Guide wire
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- ASAHI INTECC CO LTD
- Filing Date
- 2023-06-28
- Publication Date
- 2026-04-10
AI Technical Summary
Existing guidewires face limitations in flexibility, particularly at the distal end, which affects their ability to navigate through narrow lesions and maintain torque transmittance.
The guidewire design incorporates a stranded wire with alternating large and small diameter portions, where the large diameter portions are positioned on the inner circumference and small diameter portions on the outer circumference, along with a gradually changing cross-sectional area from the proximal to the distal end, enhancing flexibility and torque transmittance.
This design improves the guidewire's flexibility and ability to navigate narrow lesions while maintaining structural integrity and reducing the risk of kinking, thereby enhancing its performance in medical procedures.
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
[Technical field]
[0001] The technology disclosed herein relates to guidewires. [Background technology]
[0002] A guidewire is a medical device that is inserted into a biological lumen such as a blood vessel. The guidewire is used, for example, to guide a catheter to a lesion in a biological lumen during diagnosis or treatment of the biological lumen using the catheter. The guidewire includes a core shaft and a coil body in which a stranded wire made of a plurality of strands is wound helically around the outer periphery of the core shaft.
[0003] 2. Description of the Related Art Conventionally, guidewires have been disclosed in which the flexibility is improved by reducing the outer diameter of the coil body on the distal end side of the guidewire (see, for example, Patent Document 1). [Prior art documents] [Patent documents]
[0004] [Patent Document 1] Special Publication No. 2002-539901 Summary of the Invention [Problem to be solved by the invention]
[0005] There was room for further improvement in the flexibility of the distal end of the guidewire.
[0006] This specification discloses a technique that can solve the above-mentioned problems. [Means for solving the problem]
[0007] The technology disclosed in this specification can be realized, for example, in the following forms.
[0008] (1) A guidewire disclosed in the present specification includes a core shaft and a coil body in which a stranded wire formed by twisting a plurality of strands is wound in a spiral shape around an outer periphery of the core shaft. The plurality of strands of the stranded wire include a plurality of side wires which are strands located on the outer periphery of the stranded wire, and each of the side wires has a plurality of large diameter portions and a plurality of small diameter portions. Each of the small diameter portions is sandwiched between two of the plurality of large diameter portions in the extension direction of each of the side wires, the two large diameter portions having a larger cross-sectional area than each of the small diameter portions. Each of the side wires includes a portion in which the cross-sectional area of the plurality of large diameter portions decreases from the base end side to the tip end side of the coil body, and each of the side wires includes a portion in which the cross-sectional area of the plurality of small diameter portions decreases from the base end side to the tip end side of the coil body.
[0009] In this guidewire, the side wire has a plurality of large diameter portions and a plurality of small diameter portions, and the cross-sectional area of each of the plurality of large diameter portions and the plurality of small diameter portions includes a portion that decreases from the base end side of the coil body toward the tip end side, so that the cross-sectional area of the stranded wire at the tip end side of the coil body can be reduced, and the flexibility of the coil body and, ultimately, the tip end side of the guidewire can be improved.
[0010] Furthermore, the present guidewire has a large diameter portion having a relatively large cross-sectional area and a small diameter portion having a relatively small cross-sectional area, thereby enabling the guidewire to have both good torque transmission ability and flexibility.
[0011] (2) In the above guidewire, the large diameter portion of each of the side wires may be arranged on the inner periphery side of the coil body and the small diameter portion of each of the side wires may be arranged on the outer periphery side of the coil body at the distal end of the coil body. According to this arrangement, the large diameter portion is arranged on the inner periphery side of the coil body and the small diameter portion is arranged on the outer periphery side of the coil body at the distal end of the coil body. Therefore, compared to a configuration in which the large diameter portion is arranged on the outer periphery side, for example, the outer diameter of the coil body can be made smaller, and the flexibility can be maintained while improving the passability through a narrow lesion.
[0012] (3) In the above guidewire, the stranded wire may be configured such that the surface constituting the outer circumferential surface of the coil body at the distal end of the coil body has a flattened shape. With this configuration, the guidewire can be easily bent and returned to its original shape, compared to a configuration in which the surface constituting the outer circumferential surface is, for example, arc-shaped.
[0013] (4) In the above guidewire, in at least one cross section of the stranded wire, an outermost wire, which is the wire among the plurality of wires that is farthest from the center of the core shaft, may have a gap between it and the other adjacent wires. According to this configuration, since the outermost wire has a gap between it and the other adjacent wires, the outermost wire does not interfere with the wires adjacent to the outermost wire, thereby improving flexibility and making it easier to bend the guidewire or return it to its original shape.
[0014] (5) Another guidewire disclosed in the present specification includes a core shaft, and a coil body in which a stranded wire formed by twisting together a plurality of strands is wound in a spiral shape around an outer periphery of the core shaft. When an innermost strand is an innermost strand among the plurality of strands in each cross section of the coil body that is the shortest distance from the center of the core shaft, the cross-sectional area of the innermost strand at a tip end of the coil body is smaller than the cross-sectional area of the innermost strand at a base end of the coil body.
[0015] In this guidewire, the cross-sectional area of the innermost wire at the distal end of the coil body is smaller than the cross-sectional area of the innermost wire at the proximal end of the coil body, so that the cross-sectional area of the stranded wire at the distal end of the coil body can be reduced, thereby improving the flexibility of the coil body and, ultimately, the distal end of the guidewire.
[0016] (6) In the above guidewire, when the wire that is the furthest from the center of the core shaft among the plurality of wires in each cross section of the coil body is defined as the outermost wire, the cross-sectional area of the outermost wire at the tip of the coil body may be smaller than the cross-sectional area of the outermost wire at the base end of the coil body. According to this configuration, the cross-sectional area of the outermost wire at the tip of the coil body is smaller than the cross-sectional area of the outermost wire at the base end of the coil body. Therefore, the cross-sectional area of the tip of the coil body in the stranded wire can be reduced, and the flexibility of the coil body and therefore the tip side of the guidewire can be improved. Also, according to this configuration, the cross-sectional areas of the tip of the coil body are smaller than the cross-sectional area of the base end of the coil body for both the innermost wire and the outermost wire. Therefore, compared to a configuration in which the cross-sectional area of the entire stranded wire is approximately the same and only the cross-sectional area of the outermost wire is reduced, the wire diameter of each wire constituting the coil body can be guaranteed, and the wires can be prevented from breaking, thereby improving the safety of the guidewire.
[0017] (7) In the above guidewire, the coil body may include a gradually changing portion in which the cross-sectional area of the coil body continuously decreases from the base end side to the tip end side. With this configuration, the coil body includes a gradually changing portion, so that the change in stiffness between the base end side and the tip end side of the coil body can be made gentle. As a result, for example, damage to the guidewire due to the occurrence of kinking can be suppressed, and torque transmission can be improved.
