Patent Description:
A guide wire is a medical device used to guide, to a stenosis occurring in a blood vessel such as a coronary artery, various types of catheters for treating the stenosis.

The guide wire needs to travel through a complicated curved portion or branched portion of the blood vessel and pass through the stenosis. Therefore, a distal portion of the guide wire is required to have flexibility, restorability against an external force, and kink resistance. In order to satisfy these requirements, the distal portion of the guide wire is formed of a super-elastic alloy such as a Ni-Ti alloy.

Incidentally, before inserting the guide wire into the blood vessel, an operator may give a desired shape (shaping) to the distal portion of the guide wire for a purpose of improving operability of the guide wire in the blood vessel and blood vessel selectivity at a branch portion. Therefore, it is preferable that the distal portion of the guide wire can be easily shaped. However, when a guide wire including a distal portion formed of a super-elastic alloy has high superelasticity, even the operator applies an external force for shaping, the guide wire is restored to a shape before shaping when the external force is removed, and it is difficult for the operator to give the desired shape.

The following PTL <NUM> discloses a technique of subjecting a distal portion of a guide wire formed of a super-elastic alloy to cold working or heat treatment, thereby reducing superelasticity and enabling shaping of the distal portion of the guide wire. <CIT> discloses similar matter to PTL <NUM>.

However, when the superelasticity of the distal portion of the guide wire is excessively decreased, the shape of the guide wire is difficult to restore, and thus a shape retaining property, which is a property of retaining a shape at a time of shaping, is decreased. The guide wire inserted into the blood vessel receives an external force when the distal portion comes into contact with a blood vessel wall or a stenosis. At this time, the guide wire including the distal portion having excessively decreased superelasticity is plastically deformed into a shape different from the shape at the time of shaping. Accordingly, the operability and the blood vessel selectivity of the guide wire are decreased. When the distal portion of the guide wire is plastically deformed during an operation in the blood vessel, the operator needs to remove the guide wire from the blood vessel to reshape the guide wire or replace the guide wire with another guide wire, which complicates a procedure. Accordingly, procedure time is extended, and burden on the operator and a patient is increased.

A magnitude of the external force applied to the guide wire in the blood vessel is smaller than that of the external force applied for shaping by the operator. Therefore, the distal portion of the guide wire needs to have a physical property capable of being deformed by a large force applied by the operator for shaping, and capable of restoring the shape at the time of shaping without being plastically deformed by a small force applied during a procedure. That is, the distal portion of the guide wire needs to have both a shaping property capable of shaping into a desired shape before being inserted into a blood vessel and a shape retaining property capable of retaining a shape at the time of shaping against an external force applied in the blood vessel.

At least one embodiment of the invention is made in view of the above circumstances, and specifically, is to provide a guide wire having a shaping property capable of shaping into a desired shape and a shape retaining property of retaining a shape at a time of shaping against an external force applied in a blood vessel, and a method of manufacturing a guide wire.

The invention is defined in the appended independent claims <NUM> (device) and <NUM> (method of manufacturing). Further aspects of the device are defined in dependent claims <NUM>-<NUM>. A guide wire according to the present embodiment includes: an elongated core component including a flat portion at a distal end. The flat portion is made of a Ni-Ti alloy having an elastic portion of total indentation work of <NUM>% or more and <NUM>% or less and having a Martens hardness of <NUM> N/mm<NUM> or more and <NUM> N/mm<NUM> or less.

A method of manufacturing the guide wire according to the present embodiment is a method of manufacturing a guide wire including a core component. The method includes: performing cold working on a distal portion of the core component such that the distal portion includes a flat portion and a transition portion extending from a proximal end of the flat portion toward a proximal end side along a longitudinal direction; and performing heat treatment on the flat portion and at least a part of the transition portion such that an elastic portion of total indentation work thereof is <NUM>% or more and <NUM>% or less and a Martens hardness thereof is <NUM> N/mm<NUM> or more and <NUM> N/mm<NUM> or less.

According to an embodiment of the invention, by controlling an elastic portion of total indentation work and a Martens hardness at a distal portion of a guide wire made of a Ni-Ti alloy within a predetermined range, it is possible to provide a guide wire having a physical property capable of being deformed by a large force applied by an operator for shaping, and capable of restoring a shape at a time of shaping without being plastically deformed by a small force applied during a procedure. That is, according to an embodiment of the invention, it is possible to provide a guide wire having both a shaping property and a shape retaining property. Accordingly, the guide wire can be shaped by an operator, and can be restored to a shape at a time of shaping even when an external force that can deform the distal portion is received in a blood vessel. Therefore, the guide wire can maintain high operability and blood vessel selectivity given by shaping even during a procedure. Further, the operator does not need to remove the guide wire from the blood vessel and reshape the guide wire or replace the guide wire with another guide wire, and thus the procedure can be easily performed. Accordingly, the procedure time is shortened, and thus the burden on the operator and the patient can be reduced.

Hereinafter, an embodiment of the invention will be described in detail with reference to the drawings. The embodiment illustrated here is an example for embodying a technical idea of the invention, and does not limit the invention. Further, other aspects, examples, operational techniques, and the like that can be implemented by those skilled in the art without departing from the scope of the invention, and are included in the invention described in the claims.

Further, in the drawings attached to the present specification, for convenience of illustration and understanding, a scale, an aspect ratio, a shape, and the like may be changed from actual ones and may be schematically expressed as appropriate, and the drawings are just examples and do not limit the interpretation of the invention.

In the present specification, for convenience of description, directions in a case in which a guide wire <NUM> is in a natural state (a state where the guide wire <NUM> is extended straight without applying an external force) are defined. In <FIG>, a "longitudinal direction" is a direction in which the guide wire <NUM> extends and is a direction along a central axis C of the guide wire <NUM> (a horizontal direction in <FIG>). A "radial direction" is a direction away from or approaching a core member in a cross section orthogonal to axis (a transverse section) of the core member with the longitudinal direction of the guide wire <NUM> as a reference axis. A "circumferential direction" is a rotation direction with the longitudinal direction of the core member as the reference axis. A "thickness direction" is defined as a direction in which, when a distal end of the guide wire <NUM> includes a flat portion <NUM>, a short side of a rectangle in a traverse sectional view of the flat portion <NUM> extends (a depth direction in the drawing). A "width direction" is a direction in which, when the distal end of the guide wire <NUM> includes the flat portion <NUM>, a long side of the rectangle in the traverse sectional view of the flat portion <NUM> extends (a vertical direction in the drawing).

Further, a side on which the guide wire <NUM> is inserted into a blood vessel is referred to as a "distal end side", and a side opposite to the distal end side (a side gripped by an operator) is referred to as a "proximal end side". Further, a portion including a certain range from a distal end (a most distal end) along the longitudinal direction is referred to as a "distal portion", and a portion including a certain range from a proximal end (a most proximal end) along the longitudinal direction is referred to as a "proximal portion".

In the following description, in a case in which the description is given by adding an ordinal number such as "first" or "second", unless otherwise specified, it is used for convenience and does not define any order.

The guide wire <NUM> according to the present embodiment is a medical device that is inserted into a blood vessel in order to guide, to a stenosis, a catheter or a stent for performing intravascular treatment. The guide wire <NUM> may be inserted into a living body lumen other than the blood vessel (such as an artery, a ureter, a bile duct, a fallopian tube, and a hepatic duct) according to a treatment purpose.

As illustrated in <FIG> or <FIG>, the guide wire <NUM> according to the present embodiment includes an elongated core component <NUM>, a tubular body <NUM> that covers a periphery of a distal portion of the core component <NUM>, a fixing portion <NUM> that fixes the tubular body <NUM> to the core component <NUM>, and a cover layer <NUM> that covers each member including the core component <NUM>. Hereinafter, each part of the guide wire <NUM> will be described in detail.

The core component <NUM> includes a first core member <NUM> and a second core member <NUM> disposed on a proximal end side of the first core member <NUM> and bonded to the first core member <NUM>.

The first core member <NUM> is an elongated member extending from a distal end of the second core member <NUM> to the distal end side of the guide wire <NUM> along the longitudinal direction. The first core member <NUM> includes a first bonding portion 11a, a first constant outer diameter portion 11b, a first tapered portion 11c, a second constant outer diameter portion 11d, a second tapered portion 11e, a transition portion 11f, and a flat portion <NUM> in this order from a proximal end toward a distal end side of the first core member <NUM>. Each part is integrally formed with each other.

