GUIDE WIRE

To provide a guide wire including a core shaft having an elongated outer shape, and a coating film on an outer surface of the core shaft, the coating film containing a resin. The coating film includes a marker portion containing a pigment on an outer surface of the coating film and a resin portion not containing the pigment. On the outer surface of the coating film, the marker portion and the resin portion are alternately visible in a stretching direction. Of the coating film, a thickness of a portion where the marker portion is visible on the outer surface and a thickness of a portion where the resin portion is visible on the outer surface are substantially the same, or the thickness of the portion where the marker portion is visible is smaller than the thickness of the portion where the resin portion is visible.

TECHNICAL FIELD

The disclosed embodiments relate to a guide wire.

BACKGROUND ART

Conventionally, to observe a position or an orientation of a distal end of a guide wire inserted into a living lumen with an endoscopic camera, there is known a guide wire including a resin marker (visibility marker) provided on an outer surface of a wire main body (see Patent Literature 1, for example). For example, Patent Literature 1 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.

CITATION LIST

Patent Literature

SUMMARY

Technical Problems

However, the guide wire described in Patent Literature 1 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.

Disclosed embodiments are directed to suppressing 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.

Solutions to Problems

The disclosed embodiments have been made to solve at least one of the above-described problems, and can be realized as the following aspects.

(1) According to one aspect of the disclosed embodiments, a guide wire is provided. The guide wire includes a core shaft having an elongated outer shape, and a coating film formed on an outer surface of the core shaft, the coating film containing a resin, in which the coating film includes a marker portion containing a pigment and being linearly represented on an outer surface of the coating film and a resin portion that does not contain the pigment, and on the outer surface of the coating film, the marker portion and the resin portion are represented alternately in a stretching direction, of the coating film, a thickness of a portion where the marker portion is represented on the outer surface and a thickness of a portion where the resin portion is represented on the outer surface are substantially the same, or the thickness of the portion where the marker portion is represented is smaller than the thickness of the portion where the resin portion is represented.

According to such a configuration, of the coating film, the thickness of the portion where the marker portion is represented on the outer surface and the thickness of the portion where the resin portion is represented on the outer surface are substantially the same, or the thickness of the portion where the marker portion is represented on the outer surface is smaller than the thickness of the portion where the resin portion is represented on the outer surface, and thus, when the guide wire is provided with the marker, it is possible to suppress an increase of an outer diameter of the guide wire.

(2) In the guide wire of the above aspect, in a longitudinal section along a stretching direction of the core shaft, a cross-sectional width of the marker portion may decrease toward an inside of the core shaft in a radial direction. According to such a configuration, as compared to a case where the cross-sectional width of the marker portion is substantially constant toward the inside of the core shaft in the radial direction, it is possible to increase a contact area between the marker portion and the resin portion, and thus, it is possible to decrease a possibility that the marker portion and the resin portion peel of.

(3) In the guide wire of the above aspect, the marker portion may include a first region including the outer surface of the marker portion and a second region provided around the first region, and a content of the pigment contained in the second region may be smaller than a content of the pigment contained in the first region. According to such a configuration, when the pigment content of the marker portion contacting the resin portion is reduced, it is possible to maintain adhesion between the marker portion and the resin portion and it is possible to decrease a possibility that the marker portion and the resin portion peel off.

(4) In the guide wire of the above aspect, an average particle size of the pigment contained in the marker portion may be smaller than an average particle size of the resin portion. According to such a configuration, even if the resin portion is formed further to the distal side than the marker portion on the outer surface of the core shaft, when the pigment is heated on the resin portion, the pigment can impregnate the resin portion to form the marker portion.

It is noted that the disclosed embodiments 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.

DETAILED DESCRIPTION

First Embodiment

FIG. 1is an explanatory diagram illustrating an entire configuration of a guide wire1according to a first embodiment.FIG. 2is an explanatory diagram illustrating a cross-sectional configuration of the guide wire1. Hereinafter, the left side inFIG. 1is referred to as “distal end side” of the guide wire1and constituent members, and the right side inFIG. 1is referred to as “proximal end side” of the guide wire1and constituent members. The distal end side of the guide wire1is a side to be inserted into a body (distal side), and the proximal end side of the guide wire1is a side operated by an operator such as a doctor (near side). The left-right direction inFIG. 1is referred to as “stretching direction” or “axis direction” of the guide wire1and each constituent member.FIG. 2illustrates a longitudinal section along the stretching direction of the guide wire1. The guide wire1is a medical device used when a catheter is inserted into a blood vessel or a digestive organ, and includes a coating film10, a core shaft40, a coil body50, a distal end side joint portion60, and a proximal end side joint portion70.

