Patent Description:
There is known a guide wire used for inserting a catheter into a blood vessel, a digestive organ, or the like. A guide wire made of a metal coil typically includes a core shaft using a wire material, and a coil body wound around an outer periphery of the core shaft, and a distal end of the core shaft and a distal end of the coil body are joined. In such a guide wire, a technique is known in which a resin layer is formed on the coil body for the purpose of improving slidability by smoothing the guide wire, thrombus adhesion preventing property, operability, and the like. For example, Patent Literatures <NUM>, <NUM> and <NUM> disclose a guide wire in which a resin coating (resin layer) is formed on an outer periphery of a coil body.

However, the guide wire described in Patent Literature <NUM> has a problem that a resin layer is formed between a coil body and a core shaft without a gap, and thus, the flexibility of the guide wire is not sufficient. Further, the guide wire described in Patent Literature <NUM> has a problem that a resin layer may be peeled or damaged when a guide wire is curved. Specifically, when the guide wire is curved, a space between adjacent wires of a coil body expands at an outer side of the curve. In the guide wire described in Patent Literature <NUM>, the resin layer is formed on an outer peripheral surface of the coil body, and thus, the thickness of the resin layer is reduced by the resin layer being elongated in a gap expanded between two adjacent lines of a wire, which may lead to peeling or damage of the resin layer.

The invention has been made to resolve the above-described problems, and an object thereof is to provide a technique of suppressing peeling and damage of a resin layer while flexibility is secured in a guide wire including a coil body and a resin layer.

The invention is defined by the subject matter of the independent claim. Further aspects are disclosed in the subclaims. The invention has been made to resolve at least a part of the above-described problems, and can be implemented as the following aspects.

In general, when the guide wire is curved, a wire forming a coil body moves with the curve to decrease (reduce) or enlarge (expand) a space between the adjacent wires. With this configuration, the guide wire includes the resin layer extending toward the core shaft relative to the inner peripheral surface of the coil body, and thus, the thickness of the resin layer in a gap expanded with the curve of the guide wire between the adjacent wires, can be kept thick as compared to, for example, a configuration in which the resin layer is formed only on the outer peripheral surface of the coil body. Therefore, with this configuration, it is possible to suppress peeling and damage of the resin layer between the adjacent wires when the guide wire is curved. Further, with this configuration, a void is formed between the coil body and the core shaft, and thus, the wire forming the coil body easily moves as compared to a configuration having no voids, such as a case where the resin layer is formed between the wire of the coil body and the core shaft without a gap. Therefore, with this configuration, it is possible to reduce power required to curve the guide wire and improve the flexibility of the guide wire.

In the guide wire according to the invention, the protruding portion contacts the core shaft. With this configuration, the resin layer contacts the core shaft, and thus, the thickness of the resin layer in a gap expanded with the curve of the guide wire between the adjacent wires, can be kept much thicker. Thus, it is possible to further suppress peeling and damage of the resin layer when the guide wire is curved.

<FIG> is a schematic partial cross-sectional view illustrating an entire configuration of a guide wire <NUM> according to a first example. The guide wire <NUM> is a medical device used when a catheter is inserted into a blood vessel or a digestive organ, and includes a core shaft <NUM>, a coil body <NUM>, a resin layer <NUM>, a distal end joint part <NUM>, a proximal end joint part <NUM>, and an intermediate fixing part <NUM>.

In <FIG>, an axis passing through the center of the guide wire <NUM> is represented by an axis O (dash-dot-dash line). The left side in <FIG> is referred to as a "distal end side" of the guide wire <NUM> and components, and the right side in <FIG> is referred to as a "proximal end side" of the guide wire <NUM> and components. Further, with respect to the guide wire <NUM> and components, an end part located on the distal end side is referred to as a "distal end part" or simply a "distal end," and an end part located on the proximal end side is referred to as a "proximal end part" or simply a "proximal end". In the present embodiment, the distal end side corresponds to a "distal side," and the proximal end side corresponds to a "proximal side. " These are common to the drawings illustrating the entire configuration after <FIG>.

The core shaft <NUM> is a tapered long member having a large diameter at the proximal end side and a small diameter at the distal end side. The core shaft <NUM> may be formed of a material such as a stainless alloy (SUS304, SUS316, etc.), a superelastic alloy such as an Ni-Ti alloy, a piano wire, a nickel-chromium base alloy, a cobalt alloy, and tungsten. The core shaft <NUM> may be formed of a known material other than the above. The core shaft <NUM> includes a small-diameter part <NUM>, a first tapered part <NUM>, a first large-diameter part <NUM>, a second tapered part <NUM>, and a second large-diameter part <NUM> in this order from the distal end side to the proximal end side. An outer diameter and length at a portion of the core shaft <NUM> may be optionally determined.

The small-diameter part <NUM> is formed at the distal end part of the core shaft <NUM>. The small-diameter part <NUM> is a part where the outer diameter of the core shaft <NUM> is smallest, and has a substantially cylindrical shape having a constant outer diameter. The distal end joint part <NUM> is formed at the distal end part of the small-diameter part <NUM>. The first tapered part <NUM> is formed between the small-diameter part <NUM> and the first large-diameter part <NUM>. The first tapered part <NUM> has a tapered shape whose outer diameter increases from the distal end side toward the proximal end side. The first large-diameter part <NUM> is formed between the first tapered part <NUM> and the second tapered part <NUM>. The first large-diameter part <NUM> has a substantially cylindrical shape having a constant outer diameter larger than the outer diameter of the small-diameter part <NUM>. The proximal end joint part <NUM> is formed at the proximal end part of the first large-diameter part <NUM>. Outer peripheral surfaces of the small-diameter part <NUM>, the first tapered part <NUM>, and the first large-diameter part <NUM> are covered by the coil body <NUM> described later.