The first bonding portion 11a is a portion bonded to a second bonding portion 12b of the second core member <NUM> described later. An outer diameter of the first bonding portion 11a is larger than an outer diameter of the first constant outer diameter portion 11b and is substantially equal to an outer diameter of the second bonding portion 12b. The outer diameter of the first bonding portion 11a and the outer diameter of the second bonding portion 12b are larger than the outer diameter of the first constant outer diameter portion 11b and an outer diameter of a proximal portion 12a of the second core member <NUM>. That is, an area of a bonding surface <NUM> between the first bonding portion 11a and the second bonding portion 12b is larger than the first constant outer diameter portion 11b and the proximal portion 12a. Accordingly, a stress acting on the bonding surface <NUM> when the guide wire <NUM> is bent is dispersed to the first constant outer diameter portion 11b and the proximal portion 12a, which have an outer diameter smaller than that of the bonding surface <NUM>, and it is possible to prevent the stress from concentrating on the bonding surface <NUM>. Accordingly, the core component <NUM> has high bonding strength at the bonding surface <NUM>.

The first constant outer diameter portion 11b extends by a predetermined length from a distal end of the first bonding portion 11a to a proximal end of the first tapered portion 11c. The outer diameter of the first constant outer diameter portion 11b is substantially constant, and is substantially equal to the outer diameter of the proximal portion 12a of the second core member <NUM>.

The first tapered portion 11c extends by a predetermined length from a distal end of the first constant outer diameter portion 11b to a proximal end of the second constant outer diameter portion 11d. The first tapered portion 11c has a tapered shape whose outer diameter gradually decreases from the first constant outer diameter portion 11b toward the distal end side. The tapered shape of the first tapered portion 11c can be formed by subjecting the first core member <NUM> to mechanical grinding using a grindstone or etching using an acid.

The second constant outer diameter portion 11d extends by a predetermined length from a distal end of the first tapered portion 11c to a proximal end of the second tapered portion 11e. An outer diameter of the second constant outer diameter portion 11d is substantially constant and is smaller than the outer diameter of the first constant outer diameter portion 11b.

The second tapered portion 11e extends by a predetermined length from a distal end of the second constant outer diameter portion 11d to a proximal end of the transition portion 11f. The second tapered portion 11e has a tapered shape whose outer diameter gradually decreases from the second constant outer diameter portion 11d toward the transition portion 11f. The tapered shape of the second tapered portion 11e can be formed by subjecting the first core member <NUM> to mechanical grinding using a grindstone or etching using an acid.

The transition portion 11f extends a predetermined length from a distal end of the second tapered portion 11e to a proximal end of the flat portion <NUM>. As illustrated in <FIG> or <FIG>, the transition portion 11f has a wedge shape whose thickness gradually decreases and whose width gradually increases from the second tapered portion 11e toward the flat portion <NUM>. The wedge shape of the transition portion 11f can be formed by pressing the first core member <NUM> having a circular traverse sectional shape. The pressing is a type of cold working. The traverse sectional shape of the transition portion 11f in a plan view orthogonal to the longitudinal direction (traverse sectional view) is a circular shape having an outer diameter substantially equal to that of the second tapered portion 11e on the proximal end side, but is gradually deformed from the circular shape to a rectangular shape from the proximal end side toward the distal end side, and is a rectangular shape substantially the same as that of the flat portion <NUM> on the distal end side. A distal portion of the transition portion 11f has substantially the same thickness and width as a proximal portion of the flat portion <NUM>, and forms a surface continuous with the flat portion <NUM>. Two-dot chain lines in <FIG> are imaginary lines that partition regions of the flat portion <NUM>, the transition portion 11f, and the second tapered portion 11e. Further, the "thickness" of the flat portion <NUM> is a length of a short side of the rectangle in the traverse sectional view of the flat portion <NUM>, and the "width" of the flat portion <NUM> is a length of a long side of the rectangle in the traverse sectional view of the flat portion <NUM>.

The flat portion <NUM> extends by a predetermined length from a distal end of the transition portion 11f to the distal end of the guide wire <NUM>. The flat portion <NUM> is formed by pressing the first core member <NUM> having a circular traverse sectional shape. Accordingly, the flat portion <NUM> has a rectangular traverse sectional shape. The thickness of the flat portion <NUM> is substantially constant from the distal end of the transition portion 11f to a distal end of the flat portion <NUM>. As illustrated in <FIG> and <FIG>, a shape of the flat portion <NUM> as viewed in the thickness direction is formed in a rectangular shape rounded at the distal end of the flat portion <NUM>. Accordingly, the width of the flat portion <NUM> is substantially constant from the distal end of the transition portion 11f toward the distal end side, and is smaller at the rounded portion. The width of the flat portion <NUM> may be constant from the distal end of the transition portion 11f to the distal end of the flat portion <NUM>. The traverse sectional shape of the flat portion <NUM> is not limited to a rectangular shape, and may be a rounded rectangular shape with R-shaped corners.

A structure of the first core member <NUM> is not limited to the above. For example, the first core member <NUM> may have a constant outer shape or a constant outer diameter from a distal end to the proximal end of the first core member <NUM>.

Further, in the first core member <NUM>, at least a region where the flat portion <NUM> is located (preferably, the flat portion <NUM> and at least a part of the transition portion 11f) has both a shaping property and a shape retaining property.

The second core member <NUM> is an elongated member extending from the proximal end of the first core member <NUM> to the proximal end side of the guide wire <NUM>. The second core member <NUM> includes the proximal portion 12a and the second bonding portion 12b in this order from a proximal end toward a distal end side of the second core member <NUM>. Each part is integrally formed with each other.

The proximal portion 12a extends a predetermined length from a proximal end of the second bonding portion 12b toward the proximal end side of the guide wire <NUM>. The outer diameter of the proximal portion 12a is substantially constant, and is substantially equal to the outer diameter of the first constant outer diameter portion 11b.

The second bonding portion 12b is a portion bonded to the first bonding portion 11a. The outer diameter of the second bonding portion 12b is larger than the outer diameter of the proximal portion 12a and equal to the outer diameter of the first bonding portion 11a. The first bonding portion 11a and the second bonding portion 12b can be bonded by welding, brazing, or soldering.

Here, a specific dimension example of the guide wire <NUM> will be described. An entire length of the guide wire <NUM> in the longitudinal direction is <NUM> to <NUM>. A length of the first core member <NUM> is <NUM> to <NUM>. A total length of the first bonding portion 11a and the first constant outer diameter portion 11b is <NUM> to <NUM>. A length of the first tapered portion 11c is <NUM> to <NUM>. A length of the second constant outer diameter portion 11d is <NUM> to <NUM>. A length of the second tapered portion 11e is <NUM> to <NUM>. A length of the transition portion 11f is <NUM> to <NUM>. A length of the flat portion <NUM> is <NUM> to <NUM>.

The outer diameters of the first bonding portion 11a and the first constant outer diameter portion 11b are <NUM> to <NUM>. The outer diameters of the first tapered portion 11c and the second constant outer diameter portion 11d are <NUM> to <NUM>. The outer diameter of the second tapered portion 11e is <NUM> to <NUM>. The thickness of the transition portion 11f is <NUM> to <NUM> and the width of the transition portion 11f is <NUM> to <NUM>. The thickness of the flat portion <NUM> is <NUM> to <NUM> and the width of the flat portion <NUM> is <NUM> to <NUM>.

A length of the second core member <NUM> is <NUM> to <NUM>. An outer diameter of the second core member <NUM> is <NUM> to <NUM>.

The first core member <NUM> and the second core member <NUM> can be formed of various metal materials such as a super-elastic alloy such as Ni-Ti-based alloy, stainless steel such as SUS302, SUS304, SUS303, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429, and SUS430F, a piano wire, and a cobalt-based alloy. Further, the first core member <NUM> is preferably formed of a material having a lower rigidity than that of a material of the second core member <NUM>. For example, the first core member <NUM> is formed of a Ni-Ti-based alloy, and the second core member <NUM> is formed of a stainless steel. The materials forming the first core member <NUM> and the second core member <NUM> are not limited to the above examples. Further, the first core member <NUM> and the second core member <NUM> may be formed of the same material.

Further, the core component <NUM> may be formed from a single continuous member instead of being formed from a plurality of members such as the first core member <NUM> and the second core member <NUM>.