The core shaft40has an elongated shape, and the coating film10is formed on the outer surface of the core shaft40. The coating film10includes a marker portion20and a resin portion30. The coil body50is wound around an outer periphery of the distal end portion of the core shaft40.

The core shaft40is an elongated (tapered) member configured so that an outer diameter decreases from the proximal end side to the distal end side. The core shaft40may be formed of a material such as 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, and tungsten. The core shaft40may be formed of a well-known material other than the materials mentioned above. A length of the core shaft40is not particularly limited, but a range of 1000 mm to 5000 mm may be used as an example. The outer diameter of the core shaft40is also not particularly limited, but a range of 0.1 mm to 1.0 mm may be used as an example.

The coil body50is configured by one or a plurality of coils, and is wound around the core shaft40to cover the outer periphery on the distal end side of the core shaft40. Here, the coil body50is wound around a part of a small diameter portion and a tapered portion on the distal end side of the core shaft40. The coil configuring the coil body50may 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 body50may be configured by combining a single coil and a hollow twisted wire coil. The coil body50may 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, and a radiopaque alloy such as an alloy containing these elements (for example, a platinum-nickel alloy). The coil body50may be formed of a well-known material other than the materials mentioned above. A length of the coil body50is not particularly limited, but for example, 10 mm to 100 mm may be used as an example. An outer diameter of the coil body50is not particularly limited, but may be in a range of 0.1 mm to 1.0 mm, for example, and is configured to be constant from the distal end to the proximal end. The coil body50may include a loosely wound portion and a tightly wound portion having different coil pitches.

The distal end of the coil body50is joined to the distal end of the core shaft40by the distal end side joint portion60. The proximal end of the coil body50is joined to the core shaft40by the proximal end side joint portion70. The coil body50is fixed to the core shaft40by the distal end side joint portion60and the proximal end side joint portion70. The distal end side joint portion60and the proximal end side joint portion70are formed of a metal solder such as silver solder, gold solder, zinc, a Sn—Ag alloy, and an Au—Sn alloy, and by such a metal solder, the coil body50and the core shaft40are adhered and fixed. The distal end side joint portion60and the proximal end side joint portion70may be formed of an adhesive such as an epoxy adhesive, and by such an adhesive, the coil body50and the core shaft40may be adhered and fixed. The distal end side joint portion60and the proximal end side joint portion70may be formed of different materials.

The coating film10is formed on the outer surface of the core shaft40, and includes the marker portion20and the resin portion30. The coating film10is arranged on the proximal end side of the core shaft40relative to the proximal end side joint portion70. In the coating film10, a length of a zone where the marker portion20is formed (marker display zone) is not particularly limited, but a range of 100 mm to 500 mm may be used as an example. The coating film10may cover not only the outer surface of the core shaft40on the proximal end side relative to the proximal end side joint portion70, but also the proximal end side joint portion70, the coil body50, and the distal end side joint portion60.

The marker portion20contains a pigment and is formed on the outer surface of the core shaft40. The marker portion20forms a part of the outer surface of the coating film10. The marker portion20is a linear site formed in a part of the coating film10, and is configured to be visually distinguishable from the resin portion30. When the guide wire1is observed from outside, the marker portion20is seen as a linear pattern on the guide wire1, and when the operator observes a change of an orientation and a position of the pattern when operating the guide wire1, push-pull and rotation operations of the guide wire1may be confirmed.

The marker portion20may have a wavy pattern in a developed view obtained when the outer periphery of the core shaft40is expanded. That is, when the pigment dripping toward the core shaft40is moved along the stretching direction in a state where the core shaft40is reciprocated and rotated by a predetermined angle (for example, 180°) to the left and right with the stretching direction (axis direction) as a rotation axis, a wavy pattern may be formed. The marker portion20may be spirally formed on the core shaft40. That is, when the pigment dripping toward the core shaft40is moved along the stretching direction in a state where the core shaft40is rotated in one direction with the stretching direction (axis direction) as a rotation axis, a spiral pattern may be formed.

