Guide wire

Abstract

We provide guidewires that offer excellent compatibility with other devices and are highly insertable and safe into blood vessels. [Solution] The guide wire 10 comprises a long core 20 having an axis X extending between its tip and base, a base-side coating layer 60 made of resin covering the outer surface of the core 20, and a linearly arranged protrusion 63 on the outer surface of the base-side coating layer 60, wherein the protrusion 63 has a top that projects radially outward from the guide wire 10, and in a cross-section passing through the axis X of the core 20, the thickness T of the protrusion 63 in a direction perpendicular to the outer surface of the base-side coating layer 60 in contact with the protrusion 63. i (i=1~n) decreases as you move towards the tip.

Description

【Technical Field】 【0001】 The present invention relates to a guide wire inserted into a blood vessel to guide a medical device for intravascular treatment to a target position. 【Background Art】 【0002】 In the diagnosis and treatment of lesions occurring in blood vessels, procedures using catheters are performed. An operator inserts a guide wire into a blood vessel, reaches the tip of the guide wire near the lesion, and then inserts a catheter along the guide wire. 【0003】 In the case of diagnosing and treating lower limb lesions, the distance from the insertion part of the guide wire to the lesion is long, and it is necessary to pass through a bent part or a narrowed part of the blood vessel before reaching the lesion with the guide wire. For this reason, in order to improve the insertability into a combined device such as a catheter or into a blood vessel, a spiral convex part may be provided on the outer surface of the guide wire. (For example, refer to Patent Document 1). 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2016-87044 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 When the guide wire has a convex part on its outer surface, the convex part can cause problems such as stacking with a combined device and a decrease in the passing ability through a bent part or a narrowed part of the blood vessel. 【0006】 The present invention has been made to solve the above-described problems, and an object thereof is to provide a guide wire that suppresses stacking with a combined device and a decrease in the passing ability through a bent part or a narrowed part of the blood vessel, and has high insertability and safety into a combined device and a blood vessel. 【Means for Solving the Problems】 【0007】 The above object is achieved by the invention described in the following (1). 【0008】 (1) The guide wire according to the present invention includes a long core having an axis extending between a tip and a base end, a coating layer formed of a resin covering the outer surface of the core, and convex portions arranged linearly or dot-like on the outer surface of the coating layer. The convex portions have a top protruding radially outward of the guide wire, and in a cross section passing through the axis of the core, the thickness of the convex portions in a direction perpendicular to the outer surface of the coating layer with which the convex portions contact decreases toward the tip side. [Effect of the Invention] 【0009】 The guide wire described in the above (1) contacts the combined device in order from the convex portions having a small thickness, so that stacking of the convex portions and the combined device can be suppressed, and the insertability of the combined device and the blood vessel into the region including the convex portions is improved. In addition, since the pushing force required when the combined device exceeds the convex portions is dispersed over each pushing length, the guide wire can suppress the occurrence of blood vessel perforation due to excessive pushing force and has high safety. 【0010】 (2) In the guide wire described in the above (1), when the cross-sectional shape of the convex portion in a cross section passing through the axis of the core is a semicircle or a semi-ellipse, the inclination angle of the convex portion with respect to the axis may decrease as it approaches the top of the convex portion from the base close to the coating layer of the convex portion. When the thickness of the convex portion decreases toward the tip side of the guide wire, the convex portion located on the base end side among two adjacent convex portions contacts the combined device or the stenosis portion of the blood vessel on the top side rather than the convex portion located on the tip side. For this reason, in a guide wire in which the cross-sectional shape of the convex portion in a cross section passing through the axis of the core is a semicircle or a semi-ellipse, the pushing force required when the combined device or the stenosis portion of the blood vessel exceeds the convex portion gradually decreases toward the base end side. Therefore, the guide wire can effectively reduce the pushing force required when the combined device exceeds the convex portions. 【0011】 (3) In the guide wire described in (1) or (2) above, the coating layer has a tapered portion in which the outer diameter gradually decreases toward the tip, and at least a part of the convex portion may be arranged in the tapered portion. This makes it possible to suppress the stacking and insertion ease with the accompanying device in the tapered portion in which the outer diameter gradually decreases toward the tip of the guide wire. 【0012】 (4) In the guide wire described in any one of (1) to (3) above, the protrusion may be formed in a spiral shape. As a result, the protrusion is formed continuously in the circumferential and axial directions on the outer surface of the coating layer, making it easy to continuously or gradually reduce the tip-side inclination angle and thickness of the protrusion towards the tip. 