-section that includes the central axis AX of the guidewire 100, and a transverse cross-section of the guidewire 100 and its components refers to a cross-section perpendicular to the central axis AX.

[0047] The guide wire 100 is a long medical device inserted into a blood vessel to treat a lesion (stenosis, occlusion) in the blood vessel. The total length of the guide wire 100 is, for example, approximately 1500 mm to 2000 mm. The guide wire 100 includes a core wire 10 and a coil body 20 .

[0048] The core wire 10 is an elongated member extending along the central axis AX of the guide wire 100 and is made of a metal wire. The core wire 10 has: a large diameter portion 11; a small diameter portion 13, which is located at the front end relative to the large diameter portion 11 and has a smaller diameter than the large diameter portion 11; a tapered portion 12, which is located between the large diameter portion 11 and the small diameter portion 13 and has a diameter that gradually decreases from the boundary position with the large diameter portion 11 toward the boundary position with the small diameter portion 13; and a protrusion 14, which is located at the front end relative to the small diameter portion 13. The shape of the cross section (XY cross section) at each position of the core wire 10 (excluding the protrusion 14) can take any shape. For example, the shape of the cross section at each position of the core wire 10 is circular or rectangular. The outer diameter of the large diameter portion 11 is, for example, about 0.2 mm to 0.8 mm. The structure of the core wire 10 will be described in further detail later.

[0049] Hereinafter, the portion of the guide wire 100 excluding the protruding portion 14 of the core wire 10 is also referred to as the main body 102. The guide wire 100 includes the elongated main body 102 and the protruding portion 14 that protrudes toward the distal end of the main body 102. Since the main body 102 has a circular cross-section over almost the entire length, the outer diameter can be measured at various axial positions.

[0050] Examples of the material used to form the core wire 10 include stainless steel (SUS302, SUS304, SUS316, etc.), Ni-Ti alloy, and piano wire. The core wire 10 may be formed entirely of the same material or of different materials for each portion.

[0051] The coil body 20 is a hollow cylindrical coil-shaped component formed by winding one or more wires around the outer circumference of the core wire 10. Each wire constituting the coil body 20 may be composed of a single bare wire, or a stranded wire formed by twisting a plurality of bare wires. In the present embodiment, the coil body 20 is composed of a plurality of coils formed by winding a plurality of wires, and each wire constituting the coil body 20 is a stranded wire. In the present embodiment, the coil body 20 covers substantially the entire thin-diameter portion 13 of the core wire 10. The outer diameter of the coil body 20 is, for example, about 0.3 mm to 1.0 mm. The coil body 20 may be in a shape with a constant outer diameter over the entire length, or in a tapered shape with the outer diameter decreasing toward the front end.

[0052] As the material forming the coil body 20, for example, a radiation-transmitting material such as stainless steel (SUS302, SUS304, SUS316, etc.), a Ni-Ti alloy, or piano wire, or a radiation-opaque material such as platinum, gold, tungsten, or an alloy thereof can be used. The coil body 20 can be formed of the same material as a whole, or each part can be formed of different materials.

[0053] The coil body 20 is joined to the core wire 10. More specifically, the coil body 20 is joined to the core wire 10 via a front-end side joint 31 formed near the front end of the coil body 20, a base-end side joint 33 formed near the base end of the coil body 20, and an intermediate joint 32 formed between the front end and the base end of the coil body 20. As materials for forming the front-end side joint 31, the base-end side joint 33, and the intermediate joint 32, for example, metal solder (Au-Sn alloy, Sn-Ag alloy, Sn-Pb alloy, Pb-Ag alloy, etc.), brazing material (aluminum alloy brazing material, silver brazing material, gold brazing material, etc.), adhesive (epoxy-based adhesive, etc.), etc. are used. The materials for forming the front-end side joint 31, the base-end side joint 33, and the intermediate joint 32 can be the same or different from each other. Each of the front-end side joint 31, the base-end side joint 33, and the intermediate joint 32 can be formed of the same material as a whole, or each part can be formed of different materials.

[0054] A-2. Detailed structure of core wire 10:

[0055] Figure 2 and Figure 3 1 is an explanatory diagram showing the detailed structure of the core wire 10 constituting the guide wire 100 of the first embodiment. Figure 2The structure of the front end portion of the guide wire 100 is shown in an enlarged manner. Figure 3 The structure of a partial longitudinal section (YZ longitudinal section) of the front end portion of the guide wire 100 is shown in column A. Figure 3 The structure of another partial longitudinal section (XZ longitudinal section) of the front end portion of the guide wire 100 is shown in column B. Figure 3 Column C shows Figure 3 The structure of the cross section (XY cross section) of the protruding portion 14 of the core wire 10 at the CC position of the A column. Figure 3 In columns A and B of FIG. 1 , the protrusion 14 is not shown as a cross section. Figure 3 The outer perimeter of the protrusion 14 shown in the column A represents the outline of the protrusion 14 when viewed from the X-axis direction (ie, from the first direction). Figure 3 The outer perimeter of protrusion 14 shown in column B represents the outline of protrusion 14 as viewed from the Y-axis direction (i.e., from the second direction). Hereinafter, the outline viewed from the X-axis direction will also be referred to as the first outline. Hereinafter, the outline viewed from the Y-axis direction will also be referred to as the second outline.

