Metal wire for medical device, medical device, and method for manufacturing metal wire for medical device

Abstract

To provide a metal wire for a medical device in which the degree of easiness of forming a bending habit is changed.SOLUTION: A metal wire for a medical device includes a predetermined region having a coating film exhibiting at least a predetermined color, and a specific region having a coating film exhibiting at least a specific color different from the predetermined color.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a metal wire for a medical device, a medical device, and a method for manufacturing a metal wire for a medical device. [Background technology]

[0002] Guidewires used for inserting catheters or the like into blood vessels are known. In such guidewires, a wire (metal wire) made of a superelastic alloy, such as a nickel-titanium alloy, may be used as the core material. Superelastic alloys have the property of being resistant to bending. It is known that nickel-titanium alloys lose their superelastic properties when subjected to heat treatment, making them more susceptible to bending. For example, Patent Documents 1 and 2 disclose guidewires that utilize this property and improve shaping performance by subjecting the metal wire to heat treatment. The "metal wire" is also called a core, wire, core wire, core shaft, or metal wire for a medical device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 161832 Brochure [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-153615 Summary of the Invention [Problem to be solved by the invention]

[0004] In this way, metal wires can be processed by utilizing the changes in the physical properties of metals caused by heat treatment. Methods for heat treating metal wires include annealing in an electric furnace and heat treatment using a laser. The above patent documents do not take into consideration changing the degree of susceptibility to bending.

[0005] These issues are not limited to the vascular system, but are common to medical devices inserted into various organs within the human body, such as the lymphatic system, biliary system, urinary system, respiratory system, digestive system, secretory glands, and reproductive organs, as well as to metal wires used in these medical devices. [Means for solving the problem]

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

[0007] (1) According to one aspect of the present disclosure, there is provided a metal wire for a medical device, the metal wire for a medical device including a predetermined region having a coating with a predetermined color and a specific region having a coating with a specific color. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 10 is a diagram illustrating a shape test. [Figure 2] 1 is a table showing the physical properties of each region of a metal wire. [Figure 3] FIG. 1 is an explanatory diagram illustrating the configuration of a medical device according to a first embodiment. [Figure 4] FIG. 1 is a diagram showing the relationship between coating thickness and color. [Figure 5] FIG. 10 is a diagram showing an example of a tip of a metal wire. [Figure 6] FIG. 2 is a diagram showing an example of the surface structure of the tip of a metal wire. [Figure 7] FIG. 2 is an enlarged view of the tip of the metal wire. [Figure 8] 1 is a flowchart illustrating a method for manufacturing a medical device. [Figure 9] 10 is a diagram showing an example of a tip portion of a metal wire according to a second embodiment. FIG. [Figure 10] 10 is a diagram showing an example of a tip portion of a metal wire according to a third embodiment. FIG. [Figure 11] FIG. 10 is a diagram showing an example of a tip portion of a metal wire according to a fourth embodiment. [Figure 12]FIG. 11 is a diagram showing an example of a tip portion of a metal wire according to a fifth embodiment. [Figure 13] FIG. 13 is a diagram showing an example of a tip portion of a metal wire according to a sixth embodiment. [Figure 14] FIG. 13 is a diagram showing an example of a tip portion of a metal wire according to a seventh embodiment. [Figure 15] FIG. 13 is a diagram showing an example of a tip portion of a metal wire according to an eighth embodiment. [Figure 16] FIG. 13 is an enlarged view of a tip portion of a metal wire according to a ninth embodiment. [Figure 17] 13 is a flowchart showing a method for manufacturing a medical device according to a ninth embodiment. [Figure 18] FIG. 23 is an enlarged view of a tip portion of a metal wire according to a tenth embodiment. [Figure 19] 13 is a flowchart showing a method for manufacturing a medical device according to a tenth embodiment. [Figure 20] FIG. 23 is an enlarged view of a tip portion of a metal wire according to an eleventh embodiment. [Figure 21] FIG. 1 is a diagram showing tip coating thickness. DETAILED DESCRIPTION OF THE INVENTION

[0009] Shaping performance can be improved by applying heat treatment to metal wire. Below, we conducted shaping tests on metal wires with different physical properties, including a first region, a second region, and an unheat-treated region. The results showed that the first region was most susceptible to bending, while the second region was less susceptible to bending than the first region.

[0010] FIG. 1 is a diagram illustrating the shape test. FIG. 1(A) shows a test fixture used in the shape test. The test fixture is a measuring device 200 for measuring a shape angle θ. The measuring device 200 includes a base 211, a flat plate 213 placed on the base 211 and having a flat upper surface 212, a pin 215 supported on a support 214 on the base 211 so as to be slidable in the vertical direction, and a clamp mechanism 217 supported on a support rod 216 on the base 211 so as to be slidable in the vertical direction. The pin 215 has a spherical protrusion extending downward in the vertical direction. The diameter Φ215 of the protrusion of the pin 215 is 0.5 mm. The metal wire used as the sample SW is a nickel-titanium alloy wire having a first region, a second region, and an unheat-treated region formed by changing the heat treatment conditions.

[0011] The procedure for the shape test will be described. An operator sets the sample SW to be measured in the measuring device 200. Specifically, the operator fixes the sample SW to the clamping mechanism 217 at a position a predetermined distance (approximately 250 mm to 300 mm) from the tip of the sample SW, and the sample SW extends downward from the position fixed to the clamping mechanism 217 until it abuts against the plane 212 and then extends horizontally above the plane 212 from that position. The operator presses the portion of the sample SW that will contact the plane 212 toward the plane 212 with the convex portion of the pin 215, and places the weight 218 on the pin 215. This applies a load of 1 N to the sample SW toward the plane 212 via the pin 215. In this state, the operator moves the clamping mechanism 217 upward along the support rod 216, thereby pulling the sample SW out of the plane 212 in a direction perpendicular to the plane. The pulling length is approximately 2 mm.

[0012] For example, to measure the shape angle θ of the first region of the sample SW, the worker can pull out the central portion of the first region to impart a shape to the pulled-out portion. The worker measures the angle of the curved portion SWC in the first region of the sample SW as the shape angle θ. Figures 1(C) and 1(D) are diagrams explaining how to measure the shape angle θ. The worker draws an imaginary extension line VL1 extending the tangent of a straight portion of the sample SW located distal to the curved portion SWC, and an imaginary extension line VL2 extending the tangent of a straight portion of the sample SW located proximal to the curved portion SWC. The straight portion refers to the non-curved portion of the sample SW. The worker measures the angle θ at the intersection of the imaginary extension lines VL1 and VL2, located farther from the curved portion SWC, and defines this as the shape angle θ.

[0013] Figure 1(B) shows the results of the shape test (the shape angle θ of each pulled portion of the sample SW). Figure 2 is a table showing the physical properties of each region of the metal wire that constitutes the sample SW. The shape angle θ of the first region is 60°. The first region is heat-treated at a first temperature. The oxide film in the first region has a thickness of 100 nm or more. The oxide film in the first region exhibits at least one color selected from a first color group. The first color group includes green, blue-green, red-purple, and yellow. The shape angle θ of the second region is 18°. The second region is heat-treated at a second temperature. The oxide film in the second region has a thickness of 10 nm or more and 30 nm or less. The oxide film in the second region exhibits at least one color selected from a third color group. The third color group includes purple and gold. The shape angle θ of the transition region is estimated to be greater than 18° and less than 60°. The transition region is formed by the conduction of heat applied to the first region through the sample SW. The heat treatment temperature of the transition region is estimated to be lower than the first temperature and higher than the second temperature. The thickness of the oxide film in the transition region is greater than 30 nm and less than 100 nm. The oxide film in the transition region exhibits at least one color selected from a second color group. The second color group includes blue and white. The shape angle θ of the unheat-treated region is 9°. The thickness of the oxide film in the unheat-treated region is approximately 0 nm. The color of the oxide film in the unheat-treated region exhibits at least one color selected from a fourth color group. The fourth color group includes gray and silver. The magnitude relationship between the first temperature and the second temperature is first temperature > second temperature.

[0014] As is clear from Figures 1(B) and 2, a correlation was found: the thicker the oxide film on the metal wire, the larger the shape angle θ (the bending angle). As will be described later, there is a correlation between the thickness and color of the oxide film. In other words, it was found that there is a correlation between the color of the oxide film and the ease of bending. As shown in Figure 2, for the transition region between the first and second regions, it is inferred that the shape angle θ is in the following relationship: first region > transition region > second region. The first region corresponds to the "predetermined region" in the claims. The transition region corresponds to the "specific region" in the claims. The second region corresponds to the "predetermined region" in the claims. The first temperature corresponds to the "predetermined temperature" in the claims. The second temperature corresponds to the "specific temperature" in the claims.

[0015] Taking advantage of this, in each of the embodiments described below, medical devices with varying degrees of ease of forming bends were successfully produced.

[0016] First Embodiment FIG. 3 is an explanatory diagram illustrating the configuration of the medical device 1 of the first embodiment. The medical device 1 is a guide wire. The medical device 1 is used when inserting other medical devices (catheters, etc.) into blood vessels or digestive organs. The medical device 1 comprises a first metal wire 10. The medical device 1 comprises a second metal wire 20. The medical device 1 comprises a coil 40. The medical device 1 comprises a distal tip 51. The medical device 1 comprises a base-end joint 52. The distal portion 100 of the first metal wire 10 has a coating formed by heat treatment. The medical device 1 has improved bending tendency (shaping performance) at the distal portion 100.

[0017] For ease of explanation, Figure 3 includes portions in which the relative size ratios of the components are different from the actual ratios. Figure 3 also includes portions in which the components are exaggerated. Figure 3 shows the axis passing through the center of the medical device 1 as axis O (dash line). Axis O coincides with the axes passing through the centers of the first metal wire 10, the second metal wire 20, and the coil 40. Axis O may differ from the central axes of the components described above. Figure 3 illustrates mutually orthogonal X, Y, and Z axes. The X axis corresponds to the length direction of the medical device 1. The Y axis corresponds to the thickness direction of the medical device 1. The Z axis corresponds to the width direction of the medical device 1. The left side of Figure 3 (-X axis direction) is referred to as the "distal side" of the medical device 1 and each component, and the right side of Figure 3 (+X axis direction) is referred to as the "proximal side" of the medical device 1 and each component. For the medical device 1 and each component, the end portion located on the distal side is referred to as the "distal tip," and the distal tip and its vicinity are referred to as the "distal portion." The end located on the proximal side is called the "proximal end," and the proximal end and its vicinity are called the "proximal end portion." The distal end is inserted into the living body, and the proximal end is operated by the doctor. These points are also common to Figure 3 and subsequent figures.

