Medical device and manufacturing method of medical device

Abstract

To give a desired characteristic to a joint part of a core shaft and a coil.SOLUTION: A medical device includes a first member, a second member, and a joint part that joins the first member and the second member. The joint part is made of an alloy containing a first metal element and a second metal element. On a surface, the joint part contains the first metal element by a first mass%. In an inside region inner than the surface, the joint part contains the first metal element by a second mass% smaller than the first mass%.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] TECHNICAL FIELD The technology disclosed herein relates to medical devices and methods for manufacturing medical devices. [Background technology]

[0002] Guidewires are used to treat narrowed or blocked areas (hereinafter referred to as "lesions") in biological lumens such as blood vessels. Known guidewires include a long core shaft, a coil disposed around the core shaft, and a brazed portion that joins the tip of the core shaft to the tip of the coil (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-185351 Summary of the Invention [Problem to be solved by the invention]

[0004] In guidewires, it is necessary to provide desired properties at the junction between the core shaft and the coil, a problem that is not limited to guidewires but is common to medical devices in general.

[0005] This specification discloses a technique that can solve the above-mentioned problems. [Means for solving the problem]

[0006] The technology disclosed in this specification can be realized, for example, in the following forms. (1) A medical device disclosed herein includes a first member, a second member, and a joint that joins the first member and the second member. The joint is made of an alloy containing a first metal element and a second metal element, and includes the first metal element at 1% by mass on the surface and at a second % by mass that is less than the first % by mass in an internal region deeper than the surface.

[0007] According to the above medical device, by appropriately selecting a combination of the first metal element and the second metal element and varying the mass percentage of the first metal element between the surface and the internal region, desired properties can be imparted to the bonded portion.

[0008] (2) In the medical device described in (1) above, the first member may have a distal end and a proximal end, the joint portion may be a first joint portion, and the medical device may further include a second joint portion. The second joint portion may be located closer to the proximal end of the first member than the first joint portion, may be made of an alloy containing the first metal element and the second metal element, and may contain the first metal element in a 3% by mass ratio that is less than the 1% by mass.

[0009] According to this configuration, by making the mass percentage of the first metal element different between the surface of the first bonding portion and the second bonding portion, desired properties are imparted to the first bonding portion and the second bonding portion.

[0010] (3) In the medical device described in (2) above, the second joint portion may be disposed adjacent to the first joint portion.

[0011] When the second bonding portion is adjacent to the first bonding portion, the configuration described in (1) above is preferably applied.

[0012] (4) In the medical device described in (3) above, the melting point of the surface of the first bonding portion may be higher than the melting point of the second bonding portion.

[0013] According to this configuration, deformation of the first bonding portion due to melting is reduced when the second bonding portion is formed, and the shape of the first bonding portion is maintained.

[0014] (5) In the medical device described in any one of (2) to (4) above, the first member may be curved between the distal end and the proximal end of the second joint portion.

[0015] According to this configuration, the curved shape of the first member is maintained by the second joint portion.

[0016] (6) In the medical device according to any one of (1) to (5) above, the melting point of the second metal element may be higher than the melting point of the first metal element.

[0017] According to this configuration, by varying the mass % of the first metal element between the surface and the internal region, the melting points can be made different.

[0018] (7) In the medical device according to any one of (1) to (6) above, the joint may be a distal tip.

[0019] According to this configuration, the distal tip is given the desired characteristics.

[0020] (8) The method for manufacturing a medical device disclosed in the present specification includes joining a first member and a second member using an alloy containing a first metal element and a second metal element, and performing a process such that the mass percentage of the first metal element contained on the surface of the joint formed by the alloy is smaller than the mass percentage of the first metal element contained in the internal region of the joint.

[0021] According to the above manufacturing method, by appropriately selecting a combination of the first metal element and the second metal element and varying the mass percentage of the first metal element between the surface and the internal region, desired properties can be imparted to the joint.

[0022] (9) In the method for manufacturing a medical device described in (8) above, the joining may be performed by soldering.

[0023] According to this configuration, the first member and the second member can be joined easily.

[0024] (10) In the method for producing a medical device according to (8) or (9) above, the shape of the joint may be processed to match the shape of the finished product before the treatment.