[0056] like Figures 1 to 3 As shown, the protrusion 14 of the core wire 10 is located on the front end side of the thin-diameter portion 13 covered by the coil body 20, and is a portion that protrudes toward the front end side from the front end 21 of the coil body 20. The length of the protrusion 14 along the direction of the central axis AX is, for example, approximately 0.5 mm to 2.0 mm. The base end of the protrusion 14 is covered by the front end side joint 31. The rest of the protrusion 14 is exposed to the outside.

[0057] The protrusion 14 of the core wire 10 has a ring portion surrounding the through hole 15 extending in the X-axis direction. More specifically, the protrusion 14 has a structure in which a wire material (the middle portion 43m of the metal wire material 10m described later) with a substantially rectangular cross section is bent into a ring shape around the X-axis and closed at the base end. Figure 3 As shown in column A, the first contour of the protrusion 14 has a shape with a curved outer perimeter. In this embodiment, the outer perimeter of the first contour of the protrusion 14 is generally arc-shaped. The inner perimeter of the first contour of the protrusion 14, which defines the through-hole 15, also has a curved inner perimeter. In this embodiment, the inner perimeter of the first contour of the protrusion 14 is generally arc-shaped.

[0058] like Figure 3As shown in column A of FIG, in the first outline of the protrusion 14, the width W1 at a first central axis position P1, approximately near the center of the protrusion 14 along the central axis AX, is greater than the width W2 at a second central axis position P2, further proximally than the first central axis position P1. In the first outline of the protrusion 14, the width W1 at the first central axis position P1 is greater than the width W3 at a third central axis position P3, further distally than the first central axis position P1. More specifically, the first outline of the protrusion 14 has a shape in which, at the proximal end, the width is substantially the same as that of the thinner portion 13 of the core wire 10, gradually increases in width from the proximal end toward the distal end, reaching a maximum width at the first central axis position P1, and then gradually decreases in width from the first central axis position P1 toward the distal end. The first central axis position P1 is located further distally than the center of the protrusion 14 along the central axis AX. In this embodiment, the maximum width of the first outline of the protrusion 14 (width W1 at the first central axis position P1) is equal to the maximum width Wm1 of the entire protrusion 14. The maximum width Wm1 of the protrusion 14 is, for example, approximately 0.2 mm to 1.0 mm.

[0059] In the following description, for convenience, the surface of the protrusion 14 viewed from the positive direction of the X-axis is referred to as the upper surface S3, and the surface of the protrusion 14 viewed from the negative direction of the X-axis is referred to as the lower surface S4. In this embodiment, the upper surface S3 and the lower surface S4 of the protrusion 14 are substantially flat, and the upper surface S3 and the lower surface S4 are substantially parallel to each other. That is, the second profile of the protrusion 14 (see Figure 3 The width of column B) (which can also be expressed as the thickness of the protrusion 14) is a substantially constant value Wm2.

[0060] like Figure 3 As shown in columns A and B of the table, the maximum width W1 of the first outline of protrusion 14 (= the maximum width Wm1 of the entire protrusion 14) is greater than the maximum width Wm2 of the second outline of protrusion 14. In other words, protrusion 14 has a flat shape with varying widths at various locations around central axis AX. The maximum width W1 (= Wm1) of the first outline of protrusion 14 is preferably 1.2 times or greater, more preferably 1.5 times or greater, and even more preferably 1.8 times or greater, the maximum width Wm2 of the second outline of protrusion 14.

[0061] like Figure 2 and Figure 3As shown, the surface of the protrusion 14 has an edge 16. Here, the edge 16 is the boundary (ridge) between two surfaces. In this embodiment, the surface of the protrusion 14 has: an edge 16 that serves as the boundary between the outer peripheral surface S1 (the surface constituting the outer peripheral line in the first contour) and the upper surface S3; an edge 16 that serves as the boundary between the outer peripheral surface S1 and the lower surface S4; an edge 16 that serves as the boundary between the inner peripheral surface S2 (the surface constituting the inner peripheral line in the first contour) and the upper surface S3; and an edge 16 that serves as the boundary between the inner peripheral surface S2 and the lower surface S4. Of these edges 16, the edge 16 that serves as the boundary between the outer peripheral surface S1 and the upper surface S3 and the edge 16 that serves as the boundary between the outer peripheral surface S1 and the lower surface S4 are located in the first contour as viewed from the X-axis direction. The X-axis direction is an example of the first direction within the scope of the technical solution. The Y-axis direction is an example of the second direction within the scope of the technical solution.