【0013】 (5) In the guide wire described in any one of (1) to (4) above, the protrusions may be spaced apart along the axis, and the pitch between adjacent protrusions may decrease toward the tip. 【0014】 (6) In the guide wire described in any one of (1) to (5) above, the protrusion may be formed of resin. [Brief explanation of the drawing] 【0015】 [Figure 1] This figure shows the tip of the guide wire according to the embodiment in cross-section and the base end in plan view. [Figure 2] This is a magnified cross-sectional view showing the tip of the guidewire. [Figure 3] These are cross-sectional views showing examples of convex parts, with (A) being the first example, (B) the second example, (C) the third example, (D) the fourth example, (E) the fifth example, (F) the sixth example, and (G) the seventh example. [Figure 4] This is an enlarged cross-sectional view showing the proximal end of the guidewire. [Figure 5]This diagram shows the relationship between the indentation length and indentation force when the protrusion contacts the combined device. (A) shows the case when a guidewire with a protrusion having a constant tip-side inclination angle and thickness is inserted into the combined device, and (B) shows the case when a guidewire with a protrusion having a tip-side inclination angle and thickness that decreases towards the tip is inserted into the combined device. [Figure 6] This is a cross-sectional view showing a guide wire inserted into a curved combination device. [Figure 7] This is a plan view showing an example of a method for forming the protrusions on a guide wire. [Figure 8] This is a plan view showing another example of a method for forming a convex portion of a guide wire, where (A) shows the workpiece dipped in coating liquid, and (B) shows the layer formed by dipping being polished to form the convex portion. [Figure 9] This is a plan view showing variations of the guide wire, with (A) showing the first variation, (B) showing the second variation, (C) showing the third variation, (D) showing the fourth variation, and (E) showing the fifth variation. [Modes for carrying out the invention] 【0016】 Embodiments of the present invention will be described below with reference to the attached drawings. However, the present invention is not limited to these embodiments. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant explanations are omitted. Furthermore, the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from actual ratios. 【0017】 In this specification, in a cross-section of the guidewire (a section perpendicular to the axis) with the long axis of the guidewire as the reference axis, the direction moving away from or towards the guidewire is defined as the "radial direction." The rotational direction with the axis of the guidewire as the reference axis is defined as the "circumferential direction." Furthermore, the side of the guidewire that is inserted into the blood vessel is defined as the tip, and the end opposite the tip is defined as the proximal end. Additionally, the portion including a certain range in the long axis direction from the tip (extentmost point) is defined as the "tip portion," and the portion including a certain range in the long axis direction from the proximal end (most basal end) is defined as the "proximal end portion." 【0018】 In this specification, the range "X~Y" includes X and Y, meaning "X or greater and Y or less". 【0019】 <Guidewire> The guidewire 10 is inserted into a blood vessel and, while inserted into the lumen of a therapeutic or diagnostic catheter, is used to guide the catheter to a target site within the blood vessel. As shown in Figures 1, 2, and 4, the guidewire 10 according to this embodiment comprises a core 20 having a long axis X extending in the direction of the long axis of the guidewire 10, a coil 30 and a tip-side covering layer 70 disposed at the tip of the core 20, a cylindrical member 50 disposed at the proximal end of the tip-side covering layer 70, and a proximal-side covering layer 60 disposed at the proximal end of the core 20. 【0020】 The length of the guide wire 10 in the longitudinal direction can be between 200 mm and 5000 mm. 【0021】 (core) As shown in Figure 1, the core 20 has a first core 21 located at the tip end and a second core 22 located at the base end of the first core 21. The first core 21 and the second core 22 are solid-state bonded at a joint 37 via a joint surface d1. The joint 37 has a projection 33 that protrudes radially outward from the outer surface of the core 20. 【0022】 The first core 21 has a tip portion 36 located at the tip of the first core 21, a first constant outer diameter portion 34 located on the base end side of the tip portion 36, and a first tapered portion 35 located between the tip portion 36 and the first constant outer diameter portion 34. The tip portion 36 extends from the tip of the first core 21 to the tip of the first tapered portion 35 and has a substantially constant outer diameter along the axis X. The first tapered portion 35 extends from the base end of the tip portion 36 to the tip of the first constant outer diameter portion 34 and has an outer diameter that gradually increases along the axis X. The first constant outer diameter portion 34 extends from the base end of the first tapered portion 35 to the tip of the projection portion 33 and has a substantially constant outer diameter along the axis X. The outer diameter of the first constant outer diameter portion 34 is 0.3 mm to 0.9 mm. 