[0025] According to this configuration, the surface properties of the joint are more likely to be maintained than when processing is performed after reducing the mass % of the first metal element.

[0026] (11) In the method for producing a medical device according to any one of (8) to (10) above, the melting point of the second metal element may be higher than the melting point of the first metal element.

[0027] According to this configuration, by varying the mass % of the first metal element between the surface and the internal region, the melting points can be made different.

[0028] (12) In the method for manufacturing a medical device described in any one of (8) to (11) above, the first member may have a tip and a base end, and the tip of the first member may be joined to the second member during the joining.

[0029] According to this configuration, the joint portion disposed at the tip end of the first member is given a desired characteristic.

[0030] (13) In the method for manufacturing a medical device described in any one of (8) to (12) above, the first member may further have a tip and a base end, and a portion of the first member closer to the base end than the portion joined by the alloy may be curved, and after the processing, the first member and the second member may be joined using the alloy in a region including the curved portion of the first member.

[0031] According to this configuration, the curved shape of the first member is maintained by the second joint portion.

[0032] The techniques disclosed in this specification can be realized in various forms, for example, in the form of a medical device or a manufacturing method thereof. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a cross-sectional view of a guide wire according to an embodiment; [Figure 2] FIG. 10 is a partially enlarged cross-sectional view showing an example of a method for manufacturing a guide wire according to an embodiment. [Figure 3] FIG. 10 is a partially enlarged cross-sectional view showing an example of a method for manufacturing a guide wire according to an embodiment. [Figure 4] FIG. 1 is a partially enlarged cross-sectional view of a distal end portion of a guide wire according to an embodiment of the present invention; [Figure 5] Flowchart showing an example of a method for manufacturing a guidewire DETAILED DESCRIPTION OF THE INVENTION

[0034] A. Implementation: An embodiment will be described with reference to Figs. 1 to 5. Fig. 1 is an explanatory diagram that schematically illustrates a guidewire 10 (an example of a medical device) according to an embodiment. Fig. 1 shows a longitudinal cross section (YZ cross section) of the guidewire 10. In the guidewire 10, the positive Z-axis side is the tip end (distal side) that is inserted into the body, and the negative Z-axis side is the base end (proximal side) that is manipulated by an operator such as a doctor. In each figure, illustration of a portion of the guidewire 10 may be omitted. The guidewire 10 is flexible enough to be bent. These points also apply to the subsequent figures.

[0035] In this specification, the distal end of the guidewire 10 and each of its constituent members is referred to as the "tip," the distal end and its vicinity are referred to as the "tip portion," the proximal end is referred to as the "proximal end," and the proximal end and its vicinity are referred to as the "proximal end portion."

[0036] The guidewire 10 is a medical device that is inserted into a body lumen such as a blood vessel, etc. The length of the guidewire 10 is, for example, 1500 mm or more and 3000 mm or less.

[0037] 1, the guidewire 10 includes a core shaft 100, a first coil 210, a second coil 220, a first joint portion 310, a second joint portion 320, a third joint portion 410, and a fourth joint portion 420. The core shaft 100 is a first member. The first coil 210 is a second member. The second coil 220 is a second member.

[0038] As shown in FIG. 1 , the core shaft 100 is a long thin wire extending along the central axis Ax and has a distal end 101 and a proximal end 102. The core shaft 100 includes a thin wire portion 110, a tapered portion 120, and a proximal portion 130, which are arranged in this order from the distal end 101. The thin wire portion 110 includes the distal end 101 and has a substantially constant outer diameter. The proximal portion 130 is located closer to the proximal end 102 than the thin wire portion 110 and has a substantially constant outer diameter that is larger than the outer diameter of the thin wire portion 110. The tapered portion 120 is a portion that connects the thin wire portion 110 and the proximal portion 130. The outer diameter of the tapered portion 120 gradually decreases from the proximal portion 130 toward the thin wire portion 110. The proximal end of the core shaft 100 is a gripping portion that is gripped by a surgeon such as a doctor. The outer diameter of the thin wire portion 110 is, for example, 0.03 mm or more and 0.2 mm or less. The outer diameter of the base portion 130 is, for example, 0.2 mm or more and 0.9 mm or less. As shown in FIGS. 1 and 4, the thin wire portion 110 of the core shaft 100 is curved so that a portion including the tip end 101 forms a predetermined angle with the remaining portion closer to the base end 102. Hereinafter, the curved portion of the core shaft 100 will be referred to as the shaft curved portion 111.