[0018] (8) In the above guidewire, the gradually changing portion of the coil body may include an outer diameter gradually changing portion in which the cross-sectional area of the outermost wire is continuously reduced from the base end side to the tip end side of the coil body, and an inner diameter gradually changing portion in which the cross-sectional area of the innermost wire is continuously reduced from the base end side to the tip end side of the coil body, and the base end of the outer diameter gradually changing portion and the base end of the inner diameter gradually changing portion may be located at different positions in the axial direction of the coil body. According to this configuration, the gradually changing portion includes an outer diameter gradually changing portion and an inner diameter gradually changing portion, and the base end of the outer diameter gradually changing portion and the base end of the inner diameter gradually changing portion are located at different positions in the axial direction of the coil body, so that the change in rigidity between the base end side and the tip side of the coil body can be made more gradual. Therefore, for example, damage to the guidewire due to the occurrence of kinking can be more effectively suppressed, and torque transmissibility can be more effectively improved.
[0019] (9) In the above guidewire, the stranded wire may be configured such that a surface constituting an outer circumferential surface of the coil body at the distal end of the coil body has a flat shape. With this configuration, the guidewire can be easily bent and returned to its original shape, compared to a configuration in which the surface constituting the outer circumferential surface is, for example, arc-shaped.
[0020] (10) In the above guidewire, in at least one cross section of the stranded wire, an outermost wire, which is the wire among the plurality of wires that is farthest from the center of the core shaft, may have a gap between it and the other adjacent wires. According to this configuration, since the outermost wire has a gap between it and the other adjacent wires, the outermost wire does not interfere with the wires adjacent to the outermost wire, thereby improving flexibility and making it easier to bend the guidewire or return it to its original shape.
[0021] The techniques disclosed in this specification can be realized in various forms, for example, in the form of a guidewire and a method for manufacturing a guidewire. [Brief description of the drawings]
[0022] [Figure 1] FIG. 1 is an explanatory diagram illustrating a schematic configuration of a guidewire 100 according to a first embodiment. [Diagram 2] FIG. 2 is an explanatory diagram showing the cross-sectional configuration of the guidewire 100 taken along the line II-II in FIG. [Diagram 3] FIG. 2 is an explanatory diagram showing the cross-sectional configuration of a specific stranded wire 300X taken along the line III-III in FIG. 1; [Figure 4] FIG. 4 is an explanatory diagram showing the cross-sectional configuration of a specific stranded wire 300X taken along the line IV-IV in FIG. [Diagram 5] FIG. 2 is an explanatory diagram showing the cross-sectional configuration of a specific twisted wire 300X at the position VV in FIG. [Figure 6] FIG. 2 is an explanatory diagram showing the cross-sectional configuration of a specific stranded wire 300X taken along the line VI-VI in FIG. [Figure 7] FIG. 7 is an explanatory diagram showing the cross-sectional configuration of a specific stranded wire 300X taken at position VII-VII in FIG. [Figure 8] Detailed configuration of siding 330 [Figure 9] FIG. 13 is an explanatory diagram illustrating a schematic configuration of a guidewire 100a according to a second embodiment. [Figure 10] FIG. 2 is an explanatory diagram showing the cross-sectional configuration of a specific twisted wire 300Xa at a position XX. [Figure 11] FIG. 13 is an explanatory diagram illustrating a schematic configuration of a guidewire 100b according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] A. First embodiment: A-1. Configuration of guidewire 100: FIG. 1 is an explanatory diagram that shows a schematic configuration of the guidewire 100 in the first embodiment. FIG. 1 shows a longitudinal section of the guidewire 100. In FIG. 1, the positive Z-axis direction side is the tip side (distal side) that is inserted into the body, and the negative Z-axis direction side is the base end side (proximal side) that is operated by an operator such as a doctor. In FIG. 1, a part of the guidewire 100 is omitted. In addition, FIG. 1 shows a state in which the central axis AX of the core shaft 10 of the guidewire 100, which will be described later, is linear and parallel to the Z-axis direction, but the guidewire 100 has flexibility to the extent that it can be curved. These points are the same in the subsequent figures. In addition, in this specification, the tip end of the guidewire 100 and each of its constituent members are referred to as the "tip end", the tip end and its vicinity are referred to as the "tip portion", the base end end is referred to as the "base end", and the base end and its vicinity are referred to as the "base end portion". Furthermore, the longitudinal cross section of the guidewire 100 and each of its constituent members means a cross section including the central axis AX (YZ cross section), and the transverse cross section of the guidewire 100 and each of its constituent members means a cross section perpendicular to the central axis AX (XY cross section).
[0024] The guidewire 100 is a medical device that is inserted into a biological lumen such as a blood vessel. The guidewire 100 is used, for example, to guide another medical device such as a catheter to a desired position in a biological lumen. The total length of the guidewire 100 is, for example, about 1500 mm or more and 3000 mm or less, and the outer diameter of the guidewire 100 is, for example, about 0.1 mm or more and 1.2 mm or less.
[0025] The guidewire 100 includes a core shaft 10 , a coil body 30 , a distal joint portion 42 , a proximal joint portion 44 , and a resin portion 50 .
[0026] The core shaft 10 is an elongated member extending along the central axis AX. The core shaft 10 has a thin diameter portion 11, a tapered portion 12, and a thick diameter portion 13. The thin diameter portion 11 is a portion including the tip of the core shaft 10. The thick diameter portion 13 is located on the base end side with respect to the thin diameter portion 11. The outer diameter of the thick diameter portion 13 is larger than the outer diameter of the thin diameter portion 11, for example, about 0.2 mm or more and 0.6 mm or less. The tapered portion 12 is located between the thin diameter portion 11 and the thick diameter portion 13. The outer diameter of the tapered portion 12 gradually increases from the boundary position with the thin diameter portion 11 toward the boundary position with the thick diameter portion 13. The shape of the cross section at each position of the core shaft 10 can be any shape, for example, a circle or a rectangle.
[0027] The core shaft 10 is made of a known material, for example, a metal material, more specifically, stainless steel (SUS302, SUS304, SUS316, etc.), a superelastic alloy such as a Ni-Ti alloy, a piano wire, a nickel-chromium alloy, a cobalt alloy, tungsten, etc. The core shaft 10 may be made of the same material as a whole, or may be made of different materials in different parts.
[0028] Fig. 2 is an explanatory diagram showing the cross-sectional configuration of the guidewire 100 taken at the position II-II in Fig. 1. As shown in Fig. 1 and Fig. 2, the coil body 30 is a coil-shaped member formed into a hollow cylinder, and has a configuration in which a stranded wire 300 formed by twisting together a plurality of wires 310 is wound in a spiral shape around the outer periphery of the core shaft 10. An inner cavity H is formed between the core shaft 10 and the coil body 30. In this embodiment, the coil body 30 has a configuration in which eight stranded wires 300 are tightly wound.
[0029] The coil body 30 is made of a known material, such as a metal material, more specifically, stainless steel (SUS302, SUS304, SUS316, etc.), a superelastic alloy such as a Ni-Ti alloy, a piano wire, a nickel-chromium alloy, a cobalt alloy, tungsten, etc. The stranded wires 300 may be made of the same material or different materials. The strands 310 (described later) constituting the stranded wire 300 may be made of the same material or different materials. The detailed configuration of the coil body 300 will be described later.
[0030] The tip side joint 42 is a member that joins the tip of the core shaft 10 and the tip of the coil body 30. Specifically, the tip of the core shaft 10 and the tip of the coil body 30 are fixed so as to be embedded inside the tip side joint 42. The outer peripheral surface on the tip side of the tip side joint 42 is a smooth surface (for example, a substantially hemispherical surface).