[0018] The first metal wire 10 is a metal wire for a medical device. The first metal wire 10 is arranged on the distal side of the medical device 1. The first metal wire 10 is arranged closer to the distal side than the second metal wire 20. The first metal wire 10 is formed, for example, from a nickel-titanium alloy or an alloy of nickel-titanium and another metal. The first metal wire 10 has, in order from the distal end to the proximal end, a first section 11, a second section 12, a third section 13, a fourth section 14, and a fifth section 15. The thickness, width, and length of each section can be determined as desired.

[0019] The first portion 11 is the portion of the first metal wire 10 that is located closest to the tip. The first portion 11 is the portion of the first metal wire 10 that has the smallest thickness. A coating containing titanium oxide is formed on the surface of the first portion 11. The first portion 11 is press-formed to improve its tendency to bend (shaping performance). Details will be described later. Hereinafter, the entire first portion 11, excluding a portion on the base end side, will be referred to as the "tip portion 100 of the first metal wire 10." The tip portion 100 of the first metal wire 10 may also be simply referred to as the "tip portion 100."

[0020] The second portion 12 is a portion of the first metal wire 10 located between the first portion 11 and the third portion 13. The third portion 13 is a portion of the first metal wire 10 located between the second portion 12 and the fourth portion 14. The fourth portion 14 is a portion of the first metal wire 10 located between the third portion 13 and the fifth portion 15. The thickness of the second portion 12 decreases toward the tip. The thickness of the third portion 13 decreases toward the tip. The thickness of the fourth portion 14 decreases toward the tip. The rates of change in thickness of the second portion 12, the third portion 13, and the fourth portion 14 are all different. The fifth portion 15 is a portion of the first metal wire 10 located closest to the base end. The fifth portion 15 has a substantially cylindrical shape and is the portion of the first metal wire 10 where the thickness is greatest.

[0021] In this embodiment, "substantially constant" is synonymous with "generally constant" and means that the shape is generally constant while allowing for variations due to manufacturing errors, etc. Similarly, "generally cylindrical shape / generally truncated conical shape" is synonymous with "generally cylindrical shape / generally truncated conical shape" and means that the shape is generally in question while allowing for variations due to manufacturing errors, etc. In this embodiment, "same" and "equal" do not necessarily mean that the shape is strictly the same, but also mean that differences due to manufacturing errors, etc. are allowed.

[0022] The second metal wire 20 is arranged on the proximal side of the medical device 1. The second metal wire 20 is arranged closer to the proximal side than the first metal wire 10. The second metal wire 20 is a substantially cylindrical member having a constant outer diameter. The outer diameter of the second metal wire 20 is the same as the outer diameter of the fifth portion 15 of the first metal wire 10. The second metal wire 20 is made of a material having a larger Young's modulus in the linear deformation region than the first metal wire 10, for example, a stainless steel alloy such as SUS304 or SUS316.

[0023] The joint 30 is a portion where the first metal wire 10 and the second metal wire 20 are joined by welding. The joint 30 may be formed by fastening the first metal wire 10 and the second metal wire 20 by a means other than welding, for example, by a fixture. The member to which the first metal wire 10 and the second metal wire 20 are joined is a core shaft. The joint 30 is formed between the base end surface of the fifth portion 15 of the first metal wire 10 and the tip end surface of the second metal wire 20. In the illustrated example, the joint 30 is flat and substantially perpendicular to the axis O. The joint 30 may also be inclined with respect to the axis O. The first metal wire 10 and the second metal wire 20 are fixed by this joint 30.

[0024] The distal ends of the first portion 11, the second portion 12, and the third portion 13 of the first metal wire 10 are covered by the coil 40. The proximal end of the third portion 13, the fourth portion 14, and the fifth portion 15 of the first metal wire 10 are not covered by the coil 40 and are exposed from the coil 40. The proximal end of the second metal wire 20 is used when a doctor grasps the medical device 1.

[0025] The coil 40 is formed by wire 41 wound in a spiral shape and has a substantially cylindrical shape. The coil 40 may be a single-filament coil formed by winding a single wire. The coil 40 may be a multi-filament coil formed by winding multiple wires. The coil 40 may be a single-filament stranded coil formed by winding a singlefilament of a twisted wire obtained by twisting multiple wires together. The coil 40 may be a multi-filament stranded coil formed by using multiple twisted wires obtained by twisting multiple wires together and winding each twisted wire multiple times. The wire diameter of the wire 41 of the coil 40, the outer diameter and inner diameter of the coil 40, and the length of the coil 40 can be determined arbitrarily.

[0026] The wire 41 can be formed from, for example, stainless steel alloys such as SUS304 and SUS316, nickel-titanium alloys, piano wire, radiopaque alloys such as nickel-chromium alloys and cobalt alloys, radiopaque alloys such as gold, platinum, tungsten, and alloys containing these elements (e.g., platinum-nickel alloys), or other known materials.

[0027] The distal tip 51 is provided at the distal end of the medical device 1. The distal tip 51 integrally holds the distal end of the first portion 11 of the first metal wire 10 and the distal end of the coil 40. The proximal joint 52 faces the middle portion of the medical device 1. The proximal joint 52 integrally holds a portion of the third portion 13 of the first metal wire 10 and the proximal end of the coil 40. The distal tip 51 is formed of any bonding agent, for example, a metal solder such as silver solder, gold solder, zinc, an Sn—Ag alloy, or an Au—Sn alloy. The proximal joint 52 is formed of any bonding agent, for example, a metal solder such as silver solder, gold solder, zinc, an Sn—Ag alloy, or an Au—Sn alloy. The distal tip 51 and the proximal joint 52 may use the same bonding agent or different bonding agents.

[0028] Hereinafter, the coating formed on the tip portion 100 of the first metal wire 10 and the detailed configuration of the tip portion 100 will be described with reference to Figures 4 to 7. When a metal wire containing titanium (Ti), such as a nickel-titanium alloy or an alloy of nickel-titanium and another metal, like the first metal wire 10 described in Figure 3, is subjected to heat treatment, the titanium is oxidized, and a titanium oxide coating is formed on the surface of the metal wire. Hereinafter, the titanium oxide coating will also be simply referred to as "coating."

[0029] Figure 4 shows the relationship between coating thickness and color. The higher the heat treatment temperature, the thicker the coating formed on the metal wire. The lower the heat treatment temperature, the thinner the coating formed on the metal wire. The coating thickness is related to the heat treatment temperature. This coating thickness is related to the external color of the metal wire. As shown in Figure 4, the green coating is the thickest, the blue-green coating is the second thickest, the red-purple coating is the third thickest, the yellow coating is the fourth thickest, the white coating is the fifth thickest, the blue coating is the sixth thickest, the purple coating is the seventh thickest, and the gold coating is the eighth thickest. If no heat treatment is performed and no coating is formed, the external color of the metal wire is either gray or silver.

[0030] In this embodiment, "green" includes green as well as various green-based colors such as lime green and sky green. "Blue-green" includes peacock green as well as colors intermediate between green and blue, such as aquamarine and turquoise. "Reddish purple" includes claret as well as colors intermediate between red and purple, such as plum and magenta. "Yellow" includes yellow as well as various yellow-based colors such as lemon yellow and topaz. "White" includes white as well as various white-based colors such as silver white and oyster white. "Blue" includes blue as well as various blue-based colors such as cyan and navy blue. "Purple" includes purple as well as various purple-based colors such as violet and grape. "Gold" includes antique gold as well as various gold-based colors such as buff and beige.

[0031] The color of the coating allows visual identification of the appearance of the heat-treated metal wire. Specifically, an operator takes a photograph of the appearance of the heat-treated metal wire using a digital microscope "VHX-7000" (manufactured by Keyence Corporation). The operator then visually checks the photograph to identify the color of the coating. That is, the color of the coating described above is the color under the lighting environment of the digital microscope VHX-7000. The location where the oxide coating was observed (the location where the photograph of the appearance was taken) was the side surface viewed from the Y-axis direction (the side surface shown in Figure 7(B) described below). The first color group C1 includes green, blue-green, magenta, and yellow. At least one color selected from the first color group C1 is a predetermined color. The second color selected from the first color group is a second predetermined color. The third color selected from the first color group is a third predetermined color. The fourth color selected from the first color group is a fourth predetermined color. The third color group C3 includes purple and gold. At least one color selected from the third color group C3 is a predetermined color. The second color selected from the third color group C3 is a second predetermined color. The second color group C2 includes white and blue. The two colors selected from the second color group are a specific color and a second specific color. The first color group C1 has a relatively thick coating thickness. The third color group C3 has a relatively thin coating thickness. The second color group C2 has a coating thickness that is thinner than the coating of the first color group C1 and thicker than the coating of the third color group C3.

[0032] That is, as shown in the upper part of Figure 4, the first region has a relatively thick coating thickness. The second region has a relatively thin coating thickness. The transition region has a coating thickness that is thinner than the coating in the first region and thicker than the coating in the second region. In other words, the coating thickness in the first region is thicker than the coating thickness in the transition region. The coating thickness in the first region is thicker than the coating thickness in the second region. The coating thickness in the transition region is thicker than the coating thickness in the second region. The worker can determine the "coating thickness" by the following procedure. Specifically, the worker randomly selects three different locations in the longitudinal direction within the target region. The worker measures the coating thickness at each of the three selected locations. The worker calculates the average value of the coating thicknesses measured at the three locations. The worker determines the calculated average value as the coating thickness of the target region.

[0033] FIG. 5 is a diagram showing an example of the distal end portion 100 of the first metal wire 10. FIG. 5(A) is a line diagram in which the color of the coating of the distal end portion 100 is represented by the type of hatched line. FIG. 5(B) is a photograph of the distal end portion 100. The line diagram corresponds to the photograph. Both the line diagram and photograph in FIG. 5 show the width direction of the flat shape of the first metal wire 10. As shown in the figure, the distal end portion 100 of the first metal wire 10 has portions 91a to 91l from the distal end toward the proximal end. As the alphabet suffixes progress from a to c, the position in the longitudinal direction of the first metal wire 10 moves toward the proximal end. All or part of the unheat-treated portion at the distal end of the first metal wire 10 may be cut and removed during the manufacture of a medical device 1 using the first metal wire 10. The unheat-treated portion at the distal end of the first metal wire 10 may be used as is without being cut during the manufacture of a medical device 1 using the first metal wire 10. When this first metal wire 10 is used to produce a guide wire, a tip may be provided in the unheated portion.