[0062] A-3. Method for manufacturing the guidewire 100:

[0063] The guide wire 100 of this embodiment can be manufactured, for example, by the following method: First, the core wire 10 is produced. Figure 4 1 is an explanatory diagram showing an example of a method for producing the core wire 10 according to the first embodiment. Figure 4 As shown in the A column of FIG, a metal wire 10m is prepared as a forming material of the core wire 10. Figure 4 Column A shows a portion of the front end side of the metal wire 10m, more specifically, a portion of the thin-diameter portion 13 of the core wire 10 and a portion that becomes the protrusion 14. Figure 4 As shown in column A of , a portion of the front end side of the metal wire 10m has a first base end 41m, a second base end 42m, an intermediate portion 43m, and a front end 44m. Hereinafter, the first base end 41m and the second base end 42m are also collectively referred to as the base end 45m. The first base end 41m is a rod-shaped portion having a substantially constant diameter. The second base end 42m is a portion extending from the front end of the first base end 41m toward the front end, and has a tapered shape with a diameter gradually decreasing toward the front end. That is, the second base end 42m has a cross-section with an area smaller than that of the cross-section of the first base end 41m. The intermediate portion 43m is a portion extending from the front end of the second base end 42m toward the front end, and is a rod-shaped portion having a substantially constant diameter (a diameter substantially the same as the diameter of the front end of the second base end 42m). As Figure 4As shown in column A, the cross-section of the middle portion 43m is roughly rectangular. The front end portion 44m is the portion extending from the front end of the middle portion 43m to the front end of the metal wire 10m, and has a tapered shape with the diameter gradually decreasing toward the front end. The tapered shape of the second base end portion 42m and the tapered shape of the front end portion 44m are set to match each other, and the length of the second base end portion 42m is roughly the same as the length of the front end portion 44m. A metal wire 10m of such a shape can be produced, for example, by preparing a wire with a roughly constant cross-sectional shape and grinding the wire. The first base end portion 41m is an example of the first part within the scope of the technical solution, and the second base end portion 42m is an example of the second part within the scope of the technical solution.

[0064] Then, if Figure 4 As shown in columns A and B of the figure, the metal wire 10m is bent back, resulting in a state where the tapered surface of the front end portion 44m abuts the tapered surface of the second base end portion 42m, and the middle portion 43m is annular. Thus, the middle portion 43m forms the annular portion of the protrusion 14 of the core wire 10. The mutually abutting front end portion 44m and the second base end portion 42m form a rod-shaped portion with a substantially constant outer diameter, which, together with the first base end portion 41m, constitute the thin-diameter portion 13 of the core wire 10. The portion of the metal wire 10m closer to the base end than the first base end portion 41m is formed with the tapered portion 12 and the thick-diameter portion 11 of the core wire 10 (not shown). Thus, the above-described manufacturing method can produce a core wire 10 having a protrusion 14, a thin-diameter portion 13, a tapered portion 12, and a thick-diameter portion 11.

[0065] The core wire 10 thus manufactured is inserted into the hollow portion of the coil body 20 prepared separately. At this time, the protrusion 14 of the core wire 10 is in a state of protruding toward the front end side than the front end 21 of the coil body 20. In this state, a front end side joint 31, an intermediate joint 32, and a base end side joint 33 are formed to join the coil body 20 and the core wire 10. Through the front end side joint 31, the front end portion 44m and the second base end portion 42m of the metal wire 10m constituting the core wire 10 are joined to each other at a position covered by the coil body 20. For example, the guide wire 100 of the above-mentioned structure can be manufactured by the above method.

[0066] A-4. How to use Guidewire 100:

[0067] Figure 5This is an explanatory diagram showing an example of how to use the guidewire 100 according to the first embodiment. First, a surgeon, such as a doctor, inserts the guide catheter 110 into the blood vessel 200 and advances the guide catheter 110 until the distal end of the guide catheter 110 reaches the location of the lesion 220 (e.g., chronic total occlusion). Next, the surgeon inserts the guidewire 100 into the hollow portion of the guide catheter 110 and advances the guidewire 100 toward the lesion 220 within the blood vessel 200. When the guidewire 100 advances to the point where the distal end of the guidewire 100 protrudes from the distal end of the guide catheter 110, the surgeon rotates the guidewire 100 about the central axis AX (clockwise in this embodiment) while advancing the guidewire 100 further toward the distal side. In this way, by rotating the guidewire 100 about the central axis AX while advancing, even if the protrusion 14 of the core wire 10 at the distal end of the guidewire 100 contacts the inner wall of the blood vessel 200, damage to the inner wall of the blood vessel 200 can be suppressed.

[0068] After the front end of the guide wire 100 arrives at the lesion 220, the operator still rotates the guide wire 100 around the central axis AX while the guide wire 100 is further advanced toward the distal side. Thus, the protrusion 14 of the core wire 10 enters the lesion 220, and the protrusion 14 rotates around the central axis AX in the lesion 220, thereby cutting the lesion 220. The coil body 20 with a spiral outer peripheral surface also enters the lesion 220, and the coil body 20 rotates around the central axis AX in the lesion 220, thereby being screwed into the distal side in the lesion 220. As a result, the front end of the guide wire 100 reliably advances toward the distal side in the lesion 220, and finally penetrates the lesion 220. Afterwards, the guide wire 100 that penetrates the lesion 220 is used as a track to advance a catheter (not shown) to the position of the lesion 220.

