Patent Description:
Conventionally, a guide wire including a resin marker (visibility marker) provided on an outer surface of a wire main body is known in order to observe a position or an orientation of a distal end of the guide wire inserted into a living lumen with an endoscopic camera (see Patent Literature <NUM>, for example). For example, Patent Literature <NUM> discloses a guide wire provided with a raised portion forming layer containing a resin and a pigment, the raised portion forming layer functioning as a visual recognition marker on an outer surface of the guide wire.

However, the guide wire described in Patent Literature <NUM> has a problem in that an outer diameter of a portion of the guide wire where the marker is provided is larger than an outer diameter of a portion where the marker is not provided, and thus, there is a limit on a size of a catheter that can be used together with the guide wire. Another problem is that the marker protrudes radially outward from the resin portion, and thus, when contacting a device used together with the guide wire or an inner wall of a body cavity, the marker peels off. Still another problem is that if the outer diameter of the wire main body is reduced to suppress an increase in the outer diameter of the guide wire, the rigidity of the guide wire is reduced.

An object of the present invention is to suppress an increase of an outer diameter of a guide wire due to provision of a marker on the guide wire in a guide wire provided with a marker containing a resin on an outer surface of a core shaft.

The present invention has been made to solve at least one of the above-described problems, and can be realized as the following aspects.

It is noted that the present invention can be realized in various aspects, and may be realized in a mode such as a method of manufacturing a catheter, an endoscope, an image generation device, an inspection device, a treatment system, and a guide wire, for example. Several embodiments are defined in the dependent claims.

<FIG> is an explanatory diagram illustrating an entire configuration of a guide wire <NUM> according to a first embodiment. <FIG> is an explanatory diagram illustrating a cross-sectional configuration of the guide wire <NUM>. Hereinafter, the left side in <FIG> is referred to as "distal end side" of the guide wire <NUM> and constituent members, and the right side in <FIG> is referred to as "proximal end side" of the guide wire <NUM> and constituent members. The distal end side of the guide wire <NUM> is a side to be inserted into a body (distal side), and the proximal end side of the guide wire <NUM> is a side operated by an operator such as a doctor (near side). The left-right direction in <FIG> is referred to as "stretching direction" or "axis direction" of the guide wire <NUM> and each constituent member. <FIG> illustrates a longitudinal section along the stretching direction of the guide wire <NUM>. 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 coating film <NUM>, a core shaft <NUM>, a coil body <NUM>, a distal end side joint portion <NUM>, and a proximal end side joint portion <NUM>.

The core shaft <NUM> has an elongated shape, and the coating film <NUM> is formed on the outer surface of the core shaft <NUM>. The coating film <NUM> includes a marker portion <NUM> and a resin portion <NUM>. The coil body <NUM> is wound around an outer periphery of the distal end portion of the core shaft <NUM>.

The core shaft <NUM> is an elongated (tapered) member configured so that an outer diameter decreases from the proximal end side to the distal end side. The core shaft <NUM> may be formed of a material such as a stainless alloy (SUS302, SUS304, SUS316, and the like), a superelastic alloy such as a Ni-Ti alloy, a piano wire, a nickel-chromium base alloy, a cobalt alloy, or tungsten. The core shaft <NUM> may be formed of a well-known material other than the materials mentioned above. A length of the core shaft <NUM> is not particularly limited, but a range of <NUM> to <NUM> may be used as an example. The outer diameter of the core shaft <NUM> is also not particularly limited, but a range of <NUM> to <NUM> may be used as an example.