The tubular body <NUM> is a member formed by spirally winding a wire member around the core component <NUM>. In the present embodiment, the tubular body <NUM> is formed from a first coil <NUM> and a second coil <NUM> disposed on a proximal end side of the first coil <NUM>. The first coil <NUM> is disposed from the distal end to an intermediate portion of the first core member <NUM>. The second coil <NUM> is disposed from the intermediate portion to the proximal end side of the first core member <NUM>. The tubular body <NUM> may be formed of a single coil. The tubular body <NUM> may be formed of three or more coils.

The first coil <NUM> surrounds the first core member <NUM> of the core component <NUM> and is fixed to the first core member <NUM>. The first coil <NUM> is coaxially disposed with the first core member <NUM>. A length of the first coil <NUM> is <NUM> to <NUM>.

The first coil <NUM> is formed by spirally winding the wire member such that a gap is provided between adjacent wire members. The gaps between the adjacent wire members of the first coil <NUM> are <NUM> to <NUM>. The gaps between the adjacent wire members of the first coil <NUM> are preferably equal.

The second coil <NUM> surrounds the first core member <NUM> of the core component <NUM> and is fixed to the first core member <NUM>. The second coil <NUM> is coaxially disposed with the first core member <NUM>. A length of the second coil <NUM> is <NUM> to <NUM>.

The second coil <NUM> includes a densely wound portion in which the wire member is wound spirally and densely such that no gaps are provided between the adjacent wire members, and a sparsely wound portion in which the wire member is wound spirally and sparsely such that a gap is provided between the adjacent wire members. In the present embodiment, the densely wound portion of the second coil <NUM> is located at a distal portion and a proximal portion of the second coil <NUM>, and the sparsely wound portion is located between the densely wound portion on a distal end side and the densely wound portion on a proximal end side. The second coil <NUM> may include only the densely wound portion without the sparsely wound portion.

A proximal portion of the first coil <NUM> and the distal portion of the second coil <NUM> are partially intertwined with each other. That is, the wire member of the proximal portion of the first coil <NUM> and the wire member of the distal portion of the second coil <NUM> are alternately arranged along the longitudinal direction. Accordingly, separation between the first coil <NUM> and the second coil <NUM> is prevented. An intertwined length of the proximal portion of the first coil <NUM> and the distal portion of the second coil <NUM> is <NUM> to <NUM>. The first coil <NUM> and the second coil <NUM> have the same winding direction such that the first coil <NUM> and the second coil <NUM> can be intertwined with each other.

Outer diameters of the wire members of the first coil <NUM> and the second coil <NUM> are <NUM> to <NUM>, preferably <NUM> to <NUM>. In the present embodiment, the outer diameter of the wire member forming the first coil <NUM> is larger than the outer diameter of the wire member forming the second coil <NUM>. Further, the wire members forming the first coil <NUM> and the second coil <NUM> may be not only one wire member, but also a twisted wire formed from two or more wire members.

The wire members of the first coil <NUM> and the second coil <NUM> are not particularly limited, and can be formed of a metal such as stainless steel, a super-elastic alloy, a cobalt-based alloy, gold, platinum, or tungsten, or an alloy containing these metals. For example, the first coil <NUM> is made of a platinum-based alloy that is more flexible and has higher contrast than the second coil <NUM>, and a material of the second coil <NUM> is made of a stainless steel. As the platinum-based alloy, Pt-Ir, Pt-Ni, Pt-W, or the like is preferably used.

The outer diameters of the first coil <NUM> and the second coil <NUM> are preferably constant from a distal end to a proximal end. In the present embodiment, the outer diameter of the first coil <NUM> is substantially equal to the outer diameter of the second coil <NUM>. Accordingly, an outer diameter of the tubular body <NUM> is substantially constant from a distal end to a proximal end of the tubular body <NUM>. The outer diameters of the first coil <NUM> and the second coil <NUM> are <NUM> to <NUM>.

The material forming the wire members constituting the first coil <NUM> and the second coil <NUM>, the outer diameters of the wire members, cross-sectional shapes of the wire members, pitches of the wire members, and the like can be appropriately selected according to the purpose of the guide wire <NUM>. Further, the cross-sectional shape of the wire member is preferably a circular shape, but may be an elliptical shape or a polygonal shape. A center of a cross section of a wire member having a non-circular cross-sectional shape may be a centroid of the cross section of the wire member.

The fixing portion <NUM> is a member for fixing the tubular body <NUM> to the core component <NUM>. In the present embodiment, the fixing portion <NUM> includes a distal end fixing portion <NUM> that fixes the distal end of the tubular body <NUM> to the core component <NUM>, an intermediate fixing portion <NUM> that fixes an intermediate portion of the tubular body <NUM> to the core component <NUM>, and a proximal end fixing portion <NUM> that fixes the proximal end of the tubular body <NUM> to the core component <NUM>.

A material forming the fixing portion <NUM> is a brazing material or a soldering material. Examples of the brazing material include gold brazing and silver brazing. Examples of the soldering material include Sn-Ag alloy soldering and Sn-Pb alloy soldering. The material forming the fixing portion <NUM> may be an adhesive.

The distal end fixing portion <NUM> fixes a distal portion of the first coil <NUM> to the flat portion <NUM> of the first core member <NUM>. The distal end fixing portion <NUM> is located at a most distal end of the guide wire <NUM>, and an outer surface of the distal end fixing portion <NUM> is smoothly formed in a substantially hemispherical shape.

The intermediate fixing portion <NUM> fixes the proximal portion of the first coil <NUM> and the distal portion of the second coil <NUM> to the second tapered portion 11e of the first core member <NUM> via a cylindrical member 32a. The intermediate fixing portion <NUM> is provided at a position where the proximal portion of the first coil <NUM> and the distal portion of the second coil <NUM> are intertwined with each other in the first core member <NUM>.

The cylindrical member 32a is disposed between an inner circumferential surface of the tubular body <NUM> and an outer circumferential surface of the core component <NUM>. The cylindrical member 32a coaxially fixes the tubular body <NUM> and the core component <NUM> by reducing a gap between the inner circumferential surface of the tubular body <NUM> and the outer circumferential surface of the core component <NUM>. In the present embodiment, an outer diameter of a distal portion of the cylindrical member 32a is smaller than an outer diameter of a proximal portion of the cylindrical member 32a. Accordingly, as illustrated in <FIG>, the first coil <NUM> having a small inner diameter and the second coil <NUM> having a large inner diameter can be coaxially fixed to the core component <NUM>. The outer diameter of the distal portion of the cylindrical member 32a and the outer diameter of the proximal portion of the cylindrical member 32a may be appropriately selected according to the inner diameter of the first coil <NUM> and the inner diameter of the second coil <NUM>. The cylindrical member 32a can be formed of a metal or a resin material. The guide wire <NUM> may not include the cylindrical member 32a.

The proximal end fixing portion <NUM> fixes the proximal portion of the second coil <NUM> to the second constant outer diameter portion 11d of the first core member <NUM>.

The cover layer <NUM> includes a first cover layer <NUM>, a second cover layer <NUM>, and a third cover layer <NUM>. The cover layer <NUM> can be formed of a material capable of reducing friction generated between the guide wire <NUM> and a blood vessel or a catheter. Accordingly, the cover layer <NUM> improves operability and safety of the guide wire <NUM>.

The first cover layer <NUM> covers outer surfaces of the respective portions provided in the first core member <NUM> (the tubular body <NUM> and the fixing portion <NUM>) and a portion of the first core member <NUM> (the second constant outer diameter portion 11d).

The second cover layer <NUM> covers a portion of the core component <NUM> located proximal of the tubular body <NUM>. The second cover layer <NUM> covers an outer surface of a proximal portion of the first core member <NUM> (the first tapered portion 11c and the first constant outer diameter portion 11b) and the second core member <NUM>. That is, the second cover layer <NUM> covers a portion of the core component <NUM> located proximal of the tubular body <NUM> except for the first bonding portion 11a and the second bonding portion 12b.

The third cover layer <NUM> covers outer surfaces of the first bonding portion 11a and the second bonding portion 12b.

The second cover layer <NUM> may cover an entire portion of the core component <NUM> located proximal of the tubular body <NUM>. In this case, the third cover layer <NUM> is not provided. Alternatively, the second cover layer <NUM> may not cover a part of the portion of the core component <NUM> located proximal of the tubular body <NUM>. In this case, the third cover layer <NUM> may be provided at a portion not covered with the second cover layer <NUM>.