The second tapered part <NUM> is formed between the first large-diameter part <NUM> and the second large-diameter part <NUM>. The second tapered part <NUM> has a tapered shape whose outer diameter increases from the distal end side toward the proximal end side. The second large-diameter part <NUM> is formed at the proximal end part of the core shaft <NUM>. The second large-diameter part <NUM> is a portion where the outer diameter of the core shaft <NUM> is largest, and has a substantially cylindrical shape having a constant outer diameter. The second tapered part <NUM> and the second large-diameter part <NUM> are not covered by the coil body <NUM>, and are used when an operator grasps the guide wire <NUM>.

The coil body <NUM> has a substantially hollow cylindrical shape in which a wire <NUM> is spirally wound around the core shaft <NUM>. The coil body <NUM> of the present embodiment is arranged to cover the outer peripheral surfaces of the small-diameter part <NUM>, the first tapered part <NUM>, and the first large-diameter part <NUM> of the core shaft <NUM>, and is not arranged on the second tapered part <NUM> and the second large-diameter part <NUM> of the core shaft <NUM>. The wire <NUM> forming the coil body <NUM> may be a solid wire composed of one wire or a strand obtained by twisting a plurality of wires. If the wire <NUM> is a solid wire, the coil body <NUM> is configured as a single coil, and if the wire <NUM> is a strand, the coil body <NUM> is configured as a hollow stranded coil. Further, the coil body <NUM> may be configured by combining a single coil and a hollow stranded coil. A wire diameter of the wire <NUM> and an average coil diameter in the coil body <NUM> (an average diameter of outer and inner diameters of the coil body <NUM>) may be optionally determined.

The wire <NUM> may be formed of, for example, a stainless alloy (SUS304, SUS316, etc.), a superelastic alloy such as an Ni-Ti alloy, a piano wire, a nickel-chromium base alloy, a cobalt alloy, a radiolucent alloy such as tungsten, gold, platinum, tungsten, and a radiopaque alloy such as an alloy containing these elements (for example, a platinum-nickel alloy). The wire <NUM> may be formed of a known material other than the above.

The coil body <NUM> is fixed to the core shaft <NUM> by the distal end joint part <NUM>, the proximal end joint part <NUM>, and the intermediate fixing part <NUM>. The distal end joint part <NUM> is a member that joins a distal end part of the coil body <NUM> and the distal end part of the small-diameter part <NUM> of the core shaft <NUM>. The distal end joint part <NUM> is formed of metal solder such as silver solder, gold solder, zinc, an Sn-Ag alloy, and an Au-Sn alloy. The distal end of the coil body <NUM> and the distal end of the small-diameter part <NUM> are fixed by the metal solder. The distal end joint part <NUM> may be formed by an adhesive such as an epoxy-based adhesive.

The proximal end joint part <NUM> is a member that joins a proximal end part of the coil body <NUM> and the proximal end part of the first large-diameter part <NUM> of the core shaft <NUM>. The proximal end joint part <NUM> may be formed of a material that is same as the material of the distal end joint part <NUM>, or may be formed of a material that is different from the material of the distal end joint part <NUM>. The intermediate fixing part <NUM> is a member that fixes the coil body <NUM> and the first large-diameter part <NUM> of the core shaft <NUM>, in the vicinity of an intermediate portion of the coil body <NUM> in an axis O direction. The intermediate fixing part <NUM> may be formed of a material that is same as the materials of the distal end joint part <NUM> and the proximal end joint part <NUM>, or may be formed of a material that is different from the materials of the distal end joint part <NUM> and the proximal end joint part <NUM>. The guide wire <NUM> may include a plurality of fixing parts for fixing the coil body <NUM> and the core shaft <NUM>.

<FIG> is a partial enlarged view of the guide wire <NUM>. The upper side in <FIG> illustrates a portion of the guide wire <NUM>, from the small-diameter part <NUM> to the first large-diameter part <NUM>. The lower side in <FIG> illustrates an enlarged view of a portion surrounded by a broken-line rectangle in the upper side. As with <FIG>, the left side in <FIG> corresponds to the distal end side (distal side) of the guide wire <NUM> and components, and the right side in <FIG> corresponds to the proximal end side (proximal side) of the guide wire <NUM> and components. These are common to the partial enlarged views after <FIG>.

In the coil body <NUM>, gaps C1 are formed between the adjacent wires <NUM> over an entire region in the axis O direction (<FIG> and the lower side in <FIG>). In the present embodiment, such a gap C1 is defined as a size (length) at a portion where a distance between the adjacent wires <NUM> is closest in any cross section in the axis O direction. The size of the gap C1 may be optionally determined. In the guide wire <NUM> according to the present embodiment, as illustrated in the lower side in <FIG>, the gaps C1 formed between the adjacent wires <NUM> have a constant size equal to the wire diameter of the wire <NUM>. All the gaps C1 may have the same size, at least some of the gaps C1 may have different sizes, or all of the gaps C1 may have different sizes.