【0023】 The second core 22 has a second constant outer diameter portion 38 located at the tip of the second core 22, a third constant outer diameter portion 40 located on the base end side of the second constant outer diameter portion 38, and a second tapered portion 39 located between the second constant outer diameter portion 38 and the third constant outer diameter portion 40. The second constant outer diameter portion 38 extends from the base end of the projection portion 33 to the tip of the second tapered portion 39 and has a substantially constant outer diameter along the axis X. The outer diameter of the second constant outer diameter portion 38 is substantially equal to the outer diameter of the first constant outer diameter portion 34 of the first core 21, and is between 0.3 mm and 0.9 mm. The second tapered portion 39 extends from the base end of the second constant outer diameter portion 38 to the tip of the third constant outer diameter portion 40 and has a gradually increasing outer diameter along the axis X. The third constant outer diameter portion 40 extends from the base end of the second tapered portion 39 to the base end of the second core 22 and has a substantially constant outer diameter along the axis X. 【0024】 The core 20 is formed by solid-state bonding a first core 21 and a second core 22. The first core 21 and the second core 22 can be formed by grinding metal wires having a constant outer diameter. The outer diameter of the second core 22 before grinding is larger than the outer diameter of the first core 21 before grinding. By forming the core 20 by grinding and then joining two wires with different outer diameters, the length that needs to be ground is reduced compared to forming it by grinding a single wire. Therefore, by joining two wires with different outer diameters, a core 20 having a portion with low bending rigidity at the tip and a portion with high bending rigidity at the base can be easily manufactured. 【0025】 The first core 21 and the second core 22 both have a substantially circular cross-sectional shape. However, the first core 21 and the second core 22 may have other tapered or constant outer diameter sections between the tip portion 36 of the first core 21 and the first constant outer diameter section 34, and between the second constant outer diameter section 38 and the third constant outer diameter section 40 of the second core 22. Furthermore, the cross-sectional shape of the tip portion 36 of the first core may be rectangular. 【0026】 The first core 21 and the second core 22 are formed from a Ni-Ti alloy. Because Ni-Ti alloys are superelastic, even if they deform to the plastic deformation region when stress is applied, they easily return to their original shape after the stress is removed. This prevents the guide wire 10 from becoming plastically deformed and bent during use, which would reduce its operability. 【0027】 The joint portion 37 is the part of the core 20 that includes the joint surface d1 between the first core 21 and the second core 22, and the vicinity of the joint surface d1. The joint portion 37 is formed by solid-state bonding the base end face of the wire forming the first core 21 and the tip face of the wire forming the second core 22. The core 20 has a protrusion 33 at the joint portion 37, which is formed by mechanically polishing burrs that have formed on the joint surface d1. 【0028】 (coil) The coil 30 is positioned to cover a certain area of ​​the tip of the first core 21. The coil 30 is a radiopaque marker and is used by the operator to determine the position of the guidewire 10 inserted into the blood vessel under radiographic fluoroscopy. The coil 30 is formed by spirally winding a wire around the first core 21 in the circumferential direction. It is preferable that the coil 30 and the outer surface of the first core 21 are in close contact. It is also preferable that the coil 30 is formed so that there are gaps between adjacent windings when no external force is applied. However, the coil 30 may be formed so that there are no gaps between adjacent windings when no external force is applied. Furthermore, if radiopaqueness is sufficient, the guidewire 10 may not have a coil 30. 【0029】 The wire forming the coil 30 is preferably made of an X-ray opaque material. Examples of X-ray opaque materials include precious metals such as gold, platinum, and tungsten, or alloys containing these materials. 【0030】 The tip of the coil 30 is fixed to the tip of the first core 21 by a fixing member 31. The base end of the coil 30 is fixed to the first tapered portion 35 of the first core 21 by a fixing member 32. The materials used to form the fixing members include adhesives, brazing materials, and solder. 【0031】 (Tip side coating layer) As shown in Figures 1 and 2, the tip-side coating layer 70 is formed of a resin material and is formed to cover the tip portion of the core 20, which includes the coil 30. The tip-side coating layer 70 has a hemispherical portion 71 located on the tip side of the tip-side coating layer 70, a tip-side tapered portion 72 located adjacent to the base end of the hemispherical portion 71, a tip-side constant outer diameter portion 73 located adjacent to the base end of the tip-side tapered portion 72, a base-side tapered portion 75 located adjacent to the base end of the tip-side constant outer diameter portion 73, a base-side constant outer diameter portion 76 located adjacent to the base end of the base-side tapered portion 75, and a reduced diameter portion 77 located adjacent to the base end of the base-side constant outer diameter portion 76. The hemispherical portion 71 is located at the very tip of the guide wire 10. 【0032】 The hemispherical portion 71 is formed in a rounded hemispherical shape with a small radius of curvature R so that it can capture the entrance to the stenosis and suppress the occurrence of vascular perforation without damaging the blood vessel wall. The radius of curvature R of the hemispherical portion 71 is 0.05 mm to 0.30 mm. 