Guide wire

Abstract

A guidewire is provided with: a core shaft having: a first region provided at a tip section; and a second region which is provided closer to the base end side than the first region and which is plastically deformed more easily than the first region. A coil body covering the outer periphery of the core shaft; and a joining part that joins the tip of the first region and the tip of the coil body, and the tip of the second region is positioned closer to the base end side than the base end of the joining part in the longitudinal direction of the core shaft.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a guidewire. Background Technology

[0002] A guidewire is known for use when inserting catheters or similar devices into blood vessels. When using such a guidewire, the doctor sometimes shapes the tip of the guidewire by bending it. This shaping of the tip of the guidewire by the doctor is also known as shaping.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 4354523 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the guidewire described in Patent Document 1, when a curved shape is applied to the tip of the guidewire, coil breakage sometimes occurs at the base of the straight portion at the tip, causing the bending angle of the shaping section to increase beyond what is necessary. "Coil breakage" refers to a situation where the gaps between the wires in a portion of the coil body become larger; in other words, a portion with a larger opening in the coil spacing occurs. Thus, when the bending angle of the shaping section increases beyond what is necessary due to coil breakage, the shaping section easily comes into contact with the inner wall of the consumable device during guidewire delivery, thereby reducing the guidewire's slippage within the consumable device. A catheter can be exemplified as a consumable device. This problem is not limited to the vascular system; it is common to guidewires inserted into various organs of the human body, such as the lymphatic system, biliary system, urethral system, respiratory system, digestive system, secretory glands, and reproductive organs.

[0008] The technology disclosed in this specification was made to solve at least part of the above-mentioned problems, and provides a guide wire capable of suppressing coil breakage at the base end of the junction of the mandrel and the coil body during shaping.

[0009] Solution for solving the problem

[0010] The technology disclosed in this specification is made to solve at least a part of the above-mentioned problems and can be implemented in the following ways.

[0011] (1) According to one aspect of the present disclosure, a guidewire is provided. The guidewire comprises: a mandrel having: a first region disposed at a front end; and a second region disposed at a position closer to the base end of the first region and more easily plastically deformable than the first region; a coil body covering the outer periphery of the mandrel; and a joint that joins the front end of the first region to the front end of the coil body, wherein, in the long axis direction of the mandrel, the front end of the second region is located at a position closer to the base end of the joint.

[0012] The technology disclosed in this specification can be implemented in various ways, such as by means of a guidewire, a medical device including a guidewire, a method for manufacturing a guidewire, or a method for manufacturing a medical device including a guidewire. Attached Figure Description

[0013] Figure 1 This is an explanatory diagram illustrating the structure of the guidewire according to the first embodiment.

[0014] Figure 2 This is an enlarged view of the front end of the guidewire.

[0015] Figure 3 This is a graph showing the relationship between the thickness and color of the core coating.

[0016] Figure 4 This is a diagram illustrating an example of core coating.

[0017] Figure 5 This is a diagram illustrating the test for determining the ease of plastic deformation.

[0018] Figure 6 This is an example of an image obtained when observing the first region using a TEM.

[0019] Figure 7 This is an example of an image obtained when observing the second region using a TEM.

[0020] Figure 8 This is a flowchart illustrating the manufacturing method of the guidewire.

[0021] Figure 9 This is an enlarged view of the front end of the guidewire in the second embodiment.

[0022] Figure 10 This is a flowchart illustrating the manufacturing method of the guidewire according to the second embodiment.

[0023] Figure 11 This is an enlarged view of the front end of the guidewire in the third embodiment.

[0024] Figure 12 This is a flowchart illustrating the manufacturing method of the guidewire according to the third embodiment.

[0025] Figure 13 This illustrates an example of the core coating in the fourth embodiment.

[0026] Figure 14 This is an enlarged view of the front end of the guidewire in the fifth embodiment. Detailed Implementation

[0027] <First Implementation Method>

[0028] Figure 1 This is an explanatory diagram illustrating the structure of the guidewire 1 according to the first embodiment. The guidewire 1 is a medical device used when inserting other medical devices into blood vessels or digestive organs, and includes a first mandrel 10, a coil body 40, and a front-end junction 51. Other medical devices can include catheters, etc. The guidewire 1 includes a second mandrel 20. The guidewire 1 includes a base-end junction 52. In the guidewire 1, the first mandrel 10 has first to third regions A1 to A3 (described later), and the coil body 40 has fourth and fifth regions A4 and A5 (described later), thereby preventing coil breakage during guidewire 1 shaping.

[0029] "Shaping" of guidewire 1 mainly refers to the operation of giving the tip of guidewire 1 a curved shape in order to improve blood vessel selectivity. "Coil breakage" refers to a situation where the gaps between the wires in a portion of the coil body 40 become larger; in other words, a portion of the coil body 40 has a larger opening in the coil spacing. The first mandrel 10 corresponds to the "mandrel," and the front end side joint 51 corresponds to the "joint."

[0030] exist Figure 1 For ease of explanation, the sizes of the constituent parts are shown to differ from the actual dimensions. Some constituent parts include exaggerated portions. Figure 1 In the diagram, axis O represents the axis passing through the center of guide wire 1. Figure 1 In the diagram, axis O is represented by a dashed line. Axis O coincides with the axes passing through the centers of the first core shaft 10, the second core shaft 20, and the coil body 40, respectively. Axis O may also differ from the central axes of the aforementioned constituent components. Figure 1 The diagram illustrates the mutually orthogonal X, Y, and Z axes. The X-axis corresponds to the length direction of guidewire 1, the Y-axis corresponds to the thickness direction of guidewire 1, and the Z-axis corresponds to the width direction of guidewire 1. Figure 1 The left side, i.e., the X-axis direction, is called guidewire 1 and the "front end side" of each component. Figure 1 The right side, i.e., the +X axis direction, is referred to as the "base side" of guidewire 1 and its constituent components. Regarding guidewire 1 and its constituent components, the end located on the anterior side is called the "anterior end," and the anterior end and its vicinity are called the "anterior end portion." The end located on the base side is called the "base end," and the base end and its vicinity are called the "base end portion." The anterior side is inserted into the body, while the base side is operated by the physician. These aspects are... Figure 1 The same applies in the future.