The first cover layer <NUM> can be formed of a hydrophilic polymer. Examples of the hydrophilic polymer forming the first cover layer <NUM> include a cellulose-based polymer material, a polyethylene oxide-based polymer material, a maleic anhydride-based polymer material (for example, a maleic anhydride copolymer such as a methyl vinyl ether-maleic anhydride copolymer), an acrylamide-based polymer material (for example, polyacrylamide and a block copolymer of glycidyl methacrylate-dimethylacrylamide), a water-soluble nylon, polyvinyl alcohol, polyvinyl pyrrolidone, and derivatives thereof.

The second cover layer <NUM> and the third cover layer <NUM> can be made of a low-friction material. Examples of the low friction material include a polyolefin such as polyethylene and polypropylene, polyvinyl chloride, polyester (PET, PBT, or the like), polyamide, polyimide, polyurethane, polystyrene, polycarbonate, a silicone resin, a fluorine-based resin (PTFE, ETFE, or the like), and composite materials thereof.

The materials for forming the first cover layer <NUM>, the second cover layer <NUM>, and the third cover layer <NUM> are not limited to those described above. The first cover layer <NUM>, the second cover layer <NUM>, and the third cover layer <NUM> may be formed of different materials along the longitudinal direction of the core component <NUM>. For example, in the second cover layer <NUM>, a material covering a distal portion of the first core member <NUM> may be different from a material covering the proximal portion of the first core member <NUM>. Further, the number of layers of each of the first cover layer <NUM>, the second cover layer <NUM>, and the third cover layer <NUM> may be plural. Any one of the first cover layer <NUM>, the second cover layer <NUM>, and the third cover layer <NUM> may not be provided.

The distal portion of the guide wire <NUM> according to the present embodiment has both the shaping property and the shape retaining property. The shaping property is a property that allows the operator to shape the distal portion of the guide wire <NUM>. Since the guide wire <NUM> is given a desired shape to the distal portion by shaping, the operability of the guide wire <NUM> in a blood vessel and blood vessel selectivity at a branch portion are improved. The shape given to the guide wire <NUM> by shaping depends on an inner diameter and a shape of a blood vessel of a patient. Therefore, it is preferable that the guide wire <NUM> can be easily shaped into the desired shape. That is, an excellent shaping property is required.

The shape retaining property is a property of maintaining, during an operation of the guide wire <NUM> in the blood vessel, the shape given to the distal portion of the guide wire <NUM> by the operator by shaping. In general, the shape given to the guide wire <NUM> by shaping is a curved shape, and a curvature radius of the curved shape is larger than the inner diameter of the blood vessel. Therefore, the guide wire <NUM> is deformed in accordance with the inner diameter and the shape of the blood vessel. Further, the guide wire <NUM> may be unintentionally bent into a U-shape when the distal portion of the guide wire <NUM> comes into contact with a blood vessel wall of the branch portion or is caught on the stent. Furthermore, the guide wire <NUM> may be intentionally bent into a U-shape for a purpose of preventing blood vessel perforation when passing through the stenosis. As described above, the distal portion of the guide wire <NUM> receives an external force that can deform the distal portion during the operation in the blood vessel. When restorability of the guide wire <NUM> against the external force is low, the guide wire <NUM> is plastically deformed and cannot maintain the shape given by the operator by shaping, and the operability and the blood vessel selectivity decrease. When the distal portion of the guide wire is deformed, the operator needs to remove the guide wire from the blood vessel and reshape the guide wire. When the guide wire is deformed to such an extent of being difficult to reshape, it is necessary to replace the guide wire with another guide wire. Accordingly, procedure time is extended, and burden on the operator and the patient is increased. Therefore, it is preferable that the guide wire <NUM> has a restorability such that even the guide wire <NUM> is deformed by receiving the external force during the operation in the blood vessel, the guide wire <NUM> can be restored to the shape given by the operator by shaping when the external force is removed. That is, the guide wire <NUM> is required to have an excellent shape retaining property.

The guide wire <NUM> having both the shaping property and the shape retaining property can be obtained by controlling an elastic portion of total indentation work and Martens hardness of the distal portion of the guide wire <NUM> formed of a Ni-Ti alloy to be within predetermined ranges.

The elastic portion of total indentation work and the Martens hardness are calculated from a load-displacement curve obtained by an instrumented indentation hardness test for the flat portion <NUM> of the guide wire <NUM>. The elastic portion of total indentation work is a ratio of a work of elastic deformation to a total work (a sum of a work of plastic deformation and the work of elastic deformation). The Martens hardness is a value obtained by dividing a test load by a surface area of indentation by an indenter in the instrumented indentation hardness test.

A material having a large elastic portion of total indentation work has a high restorability of a shape caused by superelasticity. Therefore, even an external force is applied to the flat portion <NUM> of the guide wire <NUM> formed of a material having a large elastic portion of total indentation work, the flat portion <NUM> is easily restored to an original shape when the external force is removed. Accordingly, the larger the elastic portion of total indentation work, the lower the shaping property of the flat portion <NUM>, and the higher the shape retaining property. On the other hand, a material having a small elastic portion of total indentation work is likely to be plastically deformed. Therefore, a flat portion <NUM> formed of a material having a small elastic portion of total indentation work is plastically deformed when the external force is applied, and the shape thereof is easily maintained even when the external force is removed. Accordingly, the smaller the elastic portion of total indentation work, the higher the shaping property and the lower the shape retaining property of the flat portion <NUM>.

A material having a high Martens hardness is hard. Therefore, a flat portion <NUM> of the guide wire <NUM> formed of a material having a high Martens hardness is unlikely to be deformed by an external force. Accordingly, the higher the Martens hardness, the lower the shaping property of flat portion <NUM> and the higher the shape retaining property. On the other hand, a flat portion <NUM> of the guide wire <NUM> formed of a material having a low Martens hardness is likely to be plastically deformed even by a small external force received in the blood vessel. Accordingly, the smaller the Martens hardness, the higher the shaping property and the lower the shape retaining property of the flat portion <NUM>.

A magnitude of the external force received by the guide wire <NUM> in the blood vessel is smaller than that of the external force applied by the operator for shaping. Therefore, the distal portion of the guide wire <NUM> can have both the shaping property and the shape retaining property by having a physical property capable of being deformed by a large force applied by the operator for shaping, and capable of restoring the shape at the time of shaping without being plastically deformed by a small force applied during a procedure.

The Martens hardness has a greater influence on the shaping property and the shape retaining property than the elastic portion of total indentation work. Accordingly, the shaping property and the shape retaining property cannot be both improved when only the elastic portion of total indentation work is controlled, and it is particularly necessary to appropriately control the Martens hardness.

The flat portion <NUM> of the guide wire <NUM> according to the present invention is formed of a Ni-Ti alloy having an elastic portion of total indentation work of <NUM>% to <NUM>% and having a Martens hardness of <NUM> N/mm<NUM> to <NUM> N/mm<NUM>.

The distal portion of the guide wire <NUM> in which the flat portion <NUM> has the elastic portion of total indentation work and the Martens hardness in the above ranges has the physical property capable of being deformed by the large force applied by the operator for shaping, and capable of restoring the shape at the time of shaping without being plastically deformed by the small force applied during the procedure. Accordingly, the guide wire <NUM> can be shaped by the operator, and can be restored to the shape at the time of shaping even an external force that can deform the distal portion is received in a blood vessel. Therefore, the guide wire can maintain high operability and blood vessel selectivity given by shaping even during the procedure. Further, the operator does not need to remove the guide wire <NUM> from the blood vessel and reshape the guide wire <NUM> or replace the guide wire <NUM> with another guide wire, and thus the procedure can be easily performed. Accordingly, the procedure time is shortened, and thus the burden on the operator and the patient can be reduced.

Further, the flat portion <NUM> of the guide wire <NUM> has an elastic portion of total indentation work of <NUM>% to <NUM>% and has a Martens hardness of <NUM> N/mm<NUM> to <NUM> N/mm<NUM>. By setting the elastic portion of total indentation work of the flat portion <NUM> of the guide wire <NUM> in the range of <NUM>% to <NUM>% and the Martens hardness in the range of <NUM> N/mm<NUM> to <NUM> N/mm<NUM>, the flat portion <NUM> of the first core member <NUM> is more flexible, and thus the shaping property is further improved.

Further, in the guide wire <NUM>, the distal portion of the core component <NUM> is preferably subjected to heat treatment in order to set the elastic portion of total indentation work and the Martens hardness of the flat portion <NUM> in the above ranges.