[0034] As shown in the figure, portion 91a is silver, indicating that it has not been heat-treated. Portion 91b has a blue coating. Portion 91c has a white coating. Portion 91d has a yellow coating. Portion 91e has a reddish-purple coating. Portion 91f has a green coating. Portion 91g has a blue-green coating. Portion 91h has a reddish-purple coating. Portion 91i has a white coating. Portion 91j has a blue coating. Portion 91k has a purple coating. Portion 91l has a gold coating. In FIG. 5(A), for convenience of illustration, the boundary between a certain portion and another portion adjacent to it is clearly shown. However, as shown in FIG. 5(B), the boundary between a certain portion and another portion may have a gradation in which the coating color gradually transitions. As shown in FIG. 5(B), the color of the coating of each of the portions 91b to 91l (including not only the color itself but also the hue and texture) and the color gradation at the boundaries of each of the portions 91b to 91l are developed by heat treatment of the metal wire.

[0035] The "first region A1" is a region located in the center of the tip portion 100 of the first metal wire 10. The first region A1 has a coating of a color included in the first color group C1 (specifically, at least one of green, blue-green, magenta, and yellow).

[0036] The "distal transition region AT1" is a region located at a different position in the longitudinal direction from the first region A1. The distal transition region AT1 is located closer to the distal end than the first region A1 of the first metal wire 10. The distal transition region AT1 has a coating of a color included in the second color group C2 (specifically, at least one of white and blue). The distal transition region AT1 is adjacent to the distal end of the first region A1. The "proximal transition region AT2" is a region located at a different position in the longitudinal direction from the first region A1. The proximal transition region AT2 is located closer to the proximal end than the first region A1 of the first metal wire 10. The proximal transition region AT2 has a coating of a color included in the second color group C2 (specifically, at least one of white and blue). The proximal transition region AT2 is adjacent to the proximal end of the first region A1. The region having a coating of a color included in the second color group C2 is the transition region AT. The distal transition region AT1 is the transition region AT. The proximal transition region AT2 is the transition region AT. The coating in the transition region AT (the distal transition region AT1 and the proximal transition region AT2) exhibits a gradation that includes colors (white, blue) included in the second color group C2. In the transition region AT, the white coating is located closer to the first region A1 than the blue coating. The distal transition region corresponds to the "distal specific region" in the claims. The proximal transition region corresponds to the "proximal specific region" in the claims.

[0037] The "second region A2" is a region that is located at a different position in the longitudinal direction from the first region A1. The second region A2 is located on the opposite side of the first region A1 from the transition region AT (specifically, the base-end transition region AT2) of the first metal wire 10. The second region A2 has a coating of a color included in the third color group C3 (specifically, at least one of purple and gold). The second region A2 is adjacent to the base end of the transition region AT. The second region A2 is adjacent to the base end of the base-end transition region AT2. The second region A2 is located closer to the base end than the first region A1 of the first metal wire 10. The second region A2 is provided at a position away from the first region A1 in the longitudinal direction of the first metal wire 10.

[0038] FIG. 21 is a diagram showing the thickness of the coating of the tip portion 100. FIG. 21 corresponds to the diagram of FIG. 5(A). FIG. 21 shows the width direction of the flat shape of the first metal wire 10. In FIG. 21, for ease of explanation, the first metal wire 10 is shown with a dashed line, and the coating formed on the first metal wire 10 is shown with a solid line to emphasize the thickness of the coating. As is clear from FIG. 21, the coating thickness CT in the first region A1 is relatively thick. The coating thickness in the second region A2 is relatively thin. The coating thickness in the transition regions AT1 and AT2 is thinner than that of the first region A1 and thicker than that of the second region A2. In other words, the coating thickness CT in the first region A1 is thicker than that of the transition regions AT1 and AT2. The coating thickness CT in the first region A1 is thicker than that of the second region A2. The thickness of the coating in the transition regions AT1 and AT2 is thicker than the thickness of the coating in the second region A2. As shown in the figure, the first region A1 includes multiple portions 91d-91h with different coating thicknesses. Similarly, the transition regions AT1 and AT2 include multiple portions 91b, 91c, 91i, and 91j with different coating thicknesses. The second region A2 includes multiple portions 91k and 91l with different coating thicknesses. The above-described relationship in coating thickness also holds true, for example, between the thinnest coating portion 91d in the first region A1 and the thickest coating portions 91c and 91i in the transition regions AT1 and AT2. This also holds true when comparing the transition regions AT1 and AT2 with the second region A2. The above-described relationship in coating thickness also holds true, for example, between the thinnest coating portions 91b and 91j in the transition regions AT1 and AT2 and the thickest coating portion 91k in the second region A2.

[0039] As shown in FIG. 2, the first region A1 had a shape angle θ of 60° when the shape test was performed. The transition region AT had a shape angle θ of greater than 18° and less than 60° when the shape test was performed. The second region A2 had a shape angle θ of 18° when the shape test was performed. The unheat-treated region had a shape angle θ of 9° when the shape test was performed. The first region A1 had a larger shape angle θ than the transition region AT when the shape test was performed. The first region A1 had a larger shape angle θ than the second region A2 when the shape test was performed.

[0040] FIG. 6 is a diagram showing an example of the surface structure of the tip portion 100 of the first metal wire 10. FIG. 6 shows an image obtained when the first region A1 of the first metal wire 10 was observed using a TEM (transmission electron microscope) "JEM-2100F" (manufactured by JEOL Ltd.). FIG. 6(A) is a diagram of the first region A1 obtained by the TEM. FIG. 6(B) is a photograph of the first region A1 obtained by the TEM. FIG. 6(A) and FIG. 6(B) show the same image.

[0041] As shown in Figures 6(A) and 6(B), surface segregation occurs on the surface of the heat-treated first metal wire 10 as a titanium oxide coating is formed, forming layers. The outermost layer is the titanium oxide coating CO1. The thickness T1 of the coating CO1 in the first region A1 of the first metal wire 10 is 100 nm or more. A method for determining the thickness T1 of the coating CO1 will be described. An operator observes, using a TEM, the portion of the first region A1 of the first metal wire 10 that is colored to indicate the thinnest coating thickness (yellow in the case of the first metal wire 10 shown in Figure 5), and measures the thickness of the relatively thin coating portion in the TEM image to determine the thickness T1 of the coating CO1.

[0042] In the first metal wire 10, the thickness T1 of the coating CO1 in the first region A1 is thicker than the thickness of the coating in the transition region AT. A method for determining the thickness of the coating in the transition region AT will be described. An operator performs TEM observation of the portion of the first metal wire 10 that is colored to represent the thickest coating (white in the case of the first metal wire 10 shown in FIG. 5) and measures the thickness of the relatively thick portion of the coating in the image obtained by TEM, thereby determining the thickness of the coating in the transition region AT.

[0043] In the first metal wire 10, the thickness of the coating in the second region A2 is 10 nm or more and 30 nm or less. Regarding the lower limit of the thickness of the coating in the second region A2, the worker observes with a TEM the part of the color representing the thinnest coating thickness (gold in the case of the first metal wire 10 shown in FIG. 5) and measures the thickness of the relatively thin coating part in the image obtained by the TEM. Regarding the upper limit of the thickness of the coating in the second region A2, the worker observes with a TEM the part of the color representing the thickest coating thickness (purple in the case of the first metal wire 10 shown in FIG. 5) and measures the thickness of the relatively thick coating part in the image obtained by the TEM.

[0044] In the cross-sectional view of the first metal wire 10 shown in FIGS. 6(A) and 6(B), an arbitrary position in the outermost layer (titanium oxide coating CO1) is defined as a first position P1. An arbitrary position in the second outermost layer is defined as a second position P2. In this case, the titanium content at the first position P1 is greater than the titanium content at the second position P2 (titanium: first position P1 > second position P2). The nickel (Ni) content at the second position P2 is greater than the nickel content at the first position P1 (nickel: first position P1 < second position P2). The titanium content refers to the mass content. The nickel content refers to the mass content.

[0045] The above-mentioned bias in titanium and nickel is caused by the surface segregation of titanium that occurs toward the surface of the first metal wire 10 during heat treatment. 6(A) and (B) have described the titanium and nickel contents at the first position P1 and the second position P2 for the first region A1 of the first metal wire 10. Similarly to the first region A1, in the transition region AT and the second region A2 of the first metal wire 10, the titanium content is greater than the second position P2, and the nickel content is less than the first position P1.

[0046] FIG. 7 is an enlarged view of the tip portion 100 of the first metal wire 10. FIG. 7(A) shows a side view of the tip portion 100 as viewed from the Z-axis direction. FIG. 7(B) shows a side view of the tip portion 100 as viewed from the Y-axis direction. The coil 40 is not shown in FIG. 7. The first portion 11 has a flat shape including a first press portion 111, a transition portion 112, and a second press portion 113. The first press portion 111 is a portion that has been pressed at a first drawing ratio. The first press portion 111 has a relatively wide, flat shape. The second press portion 113 is a portion that has been pressed at a second drawing ratio that is smaller than the first drawing ratio. The second press portion 113 is closer to a cylinder than the first press portion 111. The second press portion 113 has an elliptical cylindrical shape. The transition section 112 is a section between the first press section 111 and the second press section 113 where the drawing rate and the outer shape gradually change.

[0047] The thickness T111 of the first pressed portion 111 is thinner than the thickness T113 of the second pressed portion 113. The thickness T1121 of the transition portion 112 at its tip is equal to the thickness T111 of the first pressed portion 111. The thickness T1122 of the transition portion 112 at its base is equal to the thickness T113 of the second pressed portion 113. The thickness T112 of the transition portion 112 gradually increases from its tip to its base. The thickness of the pressed portion refers to the vertical distance from one main surface to the other main surface of the tip portion 100 of the first metal wire 10, where the surface with the largest area is the main surface and the surface perpendicular to the main surface is the side surface.