[0031] The first mandrel 10 is disposed at the front end of the guidewire 1, in other words, it is disposed at a position further forward than the second mandrel 20. The first mandrel 10 is a slender, elongated component with a larger diameter at the base end and a smaller diameter at the front end. In this embodiment, the first mandrel 10 is formed, for example, of a nickel-titanium alloy or an alloy of nickel-titanium and other metals. The first mandrel 10 has a first portion 11, a second portion 12, a third portion 13, a fourth portion 14, and a fifth portion 15 in sequence from the front end to the base end. The thickness, width, and length of each portion can be arbitrarily determined. The first mandrel 10 is also referred to as a "metal wire for medical devices".

[0032] The first portion 11 is the portion located at the foremost end of the first mandrel 10. The first portion 11 is the portion with the smallest outer diameter of the first mandrel 10. In this embodiment, a coating made of titanium oxide is formed on the surface of a portion of the first portion 11. This coating formed on a portion of the first portion 11 is also referred to as "core coating 100". A stamping process is performed on a portion of the first portion 11 in this embodiment to suppress the twisting of the guide wire in the bending direction during shaping and to improve the flexibility of the tip. Details will be described later.

[0033] The second part 12 is the portion of the first mandrel 10 located between the first part 11 and the third part 13. The third part 13 is the portion of the first mandrel 10 located between the second part 12 and the fourth part 14. The fourth part 14 is the portion of the first mandrel 10 located between the third part 13 and the fifth part 15. The thickness of the second part 12 decreases towards the front end. The thickness of the third part 13 decreases towards the front end. The thickness of the fourth part 14 decreases towards the front end. The thickness change rates of the second part 12, the third part 13, and the fourth part 14 are different from each other. The fifth part 15 is the portion of the first mandrel 10 located at the base end. The fifth part 15 has a generally cylindrical shape and is the thickest part of the first mandrel 10.

[0034] In this embodiment, "approximately constant" and "roughly constant" are synonymous, meaning that deviations caused by manufacturing errors, etc., are allowed and the shape remains approximately constant. Similarly, "approximately cylindrical shape / approximately frustum-shaped" and "approximately cylindrical shape / approximately frustum-shaped" are synonymous, meaning that deviations caused by manufacturing errors, etc., are allowed and the shape is approximately that. In this embodiment, "same" and "equal" are not limited to the case of strict consistency, but mean that differences caused by manufacturing errors, etc., are allowed.

[0035] The second mandrel 20 is disposed on the base end side of the guide wire 1, in other words, disposed on the base end side of the first mandrel 10. The second mandrel 20 is a generally cylindrical component with a constant outer diameter. The outer diameter of the second mandrel 20 is the same as the outer diameter of the fifth portion 15 of the first mandrel 10. In this embodiment, the second mandrel 20 is formed, for example, from a stainless steel alloy such as SUS304 or SUS316.

[0036] The core joint 30 is the portion where the first mandrel 10 and the second mandrel 20 are joined by welding. The core joint 30 can also be formed by fixing the first mandrel 10 and the second mandrel 20 using a different means than welding, such as a fastener. The core joint 30 is formed between the base end face of the fifth portion 15 of the first mandrel 10 and the front end face of the second mandrel 20. In the illustrated example, the core joint 30 is planar and approximately perpendicular to the axis O. The core joint 30 can also be inclined relative to the axis O. The first mandrel 10 and the second mandrel 20 are fixed by this core joint 30.

[0037] The front ends of the first portion 11, the second portion 12, and the third portion 13 of the first mandrel 10 are covered by the coil body 40. The base end of the third portion 13, the fourth portion 14, and the fifth portion 15 of the first mandrel 10 are not covered by the coil body 40 and are exposed from the coil body 40. The base end of the second mandrel 20 is used by the doctor when holding the guidewire 1.

[0038] The coil body 40 is a component that covers the outer periphery of the first mandrel 10. The coil body 40 is formed from a spirally wound wire 41 and has a generally cylindrical shape. The coil body 40 can also be a single coil formed by winding a single wire into a single strand. The coil body 40 can also be multiple coils formed by winding multiple wires into multiple strands. The coil body 40 can also be a single stranded wire coil formed by winding multiple strands of wire together into a single strand. The coil body 40 can also be a multi-strand stranded wire coil formed by winding multiple strands of wire together into multiple strands. The wire diameter of the wire 41 of the coil body 40, the outer diameter and inner diameter of the coil body 40, and the length of the coil body 40 can be arbitrarily determined.

[0039] The wire 41 can be formed from, for example, stainless steel alloys such as SUS304 and SUS316, nickel-titanium alloys, piano wire, nickel-chromium alloys, cobalt alloys, gold, platinum, tungsten, alloys containing these elements, and other known materials. Platinum-nickel alloys can be cited as examples of gold, platinum, tungsten, and alloys containing these elements. An oxide coating is formed on the surface of the wire 41 on a portion of the base end side of the coil body 40. The composition of the oxide coating varies depending on the material of the wire 41. For example, in the case where the wire 41 is formed of a platinum-nickel alloy, a nickel oxide coating is formed on a portion of the base end side of the coil body 40. The coating formed on a portion of the coil body 40 is also referred to as "coil coating 200." Details will be described later.

[0040] The front-end joint 51 is located at the front end of the guide wire 1, integrally holding the front end of the first portion 11 of the first mandrel 10 and the front end of the coil body 40. The base-end joint 52 faces the middle portion of the guide wire 1, integrally holding a portion of the third portion 13 of the first mandrel 10 and the base end of the coil body 40. The front-end joint 51 is formed of any bonding agent, such as silver solder, gold solder, zinc, Sn-Ag alloy, Au-Sn alloy, or other metal solder. The base-end joint 52 is formed of any bonding agent, such as silver solder, gold solder, zinc, Sn-Ag alloy, Au-Sn alloy, or other metal solder. The front-end joint 51 and the base-end joint 52 may use the same bonding agent or different bonding agents.