[0039] The material of the core shaft 100 is, for example, a metal material. More specifically, the material of the core shaft 100 is stainless steel such as SUS302, SUS304, or SUS316, a superelastic alloy such as a Ni-Ti alloy, a piano wire, a nickel-chromium alloy, a cobalt alloy, or tungsten.

[0040] The first coil 210 is a cylindrical member in which one or more wire rods are wound in a spiral shape. The wire rod forming the first coil 210 may be a single strand, or may be a twisted wire in which multiple strands are twisted together. In this embodiment, the first coil 210 is a multi-thread coil in which multiple wire rods are wound. In this embodiment, each wire rod forming the first coil 210 is a single strand. In this embodiment, the outer diameter of the first coil 210 is approximately constant over its entire length. The entire length of the first coil 210 is, for example, 10 mm or more and 500 mm or less, and the outer diameter of the first coil 210 is, for example, 0.1 mm or more and 0.6 mm or less.

[0041] First coil 210 is disposed so as to surround the tip end portion of core shaft 100. More specifically, first coil 210 is disposed so as to surround the entire thin wire portion 110, the entire tapered portion 120, and a part of base portion 130. Shaft curved portion 111 is located inside first coil 210, and first coil 210 is curved according to the curved shape of thin wire portion 110. Hereinafter, the curved portion of first coil 210 will be referred to as first curved portion 211.

[0042] The material of first coil 210 is, for example, a metal material. More specifically, the material of first coil 210 is platinum, a platinum alloy, stainless steel such as SUS302, SUS304, or SUS316, a superelastic alloy such as a Ni-Ti alloy, a piano wire, a nickel-chromium alloy, a cobalt alloy, tungsten, or a tungsten alloy.

[0043] The second coil 220 is a cylindrical member in which one or more wires are wound in a spiral shape. The wire material forming the second coil 220 may be a single wire, or may be a twisted wire in which multiple wires are twisted together. In this embodiment, the second coil 220 is a multi-thread coil in which multiple wires are wound. In this embodiment, each wire material forming the second coil 220 is a single wire. The outer diameter of the second coil 220 is smaller than the inner diameter of the first coil 210 and larger than the outer diameter of the thin wire portion 110. In this embodiment, the outer diameter of the second coil 220 is approximately constant over its entire length. The entire length of the second coil 220 is smaller than the entire length of the first coil 210.

[0044] The second coil 220 is disposed inside the first coil 210, surrounding the tip end of the core shaft 100. More specifically, the second coil 220 is disposed surrounding the thin wire portion 110. The shaft curved portion 111 is located inside the second coil 220, and the second coil 220 is curved according to the curved shape of the thin wire portion 110. Hereinafter, the curved portion of the second coil 220 will be referred to as the second curved portion 221.

[0045] The material of second coil 220 is, for example, a metal material. More specifically, the material of second coil 200 is platinum, a platinum alloy, stainless steel such as SUS302, SUS304, or SUS316, a superelastic alloy such as a Ni-Ti alloy, a piano wire, a nickel-chromium alloy, a cobalt alloy, tungsten, a tungsten alloy, or the like.

[0046] 1 and 4, the first coil 210 is joined to the core shaft 100 by a first joint 310, a second joint 320, and a third joint 410. The second coil 220 is joined to the core shaft 100 by a first joint 310, a second joint 320, and a fourth joint 420.

[0047] The first joint portion 310 is a distal tip. The first joint portion 310 joins the distal end portion including the distal end 101 of the core shaft 100 to the first coil 210 and the second coil 220. The distal end portion of the first joint portion 310 is tapered such that the outer diameter gradually decreases toward the distal end. The distal end portion of the first coil 210 and the distal end portion of the second coil 220 are embedded inside the first joint portion 310. The distal end portion of the core shaft 100 passes through the first joint portion 310. The distal end surface of the core shaft 100 is exposed from the distal end of the first joint portion 310.