Hereinafter, of the coil body <NUM>, a portion having the gap C1 between the adjacent wires <NUM> is also referred to as a "sparsely wound part," and a portion having no gap C1 between the adjacent wires <NUM> (in other words, a portion where the adjacent wires <NUM> contact with each other without any gap) is also referred to as a "closely wound part. " In the guide wire <NUM> according to the present embodiment, the coil body <NUM> includes the sparsely wound part over the entire region in the axis O direction.

In the coil body <NUM>, a void C2 is formed between the outer peripheral surface of the core shaft <NUM> and an inner peripheral surface of the wire <NUM> of the coil body <NUM> (that is, an inner peripheral surface (inner surface) of the coil body <NUM>) over the entire region in the axis O direction (<FIG> and the lower side in <FIG>). In the present embodiment, the void C2 is defined as a size (length) at a portion where a distance between the inner peripheral surface of the wire <NUM> and the outer peripheral surface of the core shaft <NUM> is closest in any cross section in the axis O direction. The size of the void C2 may be optionally determined. In the guide wire <NUM> according to the present embodiment, the inner diameter of the coil body <NUM> is constant while the outer diameter of the core shaft <NUM> increases from the distal end side toward the proximal end side. Thus, as illustrated in the lower side in <FIG>, the void C2 formed between the inner peripheral surfaces of the wire <NUM> and the outer peripheral surface of the core shaft <NUM> is gradually smaller from the distal end side to the proximal end side.

The resin layer <NUM> is a layer of resins that cover at least the outer peripheral surface (outer surface) of the coil body <NUM>. The resin layer <NUM> may be formed of a resin material having hydrophobicity, a resin material having hydrophilicity, or a mixture thereof. Examples of the resin material having hydrophobicity to be employed include silicone resin, polyurethane, polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polystyrene, polyolefin elastomer, polyester elastomer, polyamide elastomer, and polyurethane elastomer. Examples of the resin material having hydrophilicity to be employed include starch-based resin such as carboxymethyl starch, cellulose-based resin such as carboxymethylcellulose, polysaccharides such as alginic acid, chitin, chitosan, and hyaluronic acid, natural water-soluble polymer substances such as gelatin, and synthetic water-soluble polymer substances such as polyvinyl alcohol, polyethylene oxide, polyethylene glycol, polypropylene glycol, polyvinylpyrrolidone, and water-soluble nylon. The resin material having hydrophilicity becomes swollen when containing water, and thus, it is possible to improve slidability and thrombus adhesion preventing property as compared to the resin material having hydrophobicity.

The resin layer <NUM> includes a surface layer <NUM>, protruding portions <NUM>, a distal end resin layer <NUM>, and a proximal end resin layer <NUM>. The surface layer <NUM> is a part of the resin layer <NUM> and is a layered portion that covers the outer peripheral surface of the coil body <NUM>. The shape of the surface layer <NUM> in the cross section illustrated in <FIG> is a wave shape. The thickness of the surface layer <NUM> may be optionally determined. The distal end resin layer <NUM> is a part of the resin layer <NUM> and is a layered portion that covers an outer peripheral surface of the distal end joint part <NUM>. The proximal end resin layer <NUM> is a part of the resin layer <NUM> and is a layered portion that covers an outer peripheral surface of the proximal end joint part <NUM>.

Such a protruding portion <NUM> is a part of the resin layer <NUM> and is a portion protruding toward the core shaft <NUM> through the gap C1 between the adjacent wires <NUM> of the coil body <NUM>. The protruding portion <NUM> extends toward the core shaft <NUM> relative to the inner peripheral surface of the coil body <NUM>, in other words, a surface of the wire <NUM> on a side of the core shaft <NUM>. The shape of a protrusion of the protruding portion <NUM> in the cross section illustrated in <FIG> is an arc shape. In the present embodiment, a protruding length L of the protruding portion <NUM> is defined as a length between the surface of the wire <NUM> on the side of the core shaft <NUM> and a protrusion distal end of the protruding portion <NUM> (a portion closest to the core shaft <NUM>) in any cross section in the axis O direction. The protruding length L may be optionally determined. In the guide wire <NUM> according to the present embodiment, as illustrated in the lower side in <FIG>, the protruding lengths L of the protruding portions <NUM> formed between the adjacent wires <NUM> are constant (same length) and are set to about half of the wire diameter of the wire <NUM>. At least some or all of the protruding lengths L of the protruding portions <NUM> may be different from each other.

In the present embodiment, a thickness Ta of the resin layer <NUM> is defined as a thickness (length) of the resin layer <NUM> in a middle part between the adjacent wires <NUM> in any cross section in the axis O direction. In the guide wire <NUM> according to the present embodiment, as illustrated in the lower side in <FIG>, the thickness Ta of the resin layer <NUM> between the adjacent wires <NUM> is constant (same thickness) and is set to about <NUM> times to about <NUM> times the wire diameter of the wire <NUM>. Further, in the present embodiment, all of the protruding portions <NUM> included in the resin layer <NUM> and the core shaft <NUM> are separated and not in contact. The thickness of the resin layer <NUM> may be optionally determined, and at least some or the thickness of the resin layer <NUM> at all or some portions may be different from each other.