[0031] The base-end joint portion 44 is a member that joins the core shaft 10 and the base end of the coil body 30 at a predetermined position between the base end and the tip end of the core shaft 10. Specifically, the base end of the coil body 30 is fixed so as to be embedded inside the base-end joint portion 44.
[0032] The material constituting the distal end joint 42 and the proximal end joint 44 is a known material, such as brazing material (aluminum alloy brazing, silver brazing, gold brazing, etc.), metal solder (Ag-Sn alloy, Au-Sn alloy, etc.), adhesive (epoxy adhesive, etc.), etc. In this embodiment, the material constituting the distal end joint 42 and the proximal end joint 44 is brazing material.
[0033] The resin portion 50 is made of resin and is a coating member that covers the outer circumferential surfaces of the coil body 30, the distal joint portion 42, and the proximal joint portion 44. A known material is used to form the resin portion 50, such as polyurethane, polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polyimide, polyvinyl propylene, fluororesins such as PTFE, silicone resins, etc. The thickness of the resin portion 50 is, for example, about 0.01 mm or more and 0.1 mm or less.
[0034] A-2. Detailed configuration of coil body 30: Next, a detailed configuration of the coil body 30 in the guidewire 100 of this embodiment will be described. As shown in Fig. 2, the coil body 30 of the guidewire 100 of this embodiment is composed of a plurality of stranded wires 300. Each stranded wire 300 is integrally formed from the base end to the tip end.
[0035] As shown in FIG. 1, the coil body 30 has a base end BP, a gradually changing portion GP, and a flat portion FP. The gradually changing portion GP includes an inner diameter gradually changing portion IP and an outer diameter gradually changing portion OP. The base end BP is a portion including the base end of the coil body 30. The inner diameter gradually changing portion IP is a portion adjacent to the base end BP on the distal side of the base end BP. The outer diameter gradually changing portion OP is a portion adjacent to the inner diameter gradually changing portion IP on the distal side of the inner diameter gradually changing portion IP. In other words, the outer diameter gradually changing portion OP and the inner diameter gradually changing portion IP do not overlap with each other in the axial direction of the coil body 30, and the base end of the outer diameter gradually changing portion OP and the base end of the inner diameter gradually changing portion IP are located at different positions in the axial direction of the coil body 30. The flat portion FP is a portion including the tip of the coil body 30, and is a portion adjacent to the outer diameter gradually changing portion OP on the distal side of the outer diameter gradually changing portion OP. The flat portion FP is an example of a tip portion in the claims.
[0036] The outer diameter DE and the inner diameter DI of the coil body 30 are not constant from the base end to the tip of the coil body 30, but change at a predetermined position from the base end to the tip. Specifically, at the base end BP, the outer diameter DE and the inner diameter DI are substantially constant from the base end to the tip. At the inner diameter gradually changing portion IP, the outer diameter DE is substantially constant from the base end to the tip, and the inner diameter DI increases continuously from the base end to the tip. At the outer diameter gradually changing portion OP, the outer diameter DE decreases continuously from the base end to the tip, and the inner diameter DI is substantially constant from the base end to the tip. At the flat portion FP, the outer diameter DE and the inner diameter DI are substantially constant from the base end to the tip. Therefore, the flat portion FP of the coil body 30 has a smaller outer diameter DE and a larger inner diameter DI than the base end BP of the coil body 30. The outer diameter DE is the diameter of the circumscribing circle OC of the coil body 30, and the inner diameter DI is the diameter of the inscribing circle IC of the coil body 30.
[0037] Each of the twisted wires 300 constituting the coil body 30 will be described with reference to Fig. 2. Fig. 2 shows a cross section of the coil body 30 at the base end BP (hereinafter, may be abbreviated simply as "cross section at the base end BP"). Note that the cross section of the coil body 30 shown in Fig. 2 is one example of a cross section of the coil body 30, and other cross sections may have a different configuration from that shown in the cross section of the coil body 30 shown in Fig. 2. Below, one twisted wire 300 (hereinafter, referred to as "specific twisted wire 300X") among the twisted wires 300 constituting the coil body 30 will be described, but the twisted wires 300 other than the specific twisted wire 300X also have the same configuration as the specific twisted wire 300X.
[0038] The specific stranded wire 300X is formed by twisting together a plurality of strands 310. Specifically, the plurality of strands 310 includes one core wire 320 and a plurality (six in this embodiment) of side wires 330. The core wire 320 is located on the center side of the specific stranded wire 300X in cross section. The side wires 330 are wound in a spiral shape along the outer circumferential surface of the core wire 320 and are located on the outer circumferential side of the specific stranded wire 300X. In the cross section of the base end BP, each strand 310 has a substantially circular shape. In the cross section of the base end BP, the core wire 320 and the side wire 330 are in contact with each other in the radial direction of the specific stranded wire 300X, and adjacent side wires 330 are in contact with each other in the circumferential direction of the specific stranded wire 300X. More specifically, each side wire 330 has no gap between adjacent strands 310. The diameter of each side wire 330 is, for example, about 0.01 mm or more and 0.1 mm or less.
[0039] 2, the side wires 330 constituting the specific stranded wire 300X are composed of a first side wire 331, a second side wire 332, a third side wire 333, a fourth side wire 334, a fifth side wire 335, and a sixth side wire 336. The first side wire 331, the second side wire 332, the third side wire 333, the fourth side wire 334, the fifth side wire 335, and the sixth side wire 336 are arranged in this order around the core wire 320 in a clockwise direction when viewed from the positive Z-axis direction.
[0040] In the cross section at the base end BP, the first side wire 331 can be said to be the wire that is the longest distance from the center O of the core shaft 10 (the position of the central axis AX in the cross section) among the wires 310 constituting the specific stranded wire 300X. Like the first side wire 331 in the cross section at the base end BP, the wire that is the longest distance from the center O of the core shaft 10 among the multiple wires 310 in each cross section of the guidewire 100 is referred to as the outermost wire OWm, and the side wire adjacent to the outermost wire OWm, such as the second side wire 332 and the sixth side wire 336, is referred to as the outer wire OW. In addition, in the cross section at the base end BP, the fourth side wire 334 can be said to be the wire that is the shortest distance from the center O of the core shaft 10 among the wires 310 constituting the specific stranded wire 300X. In each cross section of the guidewire 100, the wire that is shortest distance from the center O of the core shaft 10 among the multiple wires 310, such as the fourth side wire 334 in the cross section of the base end BP, is referred to as the innermost wire IWm, and the side wires adjacent to the innermost wire IWm, such as the third side wire 333 and the fifth side wire 335, are referred to as the inner wires IW. Note that "the wire that is longest (shortest) distance from the center O of the core shaft 10" refers to the wire that is longest (shortest) in the radial direction RD from the center O of the core shaft 10 among the wires 310 constituting the specific stranded wire 300X.