The flat portion <NUM> is formed by pressing the distal portion of the first core member <NUM> made of a Ni-Ti alloy. The flat portion <NUM> after pressing has lower superelasticity than the Ni-Ti alloy before pressing due to a strain introduced by the pressing. Therefore, the flat portion <NUM> after press has a small elastic portion of total indentation work, and thus has a low shape retaining property. By subjecting the flat portion <NUM> after pressing to heat treatment, the strain is removed from the flat portion <NUM>, and the superelasticity is improved. As a result, the flat portion <NUM> has a large elastic portion of total indentation work and has an improved shape retaining property. Further, the flat portion <NUM> after pressing is harder than the Ni-Ti alloy before pressing by work hardening. Therefore, the flat portion <NUM> after pressing has a high Martens hardness and thus has a low shaping property. By subjecting the flat portion <NUM> after pressing to heat treatment, the flat portion <NUM> is softer. As a result, flat portion <NUM> has a low Martens hardness, and has an improved shaping property. In this way, in the guide wire <NUM>, the elastic portion of total indentation work and the Martens hardness of the distal portion of the guide wire <NUM> formed of a Ni-Ti alloy can be controlled within predetermined ranges by subjecting the pressed flat portion <NUM> to heat treatment. Accordingly, the guide wire <NUM> can have both the shaping property and the shape retaining property.

Heat treatment is preferably performed in a region of the flat portion <NUM> and at least a part of the transition portion 11f of the first core member <NUM>. That is, the guide wire <NUM> according to the present embodiment has a heat treatment region H continuously extending from the distal end of the flat portion <NUM> to the at least a part of the transition portion 11f along the longitudinal direction. One end of the heat treatment region H of the guide wire <NUM> coincides with the distal end of the flat portion <NUM>, and the other end is located at the transition portion 11f. In the present specification, the heat treatment region H refers to a region where an oxide film is formed on at least a part of the outer surface of the first core member in the circumferential direction by heat treatment. Therefore, in the guide wire <NUM>, an oxide film is formed on an outer surface from the distal end of the flat portion <NUM> to the at least a part of the transition portion 11f along the longitudinal direction. Further, in the present specification, a total length from one end to the other end of the heat treatment region H of the guide wire <NUM> along the longitudinal direction is referred to as a heat treatment length. The heat treatment length of the guide wire <NUM> is longer than the length of the flat portion <NUM> along the longitudinal direction.

Since the guide wire <NUM> includes the heat treatment region H continuously extending from the distal end of the flat portion <NUM> to the at least a part of the transition portion 11f, it is possible to prevent a sudden change in rigidity of the guide wire <NUM> along the longitudinal direction. <FIG> are diagrams schematically illustrating the rigidity of the distal portion of the first core member <NUM> when the guide wire <NUM> is subjected to heat treatment. In <FIG> and <FIG>, dot groups appearing on an outer surface of the first core member <NUM> express a level of rigidity, with denser dots indicating lower rigidity and sparser dots indicating higher rigidity. Two-dot chain lines in <FIG> are imaginary lines that partition regions of the flat portion <NUM>, the transition portion 11f, and the second tapered portion 11e. As illustrated in <FIG>, in the guide wire <NUM>, the flat portion <NUM> has a flat shape with a small thickness. Therefore, rigidity of the flat portion <NUM> is low and is constant along the longitudinal direction. On the other hand, the transition portion 11f has the wedge shape in which the thickness gradually increases and the width gradually decreases from the flat portion <NUM> toward the second tapered portion 11e. Therefore, rigidity of the transition portion 11f is equal to that of the flat portion <NUM> at the distal end, and gradually increases from the distal end toward the proximal end. Here, when the first core member <NUM> is subjected to heat treatment, the rigidity of the portion of the first core member <NUM> subjected to heat treatment decreases. Accordingly, as illustrated in <FIG>, when only a part of the flat portion <NUM> is subjected to heat treatment, the rigidity of the flat portion <NUM> suddenly changes at a position of a proximal end of the heat treatment region H. Alternatively, when only the flat portion <NUM> is subjected to heat treatment, the rigidity of the first core member <NUM> suddenly changes at a boundary between the flat portion <NUM> and the transition portion 11f. The guide wire <NUM> is likely to be bent at a point where the rigidity suddenly changes along the longitudinal direction, and is likely to cause prolapse. In the present embodiment, as illustrated in <FIG>, it is preferable that the flat portion <NUM> is subjected to heat treatment over an entire length of the flat portion <NUM>, and in addition, a part of the transition portion 11f is also subjected to heat treatment. As a result, in the guide wire <NUM>, the sudden change in rigidity along the longitudinal direction is prevented, and prolapse resistance is improved.

The "prolapse" means a state in which, when the distal end of the guide wire <NUM> is inserted into a side branch from a main duct, a portion of the guide wire <NUM> proximal of the distal end is locally bent, and the bent portion deviates distal of a branch from the main duct to the side branch. When the guide wire <NUM> is in such a state, since a pushing force or torque applied to the proximal end of the guide wire <NUM> is transmitted only to the bent portion, it is difficult for the operator to advance the distal end of the guide wire <NUM> to a distal end of the side branch. Further, since a distal end of the catheter advanced along the guide wire <NUM> is guided to the bent portion, it is difficult for the operator to advance the catheter to the side branch.

The proximal end of the heat treatment region H of the guide wire <NUM> is preferably located at the transition portion 11f. That is, the proximal end of the heat treatment region H of the guide wire <NUM> is preferably not located at the second tapered portion 11e. When the second tapered portion 11e not subjected to cold working is subjected to heat treatment, the superelasticity decreases, and plastic deformation is likely to occur. As a result, the guide wire <NUM> is likely to be kinked in the blood vessel. In the present embodiment, as illustrated in <FIG>, only the flat portion <NUM> and the transition portion 11f subjected to cold working are subjected to heat treatment. Accordingly, plastic deformation of the guide wire <NUM> due to the decrease in the superelasticity is prevented, and the kink resistance is improved.

In the guide wire <NUM>, a ratio of a length from the distal end of the transition portion 11f to the proximal end of the heat treatment region H along the longitudinal direction to the length of the transition portion 11f along the longitudinal direction is preferably <NUM>% or more and <NUM>% or less. Accordingly, the guide wire <NUM> can improve the prolapse resistance and the kink resistance while having the shaping property and the shape retaining property. When the heat treatment length is longer than the above range, a portion of the first core member <NUM> not subjected to cold working, such as the second tapered portion 11e, is subjected to heat treatment. When the portion of the first core member <NUM> not subjected to cold working is subjected to heat treatment, the superelasticity decreases, and plastic deformation is likely to occur. As a result, the guide wire <NUM> is likely to be kinked in the blood vessel. Further, when the heat treatment length is shorter than the above range and only the flat portion <NUM> is subjected to heat treatment, the rigidity of the first core member <NUM> is suddenly changed at the rigidity in the boundary between the flat portion <NUM> and the transition portion 11f and prolapse is likely to occur.

In the guide wire <NUM>, the ratio of the length from the distal end of the transition portion 11f to the proximal end of the heat treatment region H along the longitudinal direction to the length of the transition portion 11f along the longitudinal direction is more preferably <NUM>% or more and <NUM>% or less. Accordingly, the guide wire <NUM> can further improve the prolapse resistance and the kink resistance while having the shaping property and the shape retaining property. When the length from the distal end of the transition portion 11f to the proximal end of the heat treatment region H along the longitudinal direction exceeds <NUM>% of the length of the transition portion 11f along the longitudinal direction, a length of the portion of the transition portion 11f having decreased rigidity due to heat treatment is longer. Therefore, when the guide wire <NUM> is pushed in a state in which the distal end of the guide wire <NUM> is inserted into a side branch from a main duct, the pushing force is not transmitted to the distal end of the guide wire <NUM>, and the guide wire <NUM> is bent at the transition portion 11f located in the main duct, and prolapse is likely to occur. On the other hand, when the length from the distal end of the transition portion 11f to the proximal end of the heat treatment region H along the longitudinal direction is less than <NUM>% of the length of the transition portion 11f along the longitudinal direction, a length of the portion of the transition portion 11f having high rigidity is longer. Further, since the proximal end of the heat treatment region H is disposed at the distal portion of the transition portion 11f having low rigidity, the rigidity of the guide wire <NUM> suddenly changes at the proximal end of the heat treatment region H, and prolapse is likely to occur. By setting the length of the heat treatment region H from the distal end of the transition portion 11f to the proximal end of the heat treatment region H along the longitudinal direction to <NUM>% or more and <NUM>% or less of the length of the transition portion 11f along the longitudinal direction, the guide wire <NUM> can further improve the prolapse resistance and the kink resistance.