The resin layer <NUM> may be formed, for example, by applying a liquidized resin material to the outer peripheral surface of the coil body <NUM>. Specifically, the surface layer <NUM> is formed through the solidification of the resin material that adheres to the outer peripheral surface of the coil body <NUM>. In addition, the protruding portion <NUM> is formed through the solidification of the resin material dropped toward the core shaft <NUM> from the gaps C1 between the adjacent wires <NUM> of the coil body <NUM>. Thus, the resin layer <NUM> can be easily formed. In the present embodiment, the surface layer <NUM> and the protruding portion <NUM> are formed integrally, but the surface layer <NUM> and the protruding portion <NUM> may be formed separately. If the surface layer <NUM> and the protruding portion <NUM> are formed separately, for example, the protruding portions <NUM> may be formed by applying a liquidized resin material, and then the surface layer <NUM> may be formed by winding a thin film-like resin material around the outer peripheral surface of the coil body <NUM>. If the surface layer <NUM> and the protruding portion <NUM> are formed separately, the surface layer <NUM> and the protruding portion <NUM> may be formed by using different resin materials. In addition, an extruder may be used to extrude a resin material, and then the extruded resin material may pass through the gaps C1 to form the protruding portion <NUM>.

<FIG> is a diagram for explaining the resin layer <NUM> when the guide wire <NUM> is curved. The upper side in <FIG> illustrates a schematic diagram representing a portion at the distal end side of the curved guide wire <NUM>. The lower side in <FIG> illustrates an enlarged view of a portion surrounded by a broken-line rectangle in the upper side. These are common to the explanatory diagrams after <FIG>.

In general, if the guide wire <NUM> is curved, the wire <NUM> forming the coil body <NUM> moves with the curve to decrease (reduce) or enlarge (expand) a space P between the adjacent wires <NUM>. Specifically, there is no change in the space P between the adjacent wires <NUM> in a region A1 having no curve. Therefore, the gap C1 between the adjacent wires <NUM> is as described with reference to <FIG> and <FIG>. On the other hand, in a region A2 having the curve, the space P between the adjacent wires <NUM> changes with the curve to cause clogging or enlargement between the adjacent wires <NUM>. With the change in the space P, the gap C1 between the adjacent wires <NUM> on an outer side of a curved part increases, and the gap C1 between the adjacent wires <NUM> on an inner side of the curved part decreases.

Here, the guide wire <NUM> according to the present embodiment includes the resin layer <NUM> (protruding portion <NUM>) extending toward the core shaft <NUM> relative to the inner peripheral surface of the coil body <NUM>. Thus, as illustrated in the lower side in <FIG>, even if the gap C1 between the adjacent wires <NUM> expands on the outer side of the curved part, and with the expansion, the resin layer <NUM> is elongated, resulting in that the thickness of the resin layer <NUM> becomes thinner from a "thickness Ta during a normal time" to a "thickness Tb while being elongated", the thickness Tb of the resin layer <NUM> at the gap C1 expanded between the adjacent wires <NUM> can be kept thick. Thus, even if a distal end of an additional device <NUM> (a device such as a catheter used together with the guide wire <NUM>) is caught on a surface of the resin layer <NUM>, and a force is applied in a direction in which the resin layer <NUM> is peeled off from the coil body <NUM> (lower side in <FIG>: white arrow), resistance to the peeling force (lower side in <FIG>: arrow with oblique hatching) can be obtained. Consequently, in the guide wire <NUM> according to the present embodiment, it is possible to suppress peeling and damage of the resin layer <NUM> between the adjacent wires <NUM> when the guide wire <NUM> is curved.

In addition, the guide wire <NUM> according to the present example includes the resin layer <NUM> (protruding portion <NUM>) extending toward the core shaft <NUM> relative to the inner peripheral surface of the coil body <NUM>. Therefore, for example, even if the core shaft <NUM> is bent inside the coil body <NUM> when the guide wire <NUM> is used, the core shaft <NUM> comes into contact with the protruding portion <NUM> of the resin layer <NUM>, and thus, is prevented from contacting with the coil body <NUM>. The resin layer <NUM> (protruding portion <NUM>) is formed of a resin material having flexibility as described above. Thus, in the guide wire <NUM> according to the present embodiment, damage and deformation of the core shaft <NUM> and the coil body <NUM> can be suppressed.

Further, in the guide wire <NUM> according to the present example, the void C2 is formed between the coil body <NUM> and the core shaft <NUM>. Therefore, the wire <NUM> forming the coil body <NUM> easily moves as compared to, for example, a configuration having no voids C2 such as a case where the resin layer <NUM> is formed between the coil body <NUM> and the core shaft <NUM> without a gap. As a result, in the guide wire <NUM> according to the present embodiment, it is possible to reduce power required to curve the guide wire <NUM> and improve the flexibility of the guide wire <NUM>. Further, in the guide wire <NUM> according to the present embodiment, the void C2 is formed between the coil body <NUM> and the core shaft <NUM>, and thus, the resin layer <NUM> can be easily formed as compared to a configuration having no voids C2.

<FIG> is a diagram for explaining a resin layer 30x when a guide wire 1x in a comparative example is curved. In the guide wire 1x in the comparative example, the resin layer 30x is composed of only the surface layer <NUM> and does not include the protruding portion <NUM>. In other words, in the guide wire 1x, the resin layer 30x is formed only on the outer peripheral surface of the coil body <NUM>.