[0041] Fig. 3 is an explanatory diagram showing the cross-sectional configuration of the specific stranded wire 300X taken at position III-III in Fig. 1, Fig. 4 is an explanatory diagram showing the cross-sectional configuration of the specific stranded wire 300X taken at position IV-IV in Fig. 1, Fig. 5 is an explanatory diagram showing the cross-sectional configuration of the specific stranded wire 300X taken at position VV in Fig. 1, Fig. 6 is an explanatory diagram showing the cross-sectional configuration of the specific stranded wire 300X taken at position VI-VI in Fig. 1, and Fig. 7 is an explanatory diagram showing the cross-sectional configuration of the specific stranded wire 300X taken at position VII-VII in Fig. 1. The cross sections of the specific stranded wire 300X at the gradual change portion GP and the flat portion FP will be described with reference to Figs. 3 to 7.
[0042] Fig. 3 shows the configuration of the specific stranded wire 300X on a cross section of the coil body 30 in the gradually changing inner diameter portion IP (hereinafter may be abbreviated as "cross section on the base end side of the gradually changing inner diameter portion IP"). Fig. 4 shows the configuration of the specific stranded wire 300X on a cross section of the coil body 30 in the gradually changing inner diameter portion IP, the cross section being closer to the tip side than the cross section shown in Fig. 3 (hereinafter may be abbreviated as "cross section on the tip side of the gradually changing inner diameter portion IP").
[0043] As shown in Fig. 2 to Fig. 4, the innermost wire IWm in the gradually changing inner diameter portion IP is smaller in diameter than the innermost wire IWm in the proximal end BP. That is, the diameters id1 and id2, which are the radial length of the innermost wire IWm in the gradually changing inner diameter portion IP, are smaller than the diameter id0, which is the radial length of the innermost wire IWm in the proximal end BP. Therefore, the diameters D1 and D2, which are the radial length of the specific stranded wire 300X in the gradually changing inner diameter portion IP, are smaller than the diameter D0, which is the radial length of the specific stranded wire 300X in the proximal end BP. In other words, the cross-sectional area of the innermost wire IWm in the gradually changing inner diameter portion IP is smaller than the cross-sectional area of the innermost wire IWm in the proximal end BP, and therefore the cross-sectional area of the specific stranded wire 300X in the gradually changing inner diameter portion IP is smaller than the cross-sectional area of the specific stranded wire 300X in the proximal end BP.
[0044] As shown in Fig. 3 and Fig. 4, the diameter od2 of the outermost wire OWm in the cross section at the tip end of the inner diameter gradually changing portion IP is substantially the same as the diameter od1 of the outermost wire OWm in the cross section at the base end of the inner diameter gradually changing portion IP. The diameter id2 of the innermost wire IWm in the cross section at the tip end of the inner diameter gradually changing portion IP is smaller than the diameter id1 of the innermost wire IWm in the cross section at the base end of the inner diameter gradually changing portion IP. That is, in the inner diameter gradually changing portion IP, the diameter of the outermost wire OWm is substantially constant from the base end to the tip, and the diameter of the innermost wire IWm is continuously smaller from the base end to the tip. Due to this configuration, as described above, the outer diameter DE of the coil body 30 in the inner diameter gradually changing portion IP is substantially constant from the base end to the tip, and the inner diameter DI of the coil body 30 in the inner diameter gradually changing portion IP is continuously larger from the base end to the tip. In addition, in the gradually changing inner diameter section IP, as the diameter of the innermost wire IWm becomes continuously smaller from the base end to the tip, the cross-sectional area of the innermost wire IWm becomes continuously smaller from the base end to the tip, and thus the cross-sectional area of the specific stranded wire 300X becomes continuously smaller from the base end to the tip.
[0045] Fig. 5 shows the configuration of the specific stranded wire 300X on a cross section of the coil body 30 in the outer diameter gradually changing portion OP (hereinafter may be abbreviated as "cross section on the base end side of the outer diameter gradually changing portion OP"). Fig. 6 shows the configuration of the specific stranded wire 300X on a cross section of the coil body 30 in the outer diameter gradually changing portion OP, the cross section being closer to the tip side than the cross section shown in Fig. 5 (hereinafter may be abbreviated as "cross section on the tip side of the outer diameter gradually changing portion OP").
[0046] 2 to 6, the innermost wire IWm in the outer diameter gradually changing portion OP is smaller in diameter than the innermost wire IWm in the base end portion BP, similar to the innermost wire IWm in the inner diameter gradually changing portion IP. Furthermore, the outermost wire OWm in the outer diameter gradually changing portion OP is missing a part on the outer periphery side of the coil body 30 compared to the outermost wire OWm in the base end portion BP and the inner diameter gradually changing portion IP, and the surface facing the outer periphery of the coil body 30 has a flat shape. That is, the diameters id3 and id4, which are the radial lengths of the innermost wire IWm in the outer diameter gradually changing portion OP, are smaller than the diameter id0 of the innermost wire IWm in the base end portion BP, and the diameters od3 and od4, which are the radial lengths of the outermost wire OWm in the outer diameter gradually changing portion OP, are smaller than the diameters od0, od1, and od2 of the outermost wire OWm in the base end portion BP and the inner diameter gradually changing portion IP. Therefore, diameters D3, D4, which are the radial lengths of the specific stranded wire 300X at the outer diameter gradually changing portion OP, are smaller than diameters D0, D1, D2 of the specific stranded wire 300X at the proximal end BP and the inner diameter gradually changing portion IP. In other words, the cross-sectional area of the outermost strand OWm at the outer diameter gradually changing portion OP is smaller than the cross-sectional area of the outermost strand OWm at the proximal end BP and the inner diameter gradually changing portion IP, and therefore the cross-sectional area of the specific stranded wire 300X at the outer diameter gradually changing portion OP is smaller than the cross-sectional area of the specific stranded wire 300X at the proximal end BP and the inner diameter gradually changing portion IP.
[0047] As shown in Fig. 5 and Fig. 6, the diameter od4 of the outermost wire OWm in the cross section at the tip side of the outer diameter gradually changing portion OP is smaller than the diameter od3 of the outermost wire OWm in the cross section at the base end side of the outer diameter gradually changing portion OP. The diameter id4 of the innermost wire IWm in the cross section at the tip side of the outer diameter gradually changing portion OP is substantially the same as the diameter id3 of the innermost wire IWm in the cross section at the base end side of the outer diameter gradually changing portion OP. That is, in the outer diameter gradually changing portion OP, the diameter of the outermost wire OWm becomes continuously smaller from the base end to the tip, and the diameter of the innermost wire IWm is substantially constant from the base end to the tip. Due to this configuration, as described above, the outer diameter DE of the coil body 30 in the outer diameter gradually changing portion OP becomes continuously smaller from the base end to the tip, and the inner diameter DI of the coil body 30 in the outer diameter gradually changing portion OP is substantially constant from the base end to the tip. In addition, in the gradually changing outer diameter section OP, as the diameter of the outermost wire OWm becomes continuously smaller from the base end to the tip, the cross-sectional area of the outermost wire OWm becomes continuously smaller from the base end to the tip, and ultimately, the cross-sectional area of the specific stranded wire 300X becomes continuously smaller from the base end to the tip.