[0048] The first bonding portion 310 is made of an alloy containing a first metal element and a second metal element. The combination of the first metal element and the second metal element may be selected arbitrarily depending on the desired properties of the first bonding portion 310. The first bonding portion 310 may further contain an element other than the first metal element and the second metal element. The first bonding portion 310 has a modified layer 311. The modified layer 311 is disposed on the surface of the first bonding portion 310 and has a different composition from the inner region. The modified layer 311 may have a thickness of, for example, 0.002 mm or less, and may be a layer that is substantially thin. Hereinafter, the region of the first bonding portion 310 that is further inside the modified layer 311 is referred to as the inner region 312. The modified layer 311 contains 1% by mass of the first metal element, and the inner region 312 contains 2% by mass of the first metal element, which is less than the 1% by mass. The second mass % may be set arbitrarily within a range smaller than the first mass %. The melting point of the second metal element may be higher than the melting point of the first metal element.

[0049] The material of the first bonding portion 310 may be, for example, a solder such as an Sn—Ag alloy or an Au—Sn alloy having a melting point below 450°C, or a brazing material such as silver solder or gold solder having a melting point of 450°C or higher. In this embodiment, the first bonding portion 310 is made of an Au—Sn alloy containing Sn (tin) as a first metal element and Au (gold) as a second metal element. The internal region 312 contains approximately 20% by mass of Sn and approximately 80% by mass of Au, and the modified layer 311 contains Sn at a mass percentage less than 20% by mass. In other words, the modified layer 311 contains Au at a mass percentage greater than 80% by mass. In the case of an Au—Sn alloy, the melting point increases as the mass percentage of Au increases beyond 80% by mass. Therefore, the first bonding portion 310 is provided with a characteristic that the modified layer 311 has a higher melting point than the melting point of the internal region 312.

[0050] The second joint portion 320 is disposed at a position closer to the base end 102 than the first joint portion 310. The second joint portion 320 joins the core shaft 100 to the first coil 210 and the second coil 220. The second joint portion 320 may be disposed away from the first joint portion 310 or adjacent to the first joint portion 310. In this embodiment, the second joint portion 320 is disposed adjacent to the first joint portion 310. In this specification, the term "adjacent" includes a case where there is a partial gap between the second joint portion 320 and the first joint portion 310 due to unavoidable circumstances in the manufacturing process. The shaft curved portion 111, the first curved portion 211, and the second curved portion 221 are located within a range where the core shaft 100 is joined to the coils 210 and 220 by the second joint portion 320. In other words, the core shaft 100 is curved between the distal end 321 and the proximal end 322 of the second joint 320. The second joint 320 maintains the curved shapes of the core shaft 100 and the two coils 210, 220. As a result, the blood vessel selectivity of the guidewire 10, that is, the ability to select a specific blood vessel from a plurality of branched blood vessels and insert the distal end of the guidewire 10 into that blood vessel, is improved.

[0051] The second bonding portion 320 is made of an alloy containing a first metal element and a second metal element. The combination of the first metal element and the second metal element may be selected as desired depending on the properties desired to be imparted to the second bonding portion 320. The second bonding portion 320 may further contain an element other than the first metal element and the second metal element. The alloy forming the second bonding portion 320 may be the same as or different from the alloy forming the first bonding portion 310. The second bonding portion 320 may contain the first metal element at 3% by mass, which is smaller than 1% by mass. The 3% by mass may be set arbitrarily within a range smaller than the 1% by mass. The 3% by mass may be approximately equal to or different from the 2% by mass. In this embodiment, the second bonding portion 320, like the first bonding portion 310, is made of an Au-Sn alloy containing Sn as the first metal element and Au as the second metal element. The second bonding portion 320 contains approximately 20 mass % Sn and approximately 80 mass % Au, similar to the internal region 312. That is, the modified layer 311 has a higher melting point than the second bonding portion 320.