【0033】 The tapered tip portion 72 extends from the base end of the hemispherical portion 71 to the tip of the constant outer diameter portion 73, and its outer diameter gradually increases along the axis X. The first core 21 and coil 30 extend toward the tip so that their tips reach at least beyond the base end of the tapered tip portion 72. This improves the passage of the guide wire 10 through the constricted section. The length L1 of the tapered tip portion 72 in the direction along the axis X is 1 mm to 10 mm. The inclination angle α1 of the tapered tip portion 72 with respect to the axis X is 0.2 degrees to 17 degrees. 【0034】 The constant outer diameter portion 73 at the tip extends from the base end of the tapered portion 72 at the tip to the tip of the tapered portion 75 at the base, and has a substantially constant outer diameter along the axis X. The length L2 of the constant outer diameter portion 73 at the tip along the axis X is greater than 0 mm and less than or equal to 20 mm. The coil 30 and the tip portion 36 of the first core 21 are arranged inside the constant outer diameter portion 73 at the tip. 【0035】 As shown in Figures 1 and 2, the base-side tapered portion 75 extends from the base end of the tip-side constant outer diameter portion 73 to the tip of the base-side constant outer diameter portion 76, and its outer diameter gradually increases along the axis X. Inside the base-side tapered portion 75 is the first tapered portion 35 of the first core 21. The length L4 of the base-side tapered portion 75 in the direction along the axis X is 30 mm to 250 mm. The inclination angle α2 of the base-side tapered portion 75 with respect to the axis X is 0.01 degrees to 1 degree. 【0036】 The base-side constant outer diameter portion 76 extends from the base end of the base-side tapered portion 75 to the tip of the reduced diameter portion 77 and has a substantially constant outer diameter along the axis X. The tip of the first constant outer diameter portion 34 of the first core 21 is located inside the base-side constant outer diameter portion 76. The length L5 of the base-side constant outer diameter portion 76 in the direction along the axis X is 10 mm to 200 mm. The outer diameter of the base-side constant outer diameter portion 76 is 0.3 mm to 0.9 mm. 【0037】 The reduced diameter portion 77 extends from the base end of the constant outer diameter portion 76 on the base end side to near the tip of the cylindrical member 50, and its outer diameter gradually decreases along the axis X. A part of the first constant outer diameter portion 34 of the first core 21 is located inside the reduced diameter portion 77. 【0038】 The coil 30 is positioned so as to be in close contact with the base end of the tip-side tapered portion 72, the inner surface of the tip-side constant outer diameter portion 73, and the outer surface of the first core 21. 【0039】 The tip-side coating layer 70 comprises a flexible resin layer 90 that adheres closely to the outer surface of the first core 21 and / or coil 30, and a low-friction layer 91 that covers the outer surface of the resin layer 90. The tip-side coating layer 70 may also consist of only the resin layer 90. 【0040】 The resin layer 90 is formed from resin. This makes the tip of the guidewire 10 flexible, preventing damage to blood vessels. Examples of resins used to form the resin layer 90 include polyethylene, polyolefins such as polypropylene, polyvinyl chloride, polyester (PET, PBT, etc.), polyamide, polyimide, polystyrene, polycarbonate, silicone resin, fluororesin (PTFE, ETFE, PFA, etc.), urethane resin, or composite materials thereof, as well as various rubber materials such as latex rubber and silicone rubber, or composite materials combining two or more of these. In particular, it is preferable that the resin layer 90 be formed from urethane resin. The resin layer 90 is not limited to a single-layer structure, but may be a laminated structure consisting of multiple layers. 【0041】 The thickness of the resin layer 90 is preferably 5 μm to 500 μm. 【0042】 The low-friction layer 91 is formed from a hydrophilic polymer. The low-friction layer 91 covers almost the entire outer surface of the resin layer 90, excluding the hemispherical portion 71 and the tip of the tapered portion 72. The outer surfaces of the hemispherical portion 71 and the tip of the tapered portion 72 of the resin layer 90 are not covered by the low-friction layer 91, making it easier to grip the entrance of the constricted portion. 【0043】 Examples of hydrophilic polymers include known hydrophilic polymers consisting of cellulose polymers, polyethylene oxide polymers, maleic anhydride polymers (e.g., maleic anhydride copolymers such as methyl vinyl ether-maleic anhydride copolymer), acrylamide polymers (e.g., polyacrylamide, block copolymer of polyglycidyl methacrylate-dimethylacrylamide (PGMA-DMAA)), water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone, and the like. 【0044】 The thickness of the low-friction layer 91 is preferably 0.1 μm to 100 μm. 【0045】 Furthermore, the material forming the low-friction layer 91 is not limited to hydrophilic polymers, but may also be fluororesins such as polytetrafluoroethylene (PTFE) or tetrafluoroethylene-ethylene copolymer (ETFE), or silicone resins. 【0046】 (Cylindrical member) The cylindrical member 50 is a tubular member positioned in the first constant outer diameter portion 34 of the first core 21. The tip of the cylindrical member is in contact with the base end of the tip-side coating layer 70, and the base end of the tip-side coating layer 70 is inserted into the lumen of the cylindrical member 50. The base end of the cylindrical member 50 is fixed to the first core 21 by a fixing member 51. The base end of the cylindrical member 50 has a tapered portion 52 in which the outer diameter gradually decreases toward the base end. The fixing member 51, which is located closer to the base end than the base end of the cylindrical member 50, is tapered so as to be continuous with the tapered portion 52 of the cylindrical member 50. 