[0048] A heat treatment coating is formed on the first pressed portion 111, the transition portion 112, and the entire second pressed portion 113 except for the base end portion. In the illustrated example, the tip side of the tip portion of the first pressed portion 111 is an unheat-treated portion. A tip-side transition region AT1 is formed on the base end side of the tip portion of the first pressed portion 111. A first region A1 is formed between the center of the first pressed portion 111 and the base end. A base-side transition region AT2 is formed between the tip and base end of the transition portion 112. A second region A2 is formed on the entire second pressed portion 113 except for the base end portion. The thickness of the first metal wire 10 in the first region A1 is thinner than the thickness of the first metal wire 10 in the second region A2. The thickness of the first metal wire 10 in the base-side transition region AT2 gradually increases from the tip to the base end. The thickness of the first metal wire 10 in the first region A1 is thinner than the thickness of the first metal wire 10 in the base-end transition region AT2. The thickness of the first metal wire 10 in the base-end transition region AT2 is thinner than the thickness of the first metal wire 10 in the second region A2. The correspondence between the first region A1, the transition region AT, the second region A2, the first pressed portion 111, the transition portion 112, and the second pressed portion 113 is merely an example and may be changed as desired.

[0049] Generally, in guidewires, the outer diameter of the core wire may be tapered toward the tip to reduce tip load, or the outer diameter of the coil may be tapered toward the tip to improve penetration. In such cases, the bending strain decreases due to a decrease in metal thickness, resulting in a smaller shape angle toward the tip of the guidewire. Even if the outer diameters of the core wire and coil are made uniform, the shape angle is merely uniform from the tip to the proximal end of the guidewire. Therefore, conventional guidewires often have either a shape shape in which the shape angle decreases toward the tip or a shape shape in which the shape angle is uniform. When a guidewire is fabricated using the first metal wire 10 of this embodiment, unlike conventional guidewires, the shape angle of the guidewire can be increased toward the tip even if the thickness of the core wire decreases toward the tip. Therefore, a guidewire using the first metal wire 10 of this embodiment can improve selectivity for small branched blood vessels such as peripheral blood vessels.

[0050] In the tip portion 100 of the first metal wire 10, the coating (first region A1, transition region AT, second region A2) is formed in the thickness direction of the flat shape of the first metal wire 10. In other words, the coating is formed on surfaces 111a, 112a, 113a in the thickness direction of the first metal wire 10. In the tip portion 100 of the first metal wire 10, the coating (first region A1, transition region AT, second region A2) is formed in the width direction of the flat shape of the first metal wire 10. In other words, the coating is formed on surfaces 111b, 112b, 113b in the width direction of the first metal wire 10.

[0051] The distal tip 51 (broken line) is attached to the distal portion 100 of the first metal wire 10, closer to the distal end than the first region A1. Specifically, the distal tip 51 is attached to a distal transition region AT1 that is provided closer to the distal end than the first region A1. In the illustrated example, the base end of the distal tip 51 is located slightly distal to the base end of the distal transition region AT1. The base end of the distal tip 51 may be located at any position within the range of the distal transition region AT1.

[0052] FIG. 8 is a flowchart showing a method for manufacturing the medical device 1. In step S10, an operator prepares a metal wire made of a nickel-titanium alloy. The metal wire may be made of an alloy of nickel-titanium and another metal. In step S12, an operator presses the tip of the metal wire. In step S12, as described in FIGS. 7(A) and (B), pressing is performed multiple times to form a first pressed portion 111, a transition portion 112, and a second pressed portion 113. In step S12, pressing may be performed only once.

[0053] In step S14, the worker heat-treats the first region A1 at a first temperature. The heat treatment is performed by "laser heat treatment," which involves irradiating a metal wire with a high-power laser to heat it. The first temperature may be set arbitrarily. The heat treatment may also be performed by other heat treatment methods (e.g., heat treatment using a heating furnace). As a result of step S14, a coating is formed on the first region A1 and the transition region AT (the distal transition region AT1 and the proximal transition region AT2). That is, the coating on the transition region AT (the distal transition region AT1 and the proximal transition region AT2) is formed by the heat from the laser irradiated on the first region A1 being conducted along the metal wire. The degree of heat treatment on the first region A1 is greater than the degree of heat treatment on the transition region AT. The first region A1 is more prone to bending than the transition region AT. Step S14 is a step of forming a coating on the first region A1 and the transition region AT. The coating color of the first region A1 is a color included in the first color group C1. The coating color of the transition region AT is a color included in the second color group C2. The coating colors of the first region A1 and the transition region AT are developed by the first heat treatment.

[0054] In step S18, the operator performs a heat treatment on the second region A2 at the second temperature. The second region A2 is located on the proximal side of the first region A1. The second region A2 is located on the proximal side of the proximal-side transition region AT2. The heat treatment at the second temperature is performed by laser heat treatment. The heat treatment at the second temperature may be performed by other heat treatment methods (for example, heat treatment using a heating furnace). The second temperature is lower than the first temperature (first temperature > second temperature). The first temperature and the second temperature can be measured by measuring the temperature of the metal wire during the heat treatment using a radiation thermometer. As a result of step S18, a film is formed on the second region A2. As a result of performing the heat treatment at the second temperature lower than the first temperature, the degree of heat treatment of the second region A2 is weaker than the degree of heat treatment of the first region A1. Consequently, the degree of ease of bending of the second region A2 becomes weaker than that of the first region A1. Step S18 is a step of forming a film on the second region A2. The color of the film on the second region A2 is a color included in the third color group C3. The color of the film on the second region A2 is manifested by the second heat treatment.

[0055] In steps S14 and S18, when the heat treatment is performed with the same laser output (output: S14 = S18), and when the heat treatment is performed with the reverse magnitude relationship (output: S14 < S18), the relationship of first temperature > second temperature holds. This is due to the fact that, among the press-worked metal wires, as a result of irradiating the laser with respect to the XZ plane shown in FIG. 7(B), the irradiation area in step S14 (the area of the first press part 111 and the transition part 112) is larger than the irradiation area in step S18 (the area of the second press part 113). In the present embodiment, the irradiation diameter of the laser is larger than the width of the first press part 111 in FIG. 7(B).

[0056] In step S22, the operator inspects the colors of the films on the first region A1, the transition region AT, and the second region A2. Specifically, the color of the film is inspected according to the following procedures a1 and a2. Procedures a1 and a2 do not need to be executed continuously. Specifically, procedure a1 may be executed before step S14. Step S22 is a step of inspecting the colors of the films on the first region A1, the transition region AT, and the second region A2. (a1) The operator determines that the heat treatment of step S14 has been completed successfully if the color of the coating in the first region A1 corresponds to any of the colors included in the first color group C1 (FIG. 4) and the color of the coating in the transition region AT corresponds to any of the colors included in the second color group C2 (FIG. 4). The operator determines that the heat treatment of step S14 has not been completed successfully if at least one of the following occurs: the color of the coating in the first region A1 does not correspond to any of the colors included in the first color group C1, and the color of the coating in the transition region AT does not correspond to any of the colors included in the second color group C2. (a2) If the color of the coating in the second region A2 corresponds to one of the colors included in the third color group C3 (FIG. 4), the worker determines that the heat treatment in step S18 has been completed normally. If the color of the coating in the second region A2 does not correspond to any of the colors included in the third color group C3, the worker determines that the heat treatment in step S18 has not been completed normally.

[0057] The first metal wire 10 described in FIG. 3 is manufactured through the above steps S10 to S22. Steps S10 to S22 are a method for manufacturing the metal wire 10 for a medical device. The metal wire 10 for a medical device manufactured through steps S10 to S22 has a coating of a color included in the first color group C1, a coating of a color included in the second color group C2, and a coating of a color included in the third color group C3, which are developed by heat treatment of the metal wire. The metal wire 10 for a medical device manufactured through steps S10 to S22 has been confirmed to have undergone normal heat treatment by inspecting each color of the coating (the color included in the first color group C1, the color included in the second color group C2, and the color included in the third color group C3). Step S22 allows accurate and easy determination of the amount of heat applied to each metal wire (the degree of heat treatment) even when multiple first metal wires 10 are manufactured using multiple metal wires with variations in dimensions, surface condition, etc., and therefore allows for the production of first metal wires 10 of consistent quality.

[0058] In step S24, the worker prepares the coil 40. In step S26, the worker forms the tip 51 by joining the tip portion 100 of the first metal wire 10 (specifically, the tip-side transition region AT1) to the tip of the coil 40 with any bonding agent, for example, a metal solder such as silver solder, gold solder, zinc, an Sn—Ag alloy, or an Au—Sn alloy. Because a titanium oxide coating has low solder wettability, if the tip 51 is formed in the portion where the titanium oxide coating is thick (the first region A1), there is a risk that the tip 51 will detach from the first metal wire 10 during use. For this reason, in step S26, it is preferable to form the tip 51 on the first metal wire 10 closer to the tip than the portion where the titanium oxide coating is thick (the first region A1). The portion of the first metal wire 10 where no titanium oxide coating is formed (the unheat-treated portion) has the property of being less prone to bending due to the superelastic properties of the first metal wire 10. The portion of the first metal wire 10 where the titanium oxide coating is relatively thin (the tip transition region AT1) has the property of being less prone to bending than the portion where the titanium oxide coating is thick (the first region A1). Therefore, if the distal tip 51 is formed in the portion where no titanium oxide coating is formed (the unheat-treated portion), the distal tip 51 adjacent to the tip transition region AT1 is less prone to bending than the first region A1, which may reduce usability during use. For this reason, in step S26, it is more preferable to form the distal tip 51 in the portion where the titanium oxide coating is relatively thin (the tip transition region AT1) so that the distal tip 51 is adjacent to the first region A1. In step S26, the distal tip 51 may be formed after removing the coating from the tip transition region AT1. Finally, the worker joins the first metal wire 10 and the second metal wire 20 together to form a joint 30.

[0059] The metal wire 10 for medical devices and the medical device 1 including the same have a first region A1, a base-side transition region AT2, and a second region A2, in which the degree of heat treatment, i.e., the degree of tendency to bend, varies from the distal end to the proximal end. As described above, the degree of heat treatment (the degree of tendency to bend) is in the order of first region A1 > transition region AT > second region A2, and increases toward the distal end. This makes it possible to provide a medical device 1 that can be shaped so that the curvature increases toward the distal end. As a result, a physician can more easily select the desired blood vessel at a blood vessel branch during a procedure using the medical device 1.