[0052] The third joint portion 410 joins the base end of the first coil 210 to the core shaft 100. The material of the third joint portion 410 is, for example, the same material as that of the first joint portion 310 described above.

[0053] The fourth joint portion 420 joins the base end of the second coil 220 to the core shaft 100. The material of the fourth joint portion 420 is, for example, the same material as that of the first joint portion 310 described above.

[0054] Next, an example of a method for manufacturing the above-described guidewire 10 will be described below.

[0055] First, the tip portion of the core shaft 100 is inserted into the second coil 220, and the second coil 220 is inserted into the first coil 210. Next, the tip portion including the tip 101 of the core shaft 100 is joined to the first coil 210 and the second coil 220 (S110). An alloy containing a first metal element and a second metal element is used for the joining. This joining forms a joint 310H. The joining method may be soldering using an alloy with a melting point of less than 450°C, or brazing using an alloy with a melting point of 450°C or higher. In this embodiment, the joining method is soldering, and the alloy used for joining is an Au-Sn alloy containing approximately 20 mass% Sn as the first metal element and approximately 80 mass% Au as the second metal element.

[0056] After the soldering is completed, the shape of the joint 310H is processed to the shape of the finished product (S120; see FIG. 2). The processing may be performed by cutting and polishing.

[0057] After the processing is completed, a process is performed to make the mass percentage of the first metal element contained in the surface of the bonding portion 310H smaller than the mass percentage of the first metal element contained in the internal region of the bonding portion 310H (S130). That is, after the processing is completed, a process is performed to make the mass percentage of the second metal element contained in the surface of the bonding portion 310H larger than the mass percentage of the second metal element contained in the internal region of the bonding portion 310H. This process is performed by an electroless plating method. This process is performed on the surface of the bonding portion 310H so that Sn is less than 20 mass%. This process is performed on the surface of the bonding portion 310H so that Au is more than 80 mass%. Alternatively, a chemical process using an acidic or alkaline chemical that dissolves tin may be used.

[0058] After the first joint portion 310 is formed, a portion of the core shaft 100 closer to the base end 102 than the first joint portion 310 is bent to form the shaft curved portion 111 (S140). Accordingly, the first coil 210 and the second coil 220 are also curved to follow the curved shape of the core shaft 100 (see FIG. 3).

[0059] After the bending is completed, a region of the core shaft 100 adjacent to the first joint portion 310 and including the shaft curved portion 111 is joined to the coils 210, 220 (S150). An alloy containing a first metal element and a second metal element is used for the joining. This alloy may be the same as or different from the alloy used to form the joint portion 310H. In this embodiment, the joining is performed by soldering, and an alloy of the same type as the alloy used to form the joint portion 310H, i.e., an Au-Sn alloy containing approximately 80% by mass of Au and approximately 20% by mass of Sn, is used. This joining forms the second joint portion 320 (see FIG. 4).

[0060] When forming the second bonding portion 320, there is a concern that the first bonding portion 310 may melt and deform due to the heat of soldering. This problem is particularly likely to occur when the material of the second bonding portion 320 is the same alloy as the material of the first bonding portion 310, or when the second bonding portion 320 is positioned adjacent to the first bonding portion 310. In this embodiment, the first bonding portion 310 has a modified layer 311 on its surface, and this modified layer 311 has a melting point higher than the melting point of the alloy used to form the second bonding portion 320. In other words, the modified layer 311 does not melt due to the heat transferred from the molten alloy when the second bonding portion 320 is formed. As a result, the shape of the first bonding portion 310 is maintained. The first joint 310 is disposed at the distal end 101 of the core shaft 100, and is the portion that guides the guidewire 10 into a biological lumen when treating a lesion in the biological lumen, and has a tapered shape to facilitate entry into the biological lumen. When the second joint 320 is formed, the shape of the first joint 310 is maintained, thereby maintaining the ease of entry of the guidewire 10 into a biological lumen.

[0061] As described above, according to this embodiment, the guidewire 10 includes the core shaft 100, the first coil 210, the second coil 220, and the first joint portion 310. The first joint portion 310 joins the core shaft 100 to the coils 210 and 220. The first joint portion 310 is made of an alloy containing a first metal element and a second metal element. The first joint portion 310 includes a surface modified layer 311 containing the first metal element at 1% by mass, and an internal region 312 located inside the modified layer 311 containing the first metal element at 2% by mass, which is less than the first% by mass.