[0041] The following uses Figures 2-7 The first to third regions A1 to A3 of the first spindle 10 and the fourth and fifth regions A4 and A5 of the coil body 40, as well as their relationships, are explained.

[0042] Figure 2 This is an enlarged view of the front end side of the guide wire 1. The first portion 11 of the first mandrel 10 has a first stamped portion 111, a second stamped portion 112, and a base end portion 113. The first stamped portion 111 and the second stamped portion 112 are portions of wire with a circular cross-section that have undergone stamping. The base end portion 113 is a portion that has not undergone stamping. The second stamped portion 112 is located between the first stamped portion 111 and the base end portion 113. The second stamped portion 112 is a portion whose outer shape gradually changes from the outer shape of the first stamped portion 111 towards the outer shape of the base end portion 113, moving from the front end side towards the base end side. The stamping of the first stamped portion 111 and the second stamped portion 112 can be performed in one operation or in multiple operations. The first stamped portion 111 and the second stamped portion 112 are also collectively referred to as "flat portions". In this way, by forming flat portions through stamping, the first portion 11 of the first mandrel 10 can be made flexible.

[0043] At the front end of the first mandrel 10, a first region A1, a third region A3, and a second region A2 are sequentially arranged from the front end side toward the base end side. The first region A1 is the front end of the first mandrel 10, located at the foremost front end of the first to third regions A1 to A3. The first region A1 is positioned corresponding to the front end of the first stamping portion 111. The first region A1 is the part of the first mandrel 10 that is least susceptible to plastic deformation among the first to third regions A1 to A3. As shown in the figure, in the first region A1, no core coating 100 is formed on the surface of the first mandrel 10.

[0044] The second region A2 is located at the front end of the first mandrel 10, closer to the base end than the first region A1 and closer to the base end than the third region A3. The second region A2 is positioned corresponding to the base end of the first stamping portion 111 and the second stamping portion 112. The second region A2 is the part of the first mandrel 10 most easily plastically deformed among the first to third regions A1 to A3. As shown in the figure, a core coating 100 is formed on the surface of the first mandrel 10 in the second region A2. The core coating 100 in the second region A2 is thicker than the core coating 100 in the third region A3. The thickness (film thickness) of the core coating 100 in the second region A2 can be, for example, 0.07 μm or more. The thickness of the core coating 100 is also referred to as the film thickness. The operator observes the film thickness using a TEM (transmission electron microscope) "JEM-2100F" and measures the thickness of the relatively thicker portion of the coating in the image obtained through the TEM. The JEM-2100F is manufactured by Nippon Electronics Corporation.

[0045] The third region A3 is the front end of the first mandrel 10, located between the first region A1 and the second region A2. In other words, it is located closer to the base end than the first region A1 and closer to the front end than the second region A2. The third region A3 is located at a position corresponding to the middle portion of the first stamping part 111. As shown in the figure, the third region A3 is adjacent to the first region A1 and the second region A2. Compared to the first region A1, the first mandrel 10 is more easily plastically deformed in the third region A3, and compared to the second region A2, the first mandrel 10 is less easily plastically deformed in the third region A3. In other words, the plastic deformation ease of the first mandrel 10 is moderate among the first to third regions A1 to A3. As shown in the figure, a core coating 100 is formed on the surface of the first mandrel 10 in the third region A3. The core coating 100 of the third region A3 is thinner than the core coating 100 of the second region A2. The thickness of the core coating 100 of the third region A3 can be, for example, 0.01 μm or more and less than 0.07 μm. The film thickness is measured as described in the second region A2.

[0046] The front end joint 51 joins the front end of the first region A1 of the first spindle 10 with the front end of the coil body 40. For example... Figure 2As shown, in the long axis direction of the first mandrel 10, the front end A2d of the second region A2 is located closer to the base end 51p of the front end side joint 51. The long axis direction of the first mandrel 10 is the axis O direction. Figure 2 The example given is that the base end 51p of the front end joint 51 is located near the center of the first region A1. The base end 51p of the front end joint 51 can be located at any part of the first region A1; for example, the base end 51p of the front end joint 51 can be located at the base end of the first region A1. In this case, in the long axis direction of the first mandrel 10, the front end A2d of the second region A2 is also located at a position closer to the base end side than the base end 51p of the front end joint 51.

[0047] In the long axis direction of the first mandrel 10, the front end A2d of the second region A2 is located at the base end 51p of the front end side joint 51. Figure 1 The distance is within 1 / 5 of the total length L40 of the coil body 40 shown. In other words, the distance La between the base end 51p of the front end side joint 51 and the front end A2d of the second region A2 satisfies the relationship La ≤ 1 / 5 × L40. Figure 2 In the example, the front end A2d of the second region A2 and the base end 51p of the front end side joint 51 both extend perpendicularly to the axis O. For example, if the film thickness in the circumferential direction of the core coating 100 is uneven and it is impossible to define the front end A2d of the second region A2 as perpendicular to the axis O, the front end A2d of the second region A2 refers to the foremost position in the second region A2. Similarly, if the front end side joint 51 is formed skewed and it is impossible to define the base end 51p of the front end side joint 51 as perpendicular to the axis O, the base end 51p of the front end side joint 51 refers to the basemost position in the front end side joint 51.

[0048] Figure 3 This diagram illustrates the relationship between the thickness and color of the core coating 100. As with the first mandrel 10 of this embodiment, when a mandrel containing titanium, such as a nickel-titanium alloy or an alloy of nickel-titanium and other metals, is heat-treated, nickel and titanium oxidize, thereby forming an oxide coating on the surface of the mandrel. The oxide coating formed on the surface of the mandrel is the core coating 100. The thickness of the core coating 100 is thicker at higher heat treatment temperatures and thinner at lower heat treatment temperatures. That is, the thickness of the core coating 100 is related to the heat treatment temperature. Furthermore, the thickness of the core coating 100 is related to the color of the first mandrel 10 when viewed visually.