The coil body <NUM> is configured by one or a plurality of coils, and is wound around the core shaft <NUM> to cover the outer periphery on the distal end side of the core shaft <NUM>. Here, the coil body <NUM> is wound around a part of a small diameter portion and a tapered portion on the distal end side of the core shaft <NUM>. The coil configuring the coil body <NUM> may be a single coil formed by spirally winding one wire having a circular cross section to form a cylindrical shape, or a hollow, twisted wire coil obtained by forming a twisted wire obtained by twisting a plurality of wires into a cylindrical shape. The coil body <NUM> may be configured by combining a single coil and a hollow twisted wire coil. The coil body <NUM> may be formed of, for example, a stainless alloy (SUS302, SUS304, SUS316, and the like), 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, or a radiopaque alloy such as an alloy containing these elements (for example, a platinum-nickel alloy). The coil body <NUM> may be formed of a well-known material other than the materials mentioned above. A length of the coil body <NUM> is not particularly limited, but for example, <NUM> to <NUM> may be used as an example. An outer diameter of the coil body <NUM> is not particularly limited, but may be in a range of <NUM> to <NUM>, for example, and is configured to be constant from the distal end to the proximal end. The coil body <NUM> may include a loosely wound portion and a tightly wound portion having different coil pitches.

The distal end of the coil body <NUM> is joined to the distal end of the core shaft <NUM> by the distal end side joint portion <NUM>. The proximal end of the coil body <NUM> is joined to the core shaft <NUM> by the proximal end side joint portion <NUM>. The coil body <NUM> is fixed to the core shaft <NUM> by the distal end side joint portion <NUM> and the proximal end side joint portion <NUM>. The distal end side joint portion <NUM> and the proximal end side joint portion <NUM> are formed of a metal solder such as silver solder, gold solder, zinc, a Sn-Ag alloy, or an Au-Sn alloy, and by such a metal solder, the coil body <NUM> and the core shaft <NUM> are adhered and fixed. It is noted that the distal end side joint portion <NUM> and the proximal end side joint portion <NUM> may be formed of an adhesive such as an epoxy adhesive, and by such an adhesive, the coil body <NUM> and the core shaft <NUM> may be adhered and fixed. The distal end side joint portion <NUM> and the proximal end side joint portion <NUM> may be formed of different materials.

The coating film <NUM> is formed on the outer surface of the core shaft <NUM>, and includes the marker portion <NUM> and the resin portion <NUM>. The coating film <NUM> is arranged on the proximal end side of the core shaft <NUM> relative to the proximal end side joint portion <NUM>. In the coating film <NUM>, a length of a zone where the marker portion <NUM> is formed (marker display zone) is not particularly limited, but a range of <NUM> to <NUM> may be used as an example. The coating film <NUM> may cover not only the outer surface of the core shaft <NUM> on the proximal end side relative to the proximal end side joint portion <NUM>, but also the proximal end side joint portion <NUM>, the coil body <NUM>, and the distal end side joint portion <NUM>.

The marker portion <NUM> contains a pigment and is formed on the outer surface of the core shaft <NUM>. The marker portion <NUM> forms a part of the outer surface of the coating film <NUM>. The marker portion <NUM> is a linear portion formed in a part of the coating film <NUM>, and is configured to be visually distinguishable from the resin portion <NUM>. When the guide wire <NUM> is observed from the outside, the marker portion <NUM> is seen as a linear pattern on the guide wire <NUM>, and when the operator observes a change of an orientation and a position of the pattern when operating the guide wire <NUM>, it is possible to confirm push-pull and rotation operations of the guide wire <NUM>.

The marker portion <NUM> is formed to have a wavy pattern in a developed view obtained when the outer periphery of the core shaft <NUM> is expanded. That is, when the pigment dripping toward the core shaft <NUM> is moved along the stretching direction in a state where the core shaft <NUM> is reciprocated and rotated by a predetermined angle (for example, <NUM>°) to the left and right with the stretching direction (axis direction) as a rotation axis, it is possible to form such a wavy pattern. The marker portion <NUM> may be spirally formed on the core shaft <NUM>. That is, when the pigment dripping toward the core shaft <NUM> is moved along the stretching direction in a state where the core shaft <NUM> is rotated in one direction with the stretching direction (axis direction) as a rotation axis, it is possible to from a spiral pattern.