Thus, as illustrated in the lower side in <FIG>, in the guide wire 1x, the thickness Tb while being elongated of the resin layer 30x cannot be kept sufficiently thick, and thus, if, for example, the distal end of the additional device <NUM> is caught on a surface of the resin layer 30x, sufficient resistance cannot be obtained against the force (lower side in <FIG>: white arrow) in a direction in which the resin layer 30x is peeled off from the coil body <NUM>. As a result, in the guide wire 1x in the comparative example, the resin layer 30x between the adjacent wires <NUM> may be peeled or damaged when the guide wire 1x is curved. In addition, the guide wire 1x in the comparative example does not include the protruding portion <NUM> (<FIG> and <FIG>) extending toward the core shaft <NUM> relative to the inner peripheral surface of the coil body <NUM>, and thus, if the core shaft <NUM> is bent inside the coil body <NUM>, the core shaft <NUM> may come into contact with the coil body <NUM> to cause damage or deformation of the core shaft <NUM> and the coil body <NUM>.

First embodiment of the invention <FIG> is a partial enlarged view of a guide wire 1a according to an embodiment of the invention. In the guide wire 1a according to the second embodiment, a resin layer 30a includes protruding portions 32a. Such a protruding portion 32a is formed so that a protrusion distal end of the protruding portion 32a (a portion closest to the core shaft <NUM>) comes into contact with the core shaft <NUM>. The shape of a protrusion of the protruding portion 32a in the cross section illustrated in <FIG> is an elliptical arc shape. The protruding portion 32a may be formed by using a material and manufacturing method similar to those of the protruding portion <NUM> according to the first embodiment.

The protruding length L of the protruding portion 32a in the guide wire 1a is equal to the size of the void C2 between the wire <NUM> and the core shaft <NUM>. Thus, the thickness Ta of the resin layer 30a can be made thicker than that in the guide wire <NUM> according to the first embodiment. All of the protruding portions 32a included in the guide wire 1a may contact the core shaft <NUM>, or at least some thereof may not contact the core shaft <NUM>.

<FIG> is a diagram for explaining the resin layer 30a when the guide wire 1a according to the embodiment of the invention above is curved. The guide wire 1a according to the second embodiment has the thickness Ta that is thick enough to cause the resin layer 30a (protruding portion 32a) to come into contact with the core shaft <NUM> (<FIG>). Thus, as illustrated in <FIG>, the thickness Tb while being elongated of the resin layer 30a at a gap expanded with the curve of the guide wire 1a between the adjacent wires <NUM>, can be kept much thicker.

Thus, if, for example, the distal end of the additional device <NUM> is caught on a surface of the resin layer 30a, larger resistance (lower side in <FIG>: arrow with oblique hatching) can be obtained against the force (lower side in <FIG>: white arrow) in a direction in which the resin layer 30a is peeled off from the coil body <NUM>. Consequently, in the guide wire 1a according to the embodiment of the invention above, it is possible to further suppress peeling and damage of the resin layer 30a when the guide wire 1a is curved. Further, in the guide wire 1a according to the embodiment of the invention above, as in the first embodiment, the core shaft <NUM> is prevented from contacting with the coil body <NUM>, and thus, damage of the core shaft <NUM> and the coil body <NUM> can be suppressed.

In addition, in the guide wire 1a according to the embodiment of the invention above, as in the first example, the void C2 is formed between the coil body <NUM> and the core shaft <NUM>. Thus, as compared to a configuration having no voids C2, the wire <NUM> forming the coil body <NUM> easily moves, and thus, it is possible to reduce power required to curve the guide wire 1a and improve the flexibility of the guide wire 1a. Further, also in the guide wire 1a according to the embodiment of the invention above, the resin layer 30a can be easily formed as compared to a configuration having no voids C2.

Second embodiment of the invention <FIG> is a partial enlarged view of a guide wire 1b according to a second embodiment of the invention. In the guide wire 1b according to this second embodiment, a resin layer 30b includes protruding portions 32b. A protrusion distal end of such a protruding portion 32b is joined to the core shaft <NUM>. The shape of a protrusion of the protruding portion 32b in the cross section illustrated in <FIG> is a substantially rectangular shape in which a diameter of the center portion is reduced. The protruding portion 32b may be formed of a material similar to that of the protruding portion <NUM> according to the first example. The protruding portion 32b may be formed, for example, by applying an adhesive such as an epoxy-based adhesive to the outer peripheral surface of the core shaft <NUM> and then applying a liquidized resin material from the outer peripheral surface of the coil body <NUM>. When the resin material is applied, the resin material is allowed to flow from the gap C1 of the coil body <NUM> to reach an adhesive layer of the core shaft <NUM>. Thus, the protruding portion 32b joined to the core shaft <NUM> may be formed. Alternatively, fine irregularities may be provided on an outer surface of the core shaft <NUM>, and then a molten resin material is poured toward the core shaft <NUM> and is physically joined to the core shaft <NUM> to form the protruding portion 32b.

The protruding length L of the protruding portion 32b in the guide wire 1b is equal to the size of the void C2 between the wire <NUM> and the core shaft <NUM>. Thus, the thickness Ta of the resin layer 30b can be made thicker than that in the guide wire <NUM> according to the first embodiment. All of the protruding portions 32b included in the guide wire 1b may be joined to the core shaft <NUM>, or at least some thereof may not be joined to the core shaft <NUM>.