[0049] Specifically, such as Figure 2As shown, the thickness of the coating is thickest when the core coating 100 is "green," second thickest when it is "blue-green," third thickest when it is "purple-red," fourth thickest when it is "yellow," fifth thickest when it is "white," sixth thickest when it is "blue," seventh thickest when it is "purple," and eighth thickest when it is "golden." When the core coating 100 is not formed without heat treatment, the first mandrel 10 has an appearance color of at least one of gray and silver.

[0050] In this embodiment, "green" includes not only green but also various shades of green such as lime green and sky green. "Blue-green" includes not only peacock green but also turquoise and other intermediate colors between green and blue, such as emerald green and turquoise. "Magenta" includes not only deep red but also various shades between red and purple, such as Prussian blue and magenta. "Yellow" includes not only yellow but also various shades of yellow such as lemon yellow and yellow flower. "White" includes not only white but also various shades of white such as silver white and clove white. "Blue" includes not only blue but also various shades of blue such as cyan and navy blue. "Purple" includes not only purple but also various shades of purple such as purple and purple. "Gold" includes not only gold but also various shades of gold such as polished wheel and beige.

[0051] The operator can identify the color of the core coating 100 by visually recognizing the appearance of the heat-treated first mandrel 10. Specifically, the operator uses a digital microscope "VHX-7000" to take photographs of the appearance of the heat-treated first mandrel 10. The VHX-7000 is manufactured by KEYENCE Co., Ltd. The operator identifies the color of the core coating 100 by visually confirming the photographs. That is, the color of the core coating 100 described above is the color under the lighting conditions of the VHX-7000 digital microscope. The confirmation position of the core coating 100 is the side view from the Y-axis direction. The confirmation location of the core coating 100 refers to the location where the photographs were taken. Green, blue-green, magenta, yellow, and white, which indicate relatively thick coatings, are colors included in "First Color Group C1". Blue, purple, and gold, which indicate relatively thin coatings, are colors included in "Second Color Group C2".

[0052] Figure 4 This is a diagram showing an example of core coating 100. Figure 4This is a line drawing that uses shaded lines to represent the color of the core coating 100. The core coating 100 of the first mandrel 10 has portions P1 to P8 from the front end toward the base end. As the numbers appended at the end advance to 1, 2, 3, the first mandrel 10 moves toward the base end side in the long axis direction.

[0053] As shown in the figure, part P1 represents untreated silver. Part P2 has a gold coating. Part P3 has a purple coating. Part P4 has a blue coating. Part P5 has a white coating. Part P6 has a yellow coating. Part P7 has a purplish-red coating. Part P8 has a blue-green coating. Figure 4 For ease of illustration, the boundaries between a certain part and other parts adjacent to it are clearly shown. The boundary between a certain part and other parts can also be a gradual change in the color of the coating. The color gradient of the coating of each part P1 to P8, as well as the color gradient at the boundary of each part P1 to P8, is achieved through the heat treatment of the mandrel. The "color of the coating" includes not only the color itself, but also the hue and texture.

[0054] like Figure 4 As shown, portion P1 of the first mandrel 10 lacks the core coating 100, corresponding to the first region A1. Therefore, an operator can visually identify the portion of the first mandrel 10 that is at least gray or silver as the first region A1. Portions P5 to P8 of the first mandrel 10 have a relatively thick core coating 100, corresponding to the second region A2. Therefore, an operator can visually identify the portion of the coating of the first mandrel 10 that displays a color included in the first color group C1 as the second region A2. Portions P2, P3, and P4 of the first mandrel 10 have a relatively thin core coating 100, corresponding to the third region A3. Therefore, an operator can visually identify the portion of the coating of the first mandrel 10 that displays a color included in the second color group C2 as the third region A3.

[0055] The superelastic alloy constituting the first mandrel 10 has the property of being difficult to plastically deform (difficult to bend). In other words, being difficult to plastically deform means being difficult to bend. It is known that by applying heat treatment, the superelastic properties disappear or decrease, and it becomes easy to plastically deform. Therefore, in the untreated first region A1, the first mandrel 10 exhibits the original properties of the superelastic alloy and becomes difficult to plastically deform. In the second region A2, which has been strongly heat-treated to form a relatively thick core coating 100, the original superelastic alloy properties of the first mandrel 10 disappear, and it becomes easy to plastically deform. In the third region A3, located between the first region A1 and the second region A2 and having been weakly heat-treated to form a relatively thin core coating 100, the original superelastic alloy properties of the first mandrel 10 decrease, thus becoming easier to plastically deform than the first region A1 and less difficult to plastically deform than the second region A2.

[0056] Figure 5 This diagram illustrates the test for determining the ease of plastic deformation. Figure 5 The upper layer represents the first step. Figure 5 The middle layer represents the second step. Figure 5 The lower layer represents the third step. First, as shown in the first step, prepare a sample S of a mandrel with any structure from the first to the third regions A1 to A3. The length L1 of sample S is 10 ± 1 mm. In the first step, as shown by the hollow arrow, by pressing one end of sample S against the metal plate W, sample S is bent to length L2 as shown in the second step. Length L2 is 1 mm. Finally, as shown in the third step, place the sample S, which has been bent in the second step, on a horizontal plane and measure the bending angle θ.

[0057] pass Figure 5 The bending angle θ of the first region A1 of the first mandrel 10 obtained by the judgment test described herein is less than 1°. Similarly, the bending angle θ of the second region A2 of the first mandrel 10 obtained is greater than 8°. Similarly, the bending angle θ of the third region A3 of the first mandrel 10 obtained is more than 1° and less than 8°. Thus, it can be seen that in the first mandrel 10 of this embodiment, the ease of plastic deformation is in the relationship of first region A1 < third region A3 < second region A2.

[0058] In this embodiment, the sizes of the metal particles contained in the first region A1 and the second region A2 of the first mandrel 10 are determined through the following steps a1 to a7. "Metal particle size" refers to the average particle size. Steps a1 to a7 are based on JIS G0551:2020. JIS G0551:2020 is equivalent to ISO 643:2012 of the ISO standard and ASTM E112-13 of the ASTM standard.