The pigment forming the marker portion <NUM> may be any one of an inorganic pigment and an organic pigment, but it is preferable to use an inorganic pigment in terms of heat resistance. As the inorganic pigment, it is possible to use carbon black, mica, titanium dioxide, titanium yellow, Prussian blue, Milori blue, cobalt blue, ultramarine, viridian, and the like. The marker portion <NUM> may contain a resin, and may contain PAI (polyamide-imide), PTFE (polytetrafluoroethylene), PVDF (polyvinylidene fluoride), PFA (perfluoroalkoxy alkane), FEP (perfluoroethylene propene), ETFE (ethylene tetrafluoroethylene), PE (polyethylene), and PP (polypropylene), for example. The marker portion <NUM> may be formed of a well-known material other than the above examples. The marker portion <NUM> may contain the same type of resin as or a type different from the resin forming the resin portion <NUM>.

The resin portion <NUM> contains a resin and is formed on the outer surface of the core shaft <NUM>. The resin portion <NUM> forms a part of the outer surface of the coating film <NUM>.

The resin portion <NUM> may be formed of PAI (polyamide-imide), PTFE (polytetrafluoroethylene), PVDF (polyvinylidene fluoride), PFA (perfluoroalkoxy alkane), FEP (perfluoroethylene propene), ETFE (ethylene tetrafluoroethylene), PE (polyethylene), and PP (polypropylene), for example. The resin portion <NUM> may be formed of a well-known material other than the above examples. The resin portion <NUM> may contain a pigment, which may be any one of an inorganic pigment and an organic pigment, but it is preferable to use the inorganic pigment in terms of heat resistance. As the inorganic pigment, it is possible to use carbon black, mica, titanium dioxide, titanium yellow, Prussian blue, Milori blue, cobalt blue, ultramarine, viridian, and the like. When the resin portion <NUM> is formed to be different in color from the marker portion <NUM>, it is possible to increase the visibility of the marker portion <NUM>.

The marker portion <NUM> and the resin portion <NUM> are repeatedly represented as a result of the marker portion <NUM> and the resin portion <NUM> being alternately and continuously present without gaps along the stretching direction of the guide wire <NUM>.

<FIG> is an explanatory diagram obtained when a detail X of <FIG> is enlarged. The detail X is a portion located on the proximal end side relative to the proximal end side joint portion <NUM> in <FIG> and provided with the coating film <NUM> on the outer surface of the core shaft <NUM>, and is provided with the marker portion <NUM>. The X portion is used as an example to describe a detailed configuration of the marker portion <NUM> and the resin portion <NUM>.

A thickness of a portion of the coating film <NUM> where the marker portion <NUM> is represented on the outer surface is defined as Hm. It is assumed here that the thickness Hm is a maximum value of a length from the outer surface of the marker portion <NUM> to the outer surface of the core shaft <NUM> in the longitudinal section of the core shaft <NUM>. The thickness Hm is not particularly limited, but a range of <NUM> to <NUM> may be used as an example. In <FIG>, the outer surface of the marker portion <NUM> is flat, and thus, the thickness Hm remains substantially the same at any point in the stretching direction of the core shaft <NUM>.

In the longitudinal section of the core shaft <NUM>, a thickness of a portion of the coating film <NUM> in which the resin portion <NUM> is represented on the outer surface, the portion existing between adjacent ones of the marker portions <NUM>, is defined as Hr. It is assumed here that the thickness Hr is a maximum value of a length from the outer surface of the resin portion <NUM> to the outer surface of the core shaft <NUM> in the longitudinal section of the core shaft <NUM>. The thickness Hr is not particularly limited, but a range of <NUM> to <NUM> may be used as an example. In <FIG>, the outer surface of the resin portion <NUM> is flat, and thus, the thickness Hr remains substantially the same at any point in the stretching direction of the core shaft <NUM>.

The thickness Hm of the portion of the coating film <NUM> where the marker portion <NUM> is represented on the outer surface is substantially the same as the thickness Hr of the portion of the coating film <NUM> where the resin portion <NUM> is represented on the outer surface. In other words, the outer surface of the marker portion <NUM> and the outer surface of the resin portion <NUM> are formed to be flat. For example, it is preferable that a difference between the thickness Hm and the thickness Hr is equal to or less than <NUM>, and more preferably equal to or less than <NUM>.