<FIG> is a diagram for explaining the resin layer 30b when the guide wire 1b according to the second embodiment of the invention. In the guide wire 1b according to the second embodiment of the invention, the resin layer 30b (protruding portion 32b) is joined to the core shaft <NUM>. Thus, as illustrated in <FIG>, the thickness Tb while being elongated of the resin layer 30b at a gap expanded with the curve of the guide wire 1b, between the adjacent wires <NUM>, can be made equal to the thickness Ta during a normal time (that is, the thickness Tb while being elongated can be kept much thicker).

Thus, if, for example, the distal end of the additional device <NUM> is caught on a surface of the resin layer 30b, larger resistance (lower side in <FIG>: arrow with oblique hatching) can be obtained against a force (lower side in <FIG>: white arrow) in a direction in which the resin layer 30b is peeled off from the coil body <NUM>. Consequently, in the guide wire 1b according to the second embodiment of the invention, it is possible to further suppress peeling and damage of the resin layer 30b when the guide wire 1b is curved. Further, in the guide wire 1b according to the second embodiment of the invention, as in the first embodiment, the core shaft <NUM> is prevented from contacting with the coil body <NUM>, and thus, damage of the core shaft <NUM> and the coil body <NUM> can be suppressed.

In addition, in the guide wire 1b according to the second embodiment of the invention, as in the first embodiment and the second embodiment, the void C2 is formed between the coil body <NUM> and the core shaft <NUM>, and thus, as compared to a configuration having no voids C2, it is possible to improve the flexibility of the guide wire 1b and easily form the resin layer 30b.

Second Example <FIG> is a schematic partial cross-sectional view illustrating an entire configuration of a guide wire 1c according to a second example. In the guide wire 1c according to the second example, a coil body 20c is formed, in a range P1 on the distal end side, as a closely wound part in which the adjacent wires <NUM> contact with each other without having the gap C1 (<FIG>), and is formed, in a range P2 on the proximal end side from the range P1, as a sparsely wound part in which there is the gap C1 between the adjacent wires <NUM>. Further, in the closely wound part (range P1) of the coil body 20c, the guide wire 1c includes, at an inner side of the coil body 20c, an inner coil body <NUM> formed by spirally winding a wire <NUM> around the core shaft <NUM>. The inner coil body <NUM> has a length shorter than a length of the coil body 20c in the axis O direction.

A winding direction of the wire <NUM> in the inner coil body <NUM> is opposite to a winding direction in the coil body 20c. The winding direction of the wire <NUM> in the inner coil body may be the same as that in the coil body 20c, or may be a different direction other than the opposite direction. As with the wire <NUM>, the wire <NUM> may be a solid wire or a strand. The inner coil body <NUM> may be configured by combining a single coil and a hollow stranded coil. A wire diameter of the wire <NUM> and an average coil diameter in the inner coil body <NUM> may be optionally determined. The wire <NUM> may be formed of a material similar to that of the wire <NUM> described in the first embodiment. The material used for the wire <NUM> may be the same as or different from that of the wire <NUM>.

The inner coil body <NUM> is fixed to the core shaft <NUM> by a distal end joint part 51c and an inner fixing part <NUM>. The distal end joint part 51c joins a distal end part of the coil body 20c, a distal end part of the inner coil body <NUM>, and the distal end part of the small-diameter part <NUM> of the core shaft <NUM>. The distal end joint part 51c may be formed of a material similar to that of the distal end joint part <NUM> described in the first example. The material employed for the distal end joint part 51c may be the same as or different from that of the distal end joint part <NUM>. The inner fixing part <NUM> joins a proximal end part of the inner coil body <NUM> and a part of the first tapered part <NUM> of the core shaft <NUM>. The inner fixing part <NUM> may be formed of a material similar to that of the distal end joint part <NUM> described in the first embodiment. The material employed for the inner fixing part <NUM> may be the same as or different from that of the distal end joint part <NUM>.

As in the first example, a resin layer 30c includes the surface layer <NUM> and the protruding portion <NUM> in a portion (range P2) where the coil body 20c includes a sparsely wound part. On the other hand, in a portion (range P1) where the coil body 20c includes a closely wound part, the resin layer 30c includes only the surface layer <NUM> and does not include the protruding portion <NUM>. Thus, the guide wire 1c may include, at a portion in the axis O direction, a closely wound part in which the adjacent wires <NUM> contact with each other without having the gap C1 (<FIG>). A range in which the closely wound part is formed may be optionally determined. In the present embodiment, the closely wound part is formed at the distal end part of the coil body 20c (guide wire 1c). However, the disclosed example is not limited to this, and the closely wound part may be formed at a rear end part of the coil body 20c (guide wire 1c). In this case, the sparsely wound part may be formed at the distal end part of the coil body 20c (guide wire 1c), and the inner coil body <NUM> may be arranged at an inner side of the sparsely wound part of the coil body 20c. Further, the protruding portion <NUM> of the resin layer 30c may not be formed in the closely wound part of the coil body 20c.

The guide wire 1c according to the second example, can also exhibit a similar effect to that in the above-described first embodiment. With the guide wire 1c according to the second example, the sparsely wound part formed with the resin layer 30c is located in a portion (range P2) where the coil body 20c does not cover the inner coil body <NUM>, and thus, the movement of the inner coil body <NUM> cannot be prevented by the protruding portion <NUM> of the resin layer 30c. Thus, according to the guide wire 1c of the present example, the flexibility of the guide wire 1c can be maintained even in the configuration including the inner coil body <NUM>.