[0059] (a1) An image of the observation area of ​​the first mandrel 10 is obtained by observing it through a TEM. The TEM used is "JEM-2100F". JEM-2100F is manufactured by Nippon Electronics Co., Ltd.

[0060] (a2) The test circle obtained in step a1 is used for particle counting. Unlike JIS G0551:2020, the size of the test circle is changed appropriately, and no adjustment is made to take more than 50 particles into the test circle.

[0061] (a3) Count the number N1 of particles that are completely contained within the test circle as set in step a2, and the number N2 of particles that are partially contained within the test circle. The number N1 refers to the number of particles that are completely contained within the test circle. The number N2 refers to the number of particles that intersect with the test circle.

[0062] (a4) Find the total number of particles “N (particles) = N1 + (N2 / 2)”.

[0063] (a5) Calculate the number of particles per unit area, N (particles) / area of ​​the test circle (mm²). 2 )".

[0064] (a6) Take the reciprocal of the number of particles per unit area and calculate the average area of ​​the particles.

[0065] (a7) Calculate the average particle size from the average area of ​​the particles.

[0066] Figure 6 This diagram illustrates an example of an image obtained when observing the first region A1 of the first mandrel 10 using a TEM. For a test circle N11 positioned arbitrarily, the number of particles N1 = 15, the number of particles N2 = 8, and the total number of particles N = 19. Therefore, according to 9 / {(0.2 / 2) × (0.2 / 2) × π}, the number of particles per unit area of ​​the test circle N11 is 605. The average area, calculated from the reciprocal of the number of particles per unit area, is 1.7 × 10⁻⁶. -3 μm 2 Furthermore, the average particle size, calculated from the average particle area, is 5.0 × 10 μm. -2 The diameter of the test circle N11 is 0.2 μm.

[0067] Figure 7This diagram illustrates an example of an image obtained when observing the second region A2 of the first mandrel 10 using a TEM. For a test circle N21 set at an arbitrary position, the number of particles N1 = 5, the number of particles N2 = 10, and the total number of particles N = 10. According to 10 / {(6.5 / 2)×(6.5 / 2)×π}, the number of particles per unit area of ​​the test circle N21 is 0.30. The average area, calculated from the reciprocal of the number of particles per unit area, is 3.3 μm. 2 Furthermore, the average particle size, calculated from the average area, is 2.06 μm. The diameter of the experimental circle N21 is 6.5 μm.

[0068] Thus, in the first mandrel 10 of this embodiment, the size of the metal particles forming the second region A2 (2.1 μm) is significantly larger than the size of the metal particles forming the first region A1 (5.0 × 10 μm). -2 The difference in grain size contributes to the ease of plastic deformation of the first mandrel 10 in the second region A2. Figure 5 In the example, the size of the metal particles forming the second region A2 of the first mandrel 10 is 2.1 μm, and the size of the metal particles forming the first region A1 of the first mandrel 10 is 5.0 × 10 μm. -2 This is just one example; the size of the metal particles in the first region A1 and the second region A2 can be any value as long as the size of the second region A2 is greater than that of the first region A1.

[0069] return Figure 2 The details of the coil body 40 are described below. A fourth region A4 and a fifth region A5 are sequentially arranged from the front end side towards the base end side of the coil body 40. The fourth region A4 is located at the front end of the coil body 40 and is positioned further from the front end side than the fifth region A5. Compared to the fifth region A5, the fourth region A4 has higher solder wettability. As shown in the figure, in the fourth region A4, no coil coating 200 is formed on the surface of the coil body 40.

[0070] The fifth region A5 extends from the center of the coil body 40 to the base end, and is located further from the base end than the fourth region A4. Compared to the fourth region A4, the fifth region A5 exhibits lower solder wettability. This is because, as shown in the figure, a coil coating 200 is formed on the surface of the coil body 40 in the fifth region A5.

[0071] like Figure 2As shown, in the long axis direction of the first mandrel 10, the front end A2d of the second region A2 of the first mandrel 10 is located closer to the base end than the front end A5d of the fifth region A5 of the coil body 40. In the illustrated example, the front end A5d of the fifth region A5 is located closer to the base end than the base end 51p of the front end side joint 51 and closer to the front end than the front end A2d of the second region A2. In other words, the front end A5d of the fifth region A5 is within the length La.

[0072] Figure 8 This is a flowchart illustrating the manufacturing method of guide wire 1. In step S10, the operator prepares a mandrel made of nickel-titanium alloy or an alloy of nickel-titanium and other metals. In step S12, the operator performs a stamping process on the front end of the mandrel. In step S12, as... Figure 2 As explained, the first stamping part 111, the second stamping part 112, and the base end 113 are formed by only one stamping process. In process S12, multiple stamping processes may also be performed.

[0073] In step S14, the operator heat-treats any portion of the mandrel intended to form the second region A2 at a first temperature. This arbitrary portion intended to form the second region A2 will also be referred to as the "first portion." The heat treatment in step S14 is performed by "laser heat treatment," which involves heating the mandrel by irradiating it with a high-output laser. The first temperature can be arbitrarily determined. The heat treatment in step S14 can also be performed by other heat treatment methods. For example, heat treatment using a heating furnace can be used. As a result of step S14, a relatively thick core coating 100, i.e., the second region A2, is formed at the position in the mandrel corresponding to the first portion. As a result of step S14, a relatively thin core coating 100, i.e., the third region A3, is formed in the portion of the mandrel heated by the heat applied to it during heat treatment. The portion of the mandrel heated by the heat applied to it during heat treatment refers to the portion of the mandrel heated by residual heat. The portion of the mandrel that is not heat-treated and does not transfer residual heat becomes the first region A1 without the core coating 100. In other words, the second region A2 and the third region A3 can be considered as part of the heat-treated mandrel.