The pigment forming the marker portion20may be any one of an inorganic pigment and an organic pigment, but an inorganic pigment may provide better 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 portion20may contain a resin, and may contain PAI (polyamide-imide), PTFE (p olytetrafluoroethylene), PVDF (polyvinylidene fluoride), PFA (perfluoroalkoxy alkane), FEP (perfluoroethylene propene), ETFE (ethylene tetrafluoroethylene), PE (polyethylene), and PP (polypropylene), for example. The marker portion20may be formed of a well-known material other than the above examples. The marker portion20may contain the same type of resin as or a type different from the resin forming the resin portion30.

The resin portion30contains a resin and is formed on the outer surface of the core shaft40. The resin portion30forms a part of the outer surface of the coating film10.

The resin portion30may 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 portion30may be formed of a well-known material other than the above examples. The resin portion30may contain a pigment, which may be any one of an inorganic pigment and an organic pigment, but the inorganic pigment may provide better 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 portion30is formed to be different in color from the marker portion20, it is possible to increase the visibility of the marker portion20.

The marker portion20and the resin portion30are repeatedly represented as a result of the marker portion20and the resin portion30being alternately and continuously present, e.g., visible, without gaps along the stretching direction of the guide wire1.

FIG. 3is an explanatory diagram obtained when an X portion ofFIG. 2is enlarged. The X portion is a portion located on the proximal end side relative to the proximal end side joint portion70inFIG. 2and provided with the coating film10on the outer surface of the core shaft40, and is provided with the marker portion20. The X portion is used as an example to describe a detailed configuration of the marker portion20and the resin portion30.

A thickness of a portion of the coating film10where the marker portion20is 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 portion20to the outer surface of the core shaft40in the longitudinal section of the core shaft40. The thickness Hm is not particularly limited, but a range of 0.01 mm to 0.1 mm may be used as an example. InFIG. 3, the outer surface of the marker portion20is flat, and thus, the thickness Hm remains substantially the same at any point in the stretching direction of the core shaft40.

In the longitudinal section of the core shaft40, a thickness of a portion of the coating film10in which the resin portion30is represented on the outer surface, the portion existing between adjacent ones of the marker portions20, 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 portion30to the outer surface of the core shaft40in the longitudinal section of the core shaft40. The thickness Hr is not particularly limited, but a range of 0.01 mm to 0.1 mm may be used as an example. InFIG. 3, the outer surface of the resin portion30is flat, and thus, the thickness Hr remains substantially the same at any point in the stretching direction of the core shaft40.

The thickness Hm of the portion of the coating film10where the marker portion20is represented on the outer surface is substantially the same as the thickness Hr of the portion of the coating film10where the resin portion30is represented on the outer surface. In other words, the outer surface of the marker portion20and the outer surface of the resin portion30are formed to be flat, i.e., flush. For example, a difference between the thickness Hm and the thickness Hr may be equal to or less than 20 μm, e.g., equal to or less than 10 μm.

In the longitudinal section of the core shaft40, a length of the marker portion20in the stretching direction of the core shaft40is defined as a cross-sectional width of the marker portion20. Further, the cross-sectional width of the marker portion20on the outer surface of the marker portion20is defined as an outer cross-sectional width Wm. The marker portion20is of arc shape, and of convex shape inward in a radial direction of the core shaft40, and thus, the cross-sectional width of the marker portion20gradually decreases inward in the radial direction of the core shaft40. In other words, the cross-sectional width of the marker portion20gradually increases outward in the radial direction of the core shaft40.

The marker portion20includes a first region20aincluding the outer surface of the marker portion20and a second region20bprovided around the first region20a. In the longitudinal section of the core shaft40, the first region20ais of arc shape, and is of convex shape toward the inside of the core shaft40in the radial direction. The second region20bis of arc shape to cover a surrounding area of the first region20a, and is of convex shape toward the inside of the core shaft40in the radial direction. Here, a content of the pigment contained in the second region20bis smaller than a content of the pigment contained in the first region20a. If the marker portion20is configured by the resin and the pigment, the content of the pigment contained in the second region20bis larger than the content of the pigment contained in the first region20a.