Third Example <FIG> is a schematic partial cross-sectional view illustrating an entire configuration of a guide wire 1d according to a third example. In the guide wire 1d according to the third example, the inner coil body <NUM> is provided at an inner side of the coil body <NUM>, the entirety of which is formed as the sparsely wound part, in the range P1 on the distal end side. The inner coil body <NUM> has a length shorter than a length of the coil body <NUM> in the axis O direction. The configuration of the inner coil body <NUM> is similar to that of the second example. In <FIG>, the inner coil body <NUM> is provided at the distal end part of the coil body <NUM> (guide wire 1d). However, the inner coil body <NUM> can be arranged at any position in the axis O direction. For example, the inner coil body <NUM> may be arranged at a center part of the coil body <NUM> or may be arranged at a rear end part of the coil body <NUM>.

Thus, the sparsely wound part formed with the resin layer <NUM> may be located at a portion (range P1) where the coil body <NUM> covers the inner coil body <NUM>. The guide wire 1d according to the fifth embodiment can also exhibit a similar effect to the above-described first embodiment and fourth embodiment.

<FIG> is a partial enlarged view of a guide wire 1e according to a third embodiment. As with <FIG> described above, the left side in <FIG> corresponds to a distal end side (distal side) of the guide wire 1e and components, and the right side in <FIG> corresponds to a proximal end side (proximal side) of the guide wire 1e and components. The same applies to the following drawings.

In the guide wire 1e according to the third embodiment, a resin layer 30e includes protruding portions 32e and a resin film <NUM>. The resin film <NUM> is a layer of resins that covers the outer peripheral surface (outer surface) of the core shaft <NUM>. The resin film <NUM> may be formed of a material optionally selected from the resin materials listed for the resin layer <NUM> in the first embodiment. The resin film <NUM> may be formed, for example, by applying a liquidized resin material to the outer peripheral surface of the core shaft <NUM>. The resin film <NUM> may be formed by joining a thin film-like resin material to the outer peripheral surface of the core shaft <NUM>. For joining, for example, an adhesive such as an epoxy-based adhesive can be used. The thickness of the resin film <NUM> may be optionally determined.

A protrusion distal end of such a protruding portion 32e is joined to the resin film <NUM>. The shape of a protrusion of the protruding portion 32e in the cross section illustrated in <FIG> is a substantially rectangular shape in which a diameter of the center portion is reduced. The protruding portion 32e may be formed of a material that is similar to that of the protruding portion <NUM> according to the first embodiment. The protruding portion 32e may be formed, for example, by applying an adhesive such as an epoxy-based adhesive to a surface of the resin film <NUM> and then applying a liquidized resin material from the outer peripheral surface of the coil body <NUM>. When the resin material is applied, the resin material is allowed to flow from the gap C1 of the coil body <NUM> to reach an adhesive layer of the resin film <NUM>. Thus, the protruding portion 32e joined to the resin film <NUM> may be formed. The protruding length L of the protruding portion 32e in the guide wire 1e is a length obtained by subtracting the thickness of the resin film <NUM> from the size of the void C2 between the wire <NUM> and the core shaft <NUM>.

Thus, the thickness Ta of the resin layer 30e can be made thicker than that in the first embodiment. All of the protruding portions 32e included in the guide wire 1e may be joined to the resin film <NUM>, or at least some thereof may not be joined to the resin film <NUM>.

The guide wire 1e according to the third embodiment can also exhibit a similar effect to the above-described first example and second embodiment of the invention.

Fourth Example <FIG> is a partial enlarged view of a guide wire 1f according to a fourth example. In the guide wire 1f according to the fourth example, a resin layer 30f includes protruding portion 32f. The shape of such a protruding portion 32f in the cross section illustrated in <FIG> is a substantially rectangular shape. The protruding portion 32f may be formed of a material similar to that of the protruding portion <NUM> according to the first embodiment. For example, the protruding portion 32f may be formed as follows. First, a core material that is made of a fluorine-based resin and has a hollow cylindrical shape having an outer diameter larger than the outer diameter of the core shaft <NUM> is arranged at the inner side of the coil body <NUM>, and in this state, a thin film-like resin material having flexibility is wound around the outer peripheral surface of the coil body <NUM>. Next, the resin material is covered with a heat-shrinkable tube and then heated. As a result, the molten resin material flows into the core shaft <NUM> from the gap C <NUM> and comes into contact with the core material. Then, the core material is removed from the coil body <NUM> to form the protruding portion 32f having a substantially rectangular shape. Finally, the coil body <NUM> formed with the protruding portion 32f having a substantially rectangular shape is assembled to the core shaft <NUM>. The protruding length L of the protruding portion 32f in the guide wire 1f may be optionally determined, as with the protruding portion <NUM> of the first example.

Thus, the protruding portion 32f can employ various shapes as long as the protruding portion 32f extends toward the core shaft <NUM> through the gap C <NUM> between the adjacent wires <NUM> of the coil body <NUM>, and extends toward the core shaft <NUM> relative to the inner peripheral surface of the coil body <NUM>. The guide wire 1f according to the fourth example can also exhibit a similar effect to the above-described first example,.