[0074] In step S18, the operator prepares the coil body. Then, the operator performs heat treatment on the entire coil body at a second temperature. The heat treatment in step S18 involves heating the coil body in a heating furnace. The heat treatment in step S18 can also be performed using other heat treatment methods. Laser heat treatment is an example of such a method. As a result of step S18, a coating is formed on the entire coil body. In step S22, the operator removes the coating formed in step S18 from any portion of the coil body intended to form the fourth region A4. This portion, intended to form the fourth region A4, is then referred to as the "second part." Through step S22, the portion with the coating removed becomes the fourth region A4, and the portion with the coating remaining becomes the fifth region A5. The operator can remove the coating by mechanically grinding the second part, which is the front end of the coil body. Alternatively, the operator can use chemical grinding instead of mechanical grinding to remove the coating. In other words, the fifth region A5 can be considered part of the heat-treated coil body.

[0075] In step S24, the operator forms a joint to integrally fix the first mandrel 10, manufactured in steps S10-S14, and the coil body 40, manufactured in steps S18-S22. Specifically, the operator arranges the first mandrel 10 and the coil body 40 as follows: Figure 2 The positional relationship described is such that the front end A2d of the second region A2 is located closer to the base end than the front end A5d of the fifth region A5. Then, the operator joins the front end of the first mandrel 10 to the front end of the coil body 40 using any solder, such as silver solder, gold solder, zinc, Sn-Ag alloy, Au-Sn alloy, etc., thereby forming the front end side joint 51. The coil coating 200 has the property of low solder wettability. In step S24, welding is performed with the front end A2d of the second region A2 located closer to the base end than the front end A5d of the fifth region A5, so the molten solder does not wet and extend into the fifth region A5 of the coil body 40. As a result, it is possible to prevent the front end side joint 51 from overlapping with the second region A2 of the first mandrel 10. The core coating 100, like the coil coating 200, has the property of low solder wettability. Therefore, by having the core coating 100, it is also possible to prevent the front end side joint 51 from overlapping with the second region A2 and the third region A3 of the first spindle 10.

[0076] As described above, in the guidewire 1 of the first embodiment, such as Figure 2As shown, compared to the second region A2, the first region A1, which is less prone to plastic deformation, is located at the base end 51p of the front end joint 51 where the first mandrel 10 joins the coil body 40. Therefore, even when a bending shape is applied to the front end of the guide wire 1 in this embodiment, since the first region A1, which is less prone to plastic deformation, is located at the base end 51p of the front end joint 51, it is possible to suppress the application of a bending shape to the base end 51p of the front end joint 51. As a result, coil breakage, which previously occurred with the application of a bending shape to the base end of the joint, can be suppressed. Coil breakage refers to the breakage of the coil body 40. With the suppression of coil breakage, excessive bending angle of the shaping portion can be suppressed, and the reduction in slippage during transport can be suppressed.

[0077] According to the guidewire 1 of the first embodiment, such as Figure 5 As shown, the size of the metal particles forming the second region A2 of the first mandrel 10 is larger than the size of the metal particles forming the first region A1. Therefore, it is easy to identify the plastic deformation of the first region A1 and the second region A2 of the first mandrel 10 from its appearance.

[0078] Furthermore, according to the guide wire 1 of the first embodiment, the first mandrel 10 has a third region A3 between the first region A1 and the second region A2, which has a greater ease of plastic deformation than the first region A1 and a smaller ease of plastic deformation than the second region A2. Therefore, the rigidity gap of the first mandrel 10 can be mitigated, and a first mandrel 10 with a gradual change in rigidity can be achieved.

[0079] Compared to the second region A2, the first mandrel 10 is less prone to plastic deformation at the front end side of the second region A2. Therefore, it is difficult to impart a bending shape to the guide wire 1 at the front end side of the second region A2. In this regard, according to the guide wire 1 of the first embodiment, in the long axis direction of the first mandrel 10, the front end A2d of the second region A2 is located within 1 / 5 of the total length L40 of the coil body 40 from the base end 51p of the front end side joint 51. Therefore, the position of the base end 51p of the front end side joint 51 can be avoided, and the guide wire 1 can be given a bending shape until it approaches the position of the base end 51p of the front end side joint 51. As a result, the occurrence of coil breakage can be suppressed, and the shaping length of the front end portion is shorter than before. In this way, during the transport of the guide wire, the shaping portion is less likely to contact the inner wall of the co-working device, and the reduction of the slippage of the guide wire in the co-working device can be suppressed.

[0080] Furthermore, according to the guidewire 1 of the first embodiment, such as Figure 2As shown in the first stamping portion 111 and the second stamping portion 112, the front end of the first mandrel 10 is flat. Therefore, it is possible to suppress the twisting of the guide wire 1 in the bending direction during shaping. Moreover, since the flat shape is formed by stamping, the front end of the guide wire 1 can be formed flexibly.

[0081] Furthermore, according to the guidewire 1 of the first embodiment, such as Figure 8 As shown, the front end of the first mandrel 10 is formed of a hyperelastic material, and the second region A2 is formed by heat treatment of the first mandrel 10. Therefore, the second region A2 can be precisely formed in a desired portion of the entire first mandrel 10. By utilizing heat treatment to eliminate or reduce the hyperelastic properties of the first mandrel 10, the second region A2 can be easily formed.

[0082] Furthermore, according to the guidewire 1 of the first embodiment, such as Figure 2 As shown, in the long axis direction of the first mandrel 10, the front end A2d of the second region A2 is located near the base end of the front end A5d of the fifth region A5, which has lower wettability than the solder. Therefore, when the first mandrel 10 is brazed to the coil body 40 to form the front end joint 51, the solder will not wet and extend into the fifth region A5, thus preventing the front end joint 51 formed by the solder from overlapping with the second region A2 of the first mandrel 10. By adjusting the length of the fourth region A4 of the coil body 40 and the boundary position of the fourth and fifth regions, the length and position of the front end joint 51 can be easily adjusted. The length of the front end joint 51 refers to the brazing length. Furthermore, if the wettability of the solder in the fifth region A5 is reduced by the coil coating 200, corrosion of the guide wire 1 can be suppressed.

[0083] <Second Implementation Method>

[0084] Figure 9 This is an enlarged view of the front end side of the guidewire 1A according to the second embodiment. In the second embodiment, an example without the third region A3 will be described. In the structure described in the first embodiment, the guidewire 1A of the second embodiment has a first mandrel 10A instead of a first mandrel 10.