[0048] 7 shows the configuration of the specific stranded wire 300X on a cross section of the coil body 30 at the flat portion FP (hereinafter sometimes abbreviated as "cross section of the flat portion FP"). The cross section of the flat portion FP has a basically identical configuration from the tip to the base end, and is also basically identical to the cross section of the specific stranded wire 300X at the tip of the portion OP with gradually changing outer diameter. Specifically, the innermost strand IWm at the flat portion FP has a smaller diameter than the innermost strand IWm at the base end BP, and the outermost strand OWm at the flat portion FP is missing a part on the outer periphery side of the coil body 30 compared to the base end BP and the outermost strand OWm at the portion IP with gradually changing inner diameter, and the surface facing the outer periphery of the coil body 30 has a flat shape. That is, the diameter id5, which is the radial length of the innermost strand IWm in the flat portion FP, is smaller than the diameter id0 of the innermost strand IWm in the base end BP, and the diameter od5, which is the radial length of the outermost strand OWm in the flat portion FP, is smaller than the diameters od0, od1, and od2 of the outermost strand OWm in the base end BP and the portion IP where the inner diameter gradually changes. Therefore, the diameter D5, which is the radial length of the specific strand 300X in the flat portion FP, is smaller than the diameters D0, D1, and D2 of the specific strand 300X in the base end BP and the portion IP where the inner diameter gradually changes. In other words, the cross-sectional area of the outermost strand OWm in the flat portion FP is smaller than the cross-sectional area of the outermost strand OWm in the base end BP and the portion IP where the inner diameter gradually changes, and therefore the cross-sectional area of the specific strand 300X in the flat portion FP is smaller than the cross-sectional area of the specific strand 300X in the base end BP and the portion IP where the inner diameter gradually changes.
[0049] In addition, in the flat portion FP, the diameter of the outermost wire OWm and the diameter of the innermost wire IWm are substantially constant from the tip to the base end, and are basically the same as the cross section of the specific stranded wire 300X at the tip of the gradually changing outer diameter portion OP. Due to this configuration, as described above, the outer diameter DE and the inner diameter DI in the flat portion FP are substantially constant from the base end to the tip. In addition, in the flat portion FP, the diameter of the outermost wire OWm and the diameter of the innermost wire IWm are substantially constant from the tip to the base end, so the cross-sectional areas of the outermost wire OWm and the innermost wire IWm and the cross-sectional area of the specific stranded wire 300X are also substantially constant from the tip to the base end.
[0050] Due to the above-described configuration, in the guidewire 100 of this embodiment, the cross-sectional area of the innermost wire IWm at the flat portion FP of the coil body 30 is smaller than the cross-sectional area of the innermost wire IWm at the base end BP of the coil body 30. Also, the cross-sectional area of the outermost wire OWm at the flat portion FP of the coil body 30 is smaller than the cross-sectional area of the outermost wire OWm at the base end BP of the coil body 30.
[0051] In the specific stranded wire 300X, at the flat portion FP of the coil body 30, a surface S33 constituting a part of the outer circumferential surface SO of the coil body 30 has a flat shape.
[0052] In this embodiment, the specific stranded wire 300X in the gradually changing portion GP and the flat portion FP has a side wire 330 in which a part of the inner circumference side of the coil body 30 is missing, in addition to the innermost strand IWm and the outermost strand OWm. For example, as shown in Figs. 2 to 7, in the gradually changing portion GP and the flat portion FP, each cross-sectional area of the inner strand IW is smaller than the cross-sectional area of the inner strand IW at the base end portion BP. Also, as shown in Figs. 2, 5 to 7, in the gradually changing portion OP of the gradually changing portion GP and the flat portion FP, each cross-sectional area of the outer strand OW is smaller than the cross-sectional area of the outer strand OW at the base end portion BP. Note that, in the gradually changing portion GP and the flat portion FP, the change in the cross-sectional area of the inner strand IW is similar to the change in the cross-sectional area of the innermost strand IWm, and the change in the cross-sectional area of the outer strand OW is similar to the change in the cross-sectional area of the outermost strand OWm. That is, the diameter of the inner wire IW becomes continuously smaller from the base end to the tip end at the inner diameter gradually changing portion IP, and the diameter of the outer wire OW becomes continuously smaller from the base end to the tip end at the outer diameter gradually changing portion OP.
[0053] 7, in the cross section of the flat portion FP, the outermost strand OWm has a gap SP between itself and the adjacent strands 310. "Having a gap SP" specifically means that the adjacent strands 310 do not abut against each other.
[0054] A-3. Method for producing the coil body 30: The method for producing coil body 30 in guidewire 100 is, for example, as follows: One wire that becomes core wire 320 and six wires that become side wires 330 are twisted together to produce a twisted wire (hereinafter referred to as an "unprocessed twisted wire") in which the cross-sectional configuration at base end BP shown in Fig. 2 is continuous from the base end to the tip.
[0055] Next, a green coil body is produced by, for example, winding a plurality of (eight in this embodiment) green stranded wires around a core to form a coil, and then removing the core and cutting the coil body to a predetermined length.
[0056] Next, the coil body 30 is produced. The coil body 30 can be produced, for example, by immersing one end of the unprocessed coil body (the portion of the coil body 30 where the gradual change portion GP and the flat portion FP are formed) in an electrolyte and reducing the diameter of the end by electrolytic polishing. Strictly speaking, the shapes of the gradual change portion GP and the flat portion FP can be adjusted by adjusting the electrolytic polishing parameters to adjust the polishing amount. Examples of the electrolytic polishing parameters include the temperature, viscosity, and current value of the electrolyte, and the pulling speed when the unprocessed coil body is pulled out from the electrolyte. The coil body 30 having the above-mentioned configuration is produced by the above-mentioned manufacturing method.
[0057] A-4. Detailed configuration of siding 330: Fig. 8 shows a detailed configuration of the side wire 330. Fig. 8 shows a schematic view of a portion of one of the side wires 330 constituting the stranded wire 300 (hereinafter referred to as a "specific side wire 330X"). Fig. 8 shows the configuration of the specific side wire 330X in a state where it is not wound into the coil body 30. The configuration of the specific side wire 330X will be described below, but the side wires 330 other than the specific side wire 330X also have a similar configuration to the specific side wire 330X.
[0058] The specific side line 330X has a plurality of large diameter parts DL and a plurality of small diameter parts DS. The small diameter part DS means a part sandwiched between two of the plurality of large diameter parts DL, each of which has a larger cross-sectional area than each of the small diameter parts DS, in the extension direction of the specific side line 330X. In other words, the large diameter part DL means a part whose cross-sectional area is relatively large in the extension direction of the specific side line 330X, and the small diameter part DS means a part whose cross-sectional area is relatively small in the extension direction of the specific side line 330X. As shown in FIG. 8, the specific side line 330X has a part in which a plurality of large diameter parts DL and a plurality of small diameter parts DS are formed alternately and continuously in a part of its configuration. In addition, the specific side line 330X includes a portion in which the cross-sectional area of the multiple large diameter portions DL decreases from the base end side to the tip end side of the coil body 30, and also includes a portion in which the cross-sectional area of the multiple small diameter portions DS decreases from the base end side to the tip end side of the coil body 30.