[0069] When the guide wire 100 is pulled out, the guide wire 100 is rotated about the central axis AX in the opposite direction to that during insertion (in the present embodiment, in the counterclockwise direction) while being withdrawn. Thus, the guide wire 100 is smoothly withdrawn by the rotation of the coil body 20 having a helical outer peripheral surface, and even if the protrusion 14 of the core wire 10 at the front end of the guide wire 100 contacts the inner wall of the blood vessel 200, damage to the inner wall of the blood vessel 200 can be suppressed.

[0070] A-5. Effects of the first embodiment:

[0071] As described above, the guidewire 100 of the first embodiment includes an elongated main body 102 and a protrusion 14 that protrudes distally from the distal end of the main body 102. The maximum width Wm1 of the first contour of the protrusion 14, as viewed in the X-axis direction perpendicular to the central axis AX of the main body 102, is greater than the maximum width Wm2 of the second contour as viewed in the Y-axis direction perpendicular to the central axis AX. When viewed in the X-axis direction, the first contour has a curved portion, and the width W1 of the first contour at the first central axis position P1 is greater than the width W2 of the first contour at the second central axis position P2, which is closer to the proximal end than the first central axis position P1.

[0072] Thus, in the guidewire 100 of the present embodiment, when observed from the X-axis direction, the protrusion 14 is shaped such that the first contour has a curved portion. In addition, the maximum value of the width of the first contour of the protrusion 14 observed from the X-axis direction is greater than the maximum value of the width of the second contour observed from the Y-axis direction. That is, the protrusion 14 has an asymmetrical shape. Therefore, when the protrusion 14 is located at the lesion 220, if the protrusion 14 is rotated around the central axis AX by rotating the guidewire 100 around the central axis AX, the lesion 220 can be efficiently perforated using the curved portion of the contour of the protrusion 14. As described above, according to the guidewire 100 of the present embodiment, the penetration performance can be improved, thereby improving the treatment efficiency of the guidewire 100.

[0073] In the guidewire 100 of this embodiment, the X-axis, the direction of sight corresponding to the first contour, is perpendicular to the Y-axis, the direction of sight corresponding to the second contour. In other words, the protrusion 14 is flat. Therefore, the guidewire 100 of this embodiment can reduce resistance when the protrusion 14 enters the lesion 220 and when the protrusion 14 advances distally within the lesion 220, effectively improving the penetration performance of the guidewire 100.

[0074] In the guidewire 100 of this embodiment, the maximum width W1 of the first contour of the protrusion 14 is equal to the maximum width Wm1 of the protrusion 14. That is, the direction in which the first contour of the protrusion 14 has a curved portion coincides with the direction in which the protrusion 14 has its maximum width Wm1. Therefore, according to the guidewire 100 of this embodiment, the width of the portion of the protrusion 14 corresponding to the curved portion can be maximized, effectively improving the perforation performance of the lesion 220 achieved by the rotation of the protrusion 14. As a result, the penetration performance of the guidewire 100 can be further effectively improved.

[0075] In the guidewire 100 of the present embodiment, the surface of the protrusion 14 has an edge 16 that serves as a boundary between two surfaces. Therefore, according to the guidewire 100 of the present embodiment, by rotating the protrusion 14 about the central axis AX, the edge 16 on the surface of the protrusion 14 can be used to perforate the lesion 220 by incising it. As a result, the penetration performance of the guidewire 100 can be more effectively improved. In the guidewire 100 of the present embodiment, the surface of the protrusion 14 has an edge 16 in the first contour observed from the X-axis direction. Therefore, according to the guidewire 100 of the present embodiment, the edge 16 can be arranged at the outermost position of the rotation trajectory when the protrusion 14 is rotated about the central axis AX. This allows the edge 16 of the rotating protrusion 14 to reliably contact the lesion 220, effectively improving the perforation performance of the lesion 220 achieved by the rotation of the protrusion 14. As a result, the penetration performance of the guidewire 100 can be extremely effectively improved.

[0076] In the guidewire 100 of this embodiment, when viewed from the X-axis direction, the width W1 of the first profile at the first center axis position P1 of the protrusion 14 is greater than the width W3 of the first profile at the third center axis position P3, which is closer to the distal end than the first center axis position P1. According to the guidewire 100 of this embodiment, the protrusion 14 has a portion that temporarily expands in diameter and then contracts in diameter from the base end toward the distal end. This allows the distal end portion of the protrusion 14 to have a shape that allows for greater penetration into the lesion 220. Furthermore, the width of the portion between the base end and the distal end of the protrusion 14 can be made relatively large, thereby improving the perforation performance of the lesion 220 achieved by rotation of the protrusion 14. Consequently, the penetration performance of the guidewire 100 can be more effectively improved.

[0077] In the guidewire 100 of this embodiment, the main body 102 includes: a core wire 10 composed of a metal wire; and a coil body 20 having a structure formed by winding one or more wires around the outer periphery of the core wire 10 and connected to the core wire 10. According to the guidewire 100 of this embodiment, since the main body 102 includes the core wire 10 and the coil body 20, when the guidewire 100 is rotated about the central axis AX, the coil body 20 also rotates about the central axis AX. The screwing action of the coil body 20 having a helical outer peripheral surface can reliably move the protrusion 14 toward the distal side within the lesion 220, and the penetration performance of the guidewire 100 can be more effectively improved. According to the guidewire 100 of this embodiment, the presence of the coil body 20 can improve the torque transmission performance of the front end of the guidewire 100 and improve the flexibility of the front end of the guidewire 100. Moreover, even if the protrusion 14 is damaged, it can be prevented from remaining in the body cavity.