[0060] As described above, the metal wire 10 for medical devices of the first embodiment has the first region A1 and the transition region AT, which have coatings of different colors (FIG. 5). Therefore, it is possible to provide a metal wire 10 for medical devices that achieves gradual changes in physical properties by changing the degree of heat treatment, i.e., the degree of tendency to bend. Since the first region A1 and the transition region AT have coatings of different colors, the tendency of the metal wire 10 for medical devices to bend can be identified by the appearance (color) of the first metal wire 10.

[0061] According to the first embodiment of the metal wire 10 for medical devices, the coating in the transition region AT has a gradation that includes two colors from the second color group C2 (FIG. 5). Therefore, even within the transition region AT of the first metal wire 10, the degree of heat treatment, i.e., the degree of tendency to bend, can be changed to achieve a gradual change in physical properties. The degree of gradual change in physical properties within the transition region AT can be identified by the appearance of the first metal wire 10 (the color gradation that changes from white to blue).

[0062] Furthermore, according to the first embodiment of the metal wire 10 for medical devices, the second region A2 is provided on the opposite side of the first region A1 from the transition region AT (specifically, the base-end transition region AT2) (FIG. 5). This allows the degree of heat treatment, i.e., the degree of tendency to bend, to be further varied to provide a metal wire 10 for medical devices that achieves more finely gradual changes in physical properties. Since the second region A2 has a coating color different from that of the first region A1 and the transition region AT, the tendency of the metal wire 10 for medical devices to bend can be identified by the appearance (color) of the first metal wire 10.

[0063] Furthermore, according to the metal wire 10 for medical devices of the first embodiment, the titanium content is high at the first position P1 (in other words, near the surface of the metal wire 10) which is located relatively outward compared to the second position P2, thereby improving the biocompatibility and corrosion resistance of the metal wire 10. Furthermore, according to the metal wire 10 for medical devices of the first embodiment, the nickel content is low at the first position P1 (in other words, near the surface of the metal wire 10) which is located relatively outward compared to the second position P2, thereby improving the biocompatibility.

[0064] Furthermore, according to the metal wire 10 for medical devices of the first embodiment, the thickness of the coating in the first region A1 is 100 nm or more, which further improves the tendency of the metal wire 10 to bend (shaping performance). Furthermore, according to the metal wire 10 for medical devices of the first embodiment, the thickness of the coating in the first region A1 is greater than the thickness of the coating in the transition region AT, which makes the first region A1 more prone to bending than the transition region AT. Furthermore, according to the metal wire 10 for medical devices of the first embodiment, the thickness of the coating in the second region A2 is 10 nm or more and 30 nm or less, which makes the second region A2 less prone to bending than the first region A1, thereby providing a metal wire 10 for medical devices that achieves more finely tuned gradual changes in physical properties.

[0065] Furthermore, according to the medical device 1 of the first embodiment, the distal tip 51 is attached to the metal wire for medical devices 10 closer to the distal end than the first region A1, which facilitates the brazing work for forming the distal tip 51 and makes it difficult for the metal wire for medical devices 10 to detach from the distal tip 51. As a result, the manufacture of the medical device 1 can be made easier and the safety of the medical device 1 can be improved.

[0066] Furthermore, according to the medical device 1 of the first embodiment, the distal tip 51 is attached to the distal transition region AT1, which facilitates the brazing work for forming the distal tip 51 and makes it difficult for the metal wire for a medical device 10 to detach from the distal tip 51. Furthermore, the distal tip 51 is attached to the distal transition region AT1, which is provided closer to the distal side than the first region A1, which improves the ease with which the medical device 1 develops a bending tendency (shaping performance).

[0067] Furthermore, according to the manufacturing method of the metal wire 10 for a medical device of the first embodiment, the metal wire is subjected to heat treatment (step S14) to form the first region A1 and the transition region AT, which have coatings with different colors. Therefore, the metal wire 10 for a medical device, which realizes gradual changes in physical properties, can be manufactured by a single heat treatment.

[0068] Furthermore, according to the manufacturing method of the metal wire 10 for a medical device of the first embodiment, the second region A2 is formed by performing heat treatment (step S18) on the metal wire closer to the base end than the first region A1. Therefore, by performing two heat treatments, steps S14 and S18, it is possible to manufacture the metal wire 10 for a medical device that achieves further gradual changes in physical properties. The temperature (second temperature) of the heat treatment for forming the second region A2 is lower than the temperature (first temperature) of the heat treatment for forming the first region A1 and the transition region AT, so the thickness of the coating in the first region A1 and the thickness of the coating in the second region A2 can be easily changed.

[0069] Furthermore, according to the manufacturing method of the metal wire 10 for a medical device of the first embodiment, since the colors of the coating are different in the first region A1 and the transition region AT, by inspecting the appearance of the metal wire (specifically, the color of the coating in the first region A1 and the color of the coating in the transition region AT), it is possible to easily determine whether the heat treatment in step S14 has been completed normally (step S22). As a result, a metal wire 10 for a medical device of stable quality can be manufactured. By inspecting the appearance of the first metal wire 10 (specifically, the color of the coating in the second region A2), it is possible to easily determine whether the heat treatment in step S18 for forming the second region A2 has been completed normally (step S22). As a result, a metal wire 10 for a medical device of stable quality can be manufactured.

[0070] Second Embodiment FIG. 9 is a diagram showing an example of a distal end portion 100A of a first metal wire 10A according to the second embodiment. The medical device 1 may include a first metal wire 10A, which will be described below, instead of the first metal wire 10 described in the first embodiment. The first metal wire 10A differs from the first embodiment in the color of the coating in the first region A1, the transition region AT, and the second region A2 of the distal end portion 100A. FIG. 9(A) is a diagram showing the color of the coating in the distal end portion 100A represented by the type of hatched line. FIG. 9(B) is a photograph of the distal end portion 100A. The diagram corresponds to the photograph. Both the diagram and photograph in FIG. 9 show the width direction of the flat shape of the first metal wire 10A.

[0071] As shown in the figure, portion 92a is silver, indicating that it is not heat-treated. Portion 92b has a blue coating. Portion 92c has a white coating. Portion 92d has a yellow coating. Portion 92e has a reddish-purple coating. Portion 92f has a green coating. Portion 92g has a reddish-purple coating. Portion 92h has a yellow coating. Portion 92i has a white coating. Portion 92j has a blue coating. Portion 92k has a purple coating. For example, as shown in FIG. 9(B), portion 92g may be a pale reddish-purple. Portion 92k may be a golden purple toward the proximal end. For example, as shown in FIG. 9(B), coatings of the same color (yellow and reddish-purple in the illustrated example) may appear repeatedly within first region A1.

[0072] The central portion of the distal end portion 100A of the first metal wire 10A is a first region A1 having a coating of a color included in the first color group C1 (specifically, green, magenta, and yellow). Further distally from the first region A1 is a distal transition region AT1 having a coating of a color included in the second color group C2 (specifically, white and blue). Further proximally from the first region A1 is a proximal transition region AT2 having a coating of a color included in the second color group C2 (specifically, white and blue). Opposite the first region A1 from the transition region AT (specifically, the proximal transition region AT2) is a second region A2 having a coating of a color included in the third color group C3 (specifically, purple).

[0073] As described above, the colors of the coatings in the first region A1, the transition region AT, and the second region A2 of the distal end portion 100A of the first metal wire 10A, the order of appearance of the colors, and the color combinations when there are multiple colors can be varied in various ways. The first region A1 may be formed with a coating of at least one color from the first color group C1 described in FIG. 4 . The transition region AT may be formed with a coating of at least one color from the second color group C2 described in FIG. 4 . The second region A2 may be formed with a coating of at least one color from the third color group C3 described in FIG. 4 . The longitudinal lengths of the first region A1, the transition region AT, and the second region A2, as well as the lengths of each portion, can also be determined arbitrarily. The metal wire 10A for a medical device of this second embodiment can also achieve the same effects as the first embodiment described above.

[0074] Third Embodiment FIG. 10 is a diagram showing an example of a distal end portion 100B of a first metal wire 10B according to the third embodiment. The medical device 1 may include a first metal wire 10B, which will be described below, instead of the first metal wire 10 described in the first embodiment. The first metal wire 10B differs from the first embodiment in the color of the coating in the first region A1, the transition region AT, and the second region A2 of the distal end portion 100B. FIG. 10(A) is a diagram showing the color of the coating in the distal end portion 100B using hatched line types. FIG. 10(B) is a photograph of the distal end portion 100B. The diagram corresponds to the photograph. Both the diagram and photograph in FIG. 10 show the width direction of the flat shape of the first metal wire 10B.

[0075] As shown, portion 93a is silver, indicating that it has not been heat-treated. Portion 93b has a blue coating. Portion 93c has a white coating. Portion 93d has a yellow coating. Portion 93e has a reddish-purple coating. Portion 93f has a yellow coating. Portion 93g has a white coating. Portion 93h has a blue coating. Portion 93i has a purple coating. Portion 93j has a gold coating. For example, as shown in FIG. 10(B), portion 93f may be yellow with reddish mottling.

[0076] The central portion of the distal end portion 100B of the first metal wire 10B is a first region A1 having a coating of a color included in the first color group C1 (specifically, reddish purple and yellow). Further distally from the first region A1 is a distal transition region AT1 having a coating of a color included in the second color group C2 (specifically, white and blue). Further proximally from the first region A1 is a proximal transition region AT2 having a coating of a color included in the second color group C2 (specifically, white and blue). On the opposite side of the first region A1 from the transition region AT (specifically, the proximal transition region AT2) is a second region A2 having a coating of a color included in the third color group C3 (specifically, purple).

[0077] As described above, the colors of the coatings in the first region A1, the transition region AT, and the second region A2 of the distal end 100B of the first metal wire 10B, the order in which the colors appear, and the color combinations when there are multiple colors can be changed in various ways. The longitudinal lengths of the first region A1, the transition region AT, and the second region A2, as well as the lengths of each region, can also be determined arbitrarily. The metal wire 10B for a medical device of this third embodiment can also achieve the same effects as the first embodiment described above.