[0059] 7, in the guidewire 100 of this embodiment, the diameter od5 of the outermost wire OWm is smaller than the diameter id5 of the innermost wire IWm in the cross section of the flat portion FP of the coil body 30. That is, in the guidewire 100 of this embodiment, in the flat portion FP of the coil body 30, the large diameter portion DL of the specific side wire 330X is disposed on the inner circumferential surface SI side of the coil body 30, and the small diameter portion DS of the specific side wire 330X is disposed on the outer circumferential surface SO side of the coil body 30.
[0060] The specific side wire 330X has the configuration shown in FIG. 8 due to the configuration of the coil body 30 and the manufacturing method of the coil body 30. That is, for example, the first side wire 331 constitutes the outermost strand OWm in the cross section shown in FIG. 2, whereas it constitutes the inner strand IW in the cross section shown in FIG. 3. In this way, in each cross section, each side wire 330 may be disposed on the outer peripheral surface SO side or on the inner peripheral surface SI side. According to the manufacturing method of the coil body 30 in this embodiment, since electrolytic polishing is performed after the unprocessed coil body is manufactured, for example, in the gradually changing outer diameter portion OP, the portion of each side wire 330 disposed on the outer peripheral surface SO side is polished, but the portion of each side wire 330 disposed on the inner peripheral surface SI side is not polished or the polishing amount is less than that of the portion disposed on the outer peripheral surface SO side. For the above reasons, the specific side wire 330X is formed with a plurality of large diameter portions DL with a relatively small amount of polishing by electrolytic polishing and a plurality of small diameter portions DS with a relatively large amount of polishing by electrolytic polishing.
[0061] A-5. Advantages of this embodiment: As described above, the guidewire 100 of the present embodiment includes the core shaft 10 and the coil body 30 in which the stranded wire 300, which is formed by stranding a plurality of strands 310, is wound in a spiral shape around the outer periphery of the core shaft 10. The strands 310 of the stranded wire 300 include a plurality of side wires 330 which are strands 310 located on the outer periphery of the stranded wire 300, and each side wire 330 has a plurality of large diameter portions DL and a plurality of small diameter portions DS. Each small diameter portion DS is sandwiched between two of the plurality of large diameter portions DL, which have a larger cross-sectional area than each small diameter portion DS, in the extension direction of each side wire 330. Each side wire 330 includes a portion in which the cross-sectional area of the plurality of large diameter portions DL decreases from the base end side to the tip end side of the coil body 30, and each side wire 330 includes a portion in which the cross-sectional area of the plurality of small diameter portions DS decreases from the base end side to the tip end side of the coil body 30.
[0062] According to the guidewire 100 of this embodiment, the side wire 330 has a plurality of large diameter portions DL and a plurality of small diameter portions DS, and includes a portion in which the cross-sectional area of each of the plurality of large diameter portions DL and the plurality of small diameter portions DS decreases from the base end side to the tip side of the coil body 30. Therefore, the cross-sectional area of the stranded wire 300 on the tip side of the coil body 30 can be reduced, and the flexibility of the coil body 30 and therefore the guidewire 100 on the tip side can be improved.
[0063] Furthermore, according to the guidewire 100 of this embodiment, since it has a large diameter portion DL having a relatively large cross-sectional area and a small diameter portion DS having a relatively small cross-sectional area, the guidewire 100 can achieve both torque transmission ability and flexibility.
[0064] Furthermore, in the guidewire 100 of this embodiment, in the flat portion FP of the coil body 30, the large diameter portion DL of each side wire 330 is disposed on the inner periphery side of the coil body 30, and the small diameter portion DS of each side wire 330 is disposed on the outer periphery side of the coil body 30. According to the guidewire 100 of this embodiment, in the flat portion FP of the coil body 30, the large diameter portion DL is disposed on the inner periphery side of the coil body 30, and the small diameter portion DS is disposed on the outer periphery side of the coil body 30. Therefore, for example, compared to a configuration in which the large diameter portion DL is disposed on the outer periphery side, the outer diameter of the coil body 30 can be made smaller, and passability through a narrow lesion can be improved while maintaining flexibility.
[0065] Furthermore, in guidewire 100 of this embodiment, the stranded wire 300 has a flattened surface S33 constituting the outer circumferential surface of coil body 30 at flat portion FP of coil body 30. According to guidewire 100 of this embodiment, guidewire 100 can be easily bent and returned to its original shape, compared to a configuration in which surface S33 constituting the outer circumferential surface is, for example, arc-shaped.
[0066] Furthermore, in the guidewire 100 of this embodiment, in at least one cross section of the stranded wire 300 (cross section of the flat portion FP), the outermost wire OWm, which is the wire among the multiple wires 310 that is farthest from the center O of the core shaft 10, has a gap SP between it and the adjacent other wires 310. According to the guidewire 100 of this embodiment, since the outermost wire OWm has a gap SP between it and the adjacent other wires 310, there is no interference between the outermost wire OWm and the wires 310 adjacent to the outermost wire OWm, and therefore flexibility can be improved and the guidewire 100 can be more easily bent or returned to its original shape.
[0067] Moreover, the guidewire 100 of the present embodiment includes a core shaft 10, and a coil body 30 in which a stranded wire 300 formed by stranding a plurality of strands 310 is wound in a spiral shape around the outer periphery of the core shaft 10. When the innermost strand IWm is the strand that is the shortest distance from the center O of the core shaft 10 among the plurality of strands 310 in each cross section of the coil body 30, the cross-sectional area of the innermost strand IWm at the flat portion FP of the coil body 30 is smaller than the cross-sectional area of the innermost strand IWm at the base end BP of the coil body 30.
[0068] According to the guidewire 100 of the present embodiment, the cross-sectional area of the innermost wire IWm at the flat portion FP of the coil body 30 is smaller than the cross-sectional area of the innermost wire IWm at the base end BP of the coil body 30. Therefore, the cross-sectional area of the stranded wire 300 on the distal end side of the coil body 30 can be reduced, and the flexibility of the coil body 30, and therefore the guidewire 100, on the distal end side can be improved.
[0069] In the guidewire 100 of the present embodiment, when the outermost wire OWm is the wire that is the longest distance from the center O of the core shaft 10 among the multiple wires 310 in each cross section of the coil body 30, the cross-sectional area of the outermost wire OWm in the flat portion FP of the coil body 30 is smaller than the cross-sectional area of the outermost wire OWm in the base end BP of the coil body 30. According to the guidewire 100 of the present embodiment, the cross-sectional area of the outermost wire OWm in the flat portion FP of the coil body 30 is smaller than the cross-sectional area of the outermost wire OWm in the base end BP of the coil body 30. Therefore, the cross-sectional area of the cross section of the distal end side of the coil body 30 in the stranded wire 300 can be reduced, and the flexibility of the distal end side of the coil body 30 and therefore the guidewire 100 can be improved. According to the guidewire 100 of the present embodiment, the cross-sectional area of the flat portion FP of the coil body 30 is smaller than the cross-sectional area of the base end BP of the coil body 30 in both the innermost wire IWm and the outermost wire OWm. Therefore, compared to a configuration in which the cross-sectional area of the entire twisted wire 300 is approximately the same and only the cross-sectional area of the outermost wire OWm is made smaller, the wire diameter of each wire 310 that constitutes the coil body 30 can be guaranteed, breakage of the wires 310 can be suppressed, and the safety of the guidewire 100 can be improved.