[0078] In the guidewire 100 of this embodiment, the protrusion 14 has a loop portion. Therefore, according to the guidewire 100 of this embodiment, the shape of the protrusion 14 can be set to have a relatively wide portion and a relatively thin linear portion, and the lesion 220 can be effectively perforated by the rotating protrusion 14, which can greatly effectively improve the penetration performance of the guidewire 100.

[0079] In the guide wire 100 of the present embodiment, the protrusion 14 has a loop portion, and the metal wire 10m constituting the core wire 10 has a front end portion 44m, a base end portion 45m, and an intermediate portion 43m located between the front end portion 44m and the base end portion 45m. The front end portion 44m and the base end portion 45m of the metal wire 10m are joined to each other at a position covered by the coil body 20. The intermediate portion 43m of the metal wire 10m constitutes the loop portion of the protrusion 14 of the core wire 10. Therefore, according to the guide wire 100 of the present embodiment, the core wire 10 having the ring-shaped protrusion 14 can be formed using a single metal wire 10m, and as a result, compared with a structure in which the protrusion 14 is formed as a separate body, it is possible to suppress the protrusion 14 from detaching.

[0080] In the guidewire 100 of this embodiment, the base end 45m of the metal wire 10m includes a first base end 41m and a second base end 42m. The second base end 42m is a portion adjacent to the first base end 41m on the front end side. The second base end 42m has a smaller cross-section than the cross-section of the first base end 41m and is joined to the front end 44m of the metal wire 10m. Therefore, according to the guidewire 100 of this embodiment, in the core wire 10, it is possible to prevent the width of the portion formed by joining the second base end 42m and the front end 44m of the metal wire 10m (a portion of the front end side of the thin-diameter portion 13) from becoming too large, and to prevent the rigid gap between the portion formed by the first base end 41m (the remaining portion of the thin-diameter portion 13) from becoming too large. Therefore, according to the guidewire 100 of this embodiment, the rigid gap of the core wire 10 can be reduced, and the durability and operability of the guidewire 100 can be improved.

[0081] In the guidewire 100 of this embodiment, the second proximal end portion 42m of the metal wire 10m constituting the core wire 10 has a tapered shape whose width gradually decreases from the boundary with the first proximal end portion 41m toward the distal end. Therefore, according to the guidewire 100 of this embodiment, compared to a structure having a step at the boundary between the second proximal end portion 42m and the first proximal end portion 41m, it is possible to suppress excessive rigidity gaps within the metal wire 10m constituting the core wire 10, effectively improving the durability and operability of the guidewire 100.

[0082] In the guidewire 100 of this embodiment, the coil body 20 is composed of multiple coils formed by winding multiple wires around the outer periphery of the core wire 10. Compared with a single coil, multiple coils have better torque transmission and flexibility. Therefore, according to the guidewire 100 of this embodiment, the torque transmission and flexibility of the front end of the guidewire 100 can be effectively improved.

[0083] B. Second embodiment:

[0084] Figure 6 1 is an explanatory diagram showing the detailed structure of the core wire 10 constituting the guide wire 100a of the second embodiment. Figure 6 The structure of a partial longitudinal section (YZ longitudinal section) of the front end portion of the guide wire 100a is shown in column A. Figure 6 The structure of another partial longitudinal section (XZ longitudinal section) of the front end portion of the guide wire 100a is shown in column B. Figure 6 Column C shows Figure 6 The structure of the cross section (XY cross section) of the protruding portion 14a of the core wire 10 at the CC position of the A column. Figure 6 In columns A and B of FIG. 1 , the protrusion 14 a is not shown as a cross section. Figure 6 The outer peripheral line of the protrusion 14 a shown in the column A represents a first outline of the protrusion 14 a viewed from the X-axis direction (ie, viewed from the first direction). Figure 6 The outer perimeter of the protrusion 14a shown in the column B represents the second profile of the protrusion 14a as viewed from the Y-axis direction (i.e., as viewed from the second direction). Hereinafter, for the structures of the guidewire 100a of the second embodiment that are identical to those of the guidewire 100 of the first embodiment, the description thereof will be appropriately omitted by attaching the same reference numerals.

[0085] The shape of the protrusion 14a of the core wire 10 constituting the guide wire 100a of the second embodiment is different from that of the first embodiment. Specifically, the protrusion 14a of the second embodiment has the following structure: a wire having a substantially semicircular cross-section (the middle portion 43m of the metal wire 10m described later) is bent into a ring shape around the X-axis and closed at the base end. In the second embodiment, as Figure 6 As shown in columns B and C, the linear portion of the wire rod with a substantially semicircular cross section constituting the protrusion 14a faces the through hole 15, and the arc portion of the substantially semicircular cross section faces the outer circumference. The other structures of the protrusion 14a of the second embodiment are the same as those of the first embodiment.