【0047】 The cylindrical member 50 is preferably made of metal. Examples of metals that form the cylindrical member 50 include stainless steel, superelastic alloys, cobalt-based alloys, and precious metals such as gold, platinum, and tungsten, or alloys containing these (platinum-iridium alloys). 【0048】 (Base-side coating layer) As shown in Figures 1 and 4, the base-side coating layer 60 (coating layer) is formed to cover at least a portion of the outer surface of the second core 22. The base-side coating layer 60 has an inner layer 61 that covers the outer surface of the second core 22 and an outer layer 62 that covers the outer surface of the inner layer 61. The base-side coating layer 60 covers the second constant outer diameter portion 38, the second tapered portion 39, and the third constant outer diameter portion 40 of the second core 22. Therefore, the base-side coating layer 60 has a tip-side constant portion 65 that covers the second constant outer diameter portion 38, a tapered portion 66 that covers the second tapered portion 39, and a base-side constant portion 67 that covers the third constant outer diameter portion 40. The constant diameter portion 65 at the tip and the constant diameter portion 67 at the base have a constant outer diameter, with the outer diameter of the base portion 67 being larger than that of the constant diameter portion 65 at the tip, and the tapered portion 66 has an outer diameter that gradually decreases in a tapered manner toward the tip. The outer diameter of the base end of the tapered portion 66 matches the outer diameter of the constant diameter portion 67 at the base, and the outer diameter of the tip of the tapered portion 66 matches the outer diameter of the constant diameter portion 65 at the tip. The base end covering layer 60 may cover only a portion of at least one of the second constant outer diameter portion 38, the second tapered portion 39, or the third constant outer diameter portion 40 of the second core 22. 【0049】 The materials forming the inner layer 61 and the outer layer 62 include fluororesins such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene-ethylene copolymer (ETFE). The inner layer 61 and the outer layer 62 may also contain pigments. 【0050】 The base end coating layer 60 may be a single layer. 【0051】 (Convex part) The protrusion 63 is a linear member that is spirally wound around the outer surface of the base-side coating layer 60 along the circumferential direction, and has a convex shape extending radially outward from the outer surface of the outer layer 62. The protrusions 63 are formed so that adjacent windings are spaced apart. The protrusions 63 have a protrusion tip surface 64 on their outer surface that faces the tip side. 【0052】 The convex portion 63 is preferably formed of resin. As the resin for forming the convex portion 63, fluororesins such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene-hexafluoropropylene copolymer (FEP) can be used. Further, the convex portion 63 may contain a pigment. 【0053】 The convex portion 63 is continuously formed across the base-end side constant portion 67, the tapered portion 66, and the tip-end side constant portion 65 of the base-end side coating layer 60. The convex portion 63 of the guide wire 10 shown in FIG. 4 is formed by winding a single linear member around the outer surface of the base-end side coating layer 60. 【0054】 In a cross section passing through the axis X of the core 20, as shown in FIG. 4, the region including the convex portion 63 is divided into n parts, and at the tip-end side end point N where the convex portion 63 contacts the base-end side coating layer 60 of the convex portion 63, between the outer surface of the convex portion 63 and the outer surface of the base-end side coating layer 60 with which the convex portion 63 is in contact, a tip-end side inclination angle θ i (i = 1 to n) is formed. In a cross section passing through the axis X of the core 20, the tip-end side inclination angle θ i (i = 1 to n) of the spiral convex portion 63 gradually decreases as it goes toward the tip-end side of the guide wire 10 (as i decreases). Therefore, the tip-end side inclination angle θ i satisfies θ i < θ i+1 (i = 1 to n - 1). The tip-end side inclination angle θ i (i = 1 to n) is, for example, from 0.1 degree to 90 degrees, preferably from 10 degrees to 60 degrees. The tip-end side inclination angle θ i of the spiral convex portion 63 preferably changes gradually and smoothly along the circumferential direction of the guide wire 10. 【0055】 Note that in a cross section passing through the axis X of the core 20, the tip-end side inclination angle θ i changes for each convex portion 63 as θ1 < θ2 < θ3 < θ4 < θ5 < θ6 ···, but is not necessarily limited to this. For example, as θ1 = θ2 < θ3 = θ4 < θ5 = θ6 ···, the tip-end side inclination angles θ iThey may be equal. That is, the inclination angle θ at the tip of the protrusion 63. i is, θ i ≤θ i+1 (i=1~n-1) and θ1<θ n The following conditions may be met: While the linear member forming the protrusion 63 encircles the outer surface of the base-side coating layer 60, the tip-side inclination angle θ of the spiral protrusion 63 i This may be constant, or it may change continuously or in steps. The guide wire 10 may also have a plurality of linear members that form the protrusion 63. In this case, the protrusion 63 may form a multi-helix in which the linear members are arranged at different phases. The protrusion 63 may have a rotationally symmetric shape about the axis X of the core 20. 