Various conditions for performing heat treatment on the distal portion of the core component <NUM> can be appropriately set. For example, a temperature at which heat treatment is performed is <NUM> to <NUM>, and time is <NUM> minutes to <NUM> minutes.

Heat treatment has an effect of softening the flat portion <NUM> hardened by cold working and making the flat portion <NUM> easier to deform, and an effect of removing the strain from the flat portion <NUM> having decreased superelasticity due to the strain introduced by cold working to appropriately improve the superelasticity. Accordingly, heat treatment is particularly effective as a method of giving the shaping property and the shape retaining property to the guide wire <NUM>. The method of giving the shaping property and the shape retaining property to the distal portion of the core component <NUM> is not limited to heat treatment, and other methods may be applied as long as the elastic portion of total indentation work and the Martens hardness can be in the above ranges.

As described above, the guide wire <NUM> according to the present embodiment includes the elongated core component <NUM> having the flat portion <NUM> at the distal end. The flat portion <NUM> is made of a Ni-Ti alloy having an elastic portion of total indentation work of <NUM>% or more and <NUM>% or less and having a Martens hardness of <NUM> N/mm<NUM> or more and <NUM> N/mm<NUM> or less.

With such a configuration, the guide wire <NUM> can have the physical property capable of being deformed by a large force applied by an operator for shaping, and capable of restoring the shape at the time of shaping without being plastically deformed by a small force applied during the procedure. That is, the guide wire <NUM> can have both the shaping property and the shape retaining property. Accordingly, the guide wire <NUM> can be shaped by the operator, and can be restored to the shape at the time of shaping even an external force that can deform the distal portion is received in a blood vessel. Therefore, the guide wire <NUM> can maintain the high operability and blood vessel selectivity given by shaping even during a procedure. Further, the operator does not need to remove the guide wire <NUM> from the blood vessel and reshape the guide wire <NUM> or replace the guide wire <NUM> with another guide wire, and thus the procedure can be easily performed. Accordingly, the procedure time is shortened, and thus the burden on the operator and the patient can be reduced.

Further, the guide wire <NUM> according to the present embodiment may have a Martens hardness of <NUM> N/mm<NUM> or more and <NUM> N/mm<NUM> or less.

With such a configuration, in the guide wire <NUM>, the flat portion <NUM> of the first core member <NUM> located at the distal end of the core component <NUM> is more flexible, and thus shaping property is further improved.

Further, the core component <NUM> of the guide wire <NUM> according to the present embodiment may include, in order from the distal end side, the flat portion <NUM> and the transition portion 11f extending from the proximal end of the flat portion <NUM> toward the proximal end side along the longitudinal direction, and the core component <NUM> may include the heat treatment region H extending from the distal end of the flat portion <NUM> to at least a part of the transition portion 11f.

With such a configuration, since the first core member <NUM> can prevent a sudden change in the rigidity along the longitudinal direction at the proximal end of the heat treatment region H, the prolapse resistance and the kink resistance can be improved while having the shaping property and the shape retaining property.

Further, in the guide wire <NUM> according to the present embodiment, the ratio of the length from the distal end of the transition portion 11f to the proximal end of the heat treatment region H along the longitudinal direction to the length of the transition portion 11f along the longitudinal direction may be <NUM>% or more and <NUM>% or less.

With such a configuration, the guide wire <NUM> can improve the prolapse resistance and the kink resistance while having the shaping property and the shape retaining property.

With such a configuration, since the guide wire <NUM> can further prevent a sudden change in the rigidity of the guide wire <NUM> along the longitudinal direction, the prolapse resistance and the kink resistance can be further improved.

Further, a method of manufacturing the guide wire <NUM> including the core component <NUM> according to the present embodiment includes: performing cold working on the distal portion of the core component <NUM> such that the distal portion includes the flat portion <NUM> and the transition portion 11f extending from the proximal end of the flat portion <NUM> toward the proximal end side along the longitudinal direction; and performing heat treatment on the flat portion <NUM> and at least a part of the transition portion 11f such that the elastic portion of total indentation work thereof is <NUM>% or more and <NUM>% or less and the Martens hardness thereof is <NUM> N/mm<NUM> or more and <NUM> N/mm<NUM> or less.

The guide wire <NUM> manufactured by the above method can have the physical property capable of being deformed by the large force applied by the operator for shaping, and capable of restoring the shape at the time of shaping without being plastically deformed by the small force applied during the procedure. That is, the guide wire <NUM> can have both the shaping property and the shape retaining property. Accordingly, the guide wire <NUM> can be shaped by the operator, and can be restored to the shape at the time of shaping even an external force that can deform the distal portion is received in a blood vessel. Therefore, the guide wire <NUM> can maintain the high operability and blood vessel selectivity given by shaping even during the procedure. Further, the operator does not need to remove the guide wire <NUM> from the blood vessel and reshape the guide wire <NUM> or replace the guide wire <NUM> with another guide wire, and thus the procedure can be easily performed. Accordingly, the procedure time is shortened, and thus the burden on the operator and the patient can be reduced. Further, heat treatment has an effect of softening the flat portion <NUM> hardened by cold working and making the flat portion <NUM> easier to deform, and an effect of removing the strain from the flat portion <NUM> having decreased superelasticity due to the strain introduced by cold working to appropriately improve the superelasticity. Therefore, heat treatment is particularly effective as a method of giving the shaping property and the shape retaining property to the guide wire <NUM>.

Hereinafter, the invention will be described in detail with reference to examples, but the scope of the invention is not limited to the following examples.

Hereinafter, "manufacture of guide wire", "evaluation method", and "evaluation result" of the guide wires <NUM> in the examples and comparative examples will be described in detail with reference to Table <NUM> to Table <NUM>. Table <NUM> illustrates manufacture conditions in Example <NUM> to Example <NUM>, and Table <NUM> illustrates manufacture conditions in Comparative Example <NUM> to Comparative Example <NUM>. A "heat treatment ratio" in each of Table <NUM> and Table <NUM> is the ratio of the length from the distal end of the transition portion 11f to the proximal end of the heat treatment region H along the longitudinal direction to the length of the transition portion 11f along the longitudinal direction.

Hereinafter, the manufacture of the guide wire <NUM> according to the examples and the comparative examples will be described. In each of the examples and the comparative examples, heat treatment performed in step <NUM> was performed at a temperature in the range of <NUM> to <NUM> and for a time in the range of <NUM> minutes to <NUM> minutes.

The distal portion of the first core member <NUM> made of a Ni-Ti alloy (Ni content: <NUM> mass% to <NUM> mass%) was tapered such that the outer diameter of the first core member <NUM> gradually decreased from the proximal end side toward the distal end side. The outer diameter of the most distal portion was <NUM>.

A range of <NUM> from the distal end toward the proximal end side of the first core member <NUM> was pressed to form the flat portion <NUM> and the transition portion 11f. At this time, a range of <NUM> from the distal end toward the proximal end side of the guide wire <NUM> was defined as the flat portion <NUM>, and was formed into a flat shape having a constant thickness of <NUM>. A range of <NUM> from the proximal end of the flat portion <NUM> toward the proximal end side of the guide wire <NUM> was defined as the transition portion 11f, and was processed into a wedge shape in which the thickness increased toward the proximal end side.

Heat treatment was performed in a range of <NUM> from the most distal end toward the proximal end side of the first core member <NUM> pressed in step <NUM>.

The tubular body <NUM> including the first coil <NUM> and the second coil <NUM> is disposed around from the flat portion <NUM> of the first core member <NUM> to a part of the second constant outer diameter portion 11d. As the first coil <NUM>, a coil having a length of <NUM> to <NUM> formed by winding a wire member (outer diameter: <NUM> to <NUM>, wire member diameter: <NUM> to <NUM>) made of a platinum-based alloy was used. As the second coil <NUM>, a coil having a length of <NUM> to <NUM> formed by winding a wire member (outer diameter: <NUM> to <NUM>, wire member diameter: <NUM> to <NUM> pm) made of a stainless steel was used. The distal portion of the first coil <NUM> was fixed to the flat portion <NUM> of the first core member <NUM> with silver brazing. The proximal portion of the first coil <NUM> and the distal portion of the second coil <NUM> were fixed to the second tapered portion 11e of the first core member <NUM> by a Sn-Ag alloy solder via the metallic cylindrical member 32a. The proximal portion of the second coil <NUM> was fixed to the second constant outer diameter portion lid of the first core member <NUM> by a Sn-Ag alloy solder.