[0086] Figure 7This is an explanatory diagram showing an example of a method for producing the core wire 10 constituting the guide wire 100a of the second embodiment. When producing the core wire 10 of the second embodiment, similarly to the first embodiment, a metal wire 10m having a first base end portion 41m, a second base end portion 42m, an intermediate portion 43m, and a front end portion 44m is produced. Figure 7 As shown in column A of FIG, the cross section of the middle portion 43m is set to be approximately semicircular instead of approximately rectangular. Figure 7 As shown in columns A and B of FIG, the metal wire 10m is bent back so that the tapered surface of the distal end portion 44m abuts the tapered surface of the second proximal end portion 42m and the intermediate portion 43m becomes annular. Thus, the intermediate portion 43m becomes the loop portion of the protruding portion 14a of the core wire 10.

[0087] As described above, the guide wire 100 a of the second embodiment has the same structure as the guide wire 100 of the first embodiment, and therefore achieves the same effects as those achieved by the guide wire 100 of the first embodiment (such as improvement in penetration performance).

[0088] C. Third embodiment:

[0089] Figure 8 1 is an explanatory diagram showing the detailed structure of the core wire 10 constituting the guide wire 100b of the third embodiment. Figure 8 The structure of a partial longitudinal section (YZ longitudinal section) of the front end portion of the guide wire 100b is shown in column A. Figure 8 The structure of another partial longitudinal section (XZ longitudinal section) of the front end portion of the guide wire 100b is shown in column B. Figure 8 Column C shows Figure 8 The structure of the cross section (XY cross section) of the protruding portion 14b of the core wire 10 at the CC position of the A column. Figure 8 In columns A and B of FIG. 1 , the protrusion 14 b is not shown as a cross section. Figure 8 The outer peripheral line of the protrusion 14 b shown in the column A represents a first outline of the protrusion 14 b viewed from the X-axis direction (ie, viewed from the first direction). Figure 8 The outer perimeter of the protrusion 14b shown in the column B represents the second profile of the protrusion 14b as viewed from the Y-axis direction (i.e., as viewed from the second direction). Hereinafter, for the structures of the guidewire 100b of the third embodiment that are identical to those of the guidewire 100a of the second embodiment described above, the description thereof will be appropriately omitted by attaching the same reference numerals.

[0090] The shape of the protrusion 14b of the core wire 10 constituting the guide wire 100b of the third embodiment is different from that of the second embodiment. Specifically, the protrusion 14b of the third embodiment is the same as the protrusion 14a of the second embodiment, and has a structure in which a wire having a substantially semicircular cross section is bent into a ring shape around the X axis. Figure 8 As shown in columns B and C of FIG, the arc-shaped portion of the wire rod with a substantially semicircular cross section of the protrusion 14b faces the through-hole 15, and the straight portion of the substantially semicircular cross section faces the outer circumference. The other structures of the protrusion 14b of the third embodiment are the same as those of the second embodiment.

[0091] When manufacturing the core wire 10 of the third embodiment, similarly to the second embodiment, a metal wire material 10m having a first base end portion 41m, a second base end portion 42m, an intermediate portion 43m, and a front end portion 44m is manufactured (see Figure 7 ). In this case, the cross section of the middle portion 43m is made substantially semicircular rather than substantially rectangular. However, in the third embodiment, when the metal wire 10m is bent so as to bend back the front end, the bending direction is opposite to that of the second embodiment, and the straight portion of the substantially semicircular cross section of the portion (middle portion 43m) of the metal wire 10m constituting the protrusion 14b is directed toward the outer peripheral side.

[0092] As described above, the guidewire 100b of the third embodiment has the same structure as the guidewire 100a of the second embodiment, and therefore has the same effect as the guidewire 100a of the second embodiment (improvement of penetration performance, etc.). In the guidewire 100b of the third embodiment, the surface of the protrusion 14b has an edge 16 in the first contour observed from the X-axis direction. Therefore, according to the guidewire 100b of the third embodiment, as with the guidewire 100 of the first embodiment, the edge 16 can be arranged at the outermost position of the rotation trajectory when the protrusion 14b is rotated around the central axis AX, so that the edge 16 of the rotating protrusion 14b can reliably contact the lesion 220, and the perforation performance of the lesion 220 achieved by the rotation of the protrusion 14b can be effectively improved. As a result, the penetration performance of the guidewire 100b can be extremely effectively improved.

[0093] D. Fourth embodiment:

[0094] Figure 9 1 is an explanatory diagram showing the detailed structure of the core wire 10 constituting the guide wire 100c of the fourth embodiment. Figure 9 The structure of a partial longitudinal section (YZ longitudinal section) of the front end portion of the guide wire 100c is shown in column A. Figure 9 The structure of another partial longitudinal section (XZ longitudinal section) of the front end portion of the guide wire 100c is shown in column B. Figure 9 Column C shows Figure 9 The structure of the cross section (XY cross section) of the protruding portion 14c of the core wire 10 at the CC position of the A column. Figure 9 In columns A and B of FIG. 1 , the protrusion 14 c is not shown as a cross section. Figure 9 The outer peripheral line of the protrusion 14 c shown in the column A represents a first outline of the protrusion 14 c viewed from the X-axis direction (ie, viewed from the first direction). Figure 9 The outer perimeter of the protrusion 14c shown in the column B represents the second profile of the protrusion 14c as viewed from the Y-axis direction (i.e., as viewed from the second direction). Hereinafter, the same reference numerals will be used to affix the same components of the guidewire 100c of the fourth embodiment as those of the guidewire 100a of the second embodiment, and description thereof will be omitted as appropriate.