[0078] <Fourth embodiment> FIG. 11 is a diagram showing an example of a distal end portion 100C of a first metal wire 10C according to the fourth embodiment. The medical device 1 may include a first metal wire 10C, which will be described below, instead of the first metal wire 10 described in the first embodiment. The first metal wire 10C differs from the first embodiment in the color of the coating in the first region A1, the transition region AT, and the second region A2 of the distal end portion 100C. FIG. 11(A) is a diagram showing the color of the coating in the distal end portion 100C represented by hatched line types. FIG. 11(B) is a photograph of the distal end portion 100C. The diagram corresponds to the photograph. Both the diagram and photograph in FIG. 11 show the width direction of the flat shape of the first metal wire 10C.

[0079] As shown, portion 94a is silver, indicating that it is not heat-treated. Portion 94b has a blue coating. Portion 94c has a white coating. Portion 94d has a yellow coating. Portion 94e has a magenta coating. Portion 94f has a yellow coating. Portion 94g has a white coating. Portion 94h has a blue coating. Portion 94i has a purple coating. Portion 94j has a gold coating. For example, as shown in FIG. 11(B), portions 94d and 94f may be pale yellow.

[0080] The central portion of the distal end portion 100C of the first metal wire 10C is a first region A1 having a coating of a color included in the first color group C1 (specifically, reddish purple and yellow). Further distally from the first region A1 is a distal transition region AT1 having a coating of a color included in the second color group C2 (specifically, white and blue). Further proximally from the first region A1 is a proximal transition region AT2 having a coating of a color included in the second color group C2 (specifically, white and blue). Opposite the first region A1 from the transition region AT (specifically, the proximal transition region AT2) is a second region A2 having a coating of a color included in the third color group C3 (specifically, purple and gold).

[0081] As described above, the colors of the coatings in the first region A1, the transition region AT, and the second region A2 of the distal end 100C of the first metal wire 10C, the order in which the colors appear, and the color combinations when there are multiple colors can be changed in various ways. The longitudinal lengths of the first region A1, the transition region AT, and the second region A2, as well as the lengths of each region, can also be determined arbitrarily. The metal wire 10C for a medical device of this fourth embodiment can also achieve the same effects as the first embodiment described above.

[0082] Fifth Embodiment FIG. 12 is a diagram showing an example of a distal end portion 100D of a first metal wire 10D according to the fifth embodiment. The medical device 1 may include a first metal wire 10D, which will be described below, instead of the first metal wire 10 described in the first embodiment. The first metal wire 10D differs from the first embodiment in the color of the coating in the first region A1, the transition region AT, and the second region A2 of the distal end portion 100D. FIG. 12(A) is a diagram showing the color of the coating in the distal end portion 100D represented by the type of hatched line. FIG. 12(B) is a photograph of the distal end portion 100D. The diagram corresponds to the photograph. Both the diagram and photograph in FIG. 12 show the width direction of the flat shape of the first metal wire 10D.

[0083] As shown, portion 95a is silver, indicating that it is not heat-treated. Portion 95b has a blue coating. Portion 95c has a white coating. Portion 95d has a yellow coating. Portion 95e has a reddish-purple coating. Portion 95f has a green coating. Portion 95g has a reddish-purple coating. Portion 95h has a yellow coating. Portion 95i has a white coating. Portion 95j has a blue coating. Portion 95k has a purple coating. Portion 95l has a gold coating. For example, as shown in FIG. 12(B), portions 95d and 95i may be yellowish-white. Portion 95f may be pale green.

[0084] The central portion of the distal end portion 100D of the first metal wire 10D is a first region A1 having a coating of a color included in the first color group C1 (specifically, green, magenta, and yellow). Further distally from the first region A1 is a distal transition region AT1 having a coating of a color included in the second color group C2 (specifically, white and blue). Further proximally from the first region A1 is a proximal transition region AT2 having a coating of a color included in the second color group C2 (specifically, white and blue). Opposite the first region A1 from the transition region AT (specifically, the proximal transition region AT2) is a second region A2 having a coating of a color included in the third color group C3 (specifically, purple and gold).

[0085] As described above, the colors of the coatings in the first region A1, the transition region AT, and the second region A2 of the distal end 100D of the first metal wire 10D, the order in which the colors appear, and the color combinations when there are multiple colors can be changed in various ways. The longitudinal lengths of the first region A1, the transition region AT, and the second region A2, as well as the lengths of each region, can also be determined arbitrarily. The metal wire 10D for a medical device of this fifth embodiment can also achieve the same effects as the first embodiment described above.

[0086] Sixth Embodiment FIG. 13 is a diagram showing an example of a distal end portion 100E of a first metal wire 10E according to the sixth embodiment. The medical device 1 may include a first metal wire 10E, which will be described below, instead of the first metal wire 10 described in the first embodiment. The first metal wire 10E differs from the first embodiment in the color of the coating in the first region A1, the transition region AT, and the second region A2 of the distal end portion 100E. FIG. 13(A) is a diagram showing the color of the coating in the distal end portion 100E represented by hatched line types. FIG. 13(B) is a photograph of the distal end portion 100E. The diagram corresponds to the photograph. Both the diagram and photograph in FIG. 13 show the width direction of the flat shape of the first metal wire 10E.

[0087] As shown, portion 96a is silver, indicating that it is not heat-treated. Portion 96b has a blue coating. Portion 96c has a white coating. Portion 96d has a yellow coating. Portion 96e has a white coating. Portion 96f has a blue coating. Portion 96g has a purple coating. Portion 96h has a gold coating. For example, as shown in FIG. 13(B), portion 96d may be brownish yellow. Portion 96e may be dark white.

[0088] The central portion of the distal end portion 100E of the first metal wire 10E is a first region A1 having a coating of a color included in the first color group C1 (specifically, yellow). Further distally from the first region A1 is a distal transition region AT1 having a coating of a color included in the second color group C2 (specifically, white and blue). Further proximally from the first region A1 is a proximal transition region AT2 having a coating of a color included in the second color group C2 (specifically, white and blue). Opposite the first region A1 from the transition region AT (specifically, the proximal transition region AT2) is a second region A2 having a coating of a color included in the third color group C3 (specifically, purple and gold).

[0089] As described above, the colors of the coatings in the first region A1, the transition region AT, and the second region A2 of the distal end 100E of the first metal wire 10E, the order in which the colors appear, and the color combinations when there are multiple colors can be changed in various ways. The longitudinal lengths of the first region A1, the transition region AT, and the second region A2, as well as the lengths of each region, can also be determined arbitrarily. The metal wire 10E for a medical device of this sixth embodiment can also achieve the same effects as the first embodiment described above.

[0090] Seventh Embodiment FIG. 14 is a diagram showing an example of a distal end portion 100F of a first metal wire 10F according to the seventh embodiment. The medical device 1 may include a first metal wire 10F, which will be described below, instead of the first metal wire 10 described in the first embodiment. The first metal wire 10F differs from the first embodiment in the color of the coating in the first region A1, the transition region AT, and the second region A2 of the distal end portion 100F. FIG. 14(A) is a diagram showing the color of the coating in the distal end portion 100F represented by the type of hatched line. FIG. 14(B) is a photograph of the distal end portion 100F. The diagram corresponds to the photograph. Both the diagram and photograph in FIG. 14 show the width direction of the flat shape of the first metal wire 10F.

[0091] As shown, portion 97a is silver, indicating that it has not been heat-treated. Portion 97b has a blue coating. Portion 97c has a white coating. Portion 97d has a yellow coating. Portion 97e has a magenta coating. Portion 97f has a blue-green coating. Portion 97g has a magenta coating. Portion 97h has a green coating. Portion 97i has a magenta coating. Portion 97j has a yellow coating. Portion 97k has a white coating. Portion 97l has a blue coating. Portion 97m has a purple coating. Portion 97n has a gold coating. For example, as shown in FIG. 14(B), the magenta colors of portions 97e and 97g and the blue-green color of portion 97f may be mixed together to form a mottled pattern.

[0092] The central portion of the distal end portion 100F of the first metal wire 10F is a first region A1 having a coating of a color included in the first color group C1 (specifically, green, cyan, magenta, and yellow). Distal to the first region A1 is a distal transition region AT1 having a coating of a color included in the second color group C2 (specifically, white and blue). Proximal to the first region A1 is a proximal transition region AT2 having a coating of a color included in the second color group C2 (specifically, white and blue). Opposite the first region A1 from the transition region AT (specifically, the proximal transition region AT2) is a second region A2 having a coating of a color included in the third color group C3 (specifically, purple and gold).

[0093] As described above, the colors of the coatings in the first region A1, the transition region AT, and the second region A2 of the distal end 100F of the first metal wire 10F, the order in which the colors appear, and the color combinations when there are multiple colors can be changed in various ways. The longitudinal lengths of the first region A1, the transition region AT, and the second region A2, as well as the lengths of each region, can also be determined arbitrarily. The metal wire 10F for a medical device of this seventh embodiment can also achieve the same effects as the first embodiment described above.

[0094] Eighth Embodiment FIG. 15 is a diagram showing an example of a distal end portion 100G of a first metal wire 10G according to the eighth embodiment. The medical device 1 may include a first metal wire 10G, which will be described below, instead of the first metal wire 10 described in the first embodiment. The first metal wire 10G differs from the first embodiment in the color of the coating in the first region A1, the transition region AT, and the second region A2 of the distal end portion 100G. FIG. 15(A) is a diagram showing the color of the coating in the distal end portion 100G represented by hatched lines. FIG. 15(B) is a photograph of the distal end portion 100G. The diagram corresponds to the photograph. Both the diagram and photograph in FIG. 15 show the thickness direction of the flattened shape of the first metal wire 10G.

[0095] As shown in the figure, portion 98a is silver, indicating that it has not been heat-treated. Portion 98b has a blue coating. Portion 98c has a white coating. Portion 98d has a yellow coating. Portion 98e has a reddish-purple coating. Portion 98f has a green coating. Portion 98g has a reddish-purple coating. Portion 98h has a yellow coating. Portion 98i has a white coating. Portion 98j has a blue coating. Portion 98k has a purple coating. Portion 98l has a gold coating. For example, as shown in FIG. 15(B), portions 98b to 98l may each have a color with a relatively high brightness (a light color, a pale color).