[0070] Furthermore, in the guidewire 100 of this embodiment, the coil body 30 includes a gradually changing portion GP, which is a portion in which the cross-sectional area continuously decreases from the base end side toward the tip end side of the coil body 30. According to the guidewire 100 of this embodiment, the coil body 30 includes the gradually changing portion GP, so that the change in stiffness between the base end side and the tip end side of the coil body 30 can be made gentle. Therefore, for example, damage to the guidewire 100 due to the occurrence of kinking can be suppressed, and torque transmissibility can be improved.
[0071] In the guidewire 100 of this embodiment, the gradually changing portion GP of the coil body 30 includes an outer diameter gradually changing portion OP, which is a portion in which the cross-sectional area of the outermost wire OWm is continuously reduced from the base end side to the tip side of the coil body 30, and an inner diameter gradually changing portion IP, which is a portion in which the cross-sectional area of the innermost wire IWm is continuously reduced from the base end side to the tip side of the coil body 30, and the base end of the outer diameter gradually changing portion OP and the base end of the inner diameter gradually changing portion IP are located at different positions in the axial direction of the coil body 30. According to the guidewire 100 of this embodiment, the gradually changing portion GP includes the outer diameter gradually changing portion OP and the inner diameter gradually changing portion IP, and the base end of the outer diameter gradually changing portion OP and the base end of the inner diameter gradually changing portion IP are located at different positions in the axial direction of the coil body 30, so that the change in rigidity between the base end side and the tip side of the coil body 30 can be made more gradual. Therefore, for example, damage to the guidewire 100 due to the occurrence of kinks can be more effectively suppressed, and torque transmissibility can be more effectively improved.
[0072] B. Second embodiment: 9 is an explanatory diagram illustrating a schematic configuration of a guidewire 100a according to the second embodiment. In the following, among the configuration of the guidewire 100a according to the second embodiment, the same configuration as that of the guidewire 100 according to the first embodiment described above is denoted by the same reference numerals and description thereof will be omitted as appropriate.
[0073] In the guidewire 100a of the second embodiment, first, the positional relationship between the inner diameter gradually changing portion IPa and the outer diameter gradually changing portion OPa in the gradually changing portion GPa is different from the positional relationship between the inner diameter gradually changing portion IP and the outer diameter gradually changing portion OP in the gradually changing portion GP of the guidewire 100 of the first embodiment. Specifically, the guidewire 100 of the first embodiment has the inner diameter gradually changing portion IP on the base end side of the gradually changing portion GP and the outer diameter gradually changing portion OP on the tip side, but the guidewire 100a of the second embodiment has the outer diameter gradually changing portion OPa on the base end side of the gradually changing portion GPa and the inner diameter gradually changing portion IPa on the tip side. Thus, in the guidewire 100, the positional relationship between the outer diameter gradually changing portion OP and the inner diameter gradually changing portion IP is not limited.
[0074] The guidewire 100a of the second embodiment further differs in cross-sectional configuration from the cross-sectional configuration of the guidewire 100 of the first embodiment. Fig. 10 is an explanatory diagram showing the cross-sectional configuration of the specific stranded wire 300Xa at the position XX. Fig. 10 shows the configuration of the specific stranded wire 300Xa on the cross section of the flat portion FPa. In the guidewire 100 of the first embodiment, the diameter od5 of the outermost strand OWm is smaller than the diameter id5 of the innermost strand IWm in the cross section of the flat portion FP, but in the guidewire 100a of the second embodiment, the diameter od5a of the outermost strand OWm is larger than the diameter id5a of the innermost strand IWm in the cross section of the flat portion FPa. In other words, in the first embodiment, in the flat portion FP, the large diameter portion DL of the specific side wire 330X is disposed on the inner circumferential surface SI side of the coil body 30, and the small diameter portion DS of the specific side wire 330X is disposed on the outer circumferential surface SO side of the coil body 30, whereas in the second embodiment, in the flat portion FPa, the large diameter portion DL of the specific side wire 330Xa is disposed on the outer circumferential surface SO side of the coil body 30, and the small diameter portion DS of the specific side wire 330Xa is disposed on the inner circumferential surface SI side of the coil body 30. Thus, in the guidewire 100, the large diameter portion DL may be disposed on the inner circumferential surface SI side or on the outer circumferential surface SO side. Also, the small diameter portion DS may be disposed on the outer circumferential surface SO side or on the inner circumferential surface SI side.
[0075] C. Third embodiment: 11 is an explanatory diagram illustrating a schematic configuration of a guidewire 100b according to a third embodiment. In the following, among the configuration of the guidewire 100b according to the third embodiment, the same configuration as that of the guidewire 100 according to the first embodiment described above is denoted by the same reference numerals, and description thereof will be omitted as appropriate.
[0076] In the guidewire 100b of the third embodiment, the configuration of the gradually changing portion GPb is different from that of the guidewire 100 of the first embodiment. Specifically, in the guidewire 100 of the first embodiment, the gradually changing inner diameter portion IP and the gradually changing outer diameter portion OP in the gradually changing portion GP are adjacent to each other, and the gradually changing inner diameter portion IP and the gradually changing outer diameter portion OP are not overlapped with each other in the axial direction of the coil body 30. However, in the guidewire 100b of the third embodiment, a part of the gradually changing inner diameter portion IPb and a part of the gradually changing outer diameter portion OPb overlap with each other in the axial direction of the coil body 30. In this way, in the guidewire 100, the gradually changing inner diameter portion IP and the gradually changing outer diameter portion OP may be configured to overlap with each other partially or entirely in the axial direction of the coil body 30.
[0077] In addition, when the gradually changing inner diameter portion IPb and the gradually changing outer diameter portion OPb have an overlapping portion, the axial length of the overlapping portion is preferably greater than 0% and less than 50% of the axial length of the gradually changing inner diameter portion IPb, and more preferably greater than 20% and less than 30% of the axial length of the gradually changing inner diameter portion IPb. With this configuration, the change in rigidity between the base end side and the tip end side of the coil body 30 can be made more gradual, and the wire diameter can be secured, compared to a configuration in which the gradually changing inner diameter portion IPb and the gradually changing outer diameter portion OPb do not overlap. Therefore, for example, damage to the guidewire 100 due to the occurrence of kinks can be more effectively suppressed, and torque transmission and safety can be improved.
[0078] D. Variations: The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.
[0079] The configuration of the guidewire 100 in the above embodiment is merely an example, and various modifications are possible. For example, in the above embodiment, the coil body 30 of the guidewire 100 is composed of eight stranded wires 300, but the number of stranded wires 300 is not limited to this.
[0080] In the above embodiment, the core shaft 10 has the thin diameter portion 11, the tapered portion 12, and the thick diameter portion 13, but the shape of the core shaft 10 is not particularly limited, and the core shaft 10 may not have at least one of these three portions, or may have other portions in addition to the three portions. For example, the base end side of the thick diameter portion 13 of the core shaft 10 may be connected to a portion having a diameter larger than that of the thick diameter portion 13.