[0085] The shape of the first mandrel 10A is the same as that of the first mandrel 10 in the first embodiment. At the front end of the first mandrel 10A, a first region A1 and a second region A2 are sequentially provided from the front end side toward the base end side. The first region A1 and the second region A2 have the same structure as in the first embodiment, except that they are adjacent to each other. The core coating 100A of the second embodiment only has a portion corresponding to the second region A2, that is, a portion where the core coating 100A is relatively thick. Thus, the third region A3 described in the first embodiment is not provided on the first mandrel 10A.

[0086] Figure 10 This is a flowchart illustrating a method for manufacturing the guidewire 1A according to the second embodiment. Figure 8 The difference in the first embodiment described is that a step S30 is added between step S14 and step S18. In step S30, the operator removes the coating from the front end of the mandrel. Specifically, the operator removes the relatively thin core coating formed in step S14 by heating with residual heat. In other words, the operator removes the third region A3 of the coating formed in step S14. To determine the extent of coating removal, the operator refers to the color of the coating on the heated mandrel and removes the portion of the coating whose color is included in the second color group C2. The portion of the coating whose color is included in the second color group C2... Figure 3 In the example, this refers to the areas with blue, purple, and gold coatings. The coating can be removed by mechanical grinding. Alternatively, operators can use chemical grinding to remove the coating instead of mechanical grinding.

[0087] In this way, the structure of guidewire 1A can be modified in various ways, and the first mandrel 10A can also have only the first region A1 and the second region A2 without the third region A3. In this second embodiment of guidewire 1A, the same effect as the first embodiment described above can be achieved.

[0088] <Third Implementation Method>

[0089] Figure 11 This is an enlarged view of the front end side of the guide wire 1B according to the third embodiment. In the third embodiment, an example without the coil coating 200 will be described. The guide wire 1B of the third embodiment... Figure 9 In the structure described in the second embodiment, a coil body 40B is provided instead of a coil body 40.

[0090] The coil coating 200 described in the first embodiment is not formed on the coil body 40B. That is, the coil body 40 does not have the fourth region A4 and the fifth region A5 described in the first embodiment.

[0091] Figure 12 This is a flowchart illustrating the manufacturing method of the guide wire 1B according to the third embodiment. Figure 10 The difference in the second embodiment described herein is that processes S18 to S22 for processing the coil body are not performed. Figure 12 The manufacturing method also suppresses the wetting and propagation of solder into the second region A2 of the first mandrel 10A in step S24 by using a core coating 100A covering the surface of the first mandrel 10A.

[0092] In this way, the structure of the guide wire 1B can be modified in various ways, and the coil body 40B may not have the fourth region A4 and the fifth region A5, while the wettability of the solder remains constant. In this third embodiment of the guide wire 1B, the same effects as the first and second embodiments described above can be achieved.

[0093] <Fourth Implementation Method>

[0094] Figure 13 This illustrates an example of the core coating 100C according to the fourth embodiment. In the fourth embodiment, an example where the color of the core coating 100C differs from that of the first embodiment will be described. In the structure described in the first embodiment, the guide wire 1C of the fourth embodiment includes a first mandrel 10C instead of the first mandrel 10. A [material / structure] is formed on the surface of the first mandrel 10C. Figure 13 The core coating shown is 100C. Figure 13 and Figure 4 Similarly, the line drawing uses shaded lines to represent the color of the core coating 100C.

[0095] like Figure 13 As shown, the second region A2 of the first mandrel 10C has a white portion P13, a yellow portion P14, a magenta portion P15, and a yellow portion P16 from the front end side towards the base end side. Thus, the color pattern of the second region A2 can differ from that in the first embodiment. The same color can also be repeated, as in portions P14 and P16. The third region A3 of the first mandrel 10C is entirely blue, as shown in portion P12. Thus, the third region A3 can also be a single color.

[0096] In this way, the structure of the core coating 100C can be modified in various ways, as long as the first region A1, the second region A2, and the third region A3 respectively have Figure 3 The colors described herein can have any number of colors or color patterns. Specifically, as long as a film of at least one color included in the first color group C1 is formed in the second region A2, and a film of at least one color included in the second color group C2 is formed in the third region A3, the colors can be arbitrarily changed. It is not necessary to explicitly define the boundary between a certain color and other colors; a gradient is also possible. In this fourth embodiment of the guidewire 1C, the same effect as the first embodiment described above can be achieved.

[0097] <Fifth Implementation Method>

[0098] Figure 14This is an enlarged view of the front end of the guidewire 1D according to the fifth embodiment. In the fifth embodiment, an example where the front end of the first mandrel 10D is not flat will be described. In the structure described in the first embodiment, the guidewire 1D of the fifth embodiment has a first mandrel 10D instead of a first mandrel 10. The first mandrel 10D has a first portion 11D instead of a first portion 11.

[0099] The front end of the first portion 11D is not stamped and has a cylindrical shape. In other words, the first portion 11D does not have the first stamped portion 111 and the second stamped portion 112 described in the first embodiment. The manufacturing of the guide wire 1D only requires... Figure 8 The stamping process S12 at the front end can be omitted in the manufacturing method described herein.

[0100] In this way, the structure of the guide wire 1D can be modified in various ways, and the shape of each component can be arbitrarily changed. In addition to the above, a portion of the second part 12, the third part 13, and the fourth part 14 in the first mandrel 10 can also be omitted. Alternatively, an inner coil body can be provided between the first mandrel 10 and the coil body 40, and the front end joint 51 can fix the front end of the inner coil body in addition to fixing the first mandrel 10 and the coil body 40.

[0101] <Modifications of this embodiment>

[0102] This disclosure is not limited to the embodiments described above, and can be implemented in various ways without departing from its spirit, for example, the following modifications are also possible.