[0096] The central portion of the distal end portion 100G of the first metal wire 10G is a first region A1 having a coating of a color included in the first color group C1 (specifically, green, magenta, and yellow). Further distally from the first region A1 is a distal transition region AT1 having a coating of a color included in the second color group C2 (specifically, white and blue). Further proximally from the first region A1 is a proximal transition region AT2 having a coating of a color included in the second color group C2 (specifically, white and blue). Opposite the first region A1 from the transition region AT (specifically, the proximal transition region AT2) is a second region A2 having a coating of a color included in the third color group C3 (specifically, purple and gold).

[0097] As described above, the colors of the coatings in the first region A1, the transition region AT, and the second region A2 of the distal end 100G of the first metal wire 10G, the order in which the colors appear, and the color combinations when there are multiple colors can be changed in various ways. The longitudinal lengths of the first region A1, the transition region AT, and the second region A2, as well as the lengths of each region, can also be determined arbitrarily. The metal wire 10G for a medical device of this eighth embodiment can also achieve the same effects as the first embodiment described above.

[0098] Ninth Embodiment FIG. 16 is an enlarged view of the distal end portion 100H of the first metal wire 10H of the ninth embodiment. The medical device 1H of the ninth embodiment includes a first metal wire 10H, which will be described below, instead of the first metal wire 10 described in the first embodiment. The first metal wire 10H differs from the first embodiment in that it does not have a distal transition region AT1 and a second region A2. FIG. 16(A) shows a side view of the distal end portion 100H as viewed from the Z-axis direction. FIG. 16(B) shows a side view of the distal end portion 100H as viewed from the Y-axis direction. The coil 40 is not shown in FIG. 16.

[0099] 16(A) and 16(B), in the medical device 1H, the distal tip 51 (broken line) is attached to the distal portion 100H of the first metal wire 10H, closer to the distal end than the first region A1. In the illustrated example, the base end of the distal tip 51 is located slightly closer to the distal end than the tip of the first region A1. The base end of the distal tip 51 may be located anywhere within the range closer to the distal end than the first region A1.

[0100] Fig. 17 is a flowchart showing a method for manufacturing a medical device 1H according to the ninth embodiment. The difference from the first embodiment shown in Fig. 8 is that step S18 is not performed and step S22H is performed instead of step S22. In step S22H, the operator inspects the color of the coating in the first region A1 and the transition region AT. Specifically, the operator performs only step a1 described in the first embodiment, and does not perform step a2.

[0101] As described above, the configuration of the medical device 1H can be modified in various ways. The first metal wire 10H may have a first region A1 and a transition region AT (proximal transition region AT2) adjacent to the proximal side of the first region A1. The first metal wire 10H may have a first region A1 and a transition region AT (distal transition region AT1) located distally of the first region A1. The first metal wire 10H may have a first region A1, a distal transition region AT1, and a proximal transition region AT2. The medical device 1H and the metal wire 10H for a medical device of the ninth embodiment can also achieve the same effects as those of the first embodiment described above. The metal wire 10H for a medical device of the ninth embodiment does not have the second region A2, so that step S18 (FIG. 8) of forming the second region A2 can be omitted and the inspection step (FIG. 17: S22H) can be simplified. As a result, the manufacturing costs of the medical device 1H and the metal wire 10H for a medical device can be reduced.

[0102] Tenth Embodiment FIG. 18 is an enlarged view of the distal end portion 100I of the first metal wire 10I of the tenth embodiment. The medical device 1I of the tenth embodiment includes a first metal wire 10I described below instead of the first metal wire 10 described in the first embodiment. The first metal wire 10I differs from the first embodiment in that it does not have a first pressed portion 111, a transition portion 112, or a second pressed portion 113. FIG. 17(A) shows a side view of the distal end portion 100I as viewed from the Z-axis direction. FIG. 18(B) shows a side view of the distal end portion 100I as viewed from the Y-axis direction. The coil 40 is not shown in FIG. 17.

[0103] 18(A) and 18(B), the tip portion 100I of the first metal wire 10I is not pressed, and the first portion 11I has a cylindrical shape. In other words, the shape of the first portion 11I when viewed from the Z-axis direction is the same as the shape when viewed from the Y-axis direction.

[0104] Fig. 19 is a flowchart showing a method for manufacturing a medical device 1I according to the tenth embodiment. This method differs from the first embodiment shown in Fig. 8 in that steps S12 and S22 are not performed. That is, according to this manufacturing method, the heat treatment is performed without pressing the metal wire. According to this manufacturing method, the colors of the coatings in the first region A1, the transition region AT, and the second region A2 are not inspected.

[0105] As described above, the configuration of the medical device 1I can be modified in various ways, and the tip portion 100I of the first metal wire 10I (first portion 11I of the first metal wire 10I) may be a round wire that is not pressed. The medical device 1I and the metal wire 10I for a medical device of the tenth embodiment can also achieve the same effects as those of the first embodiment described above. According to the metal wire 10I for a medical device of the tenth embodiment, the pressing step S12 (FIG. 8) and the inspection step S22 (FIG. 8) can be omitted, thereby reducing the manufacturing costs of the medical device 1I and the metal wire 10I for a medical device.

[0106] Eleventh Embodiment Figure 20 is an enlarged view of the distal end portion 100 of the first metal wire 10 of the 11th embodiment. The medical device 1J of the 11th embodiment includes a distal end tip 51J, which will be described below, instead of the distal end tip 51 described in the first embodiment. The distal end tip 51J differs from the first embodiment in the position at which it is attached to the first metal wire 10. Figure 20(A) shows a side view of the distal end portion 100 as viewed from the Z-axis direction. Figure 20(B) shows a side view of the distal end portion 100 as viewed from the Y-axis direction. The coil 40 is not shown in Figure 20.

[0107] 20(A) and 20(B), the distal tip 51J (broken line) is attached to the distal end portion 100 of the first metal wire 10, closer to the distal end than the first region A1 and closer to the distal end than the distal transition region AT1. In the illustrated example, the base end of the distal tip 51J is located slightly distal to the distal end of the distal transition region AT1.

[0108] As described above, the configuration of the medical device 1J can be modified in various ways, and the distal tip 51J may be provided at any position on the distal portion 100 of the first metal wire 10. In the example shown, the distal tip 51J is attached further distal than the distal transition region AT1. However, the distal tip 51J may also be provided within the first region A1 (for example, at the distal portion of the first region A1). The medical device 1J of this eleventh embodiment can also achieve the same effects as those of the first embodiment described above.

[0109] <Modification of this embodiment> The present disclosure is not limited to the above-described embodiments, and can be implemented in various forms without departing from the spirit thereof. For example, the following modifications are also possible.

[0110] [Variation 1] In the above first to eleventh embodiments, the configurations of the medical devices 1, 1H, 1I, and 1J have been illustrated. However, the configuration of the medical device 1 can be modified in various ways. For example, the medical device 1 may further include coating layers formed of either a hydrophilic resin or a hydrophobic resin on the surfaces of the first metal wire 10, the second metal wire 20, and the coil 40. For example, the longitudinal length of the coil 40, in other words, the area over which the coil 40 covers the first metal wire 10, may be modified as desired. For example, the medical device 1 may further include an intermediate joint between the distal tip 51 and the proximal joint 52 for joining the first metal wire 10 and the coil 40. For example, the shape of the second metal wire 20 can be modified in various ways. The medical device 1 may not include the second metal wire 20. The medical device 1 may not include the coil 40.

[0111] [Variation 2] In the first to eleventh embodiments described above, the configurations of the metal wires 10, 10A to 10I for medical devices are illustrated. However, the configuration of the first metal wire 10 can be modified in various ways. For example, the shape of the first metal wire 10 described in FIG. 3 is merely an example, and various modifications are possible. For example, at least one of the second portion 12, the third portion 13, and the fourth portion 14 may be omitted. The third portion 13 may be cylindrical rather than tapered.

[0112] In the above embodiment, the entire first portion 11 of the first metal wire 10, excluding a portion on the base end side, corresponds to the "tip portion 100 of the first metal wire 10." The scope of the tip portion 100 can be changed in various ways. For example, the entire first portion 11 and a portion on the tip side of the second portion 12 of the first metal wire 10 may correspond to the "tip portion 100."

[0113] In the above embodiment, the color patterns of the coating in the first region A1, the transition region AT, and the second region A2 of the tip portion 100 of the first metal wire 10 are exemplified. However, the color patterns of the coating in the first region A1, the transition region AT, and the second region A2 of the tip portion 100 may be changed as desired, as long as the first region A1 is coated with at least one color included in the first color group C1, the transition region AT is coated with at least one color included in the second color group C2, and the second region A2 is coated with at least one color included in the third color group C3. The tip portion 100 of the first metal wire 10 does not need to include an unheat-treated portion.

[0114] In the above embodiment, the thickness T1 of the coating CO1 in the first region A1 of the first metal wire 10 is 100 nm or more. The thickness T1 of the coating CO1 in the first region A1 may be less than 100 nm. The thickness T1 of the coating CO1 in the first region A1 is thicker than the thickness of the coating in the transition region AT. The thickness T1 may be thinner than the thickness of the coating in the transition region AT or may be the same as the thickness of the coating in the transition region AT.

[0115] In the above embodiment, the thickness of the coating in the second region A2 of the first metal wire 10 is 10 nm or more and 30 nm or less. The thickness of the coating in the second region A2 may be less than 10 nm. The thickness of the coating in the second region A2 may be greater than 30 nm.

[0116] The results of the shape test described in FIG. 2 are merely an example. The shape angle θ when the shape test is performed may be such that the first region A1 is equal to the transition region AT. The shape angle θ when the shape test is performed may be such that the first region A1 is less than the transition region AT. The shape angle θ when the shape test is performed may be such that the first region A1 is equal to the second region A2. The shape angle θ when the shape test is performed may be such that the first region A1 is less than the second region A2.

[0117] In the above embodiment, the first position P1 is any position in the outermost layer (titanium oxide coating CO1), and the second position P2 is any position in the second outermost layer. However, the first position P1 and the second position P2 may be set arbitrarily as long as the first position P1 is located outside the second position P2 (on the surface side of the first metal wire 10). In the above embodiment, the titanium content is higher at the first position P1 than at the second position P2. The titanium content may be lower at the first position P1 than at the second position P2. The titanium content may be the same at the first position P1 and the second position P2. In the above embodiment, the nickel content is lower at the first position P1 than at the second position P2. The nickel content may be higher at the first position P1 than at the second position P2. The nickel content may be the same at the first position P1 and the second position P2.