Fifth Example <FIG> is a partial enlarged view of a guide wire <NUM> according to an fifth example. In the guide wire <NUM> according to the eighth embodiment, a resin layer <NUM> includes a surface layer <NUM>. The shape of the surface layer <NUM> in the cross section illustrated in <FIG> is linear without any irregularities. The surface layer <NUM> may be formed of a material similar to that of the surface layer <NUM> according to the first example. For example, the surface layer <NUM> whose cross section is linear may be formed as follows. That is, a resin material having flexibility is wound around the outer peripheral surface of the coil body <NUM>. Next, the resin material is covered with a heat-shrinkable tube having a flat outer surface (no irregularities) and then heated. As a result, the molten resin material flows into the core shaft <NUM> from the gap C1 to form the protruding portion <NUM> and the surface layer <NUM> whose cross section is linear. Finally, the coil body <NUM> formed with the protruding portion <NUM> and the surface layer <NUM> is assembled to the core shaft <NUM>.

Thus, the surface layer <NUM> can function in various forms as long as the surface layer <NUM> covers at least the outer peripheral surface of the coil body <NUM>. The guide wire <NUM> according to the fifth example can also exhibit a similar effect to the above-described first example.

Fourth Embodiment of the Invention <FIG> is a partial enlarged view of a guide wire <NUM> according to a fourth embodiment. In the guide wire <NUM> according to the ninth embodiment, a resin layer <NUM> includes a protruding portion 32h1, a protruding portion 32h2, a protruding portion 32h3, and a protruding portion 32h4. The protruding portions 32h1 to 32h4 each have different shapes. In the cross section illustrated in <FIG>, the shape of the protruding portion 32h1 is a substantially triangular shape, the shape of the protruding portion 32h2 is a trapezoidal shape, the shape of the protruding portion 32h3 is a substantially triangular shape having a height different from that of the protruding portion 32h1, and the shape of the protruding portion 32h4 is a trapezoidal shape having a height different from that of the protruding portion 32h2. The protruding portion 32h1 and the protruding portion 32h2 contact the core shaft <NUM>. On the other hand, the protruding portion 32h3 and the protruding portion 32h4 do not contact the core shaft <NUM>. The protruding portions 32h1 to 32h4 may be formed by using a material and manufacturing method similar to those of the protruding portion <NUM> of the first example and the protruding portion 32f of the fourth example.

Thus, the guide wire <NUM> may include various shapes of the protruding portions 32h1 to 32h4 as long as the protruding portions 32h1 to 32h4 extend toward the core shaft <NUM> through the gap C1 between the adjacent wires <NUM> of the coil body <NUM>, and extend toward the core shaft <NUM> relative to the inner peripheral surface of the coil body <NUM>. Further, the shapes of the protruding portions 32h1 to 32h4 may be different from each other as illustrated in <FIG>. The guide wire <NUM> according to the fourth embodiment can also exhibit a similar effect to the above-described first embodiment.

The disclosed embodiment is not limited to the above-described embodiments, and may be executed in various modes without departing from the spirit and scope of the disclosed embodiment. The following modifications can be applied, for example.

In the above-described examples and embodiments, configurations of the guide wire <NUM> have been described. However, the configuration of the guide wire <NUM> can be variously modified. For example, the guide wire <NUM> may have a configuration that does not include the second tapered part <NUM> and the second large-diameter part <NUM> (that is, a configuration in which the core shaft <NUM> is entirely covered with the coil body <NUM>). For example, the guide wire <NUM> may be configured to not include a tapered part and have the same diameter over the entire region in the axis O direction.

In the above-described examples and embodiments, configurations of the coil body <NUM> have been described. However, the configuration of the coil body <NUM> can be variously modified. For example, the coil body <NUM> may be arranged to cover the second tapered part <NUM> and the second large-diameter part <NUM> of the core shaft <NUM> in addition to the small-diameter part <NUM> to the first large-diameter part <NUM> of the core shaft <NUM> described above. For example, the arrangement of the closely wound part and the sparsely wound part of the coil body <NUM> may be optionally determined, and the closely wound part may be formed at a position other than the distal end part of the guide wire <NUM> (for example, at an almost center part in the axis O direction).

In the above-described examples and iist embodiments, configurations of the resin layer <NUM> have been described. However, the configuration of the resin layer <NUM> can be variously modified. For example, at least one of the distal end resin layer <NUM> and the proximal end resin layer <NUM> included in the resin layer <NUM> may be omitted. For example, a configuration in which the resin layer <NUM> is not provided in the closely wound part of the coil body <NUM> (<FIG>, fourth embodiment) may be employed. For example, the resin layer <NUM> may include the surface layer <NUM>, the protruding portion <NUM> (<FIG>) not contacting with the core shaft <NUM>, and the resin film <NUM> (<FIG>).

Claim 1:
A guide wire(1a- 1e, <NUM>) comprising:
a core shaft(<NUM>);
a coil body(<NUM>,20c) formed by winding a wire around the core shaft(<NUM>); and
a resin layer(30a,30b,30e,<NUM>) covering at least an outer peripheral surface of the coil body(<NUM>,20c), wherein
the coil body(<NUM>,20c) includes a sparsely wound part in which a gap is formed between adjacent wires,
a void is formed between the coil body(<NUM>,20c) and the core shaft(<NUM>), and
the resin layer(30a,30b,30e,<NUM>) includes a protruding portion(32a,32b,32e,32h1,32h2) protruding toward the core shaft through the gap between the adjacent wires in the sparsely wound part, and the protruding portion(32a,32b,32e,32h1,32h2) extends toward the core shaft(<NUM>) relative to an inner peripheral surface of the coil body(<NUM>,20c), characterized in that
the protruding portion(32a,32b,32e,32h1,32h2) contacts the core shaft(<NUM>).