[0095] The guide wire 100 c of the fourth embodiment is different from that of the second embodiment in the structure of the metal wire 10 m constituting the core wire 10 . Figure 10 This is an explanatory diagram showing an example of a method for producing the core wire 10 constituting the guide wire 100c of the fourth embodiment. When producing the core wire 10 of the fourth embodiment, a metal wire material 10m having a first base end portion 41m, a second base end portion 42m, an intermediate portion 43m, and a front end portion 44m is produced in the same manner as in the second embodiment. Figure 10 As shown in the A column of FIG, a step is provided at the boundary between the first base end portion 41m and the second base end portion 42m, so that the cross-sectional area of ​​the second base end portion 42m is smaller than the cross-sectional area of ​​the first base end portion 41m. The second base end portion 42m is formed as a rod-shaped portion having a substantially constant diameter, and its cross-sectional shape is formed to be substantially the same as the cross-sectional shape of the middle portion 43m. Figure 10 As shown in columns A and B of FIG, the metal wire 10m with such a structure is bent back, resulting in a state in which the outer peripheral surface of the tip end portion 44m abuts the outer peripheral surface of the second base end portion 42m, and the intermediate portion 43m is annular. Thus, the intermediate portion 43m forms the annular portion of the protruding portion 14c of the core wire 10, and the tip end portion 44m and the second base end portion 42m, which abut each other, form a rod-like shape with a substantially constant outer diameter, which, together with the first base end portion 41m, constitute the thin-diameter portion 13 of the core wire 10.

[0096] As described above, the guide wire 100c of the fourth embodiment has the same structure as the guide wire 100a of the second embodiment, and therefore achieves the same effects (such as improvement in penetration performance) as those achieved by the guide wire 100a of the second embodiment.

[0097] E. Fifth embodiment:

[0098] Figure 11 1 is an explanatory diagram showing the detailed structure of the core wire 10 constituting the guide wire 100d of the fifth embodiment. Figure 11 Hereinafter, the same components as those of the guide wire 100 of the first embodiment will be assigned the same reference numerals and their description will be omitted as appropriate.

[0099] The shape of the protrusion 14d of the core wire 10 constituting the guide wire 100d of the fifth embodiment is different from that of the first embodiment. Specifically, the protrusion 14d of the fifth embodiment is not in the shape of a ring portion, but in the shape of a paddle. That is, the protrusion 14d of the fifth embodiment has a structure in which a through hole 15 is embedded in the protrusion 14 of the first embodiment. Therefore, except for the absence of the through hole 15, the YZ longitudinal section and the XZ longitudinal section of the protrusion 14d of the fifth embodiment are the same shape as the YZ longitudinal section and the XZ longitudinal section of the protrusion 14 of the first embodiment. It should be noted that the protrusion 14d of such a shape can be produced by, for example, stamping or grinding a wire rod.

[0100] As described above, the guide wire 100d of the fifth embodiment has the same structure as the guide wire 100 of the first embodiment, and therefore achieves the same effects (such as improvement in penetration performance) as those achieved by the guide wire 100 of the first embodiment.

[0101] F. Sixth embodiment:

[0102] Figure 12 1 is an explanatory diagram showing the detailed structure of the core wire 10 constituting the guide wire 100e of the sixth embodiment. Figure 12 Hereinafter, the same components as those of the guide wire 100 of the first embodiment will be assigned the same reference numerals and their description will be omitted as appropriate.

[0103] The shape of the protrusion 14e of the core wire 10 constituting the guide wire 100e of the sixth embodiment is different from that of the first embodiment. Specifically, the protrusion 14e of the sixth embodiment is not in the shape of a ring portion, but in the shape of a spoon. That is, the protrusion 14e of the sixth embodiment has a structure in which a through hole 15 is embedded in the protrusion 14 of the first embodiment and a recess is formed on the upper surface S3. Therefore, except for the presence of a recess instead of the through hole 15, the YZ longitudinal section and XZ longitudinal section of the protrusion 14e of the sixth embodiment are the same shape as the YZ longitudinal section and XZ longitudinal section of the protrusion 14 of the first embodiment. It should be noted that a protrusion 14e of such a shape can be produced, for example, by stamping or grinding a wire rod.

[0104] As described above, the guide wire 100e of the sixth embodiment has the same structure as the guide wire 100 of the first embodiment, and thus achieves the same effects (such as improvement in penetration performance) as those achieved by the guide wire 100 of the first embodiment.