The first core member <NUM> and the second core member <NUM> were bonded by resistance butt welding.

Outer surfaces of the first coil <NUM>, the second coil <NUM>, and a part of the second constant outer diameter portion lid were coated with a hydrophilic polymer to form the first cover layer <NUM>. Outer surfaces of the first constant outer diameter portion 11b, the first tapered portion 11c of the first core member <NUM> and the second core member <NUM> were coated with a fluorine-based resin to form the second cover layer <NUM>. Outer surfaces of the first bonding portion 11a and the second bonding portion 12b were coated with a silicone resin to form the third cover layer <NUM>.

The guide wires in Examples <NUM> to <NUM> were manufactured as follows. The guide wires in Examples <NUM> to <NUM> and <NUM> to <NUM> were manufactured in the same manner as in Example <NUM> in step <NUM>, step <NUM>, and step <NUM> to step <NUM>, and were manufactured in step <NUM> as follows.

In step <NUM>, heat treatment was performed in a range of <NUM> from the most distal end toward the proximal end side of the first core member <NUM> pressed in step <NUM>.

Further, the guide wires in Example <NUM> and Example <NUM> were manufactured in the same manner as in Example <NUM> in step <NUM> and step <NUM> to step <NUM>, and were manufactured in step <NUM> and step <NUM> as follows.

The range of <NUM> from the distal end toward the proximal end side of the first core member <NUM> was pressed to form the flat portion <NUM> and the transition portion 11f. At this time, a range of <NUM> from the distal end toward the proximal end side of the guide wire <NUM> was defined as the flat portion <NUM>, and was formed into a flat shape having a constant thickness of <NUM>. A range of <NUM> from the proximal end of the flat portion <NUM> toward the proximal end side of the guide wire <NUM> was defined as the transition portion 11f, and was processed into a wedge shape in which the thickness increased toward the proximal end side.

The guide wires in Comparative Examples <NUM> to <NUM> were manufactured as follows. The guide wires in Comparative Example <NUM> and Comparative Example <NUM> were manufactured in the same manner as in Example <NUM> in step <NUM>, step <NUM>, and step <NUM> to step <NUM>, and were manufactured in step <NUM> as follows.

In step <NUM>, the first core member <NUM> pressed in step <NUM> was not subjected to the heat treatment.

Further, the guide wires in Comparative Example <NUM> and Comparative Example <NUM> were manufactured as follows. The guide wires in Comparative Example <NUM> and Comparative Example <NUM> were manufactured in the same manner as in Example <NUM> in step <NUM> and step <NUM> to step <NUM>, and were manufactured in step <NUM> and step <NUM> as follows.

Evaluation of the guide wires <NUM> in Example <NUM> to Example <NUM> and Comparative Example <NUM> to Comparative Example <NUM> was performed as follows.

Dynamic Ultra Micro Rigidity Tester DUH-<NUM> manufactured by Shimadzu Corporation.

The elastic portion of total indentation work and the Martens hardness of the guide wire <NUM> in each of the examples and the comparative examples were average values of measured values at any <NUM> locations on the cross section parallel to the plane viewed from the thickness direction of the flat portion <NUM>. The elastic portion of total indentation work was rounded to one decimal place, and the Martens hardness was rounded to an integer.

A shaping test was performed as follows. First, a portion of <NUM> from the distal end of the guide wire <NUM> was sandwiched between a silicone rubber plate placed on a substantially horizontal surface and a round rod (ϕ <NUM>) made of stainless steel, and the round rod was pressed with a load of <NUM>. Next, the guide wire <NUM> was pulled out from the silicone rubber plate in a vertical direction, and the shape of the distal portion of the guide wire <NUM> was visually observed. In a case in which the distal portion of the guide wire <NUM> after the test was significantly deformed as compared with that before the test, the evaluation was "good", in a case in which the distal portion was deformed but by a small degree, the evaluation was "fair", and in a case in which the distal portion was not deformed, the evaluation was "poor".

A shape retaining property test was performed as follows. The guide wire <NUM> was deformed and shaped at a radius of curvature of <NUM> from a position of <NUM> to a position of <NUM> from the distal end of the guide wire <NUM>. The shaped guide wire <NUM> was inserted into a U-shaped passage having a radius of curvature of <NUM>, and the guide wire <NUM> was pulled out after being alternately rotated <NUM> times in total on left and right sides, and the shape of the distal portion of the guide wire <NUM> was confirmed. When a perpendicular line was drawn from the distal end of the guide wire <NUM> to the central axis C, in a case in which a distance between a foot of the perpendicular line before the test and a foot of the perpendicular line after the test on the central axis C was <NUM> or less, the shape was considered to be retained and the evaluation was "good", and in a case in which the distance was larger than <NUM>, the shape was considered to be unable to be retained, and the evaluation was "poor". The smaller the radius of curvature of the U-shaped passage, the greater the external force applied to the guide wire <NUM>, which makes it difficult to maintain the shape of the guide wire <NUM> during shaping.

A prolapse resistance test was performed as follows. First, a branch model <NUM> made of a silicone resin tube illustrated in <FIG> was prepared. The branch model <NUM> includes a main duct <NUM> and a plurality of side branches <NUM> disposed along a longitudinal direction of the main duct <NUM>. The main duct <NUM> has an inner diameter of <NUM>, and the side branch <NUM> has an inner diameter of <NUM>. In <FIG>, angles θ (θ1 to θ7) between a central axis of the main duct <NUM> and central axes of the side branches <NUM> on the distal end side were θ1 = <NUM>°, θ2 = <NUM>°, θ3 = <NUM>°, θ4 = <NUM>°, θ5 = <NUM>°, θ6 = <NUM>°, and <NUM> = <NUM>°.

Next, the distal portion of the guide wire <NUM> was shaped. As illustrated in <FIG>, the shaping was performed by deforming the guide wire <NUM> in the same direction by approximately <NUM>° at each of a first bending point P1 at a position <NUM> from the distal end of the guide wire <NUM> and a second bending point P2 at a position <NUM> from the distal end. Next, the guide wire <NUM> was inserted into each side branch <NUM> from an insertion opening 200a of the branch model <NUM> filled with water. Among the side branches <NUM> into which the guide wire <NUM> could be inserted, a maximum angle θ was recorded. When the maximum angle θ at which the guide wire <NUM> can be inserted is small, it can be said that prolapse is likely to occur. Therefore, among the side branches <NUM> into which the guide wire <NUM> could be inserted, in a case in which the maximum angle θ was θ ≤ <NUM>°, the evaluation was "poor", in a case in which the angle θ was <NUM>° < θ ≤ <NUM>°, the evaluation was "fair", and in a case in which the angle θ was <NUM>° < θ ≤ <NUM>°, the evaluation was "good".

A kink resistance test was performed as follows. As illustrated in <FIG>, a stenosis model <NUM> in which one end of a tube having an inner diameter of <NUM> was used as an occlusion end was prepared. The distal portion of the guide wire <NUM> was shaped into the shape illustrated in <FIG>. The distal end of the guide wire <NUM> was inserted from an opening of the stenosis model <NUM> filled with water, and came into contact with the occlusion end as in the guide wire <NUM> indicated by a two-dot chain line in <FIG>. Next, the guide wire <NUM> was pushed <NUM> in the distal end direction while applying a torque, and the distal portion of the guide wire <NUM> was bent into a U-shape as in the guide wire <NUM> indicated by a solid line in <FIG>. Thereafter, the guide wire <NUM> was pulled by <NUM> in the longitudinal direction to return to a state in which the distal portion was not bent in a U-shape. This operation was performed three times in total. The torque to the guide wire <NUM> was applied by a tester rotating the guide wire <NUM> once while holding the proximal portion of the guide wire <NUM>. The guide wire <NUM> was removed from the stenosis model <NUM>, and a bending height L of the guide wire <NUM> was confirmed with a digital microscope. As illustrated in <FIG>, the "bending height L" refers to a length from the distal end of the guide wire <NUM> before shaping (in a linear state) to the distal end of the guide wire <NUM> after the kink resistance test on a plane passing through the central axis C of the guide wire <NUM> when the guide wire <NUM> is in a natural state. In a case in which the bending height L of the guide wire <NUM> after the kink resistance test was less than <NUM>, the evaluation was "good", and in a case in which the bending height L was <NUM> or more, the evaluation was "poor".