In the longitudinal section of the core shaft <NUM>, a length of the marker portion <NUM> in the stretching direction of the core shaft <NUM> is defined as a cross-sectional width of the marker portion <NUM>. Further, the cross-sectional width of the marker portion <NUM> on the outer surface of the marker portion <NUM> is defined as an outer cross-sectional width Wm. The marker portion <NUM> is of arc shape, and of convex shape inward in a radial direction of the core shaft <NUM>, and thus, the cross-sectional width of the marker portion <NUM> gradually decreases inward in the radial direction of the core shaft <NUM>. In other words, the cross-sectional width of the marker portion <NUM> gradually increases outward in the radial direction of the core shaft <NUM>.

The marker portion <NUM> includes a first region 20a including the outer surface of the marker portion <NUM> and a second region 20b provided around the first region 20a. In the longitudinal section of the core shaft <NUM>, the first region 20a is of arc shape, and is of convex shape toward the inside of the core shaft <NUM> in the radial direction. The second region 20b is of arc shape to cover a surrounding area of the first region 20a, and is of convex shape toward the inside of the core shaft <NUM> in the radial direction. Here, a content of the pigment contained in the second region 20b is smaller than a content of the pigment contained in the first region 20a. If the marker portion <NUM> consists of the resin and the pigment, the content of the pigment contained in the second region 20b is larger than the content of the pigment contained in the first region 20a.

<FIG> is an explanatory diagram illustrating a method of manufacturing the guide wire <NUM>. If an average particle size of a pigment <NUM> contained in the marker portion <NUM> is smaller than an average particle size of the resin of the resin portion <NUM>, it is possible to manufacture the marker portion <NUM> represented by a wavy pattern on the resin portion <NUM> according to the following steps, for example. Firstly, the resin portion <NUM> is coated on the outer surface of the core shaft <NUM>. Next, in a state where the core shaft <NUM> is reciprocated and rotated by a predetermined angle (for example, <NUM>°) to the left and right with the stretching direction (axis direction) as a rotation axis, the pigment <NUM> dripping toward the core shaft <NUM> is moved along the stretching direction. As a result, the pigment <NUM> is applied in a wavy pattern on the outer surface of the resin portion <NUM>. Next, when the pigment <NUM> is heated with a heater or the like, particles of the pigment <NUM> enter between particles of the resin portion <NUM>. Finally, when the pigment <NUM> and the resin portion <NUM> are dried, the pigment <NUM> and the resin portion <NUM> are fixed, and the coating film <NUM> is formed. According to this method, the marker portion <NUM> is formed in an arc shape to be convex toward the inside of the core shaft <NUM> in the radial direction around a point where the pigment <NUM> is applied. As a result, in the marker portion <NUM>, in an area near the point where the pigment <NUM> is applied, a content of the pigment <NUM> is large, and the content of the pigment <NUM> gradually decreases as a distance from the point where the pigment <NUM> is applied increases. According to such a procedure, it is possible to form the first region 20a and the second region 20b.

According to the configuration of the present embodiment, when the guide wire <NUM> is provided with the marker portion <NUM>, it is possible to suppress an increase of the outer diameter of the guide wire <NUM>. When the increase of the outer diameter of the guide wire <NUM> is suppressed, the operator is capable of selecting a device having a smaller inner diameter of a lumen in using a device used with the guide wire such as a catheter having a lumen through which the guide wire is inserted. It is also easier for the operator to insert the guide wire into a site having a small diameter such as a peripheral blood vessel.

According to the configuration of the present embodiment, as compared to a case where the cross-sectional width of the marker portion <NUM> is substantially constant toward the inside of the core shaft <NUM> in the radial direction, it is possible to increase a contact area between the marker portion <NUM> and the resin portion <NUM>, and thus, it is possible to decrease a possibility that the marker portion <NUM> and the resin portion <NUM> peel off. As a result, it is possible to prevent the marker portion <NUM> from peeling off and remaining in a body of a patient or in the device used with the guide wire such as a catheter.

According to the configuration of the present embodiment, when the content of pigment contained in a marker portion 20b contacting the resin portion <NUM> is reduced, it is possible to maintain adhesion between the marker portion 20b and the resin portion <NUM> and it is possible to decrease a possibility that the marker portion 20b and the resin portion <NUM> peel off.