[0105] G. Modification:

[0106] The technology disclosed in this specification is not limited to the above-described embodiment, and can be modified in various forms without departing from the spirit and scope of the invention. For example, the following modifications are also possible.

[0107] The structure of the guide wire 100 of the above embodiment is merely an example and can be modified in various ways. For example, in the above embodiment, the coil body 20 is composed of a plurality of coils wound with a plurality of wires, and each wire constituting the coil body 20 is a twisted wire. Each wire constituting the coil body 20 may also be a single bare wire instead of a twisted wire. The coil body 20 may also be a single coil wound with a single wire instead of a plurality of coils. The coil body 20 may be a tightly wound coil or a loosely wound coil.

[0108] In the above embodiment, the core wire 10 includes the large diameter portion 11, the tapered portion 12, and the small diameter portion 13. The core wire 10 may not include at least one of these three portions, or may include other portions in addition to these three portions.

[0109] In the above embodiment, the shape and size of the protrusion 14 are merely examples. As long as the first contour of the protrusion 14 has a curved portion when viewed from the first direction, and the width of the first contour at the first central axis is greater than the width of the first contour at the second central axis, which is closer to the base end than the first central axis, the protrusion 14 may have other shapes and sizes. In the core wire 10, the protrusion 14 may be prepared separately and brazed to the thin-diameter portion 13.

[0110] In the above-described embodiment, at least one of the distal end side joint portion 31 , the intermediate joint portion 32 , and the proximal end side joint portion 33 may be omitted.

[0111] In the above embodiment, at least a portion of the guide wire 100 may be coated with resin, for example.

[0112] The materials of the components in the above embodiment are merely examples, and various modifications are possible. The method of manufacturing the guide wire 100 in the above embodiment is merely an example, and various modifications are possible.

[0113] In the above embodiment, the guidewire 100 for treating a lesion in a blood vessel is used as an example. The technology disclosed in this specification can also be applied to medical devices for treating lesions in body cavities (blood vessels, digestive tract, urinary tract, etc.).

[0114] Explanation of symbols

[0115] 10—core wire, 10m—metal wire, 11—thick diameter portion, 12—tapered portion, 13—thin diameter portion, 14—protrusion, 15—through hole, 16—edge, 20—coil body, 21—front end, 31—front end side joint, 32—middle joint, 33—base end side joint, 41m—first base end portion, 42m—second base end portion, 43m—middle portion, 44m—front end portion, 45m—base end portion, 100—guide wire, 102—main body, 110—guide catheter, 200—blood vessel, 220—lesion portion, AX—center axis, S1—outer circumference, S2—inner circumference, S3—upper surface, S4—lower surface.

Claims

1. A medical device, characterized in that have: a long, rectangular body; and a protrusion that protrudes toward the front end side from the front end of the main body, and the maximum width of the outline observed from a first direction perpendicular to the central axis of the main body is greater than the maximum width of the outline observed from a second direction perpendicular to the central axis, When viewed from the first direction, the contour has a curved portion, and a width of the contour at a first central axis position is larger than a width of the contour at a second central axis position closer to the base end than the first central axis position.

2. The medical device according to claim 1, wherein The first direction is orthogonal to the second direction.

3. The medical device according to claim 2, characterized in that The maximum value of the width of the outline viewed from the first direction is equal to the maximum width of the protrusion.

4. The medical device according to any one of claims 1 to 3, characterized in that The surface of the protrusion has an edge that serves as a boundary between two faces.

5. The medical device according to claim 4, characterized in that The surface of the protrusion has the edge in its outline viewed from the first direction.

6. The medical device according to any one of claims 1 to 5, characterized in that When viewed from the first direction, the width of the outline of the protruding portion at the first central axis position is larger than the width of the outline at a third central axis position closer to the front end than the first central axis position.

7. The medical device according to any one of claims 1 to 6, characterized in that The main body includes a core wire formed of a metal wire and a coil body having a structure in which one or more wires are wound around the outer circumference of the core wire and joined to the core wire.

8. The medical device according to any one of claims 1 to 7, characterized in that The protrusion has a ring portion.

9. The medical device according to claim 7, characterized in that The protrusion has a ring portion, The metal wire material constituting the core wire has a front end portion, a base end portion, and an intermediate portion located between the front end portion and the base end portion. The front end portion and the base end portion of the metal wire are joined to each other at a position covered by the coil body. The middle portion of the metal wire constitutes the loop portion.

10. The medical device according to claim 9, characterized in that The base end portion of the metal wire material constituting the core wire has: Part I; as well as The second portion is adjacent to the first portion at the front end side, is joined to the front end portion of the metal wire, and has a cross section smaller in area than the cross section of the first portion.

11. The medical device according to claim 10, characterized in that The second portion of the base end portion of the metal wire material constituting the core wire has a tapered shape in which the width gradually decreases from a boundary position with the first portion toward a distal end side.

12. The medical device according to any one of claims 9 to 11, characterized in that The coil body is composed of a plurality of coils formed by winding a plurality of the wires around the outer circumference of the core wire.

13. The medical device according to any one of claims 1 to 12, characterized in that The first central axis position is located on the distal side of the center of the central axis position of the protruding portion.

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