【0056】 Furthermore, in a cross-section passing through the axis X of the core 20, the protrusion 63 has a thickness T in a direction perpendicular to the outer surface of the base end side coating layer 60 that is in contact with the protrusion 63. i (i=1~n) is present. Furthermore, in a cross-section passing through the axis X of the core 20, the protrusions 63 have a width W in the direction of the axis X along the outer surface of the base end side coating layer 60 that is in contact with the protrusions 63, and are arranged spirally at a pitch P along the axis X. Thickness T i (i=1~n) is, for example, 5μm~15μm, preferably 7μm~13μm. The width W is, for example, 0.1mm~1.2mm, preferably 0.3mm~0.9mm. The width W may be constant along the axis X, but may decrease towards the tip, or may increase towards the tip. The pitch P is, for example, 0.4mm~3.0mm, preferably 0.8mm~2.4mm. The pitch P may be constant along the axis X, but may decrease towards the tip, or may increase towards the tip. 【0057】 In a cross-section passing through the axis X of the core 20, the thickness T of the protrusion 63 is... i (i=1~n) decreases as you move towards the tip. Therefore, the thickness T of the protrusion 63 is i is, T i <T i+1 The condition (i=1~n-1) is satisfied. Thickness T of the spiral convex portion 63.i Preferably, it gradually and smoothly changes along the circumferential direction of the guide wire 10. 【0058】 In addition, in the cross section passing through the axis X of the core 20, the thickness T of the convex portion 63 i changes for each convex portion 63 as T1 < T2 < T3 < T4 < T5 < T6 ···, but is not necessarily limited to this. For example, the thickness T of a plurality of adjacent convex portions 63 along the axis X may be equal, such as T1 = T2 < T3 = T4 < T5 = T6 ···. i That is, the thickness T of the convex portion 63 i is T i ≦ T i+1 (i = 1 to n - 1) and T1 < T n may be satisfied. While the linear member forming the convex portion 63 makes one round around the outer surface of the proximal end side covering layer 60, the thickness T of the spiral convex portion 63 i may be constant, or may change continuously or stepwise. 【0059】 When inserting the guide wire 10 into a combined device 100 such as a catheter or a sheath, in the cross section passing through the axis X of the core 20, the tip side inclination angle θ i (i = 1 to n) and the thickness T i (i = 1 to n) of the guide wire 10 provided with the convex portion 63 that is constant requires a large pushing force when the combined device 100 exceeds the convex portion 63 at the most distal end, that is, at the pushing length A, as shown in FIG. 5(A). And when the combined device 100 exceeds the convex portions 63 from the second one and subsequent ones on the tip side, that is, at the pushing lengths B, C, D, E ···, the guide wire 10 requires almost no pushing force. 【0060】 On the other hand, in the cross section passing through the axis X of the core 20, the tip side inclination angle θ i (i = 1 to n) and the thickness T i (i = 1 to n) of the guide wire 10 provided with the convex portion 63 that becomes smaller as it goes toward the tip side, as shown in FIG. 5(B), the tip side inclination angle θ i and the thickness T iThe protrusions 63 make contact with the combined device 100 in order from the smallest to the largest. As a result, the guidewire 10 can suppress stacking between the protrusions 63 and the combined device 100, and improve the insertability of the combined device 100 and blood vessels in the region including the protrusions 63. Furthermore, the pushing force required when the combined device 100 exceeds the protrusions 63 is distributed over the pushing lengths A, B, C, D, E, etc. As a result, the guidewire 10 can suppress the occurrence of vascular perforation due to excessive pushing force, thus ensuring high safety. 【0061】 Furthermore, the guide wire 10 has a tip-side inclination angle θ such that the protrusion 63 becomes smaller as it approaches the tip. i (i=1~n) and thickness T i Having (i=1~n) can suppress stacking with the stent (combined device 100) placed in the blood vessel. 【0062】 The shape of the protrusion 63 in the cross-section passing through the axis X of the core 20 is preferably a roughly semicircular shape as shown in Figure 3(A) or a roughly semielliptical shape as shown in Figure 3(B). When the cross-sectional shape of the protrusion 63 in the cross-section passing through the axis X of the core 20 is a semicircular or semielliptical shape, the angle of inclination of the protrusion 63 with respect to the axis X decreases as it approaches the top of the protrusion 63 from the base, which is close to the coating layer 60 on the base side of the protrusion 63. And the thickness T of the protrusion 63 i If (i=1~n) decreases towards the tip, the proximal protrusion 63 of two adjacent protrusions 63 will contact the combined device 100 or blood vessel at a more apical position than the proximal protrusion 63. Therefore, for a guidewire 10 in which the cross-sectional shape of the protrusion 63 in a section passing through the axis X of the core 20 is semicircular or semielliptical, the pushing force required for the combined device 100 or blood vessel to pass over the protrusion 63 decreases gradually towards the proximal end. Thus, the guidewire 10 can effectively reduce the pushing force required for the combined device 100 to pass over the protrusion 63. 【0063】 The shape of the protrusion 63 in the cross-section passing through the axis X of the core 20 may be, for example, an asymmetrical shape along the axis X as shown in Figure 3(C), a triangle as shown in Figure 3(D), a trapezoid as shown in Figure 3(E), a polygon as shown in Figure 3(F), or a shape in which the concavity and concavity are reversed in the middle of a curve as shown in Figure 3(G). 