<FIG> is an explanatory diagram illustrating a cross-sectional configuration of a guide wire 1A according to a second embodiment. The guide wire 1A includes a coating film <NUM>, and the coating film <NUM> includes a marker portion <NUM> instead of the marker portion <NUM> of the first embodiment in <FIG>. The thickness Hm of the portion of the coating film <NUM> where the marker portion <NUM> is represented on the outer surface is smaller than the thickness Hr of the portion of the coating film <NUM> where the resin portion <NUM> is represented on the outer surface. In other words, the outer surface of the marker portion <NUM> is radially inside the core shaft <NUM> relative to the outer surface of the resin portion <NUM>.

According to the configuration of the present embodiment, the outer surface of the marker portion <NUM> does not easily contact an inner peripheral surface of a device used with the guide wire such as a catheter (not illustrated) or a wall surface (not illustrated) of an internal organ or a blood vessel of a body, and it is possible to decrease a possibility that the marker portion <NUM> peels off. A contact of an inner peripheral surface of the device used with the guide wire such as a catheter (not illustrated) and a wall surface (not illustrated) of an internal organ, a blood vessel, or the like of a body, with the outer surface of the marker portion <NUM> is not easy, but a contact thereof with the outer surface of the resin portion <NUM> is easier, and thus, it is possible to improve slidability of the guide wire 1A.

<FIG> is an explanatory diagram illustrating a cross-sectional configuration of a guide wire 1B according to a third embodiment. The guide wire 1B includes a coating film <NUM>, and the coating film <NUM> includes a marker portion <NUM> instead of the marker portion <NUM> of the first embodiment in <FIG>. In the marker portion <NUM>, a cross-sectional width of the marker portion <NUM> is substantially constant in a radial direction of the core shaft <NUM>. The marker portion <NUM> has a substantially constant overall pigment content over the longitudinal section of the marker portion <NUM>. For example, the coating film <NUM> covers the outer surface of the core shaft <NUM> with the resin portion <NUM> having a groove formed in a wavy shape or a spiral shape toward the stretching direction of the core shaft <NUM>, and may be formed by fitting the linearly formed marker portion <NUM> into the groove formed in the resin portion <NUM>.

According to the configuration of the present embodiment, as compared to a case where the cross-sectional width of the marker portion decreases toward the inside of the core shaft <NUM> in the radial direction, it is possible to increase a thickness of an end portion of the marker portion <NUM>, and thus, it is possible to prevent the marker portion <NUM> from being damaged starting from the end portion of the marker portion <NUM>.

<FIG> is an explanatory diagram illustrating a cross-sectional configuration of a guide wire 1C according to a fourth embodiment. The guide wire 1C includes a coating film <NUM>, and the coating film <NUM> includes a marker portion <NUM> instead of the marker portion <NUM> of the first embodiment in <FIG>. An inner surface of the marker portion <NUM> contacts the outer surface of the core shaft <NUM>. In this case, a maximum width of the marker portion <NUM> and the thickness Hm of a portion of the coating film <NUM> where the marker portion <NUM> is represented on the outer surface are equal.

According to the configuration of the present embodiment, as compared to a case where the inner surface of the marker portion does not contact the outer surface of the core shaft <NUM>, it is possible to increase a thickness of the marker portion <NUM>, and thus, a strength of the marker portion <NUM> is improved.

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

It is assumed that the marker portions <NUM>, <NUM>, <NUM>, and <NUM> (see <FIG>, <FIG>, <FIG>, and <FIG>) of the first to fourth embodiments are displayed in a part (marker display zone) of the core shaft <NUM>. However, the marker portions <NUM>, <NUM>, <NUM>, and <NUM> may be formed over the entire core shaft <NUM>. The marker portions <NUM>, <NUM>, <NUM>, and <NUM> are assumed to be drawn with one pattern. However, the marker portions <NUM>, <NUM>, <NUM>, and <NUM> may have a plurality of types of patterns. In this case, the marker portions <NUM>, <NUM>, <NUM>, and <NUM> may have a mode in which the pattern changes continuously, or may have a different pattern for each predetermined zone. The marker portions <NUM>, <NUM>, <NUM>, and <NUM> may be cut somewhere in the core shaft <NUM> and drawn at a plurality of locations. For example, in the marker portions <NUM>, <NUM>, <NUM>, and <NUM>, a plurality of types of patterns may be drawn at a plurality of locations at predetermined intervals, or an annular pattern may be continuously drawn at equal intervals.