[0118] In the above embodiment, the metal wire 10 for a medical device is exemplified as being incorporated into the medical device 1. However, the metal wire 10 for a medical device may be manufactured as a standalone product, in other words, without the second metal wire 20, the coil 40, the distal tip 51, and the base-end joint portion 52.

[0119] [Variation 3] The configurations of the medical devices and metal wires for medical devices of the first to eleventh embodiments and the configurations of the medical devices and metal wires for medical devices of the first and second modifications may be combined as appropriate. For example, the first metal wires 10A to 10G of any of the second to eighth embodiments (different color patterns of the first region A1, the transition region AT, and the second region A2) may be combined with the configuration of the ninth embodiment (no second region A2 or distal transition region AT1), the configuration of the tenth embodiment (no pressing, no inspection process), or the configuration of the eleventh embodiment (different position of the distal tip 51). For example, the first metal wire 10H of the ninth embodiment (no second region A2 or distal transition region AT1) may be combined with the configuration of the tenth embodiment (no pressing, no inspection process), or the configuration of the eleventh embodiment (different position of the distal tip 51). For example, the first metal wire 10I of the tenth embodiment (no pressing, no inspection process) may be combined with the configuration of the eleventh embodiment (different position of the distal tip 51).

[0120] This aspect has been described above based on embodiments and modifications. The above-described embodiments of the aspect are intended to facilitate understanding of this aspect and are not intended to limit this aspect. This aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents thereof are included in this aspect. If a technical feature is not described as essential in this specification, it may be deleted as appropriate. [Explanation of symbols]

[0121] 1, 1H, 1I, 1J...Medical devices 10, 10A~10I...Metal wire for medical devices 11,11I…Part 1 12…Part 2 13…Part 3 14…Part 4 15…Part 5 20...Second metal wire 30…Joint part 40...Coil 41...Elemental wire 51,51J...Tip 52…Proximal side joint part 100, 100A~100I...Tip 111...1st Press Department 112...Transition part 113...Second Press Department 200...Measuring device 211...Foundation 212…Plane 213…flat plate 214…post 215...pin 216...Support rod 217...Clamping mechanism 218…weight

Claims

1. A metal wire for a medical device, a predetermined region having a coating exhibiting at least a predetermined color; a specific region having a coating that exhibits a specific color different from at least the predetermined color; A metal wire for a medical device comprising:

2. The metal wire for a medical device according to claim 1, A metal wire for a medical device, wherein the predetermined region has a larger shape angle when a shape test is performed than the specific region.

3. The metal wire for a medical device according to claim 1 or 2, further comprising: A metal wire for a medical device, comprising a predetermined region adjacent to the specific region and located on the opposite side of the specific region from the specified region, the predetermined region having a coating that exhibits at least a predetermined color.

4. A metal wire for a medical device, a predetermined region having a coating exhibiting at least a predetermined color; a predetermined region having a coating exhibiting a predetermined color different from at least the predetermined color; A metal wire for a medical device comprising:

5. The metal wire for a medical device according to claim 4, A metal wire for a medical device, wherein the specified region has a shape angle greater than that of the predetermined region when a shape test is performed.

6. The metal wire for a medical device according to claim 4 or 5, further comprising: A metal wire for a medical device, comprising a specific region between the specified region and the predetermined region, the specific region having a coating exhibiting at least a specific color.

7. The metal wire for a medical device according to any one of claims 1 to 3 or claim 6, The metal wire for a medical device, wherein the coating in the specific region further exhibits a second specific color different from the first specific color.

8. A metal wire for a medical device, a predetermined region having a coating exhibiting at least a predetermined color; a specific region having a coating exhibiting at least a specific color; a predetermined region adjacent to the specific region and located on the opposite side of the specific region from the predetermined region, the predetermined region having a coating exhibiting at least a predetermined color; Equipped with the thickness of the coating in the predetermined region is greater than the thickness of the coating in the specific region; A metal wire for a medical device, wherein the thickness of the coating in the specific region is greater than the thickness of the coating in the predetermined region.

9. The metal wire for a medical device according to claim 8, The metal wire for a medical device, wherein the coating in the specific region further exhibits a second specific color different from the first specific color.

10. The metal wire for a medical device according to any one of claims 3, 6 and 8, A metal wire for a medical device, wherein, in a cross-sectional view of at least one of the specified region, the specific region, and the predetermined region, the titanium content at a first position is greater than the titanium content at a second position that is more inward than the first position.

11. The metal wire for a medical device according to any one of claims 3, 6, 8 and 10, A metal wire for a medical device, wherein, in a cross-sectional view of at least one of the specified region, the specific region, and the predetermined region, the nickel content at a second position is greater than the nickel content at a first position outside the second position.

12. The metal wire for a medical device according to any one of claims 1 to 11, A metal wire for a medical device, wherein the thickness of the coating in the predetermined region is 100 nm or more.

13. The metal wire for a medical device according to any one of claims 1 to 3 or any one of claims 6 to 11, A metal wire for a medical device, wherein the thickness of the coating in the predetermined region is greater than the thickness of the coating in the specific region.

14. The metal wire for a medical device according to any one of claims 3 to 6, or any one of claims 8, 10 and 11, A metal wire for a medical device, wherein the thickness of the coating in the specified region is greater than the thickness of the coating in the predetermined region.

15. The metal wire for a medical device according to any one of claims 3, 6, 8, 10 and 11, A metal wire for a medical device, wherein the thickness of the coating in the specific region is greater than the thickness of the coating in the predetermined region.

16. The metal wire for a medical device according to any one of claims 3 to 6, any one of claims 8 to 11, or any one of claims 14 and 15, A metal wire for a medical device, wherein the thickness of the coating in the predetermined region is 10 nm or more and 30 nm or less.

17. The metal wire for a medical device according to any one of claims 3 to 6, any one of claims 8 to 11, or any one of claims 14 and 15, A metal wire for a medical device, wherein the thickness of the metal wire for a medical device in the specified region is thinner than the thickness of the metal wire for a medical device in the predetermined region.

18. The metal wire for a medical device according to any one of claims 1 to 3, any one of claims 6 to 11, or any one of claims 13 to 15, A metal wire for a medical device, wherein the thickness of the metal wire for a medical device in the predetermined region is thinner than the thickness of the metal wire for a medical device in the specific region.

19. The metal wire for a medical device according to any one of claims 3 and 6, any one of claims 8 to 11, or any one of claims 13 to 15, The metal wire for a medical device has thicknesses in the order of thinnest to thinnest in the specified region, the specific region, and the predetermined region.

20. 20. The metal wire for a medical device according to any one of claims 1 to 19, The metal wire for a medical device has a flat shape, The metal wire for a medical device, wherein the coating is formed along the thickness direction of the flat shape.

21. The metal wire for a medical device according to any one of claims 1 to 20, The metal wire for a medical device has a flat shape, The metal wire for a medical device, wherein the coating is formed along the width direction of the flat shape.

22. The metal wire for a medical device according to any one of claims 1 to 21, The metal wire for a medical device has an unheat-treated portion.

23. 23. The metal wire for a medical device according to any one of claims 1 to 22, The metal wire for a medical device, wherein the coating is a coating containing titanium oxide.

24. A medical device comprising: The metal wire for a medical device according to any one of claims 1 to 23; a distal tip attached to the metal wire for a medical device on the distal side of the predetermined region; A medical device comprising:

25. 25. The medical device of claim 24, A medical device comprising the metal wire for a medical device according to any one of claims 1 to 3, any one of claims 6 to 11, any one of claims 13 and 15, or any one of claims 18 and 19, the specific region of the metal wire for a medical device includes a distal specific region provided on the distal side of the predetermined region and a proximal specific region provided on the proximal side of the predetermined region, A medical device, wherein the distal tip is attached to the distal side specific region.

26. A method for manufacturing a metal wire for a medical device, comprising: A method for manufacturing a metal wire for a medical device, comprising: forming a coating having at least a predetermined color in a predetermined region by subjecting the metal wire to heat treatment; and forming a coating having at least a specific color in a specific region.

27. 27. The method for producing a metal wire for a medical device according to claim 26, further comprising: A method for manufacturing a metal wire for a medical device, wherein the color of the coating in the predetermined area and the color of the coating in the specific area are inspected to determine whether the heat treatment has been completed normally.

28. 28. A method for producing a metal wire for a medical device according to claim 26 or 27, comprising: The temperature of the heat treatment for forming the predetermined region and the specific region is a predetermined temperature, and further A method for manufacturing a metal wire for a medical device, comprising: forming a coating having at least a predetermined color in a predetermined region of the metal wire by performing heat treatment at a specific temperature lower than the predetermined temperature on the base end side of the predetermined region of the metal wire.

29. 29. The method for producing a metal wire for a medical device according to claim 28, further comprising: A method for manufacturing a metal wire for a medical device, comprising inspecting the color of the coating in the predetermined area to determine whether the heat treatment for forming the predetermined area was completed successfully.

30. A metal wire for a medical device, The ink jet recording medium has a predetermined region having a coating that exhibits at least a predetermined color, and a specific region having a coating that exhibits at least a specific color, The metal wire for a medical device, wherein the coating on the predetermined region and the coating on the specific region are formed by subjecting the metal wire for a medical device to a heat treatment.

31. 31. The metal wire for a medical device according to claim 30, The temperature of the heat treatment for forming the predetermined region and the specific region is a predetermined temperature, and further A metal wire for a medical device, comprising a predetermined region of the metal wire located proximal to the specified region, the predetermined region having a coating exhibiting at least a predetermined color formed by heat treatment at a specific temperature lower than the specified temperature.

32. A metal wire for a medical device, a predetermined region having a coating film containing titanium oxide and exhibiting at least a predetermined color; a specific region that exhibits at least a specific color and a second specific color and has a coating containing titanium oxide; a predetermined region adjacent to the specific region and located on the opposite side of the specific region from the predetermined region, the predetermined region exhibiting at least a predetermined color and having a coating containing titanium oxide; Equipped with the thickness of the coating in the predetermined region is greater than the thickness of the coating in the specific region; A metal wire for a medical device, wherein the thickness of the coating in the specific region is greater than the thickness of the coating in the predetermined region.

Images