【0064】 Tip-side inclination angle θ of the protrusion 63 i (i=1~n) and thickness T i As shown in Figure 6, the guide wire 10, in which (i=1~n) decreases towards the tip, has a tip-side inclination angle θ of the convex portion 63. i (i=1~n) and thickness T i Compared to the case of a guidewire 10 where (i=1~n) is constant (see the dashed line in the figure), the degree of curvature when inserted into a curved catheter or other concomitant device 100 becomes gentler. As a result, the radius of curvature of the guidewire 10 increases, and bending stress can be reduced. Consequently, the surgeon can perform the procedure without applying excessive force. 【0065】 As shown in Figure 4, the protruding portion 63 has a tip-side inclination angle θ that decreases as it approaches the tip side in the tapering portion 66. i and thickness T i The tapered portion 66 has an outer diameter that gradually tapers toward the tip. Therefore, in a cross-section passing through the axis X of the core 20, the angle β between the outer surface of the protrusion 63 at the tip end point N, which is in contact with the base end coating layer 60 of the protrusion 63, and the axis X of the core 20 is the tip-side inclination angle θ i The angle γ between the outer surface of the tapering section 66 and the axis X of the core 20 is added together to form β = θ i This results in +γ. Therefore, the protrusions 63 located in the tapering section 66 are more likely to get stuck with the combined device 100 than the protrusions 63 located in the constant tip section 65 or the constant proximal section 67, which can lead to a decrease in the insertability of the combined device 100 and the blood vessel. The tip-side inclination angle θ of the protrusions 63 located in the tapering section 66 decreases as it approaches the tip. i and thickness T iBy having this feature, the guide wire 10 can suppress stacking with the combined device 100 in the tapering section 66 and a decrease in insertability. 【0066】 One example of a method for forming spiral protrusions 63 on the outer surface of the base-side coating layer 60 is to apply the coating liquid 130 in a spiral manner, as shown in Figure 7. In this method, the workpiece 110, on which the base-side coating layer 60 has been formed on the core 20, is rotated around the axis X and moved along the axis X, and the coating liquid 130 is discharged from a tubular dispenser 120 onto the outer surface of the base-side coating layer 60 and solidified. As a result, spiral protrusions 63 are formed on the outer surface of the base-side coating layer 60. 【0067】 Alternatively, by reducing the amount of coating liquid 130 dispensed per hour from the dispenser 120 towards the tip of the base-side coating layer 60, the amount of coating liquid 130 applied is reduced, thereby reducing the tip-side inclination angle θ of the protrusion 63. i (i=1~n) and thickness T i (i=1~n) can be made small. 【0068】 Alternatively, by increasing the rotation speed of the workpiece 110 as the coating position moves towards the tip side of the base-side coating layer 60, the amount of coating liquid 130 applied is reduced, thereby reducing the tip-side inclination angle θ of the protrusion 63. i (i=1~n) and thickness T i (i=1~n) can be made small. 【0069】 Another example of a method for forming a spiral projection 63 on the outer surface of the base end coating layer 60 is, for example, a method of forming the projection by polishing, as shown in Figure 8. In this method, the workpiece 110 is almost entirely immersed in the coating liquid, the coating liquid 130 is solidified to form a layer 140, and then, as shown in Figure 8(B), the layer 140 is polished with a polishing jig 150 to form a spiral projection 63. When polishing, the amount of polishing and the polishing position using a polishing jig 150 such as a grinding wheel can be adjusted to achieve the desired tip-side inclination angle θ. i (i=1~n), thickness T i(i=1~n), a protrusion 63 having a width W and a pitch P can be formed. 【0070】 As described above, the guide wire 10 according to this embodiment has a long core 20 with an axis X extending between the tip and the base, a base-side coating layer 60 (coating layer) made of resin that covers the outer surface of the core 20, and a protrusion 63 arranged linearly on the outer surface of the base-side coating layer 60, and in a cross section passing through the axis X of the core 20, the tip-side inclination angle θ is between the outer surface of the base-side coating layer 60 that the protrusion 63 is in contact with and the outer surface of the protrusion 63 at the tip-side endpoint N that the protrusion 63 is in contact with the base-side coating layer 60. i (i=1~n) decreases as it approaches the tip. As a result, the guide wire 10 has a small tip-side inclination angle θ i Since the protrusions 63 make contact with the combined device 100 in order, stacking between the protrusions 63 and the combined device 100 can be suppressed, and the insertability of the combined device 100 and blood vessels in the region including the protrusions 63 is improved. In addition, since the pushing force required when the combined device 100 exceeds the protrusions 63 is distributed over the pushing lengths A, B, C, D, E, etc., the guidewire 10 can suppress the occurrence of vascular perforation due to excessive pushing force, resulting in high safety. 【0071】 Furthermore, the guide wire 10 according to this embodiment has a long core 20 with an axis X extending between the tip and the base end, a coating layer made of resin covering the outer surface of the core 20, and a linearly arranged protrusion 63 on the outer surface of the base end coating layer 60 (coating layer), and in a cross section passing through the axis X of the core 20, the thickness T of the protrusion 63 in the direction perpendicular to the outer surface of the base end coating layer 60 that the protrusion 63 is in contact with. i (i=1~n) decreases as you move towards the tip. As a result, the guide wire 10 has a small thickness T iSince the protrusions 63 make contact with the combined device 100 in order, stacking between the protrusions 63 and the combined device 100 can be suppressed, and the insertability of the combined device 100 and blood vessels in the region including the protrusions 63 is improved. In addition, since the pushing force required when the combined device 100 exceeds the protrusions 63 is distributed over the pushing lengths A, B, C, D, E, etc., the guidewire 10 can suppress the occurrence of vascular perforation due to excessive pushing force, resulting in high safety. 