<FIG> illustrates a guide wire 1D which is a modification of the first to fourth embodiments. The guide wire 1D includes a coating film <NUM>, and the coating film <NUM> includes a marker portion <NUM>. An outer surface of the marker portion <NUM> is of arc shape and is recessed toward the inside of the core shaft <NUM> in the radial direction. Therefore, the thickness Hm of the portion of the coating film <NUM> where the marker portion <NUM> is represented on the outer surface is not substantially constant in the stretching direction of the core shaft <NUM>. In the case of <FIG>, the thickness of the end portion of the marker portion <NUM> is a maximum value of the thickness of the portion of the coating film <NUM> where the marker portion <NUM> is represented on the outer surface. In the marker portions <NUM>, <NUM>, <NUM>, and <NUM> according to the first to fourth embodiments, in the longitudinal section of the core shaft <NUM>, similarly to the marker portion <NUM>, the outer surface of the marker portions <NUM>, <NUM>, <NUM>, and <NUM> may be recessed toward the inside of the core shaft <NUM> in the radial direction. As long as the outer surface of the marker portions <NUM>, <NUM>, <NUM>, and <NUM> does not protrude outward in the radial direction of the core shaft <NUM> from the outer surface of the resin, the outer surface of the marker portions <NUM>, <NUM>, <NUM>, and <NUM> may be recessed outward in the radial direction of the core shaft <NUM>.

The guide wires <NUM>, 1A, 1B, and 1C of the first to fourth embodiments are assumed to include the coil body <NUM> at the distal end. However, it is not required that the guide wires <NUM>, 1A, 1B, and 1C include the coil body <NUM>. In this case, the coating films <NUM>, <NUM>, <NUM>, and <NUM> may be provided at the distal end portion of the core shaft <NUM>.

Claim 1:
A guide wire (<NUM>, 1A, 1C, 1D) comprising:
a core shaft (<NUM>) having an elongated outer shape; and
a coating film (<NUM>, <NUM>, <NUM>, <NUM>) formed on an outer surface of the core shaft (<NUM>), the coating film (<NUM>, <NUM>, <NUM>, <NUM>) containing a resin,
wherein the coating film (<NUM>, <NUM>, <NUM>, <NUM>) includes a marker portion (<NUM>, <NUM>, <NUM>, <NUM>) that contains a pigment linearly represented on an outer surface of the coating film (<NUM>, <NUM>, <NUM>, <NUM>) and a resin portion (<NUM>) that does not contain the pigment,
wherein, on the outer surface of the coating film (<NUM>, <NUM>, <NUM>, <NUM>), the marker portion (<NUM>, <NUM>, <NUM>, <NUM>) and the resin portion (<NUM>) are alternately represented in a stretching direction, and
wherein a thickness of a portion of the coating film (<NUM>, <NUM>, <NUM>, <NUM>) where the marker portion (<NUM>, <NUM>, <NUM>, <NUM>) is represented on the outer surface and a thickness of a portion of the coating film (<NUM>, <NUM>, <NUM>, <NUM>) where the resin portion (<NUM>) is represented on the outer surface are substantially the same, or the thickness of the portion of the coating film (<NUM>, <NUM>, <NUM>, <NUM>) where the marker portion (<NUM>, <NUM>, <NUM>, <NUM>) is represented is smaller than the thickness of the portion of the coating film (<NUM>, <NUM>, <NUM>, <NUM>) where the resin portion (<NUM>) is represented, and
wherein in a longitudinal section along a stretching direction of the core shaft (<NUM>), a cross-sectional width of the marker portion (<NUM>, <NUM>, <NUM>, <NUM>) decreases toward an inside of the core shaft (<NUM>) in a radial direction.