[0103] (Variation Example 1)

[0104] In the first to fifth embodiments described above, the structures of guide wires 1, 1A to 1D are illustrated. The structure of guide wire 1 can be modified in various ways. For example, guide wire 1 may also have a coating formed of at least one of a hydrophilic resin and a hydrophobic resin on the surfaces of the first spindle 10, the second spindle 20, and the coil body 40. For example, the length of the coil body 40 in the longitudinal direction, in other words, the extent to which the coil body 40 covers the first spindle 10, can be arbitrarily changed. For example, guide wire 1 may also have an intermediate joint between the front end side joint 51 and the base end side joint 52 for joining the first spindle 10 and the coil body 40. For example, the shape of the second spindle 20 can be modified in various ways. Guide wire 1 may also be without a second spindle 20.

[0105] In the above embodiment, the first stamped portion 111 and the second stamped portion 112, which are flat portions, are formed by stamping. The flat portion may also be formed without stamping by using a wire with a rectangular cross-section in the first portion 11. The base end portion 113 may also be stamped. In this case, the base end portion 113 is also included in the flat portion.

[0106] In the above embodiments, a method for manufacturing guide wires 1, 1A to 1D is illustrated. The method for manufacturing guide wire 1 can be modified in various ways. For example, the heat treatment of the mandrel and the coil body can be achieved by various known methods, in addition to laser heat treatment and heating using a furnace. The heat treatment temperature of the mandrel, i.e., the first temperature, and the heat treatment temperature of the coil body, i.e., the second temperature, can be the same, or the first temperature can be lower than the second temperature. For example, the method for manufacturing guide wire 1 can include other steps described above, and the order of execution of the steps can be changed. As other steps, a first determination step of determining whether a second region A2 is formed by checking the color of the core coating 100, and a second determination step of determining whether a fifth region A5 is formed by checking the color of the coil coating 200 can be illustrated.

[0107] (Variation Example 2)

[0108] In the first to fifth embodiments described above, the structures of the first mandrels 10, 10A to 10D are illustrated. The structure of the first mandrel 10 can be modified in various ways. For example, Figure 1 The shape of the first spindle 10 described herein is just one example and can be modified in various ways.

[0109] For example, in the long axis direction of the first spindle 10, the front end A2d of the second region A2 may not be located within 1 / 5 of the total length L40 of the coil body 40 from the base end 51p of the front end side joint 51. In other words, the front end A2d of the second region A2 may also be located at a position further from the base end 51p of the front end side joint 51 than 1 / 5 of the total length L40 of the coil body 40.

[0110] For example, the thickness of the core coating 100 of the first mandrel 10 described above is just one example and can be varied. For example, the thickness of the core coating 100 in the second region A2 of the first mandrel 10 can be less than 0.07 μm. Similarly, the thickness of the core coating 100 in the third region A3 can be less than 0.01 μm or greater than 0.07 μm.

[0111] For example, the bending angle of the first mandrel 10 described above is just one example, and various changes can be made. For example, the bending angle of the first region A1 of the first mandrel 10 can be 1° or more. The bending angle of the second region A2 of the first mandrel 10 can be 8° or less. The bending angle of the third region A3 of the first mandrel 10 can also be outside the range of 1° or more and 8° or less.

[0112] (Variation Example 3)

[0113] The structures of guide wires 1, 1A-1D and first mandrels 10, 10A-10D in the first to fifth embodiments, as well as the structures of guide wires 1, 1A-1D and first mandrels 10, 10A-10D in the above-described variations 1 and 2, can also be appropriately combined. For example, in either the second embodiment described with an example without the third region A3 or the third embodiment described with an example without the fourth region A4 and the fifth region A5, the coating color of the fourth embodiment can be applied, and the mandrel shape of the fifth embodiment can also be applied. For example, the third embodiment was described as a variation of the second embodiment. The third embodiment can also be implemented as any variation of the first, fourth, and fifth embodiments.

[0114] The present invention has been described above based on its implementation methods and variations. The implementation methods described above are for ease of understanding and are not intended to limit the scope of the invention. The present invention can be modified and improved without departing from its spirit and technical solution, and its equivalents are included. If a technical feature is not described as a necessary feature in this specification, it may be appropriately deleted.

Claims

1. A guidewire (1, 1A~1D), characterized in that, have: The mandrel (10, 10A to 10D) has: a first region (A1) disposed at the front end; and a second region (A2) disposed at a position closer to the base end than the first region (A1) and more easily plastically deformed than the first region; The coil body (40, 40B) covers the outer periphery of the mandrel (10, 10A-10D); and A joining portion (51) joins the front end of the first region (A1) to the front end of the coil body (40, 40B). In the long axis direction of the mandrel (10, 10A~10D), the front end of the second region (A2) is located on the base end side of the joint (51) compared to the base end side.

2. The guidewire (1, 1A~1D) according to claim 1, characterized in that, The size of the metal particles forming the second region (A2) is larger than the size of the metal particles forming the first region (A1).

3. The guidewire (1, 1C, 1D) according to claim 1 or 2, characterized in that, The mandrels (10, 10C, 10D) also have a third region (A3) disposed between the first region (A1) and the second region (A2). The third region (A3) is more easily plastically deformed than the first region (A1) and less easily plastically deformed than the second region (A2).

4. The guidewire (1, 1A-1D) according to any one of claims 1 to 3, characterized in that, In the long axis direction of the mandrel (10, 10A~10D), the front end of the second region (A2) is located within 1 / 5 of the total length of the coil body (40, 40B) from the base end of the joint (51).

5. The guidewire (1, 1A-1C) according to any one of claims 1 to 4, characterized in that, The front end of the mandrel (10, 10A~10C) is flat.

6. The guidewire (1, 1A to 1D) according to any one of claims 1 to 5, characterized in that, The front end of the mandrel (10, 10A~10D) is formed of a hyperelastic material. The second region (A2) is a part of the heat-treated mandrel (10, 10A to 10D).

7. The guidewire (1, 1A, 1C, 1D) according to any one of claims 1 to 6, characterized in that, The coil body (40) has: a fourth region (A4) disposed at the front end; and a fifth region (A5) disposed at a position closer to the base end than the fourth region (A4), and the solder wettability is lower than that of the fourth region (A4). In the long axis direction of the mandrels (10, 10A, 10C, 10D), the front end of the second region (A2) is located on the base end side compared to the front end of the fifth region (A5).

Images