[0062] The manufacturing method of the guide wire 10 of this embodiment involves joining the core shaft 100 and the coils 210, 220 using an alloy containing a first metal element and a second metal element, and then performing a process such that the mass percentage of the first metal element contained on the surface of the joint 310H formed by this alloy is smaller than the mass percentage of the first metal element contained in the internal region 312 of the joint 310H.

[0063] According to the above-mentioned guide wire 10 and its manufacturing method, the desired characteristics are imparted to the first joint 310 by appropriately selecting a combination of the first metal element and the second metal element and varying the mass percentage of the first metal element between the modified layer 311 and the internal region 312.

[0064] In this embodiment, the first metal element is Sn, and the second metal element is Au, which has a higher melting point than Sn. This provides the first bonding portion 310 with a characteristic that the modified layer 311 has a higher melting point than the internal region 312.

[0065] The core shaft 100 has a distal end 101 and a proximal end 102. The guidewire 10 further includes a second joint 320. The second joint 320 is disposed closer to the proximal end 102 of the core shaft 100 than the first joint 310. More specifically, the second joint 320 is disposed adjacent to the first joint 310. The second joint 320 is made of an alloy containing Sn as a first metal element and Au as a second metal element, and contains 3% Sn by mass, which is less than the first% by mass.

[0066] According to this configuration, by making the mass percentage of the first metal element different between the modified layer 311 of the first bonding portion 310 and the second bonding portion 320, desired characteristics are imparted to the first bonding portion 310 and the second bonding portion 320. In this embodiment, the modified layer 311 is imparted with the characteristic of having a melting point higher than the melting point of the second bonding portion 320. Therefore, when the second bonding portion 320 is formed by, for example, soldering, deformation due to melting of the first bonding portion 310 is reduced, and the shape of the first bonding portion 310 is maintained.

[0067] The core shaft 100 is curved between the distal end 321 and the proximal end 322 of the second joint 320. According to this configuration, the curved shape of the core shaft 100 is maintained by the second joint 320.

[0068] The first joint portion 310 is the distal tip. With this configuration, the distal tip is given desired characteristics.

[0069] In the method for manufacturing the guide wire 10 of this embodiment, the joining is performed by soldering, which allows the core shaft 100 and the coils 210, 220 to be joined easily.

[0070] Before the above treatment, the first bonding portion 310 is processed to have the shape of the finished product. Therefore, the surface properties of the first bonding portion 310 are more likely to be maintained than when processing is performed after the mass % of the first metal element is relatively reduced.

[0071] A portion of the core shaft 100 closer to the base end 102 than the portion joined by the first joint 310 is curved. After the above process, the core shaft 100 and the coils 210, 220 are joined using an alloy in a region of the core shaft 100 including the curved portion. As a result, the curved shape of the core shaft 100 is maintained by the second joint 320.

[0072] B. Working Example: The techniques disclosed herein will be described in more detail with reference to examples. In the following experiments, a guidewire sample having a first joint similar to that of the above embodiment was fabricated, and the compositions of the surface and inner regions were confirmed.

[0073] A stainless steel core shaft and coil were prepared. The tip of the core shaft and the tip of the coil were soldered together using an Au-Sn alloy containing approximately 80% by mass of Au and approximately 20% by mass of Sn. The soldered joint was then treated so that the mass percentage of Sn contained on the surface was smaller than the mass percentage of Sn contained in the inner region.

[0074] A portion of the joint surface was removed to expose the internal region where the tin had not been removed. The proportions of Sn and Au were measured by quantitative analysis using EDX (Energy Dispersive X-ray Spectroscopy) for the exposed internal region and the unexposed surface region. The internal region contained 21% Sn by mass and 79% Au by mass. The surface region contained 2% Sn by mass and 98% Au by mass.