[0081] In the above embodiment, the stranded wire 300 includes the core wire 320 and six side wires 330, but the number of side wires 330 constituting the stranded wire 300 is not limited to this. In addition, the stranded wire 300 does not need to include the core wire 320, and may be composed of only a plurality of side wires 330.
[0082] In the above embodiment, each stranded wire 300 is integrally formed from its base end to its tip end, but each stranded wire 300 does not necessarily have to be integrally formed from its base end to its tip end.
[0083] In the above embodiment, the outermost strand OWm has a gap SP between it and the adjacent strands 310, but the outermost strand OWm does not necessarily have to have a gap SP.
[0084] In the above embodiment, a configuration is shown in which the surface S33 constituting part of the outer peripheral surface SO of the coil body 30 at the flat portion FP of the coil body 30 has a flat shape, but the surface S33 does not necessarily have to have a flat shape and may be, for example, an arc shape.
[0085] In the above embodiment, the gradually changing portion GP includes the gradually changing inner diameter portion IP and the gradually changing outer diameter portion OP, but the gradually changing outer diameter portion OP is not necessarily required.
[0086] The configurations of the proximal end BP, the gradually changing portion GP, and the flat portion FP of the guidewire 100 in the above embodiment are not limited to those described above. For example, the cross-sectional area of the proximal end BP or the flat portion FP may have a portion that changes from the proximal end side to the distal end side.
[0087] The guidewire 100 in the above embodiment may not include the resin portion 50, or may be configured to include the resin portion 50 in a portion thereof.
[0088] In the above embodiment, for each twisted wire 300 constituting the coil body 30, the twisted wires 300 other than the specific twisted wire 300X also have a configuration similar to that of the specific twisted wire 300X, but this is not limited to the above, and some of the twisted wires 300 may not have a configuration similar to that of the specific twisted wire 300X.
[0089] In the above embodiment, a member capable of imparting various performances may be disposed in the lumen H formed between the core shaft 10 and the coil body 30. Examples of such members include an X-ray opaque member, a member capable of improving rotation performance, an auxiliary member capable of improving shapeability (ease of bending the distal end portion of the guidewire), and a member capable of improving safety. By disposing an X-ray opaque member at the distal end portion of the lumen H, visibility under X-ray fluoroscopy can be improved, and the operability of the operator can be improved. Examples of the X-ray opaque member include a single coil, a twisted coil, or a pipe made of platinum, tungsten, or the like. Examples of the member capable of improving rotation performance include a coil body, a twisted coil body, and the like. Examples of the auxiliary member capable of improving shapeability include a wire material made of stainless steel or annealed Ni-Ti. Examples of the member capable of improving safety include a twisted wire body made of stainless steel. By disposing a twisted wire body made of stainless steel, the tensile strength of the guidewire can be further ensured.
[0090] The manufacturing method of the coil body 30 in the above embodiment is merely an example, and various modifications are possible. For example, the coil body 30 may be manufactured from an unprocessed coil body by chemical processing other than electrolytic polishing, or physical processing such as grinding or polishing. [Explanation of symbols]
[0091] 10: Core shaft 11: Thin diameter section 12: Tapered section 13: Thick diameter section 30: Coil body 42: Tip-side joint section 44: Base-side joint section 50: Resin section 100, 100a, 100b: Guide wire 300: Stranded wire 300X, 300Xa: Specific stranded wire 310: Wire 320: Core wire 330: Side wire 330X, 330Xa: Specific side wire 331: First side wire 332: Second side wire 333: Third side wire 334: Fourth side wire 335: Fifth side wire 336: Sixth side wire AX: Central axis BP: Base end section GP, GPa, GPb: Gradual change section IP, IPa, IPb: Gradual change section of inner diameter OP, OPa, OPb: Gradual change section of outer diameter FP, FPa: Flat section IWm: Innermost wire IW: Inner wire OWm: Outermost wire OW: Outer wire DL: Large diameter portion DS: Small diameter portion SI: Inner circumferential surface SO: Outer circumferential surface SP: Gap
Claims
1. It is a guide wire, Core shaft and A coil body in which a stranded wire, formed by twisting multiple strands together, is wound spirally around the outer circumference of the core shaft, Equipped with, The stranded wire includes a plurality of side wires which are strands located on the outer circumference of the stranded wire. Each of the aforementioned side lines is, Multiple diameter-enlarged sections, A plurality of small diameter portions, each of which, in the extending direction of each side line, is sandwiched between two of the plurality of large diameter portions, each of which has a larger cross-sectional area than each of the small diameter portions, Each of the aforementioned side lines includes a portion in which the area of the cross-sectional surface of the plurality of large diameter portions decreases as it moves from the base end to the tip end of the coil body. Each of the aforementioned side wires is a guide wire that includes a portion in which the area of the cross-section of the plurality of small-diameter portions decreases as it moves from the base end to the tip end of the coil body.
2. A guide wire according to claim 1, A guide wire in which, at the tip of the coil body, the larger diameter portion of each side wire is positioned on the inner circumference side of the coil body, and the smaller diameter portion of each side wire is positioned on the outer circumference side of the coil body.
3. A guide wire according to claim 1 or claim 2, The stranded wire is a guide wire in which the surface constituting the outer surface of the coil body is flattened at the tip of the coil body.
4. A guide wire according to claim 1 or claim 2, A guide wire in which, in at least one cross-section of the stranded wire, the outermost strand, which is the strand with the longest distance from the center of the core shaft among the plurality of strands, has a gap between it and the other adjacent strands.
5. It is a guide wire, Core shaft and A coil body in which a stranded wire, formed by twisting multiple strands together, is wound spirally around the outer circumference of the core shaft, Equipped with, A guide wire in which, when the innermost strand is defined as the strand with the shortest distance from the center of the core shaft among the plurality of strands in each cross-section of the coil body, the area of the cross-section of the innermost strand at the tip of the coil body is smaller than the area of the cross-section of the innermost strand at the base of the coil body.
6. A guide wire according to claim 5, A guide wire in which, when the wire with the longest distance from the center of the core shaft among the plurality of wires in each cross-section of the coil body is defined as the outermost wire, the area of the cross-section of the outermost wire at the tip of the coil body is smaller than the area of the cross-section of the outermost wire at the base of the coil body.
7. A guide wire according to claim 6, The guide wire includes a coil body which has a gradually changing portion in which the area of the cross-section decreases continuously from the base end to the tip end of the coil body.
8. A guide wire according to claim 7, The variable diameter portion of the coil body includes an outer diameter variable portion, which is the portion in which the area of the cross-sectional surface of the outermost strand decreases continuously as the coil body moves from the base end to the tip end, and an inner diameter variable portion, which is the portion in which the area of the cross-sectional surface of the innermost strand decreases continuously as the coil body moves from the base end to the tip end. A guide wire in which the base end of the outer diameter change portion and the base end of the inner diameter change portion are located at different positions in the axial direction of the coil body.
9. A guide wire according to any one of claims 5 to 8, The stranded wire is a guide wire in which the surface constituting the outer surface of the coil body is flattened at the tip of the coil body.
10. A guide wire according to any one of claims 5 to 8, A guide wire in which, in at least one cross-section of the stranded wire, the outermost strand, which is the strand with the longest distance from the center of the core shaft among the plurality of strands, has a gap between it and the other adjacent strands.