【0072】 If the cross-sectional shape of the protrusion 63 in the section passing through the axis X of the core 20 is semicircular or semi-elliptical, the inclination angle of the protrusion 63 with respect to the axis X decreases as it approaches the top of the protrusion 63 from the base, which is close to the coating layer 60 on the base side of the protrusion 63. And the thickness T of the protrusion 63 i If (i=1~n) decreases towards the tip, the proximal protrusion 63 of two adjacent protrusions 63 will contact the combined device 100 or the narrowed portion of the blood vessel at a more apical position than the proximal protrusion 63. Therefore, for a guidewire 10 in which the cross-sectional shape of the protrusion 63 in a section passing through the axis X of the core 20 is semicircular or semielliptical, the pushing force required when the combined device 100 or the narrowed portion of the blood vessel exceeds the protrusion 63 decreases in stages towards the proximal end. Thus, the guidewire 10 can effectively reduce the pushing force required when the combined device 100 exceeds the protrusion 63. 【0073】 The proximal end coating layer 60 (coating layer) has a tapered section 66 in which the outer diameter gradually decreases toward the tip, and at least a portion of the protrusion 63 is positioned in the tapered section 66. This makes it possible for the guide wire 10 to suppress stacking with the combined device 100 and a decrease in insertability in the tapered section 66 in which the outer diameter gradually decreases toward the tip. 【0074】 The protrusion 63 is formed in a spiral shape. As a result, the protrusion 63 is continuously formed on the outer surface of the base end coating layer 60 (coating layer) in the circumferential direction and in the direction along the axis X, so the tip-side inclination angle θ of the protrusion 63 i (i=1~n) and thickness T iIt is easy to continuously or gradually decrease (i=1~n) as you move towards the tip. 【0075】 It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made by those skilled in the art within the technical framework of the present invention. For example, as shown in the modified example in Figure 9(A), two spiral protrusions 63 wound in opposite directions may be formed to intersect on the outer surface of the base-side coating layer 60. Alternatively, as shown in another modified example in Figure 9(B), a plurality of independent protrusions 63 formed in a ring shape may be formed to align along the axis X on the outer surface of the base-side coating layer 60. Another modified example in Figure 9(C) may be formed to align in the circumferential direction on the outer surface of the base-side coating layer 60, with a plurality of linear protrusions 63 parallel to the axis X. Yet another modified example in Figure 9(D) may be formed to align in the circumferential direction and along the axis X on the outer surface of the base-side coating layer 60. Furthermore, as shown in yet another modification in Figure 9(E), a plurality of point-like protrusions 63 may be formed on the outer surface of the base-side coating layer 60 so as to be aligned in the circumferential direction and in the direction of the axis X. 【0076】 Furthermore, the guidewire 10 may be inserted into blood vessels, ureters, bile ducts, fallopian tubes, hepatic ducts, etc. [Explanation of Symbols] 【0077】 10 Guidewires 20 cores 60. Proximal end coating layer (coating layer) 63 Convex part 65 Constant part on the tip side 66. Gradual Decrease 67 Proximal constant part 70 Tip-side coating layer 100 Combined Devices θ i (i=1~n) Tip side inclination angle T i (i=1~n) Thickness N end point X-axis center

Claims

[Claim 1] A guide wire having an elongated core with an axis extending between its tip and base, a coating layer made of resin covering the outer surface of the core, and linear or dot-shaped protrusions arranged on the outer surface of the coating layer, The convex portion has a top that protrudes radially outward from the guide wire, and in a cross-section passing through the axis of the core, the thickness of the convex portion in a direction perpendicular to the outer surface of the coating layer in contact with the convex portion decreases towards the tip side of the guide wire. [Claim 2] The guide wire according to claim 1, wherein, if the cross-sectional shape of the protrusion in the cross-section passing through the axis of the core is semicircular or semielliptical, the angle of inclination of the protrusion with respect to the axis decreases as it approaches the top of the protrusion from the base of the protrusion which is close to the coating layer. [Claim 3] The guide wire according to claim 1 or 2, wherein the coating layer has a tapering portion whose outer diameter gradually decreases toward the tip, and at least a portion of the convex portion is arranged in the tapering portion. [Claim 4] The guide wire according to claim 1 or 2, wherein the convex portion is formed in a spiral shape. [Claim 5] The guide wire according to claim 1 or 2, characterized in that the protrusions are spaced apart along the axis, and the pitch between adjacent protrusions decreases towards the tip. [Claim 6] The guide wire according to claim 1 or 2, characterized in that the protrusion is formed of resin.

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