[0075] C. Variations: The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified into various forms without departing from the spirit thereof, for example, the following modifications are also possible. (1) The combination of the first metal element and the second metal element is not limited to the combination of Sn and Au, but may be any combination. (2) The combination of the first and second mass % values ​​and the combination of the first and third mass % values ​​may be set arbitrarily depending on the desired properties. (3) The second mass % and the third mass % may be different values. (4) The material of the first joint portion and the material of the second joint portion may be different types of alloys. (5) The medical device does not have to include a second coil. (6) The medical device does not have to have a second joint. (7) The core shaft and the coil do not have to be curved. (8) The first joint may join a portion of the core shaft other than the tip to the coil. (9) The second joint portion may be disposed closer to the tip of the core shaft than the first joint portion. (10) The materials of the components in the above embodiment are merely examples and can be modified in various ways. The method for manufacturing the guidewire 10 in the above embodiment is merely an example and can be modified in various ways. (11) The medical device may be a device other than a guidewire. The technology disclosed in this specification is similarly applicable to general medical devices for treating lesions in biological lumens. Examples include basket-equipped embolus removal devices (microbaskets), pressure sensor-equipped guidewires (e.g., guidewires for measuring fractional flow reserve), and atherectomy devices.

Claims

1. A first member (100); A second member (210, 220); A joint (310) that joins the first member (100) and the second member (210, 220), made of an alloy containing a first metal element and a second metal element, The surface (311) contains the first metal element in an amount of 1% by mass, a joint (310) including the first metal element in an inner region (312) inside the surface (311) at a second mass % that is smaller than the first mass %; A medical device (10).

2. 10. The medical device (10) of claim 1, The first member (100) has a distal end (101) and a proximal end (102), the joint (310) is a first joint (310), a second joint portion (320) that is disposed closer to the base end (102) of the first member (100) than the first joint portion (310) and is made of an alloy containing the first metal element and the second metal element; The second bonding portion (320) contains the first metal element in a third mass % that is smaller than the first mass %. Medical devices (10).

3. 3. The medical device (10) of claim 2, The second joint (320) is disposed adjacent to the first joint (310). Medical devices (10).

4. 4. The medical device (10) of claim 3, The melting point of the surface of the first bonding portion (310) is higher than the melting point of the second bonding portion (320). Medical devices (10).

5. A medical device (10) according to any one of claims 2 to 4, The first member (100) is curved between the tip (101) and the base end (102) of the second joint portion (320). Medical devices (10).

6. A medical device (10) according to any one of claims 1 to 5, The melting point of the second metal element is higher than the melting point of the first metal element. Medical devices (10).

7. A medical device (10) according to any one of claims 1 to 6, The joint (310) is a distal tip. Medical devices (10).

8. The first member (100) and the second member (210, 220) are joined together using an alloy containing a first metal element and a second metal element; performing a treatment such that the mass % of the first metal element contained in the surface of the joint (310H) formed by the alloy becomes smaller than the mass % of the first metal element contained in the internal region of the joint (310H); A method for manufacturing a medical device (10).

9. 9. A method for manufacturing a medical device (10) according to claim 8, comprising: The joining is by soldering. A method for manufacturing a medical device (10).

10. 10. A method for manufacturing a medical device (10) according to claim 8 or claim 9, comprising: Before the treatment, the shape of the joint (310H) is processed to match the shape of the finished product. A method for manufacturing a medical device (10).

11. A method for manufacturing a medical device (10) according to any one of claims 8 to 10, comprising the steps of: The melting point of the second metal element is higher than the melting point of the first metal element. A method for manufacturing a medical device (10).

12. A method for manufacturing a medical device (10) according to any one of claims 8 to 11, comprising the steps of: The first member (100) has a distal end (101) and a proximal end (102), In the joining, the tip (101) of the first member (100) is joined to the second member (210, 220). A method for manufacturing a medical device (10).

13. 13. A method of manufacturing a medical device (10) according to any one of claims 8 to 12, further comprising: The first member (100) has a tip (101) and a base (102), and a portion of the first member (100) that is closer to the base (102) than a portion of the first member (100) that is joined by the alloy is curved, After the treatment, the first member (100) and the second member (210, 220) are joined together using the alloy in a region (312) including the curved portion of the first member (100). A method for manufacturing a medical device (10).

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