Table <NUM> shows evaluation results in Example <NUM> to Example <NUM>, and Table <NUM> shows evaluation results in Comparative Example <NUM> to Comparative Example <NUM>. "ND" in the table means not measured.

As illustrated in Table <NUM>, the guide wires <NUM> in Example <NUM> to Example <NUM> have results of either "good" or "fair" in both the shaping property test and the shape retaining property test. The guide wires <NUM> in Example <NUM> to Example <NUM> have an elastic portion of total indentation work of the Ni-Ti alloy of the flat portion <NUM> of <NUM>% or more and <NUM>% or less, and have a Martens hardness of <NUM> N/mm<NUM> or more and <NUM> N/mm<NUM> or less (condition <NUM>).

On the other hand, as illustrated in Table <NUM>, the guide wires <NUM> in Comparative Example <NUM> to Comparative Example <NUM> have results of "poor" in either the shaping property test or the shape retaining property test. The guide wires <NUM> in Comparative Example <NUM> and Comparative Example <NUM> have results of "good" in the shaping property test, but have results of "poor" in the shape retaining property test. It is deduced that the guide wire <NUM> in Comparative Example <NUM> was unable to be shaped because the guide wire <NUM> has a Martens hardness larger than an upper limit value of condition <NUM> and is harder than those in Example <NUM> to Example <NUM>. It is deduced that the guide wire <NUM> in Comparative Example <NUM> was unable to be shaped because the guide wire <NUM> has an elastic portion of total indentation work larger than the upper limit value of condition <NUM> and has a superelasticity higher than those in Example <NUM> to Example <NUM>. Further, as illustrated in Table <NUM>, the guide wires <NUM> in Comparative Example <NUM> and Comparative Example <NUM> have results of "good" in the shaping property test, but have results of "poor" in the shape retaining property test. It is deduced that the guide wire <NUM> in Comparative Example <NUM> was easily plastically deformed because the guide wire <NUM> has a Martens hardness smaller than a lower limit value of condition <NUM>, and is softer than those in Example <NUM> to Example <NUM>. It is deduced that the guide wire <NUM> in Comparative Example <NUM> was easily plastically deformed because the guide wire <NUM> has an elastic portion of total indentation work lower than the lower limit value of condition <NUM>, and has a superelasticity lower than those in Example <NUM> to Example <NUM>.

As described above, the guide wires <NUM> in which the flat portion <NUM> is formed of a Ni-Ti alloy satisfying condition <NUM> have both the shaping property and the shape retaining property.

Further, as illustrated in Table <NUM>, the guide wires <NUM> in Example <NUM> to Example <NUM> has a result of "fair" in the shaping test, and the guide wires <NUM> in Example <NUM> to Example <NUM> has a result of "good" in the shaping test. The guide wires <NUM> in Example <NUM> to Example <NUM> have an elastic portion of total indentation work of the Ni-Ti alloy of the flat portion <NUM> of <NUM>% or more and <NUM>% or less, and have a Martens hardness of <NUM> N/mm<NUM> or more and <NUM> N/mm<NUM> or less (condition <NUM>). It is deduced that the guide wires <NUM> in Example <NUM> to Example <NUM> were difficult to shape because the guide wires <NUM> have a Martens hardness larger than an upper limit value of condition <NUM> and are harder than the guide wires <NUM> in Example <NUM> to Example <NUM>.

As described above, the guide wires <NUM> in which the flat portion <NUM> is formed of a Ni-Ti alloy satisfying condition <NUM> are more excellent in both the shaping property and the shape retaining property.

As illustrated in Table <NUM>, the guide wires <NUM> in Example <NUM>, Example <NUM> and Example <NUM>, Example <NUM> to Example <NUM>, and Example <NUM> to Example <NUM> have results of either "good" or "fair" in the prolapse resistance test. On the other hand, the guide wires <NUM> in Example <NUM> and Example <NUM> have results of "poor" in the prolapse resistance test. In each of the guide wires <NUM> in Example <NUM>, Example <NUM> and Example <NUM>, Example <NUM> to Example <NUM>, and Example <NUM> to Example <NUM>, the ratio of the length from the distal end of the transition portion 11f to the proximal end of the heat treatment region H along the longitudinal direction to the length of the transition portion 11f along the longitudinal direction (the heat treatment ratio) is <NUM>% or more and <NUM>% or less (condition <NUM>). On the other hand, in each of the guide wires <NUM> in Example <NUM> and Example <NUM>, the heat treatment ratio is smaller than a lower limit value of condition <NUM>, and only a part of the flat portion <NUM> or only the flat portion <NUM> and a very small part of the distal end side of the transition portion 11f are subjected to the heat treatment. Therefore, as illustrated in <FIG>, it is deduced that the guide wires <NUM> in Example <NUM> and Example <NUM> have decreased prolapse resistance due to a sudden change in the rigidity occurred in a vicinity of the boundary between the flat portion <NUM> and the transition portion 11f.

Further, as illustrated in Table <NUM>, the guide wires <NUM> in Example <NUM> and Example <NUM> to Example <NUM> have results of "good" in the prolapse resistance test. On the other hand, for example, the guide wires <NUM> in Example <NUM> and Example <NUM> have results of "fair" in the prolapse resistance test. In each of the guide wires <NUM> in Example <NUM> and Example <NUM> to Example <NUM>, the ratio of the length from the distal end of the transition portion 11f to the proximal end of the heat treatment region H along the longitudinal direction to the length of the transition portion 11f along the longitudinal direction is <NUM>% or more and <NUM>% or less (condition <NUM>). On the other hand, in the guide wire <NUM> in Example <NUM>, the heat treatment ratio is smaller than a lower limit value of condition <NUM>, and the proximal end of the heat treatment region H is disposed at the distal portion of the transition portion 11f having low rigidity. Therefore, it is deduced that the guide wire <NUM> in Example <NUM> has decreased prolapse resistance due to a sudden change in the rigidity occurred at the proximal end of the thermally treated region H. Further, in the guide wire <NUM> in Example <NUM>, the heat treatment ratio is larger than an upper limit value of condition <NUM>, and a length of the portion of the transition portion 11f where the rigidity is lower due to the heat treatment is long. Therefore, it is deduced that in the guide wire <NUM> in Example <NUM> has decreased prolapse resistance because it is difficult to transmit the pushing force to the distal end of the guide wire <NUM>.

As described above, the guide wire <NUM> in which the ratio of the length from the distal end of the transition portion 11f to the proximal end of the heat treatment region H along the longitudinal direction to the length of the transition portion 11f along the longitudinal direction satisfies condition <NUM>, and more preferably satisfies condition <NUM> is excellent in the prolapse resistance.

As illustrated in Table <NUM>, the guide wires <NUM> in Example <NUM>, Example <NUM> and Example <NUM>, and Example <NUM> to Example <NUM> have results of "good" in the kink resistance test. On the other hand, the guide wires <NUM> in Example <NUM> and Example <NUM> have results of "poor" in the kink resistance test. In each of the guide wires <NUM> in Example <NUM>, Example <NUM> and Example <NUM>, and Example <NUM> to Example <NUM>, the ratio of the length from the distal end of the transition portion 11f to the proximal end of the heat treatment region H along the longitudinal direction to the length of the transition portion 11f along the longitudinal direction is <NUM>% or more and <NUM>% or less (condition <NUM>). On the other hand, in Example <NUM> and Example <NUM>, the heat treatment ratio is larger than the upper limit value of condition <NUM>, and even portions not subjected to cold working are subjected to heat treatment. Since the core component <NUM> is made of a Ni-Ti alloy, when a portion not subjected to cold working is subjected to heat treatment, the superelasticity is decreased, and plastic deformation is likely to occur. Therefore, it is deduced that the guide wires <NUM> in Example <NUM> and Example <NUM> have decreased kink resistance.

As described above, the guide wire <NUM> in which the heat treatment ratio in the transition portion 11f satisfies condition <NUM> is excellent in the kink resistance.

Claim 1:
A guide wire (<NUM>), comprising:
an elongated core component (<NUM>) including a flat portion (<NUM>) at a distal end, wherein
the flat portion is made of a Ni-Ti alloy having an elastic portion of total indentation work of <NUM>% or more and <NUM>% or less and having a Martens hardness of <NUM> N/mm<NUM> or more and <NUM> N/mm<NUM> or less.