FIG. 4is an explanatory diagram illustrating a method of manufacturing the guide wire1. If an average particle size of a pigment100contained in the marker portion20is smaller than an average particle size of the resin of the resin portion30, the marker portion20represented by a wavy pattern on the resin portion30may be manufactured according to the following steps, for example. Firstly, the resin portion30is coated on the outer surface of the core shaft40. Next, in a state where the core shaft40is reciprocated and rotated by a predetermined angle (for example, 180°) to the left and right with the stretching direction (axis direction) as a rotation axis, the pigment100dripping toward the core shaft40is moved along the stretching direction. As a result, the pigment100is applied in a wavy pattern on the outer surface of the resin portion30. Next, when the pigment100is heated with a heater or the like, particles of the pigment100enter between particles of the resin portion30. Finally, when the pigment100and the resin portion30are dried, the pigment100and the resin portion30are fixed, and the coating film10is formed. According to this method, the marker portion20is formed in an arc shape to be convex toward the inside of the core shaft40in the radial direction around a point where the pigment100is applied. As a result, in the marker portion20, in an area near the point where the pigment100is applied, a content of the pigment100is large, and the content of the pigment100gradually decreases as a distance from the point where the pigment100is applied increases. According to such a procedure, the first region20aand the second region20bmay be formed.

According to the configuration of the present embodiment, when the guide wire1is provided with the marker portion20, an increase of the outer diameter of the guide wire1may be suppressed. When the increase of the outer diameter of the guide wire1is 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 portion20is substantially constant toward the inside of the core shaft40in the radial direction, a contact area between the marker portion20and the resin portion30may be increased, decreasing a possibility that the marker portion20and the resin portion30peel off. As a result, the marker portion20may be prevented 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 portion20contacting the resin portion30is reduced, adhesion between the marker portion20and the resin portion30may be maintained, decreasing a possibility that the marker portion20and the resin portion30peel off.

Second Embodiment

FIG. 5is an explanatory diagram illustrating a cross-sectional configuration of a guide wire1A according to a second embodiment. The guide wire1A includes a coating film11, and the coating film11includes a marker portion21instead of the marker portion20of the first embodiment inFIG. 3. A thickness Hm′ of the portion of the coating film11where the marker portion21is visible on the outer surface is smaller than the thickness Hr of the portion of the coating film11where the resin portion30is visible on the outer surface. In other words, the outer surface of the marker portion21is radially inside the core shaft40relative to the outer surface of the resin portion30. Further, the marker portion21may be in direct contact with the core shaft40, i.e., there is no resin portion30between the marker portion21and the core shaft40, to maximize a thickness Hm′ of the recessed marker portion21.

According to the configuration of the present embodiment, the outer surface of the marker portion21does not easily contact an inner peripheral surface of a device used with the guide wire such as a catheter or a wall surface of an internal organ or a blood vessel of a body, thereby decreasing a possibility that the marker portion21peels off. A contact of an inner peripheral surface of the device used with the guide wire such as a catheter and a wall surface of an internal organ, a blood vessel, or the like of a body, with the outer surface of the marker portion21is not easy, but a contact thereof with the outer surface of the resin portion30is easier, and thus, improving slidability of the guide wire1A.

FIG. 6is an explanatory diagram illustrating a cross-sectional configuration of a guide wire1B according to a third embodiment. The guide wire1B includes a coating film12, and the coating film12includes a marker portion22instead of the marker portion20of the first embodiment inFIG. 3. In the marker portion22, a cross-sectional width of the marker portion22is substantially constant in a radial direction of the core shaft40. The marker portion22has a substantially constant overall pigment content over the longitudinal section of the marker portion22. For example, the coating film12covers the outer surface of the core shaft40with the resin portion30having a groove formed in a wavy shape or a spiral shape toward the stretching direction of the core shaft40, and may be formed by fitting the linearly formed marker portion22into the groove formed in the resin portion30.

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 shaft40in the radial direction, a thickness of an end portion of the marker portion22may be increased, preventing or minimizing the marker portion22from being damaged starting from the end portion of the marker portion22.

FIG. 7is an explanatory diagram illustrating a cross-sectional configuration of a guide wire1C according to a fourth embodiment. The guide wire1C includes a coating film13, and the coating film13includes a marker portion23instead of the marker portion20of the first embodiment inFIG. 3. An inner surface of the marker portion23contacts, e.g., directly contacts, the outer surface of the core shaft40. In this case, a maximum width of the marker portion23and the thickness Hm of a portion of the coating film13where the marker portion23is 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 shaft40, a thickness of the marker portion23may be increased, improving strength of the marker portion23.

Modifications of Embodiment

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

First Modification

It is assumed that the marker portions20,21,22, and23(seeFIGS. 3, 5, 6, and 7) of the first to fourth embodiments are displayed in a part (marker display zone) of the core shaft40. However, the marker portions20,21,22, and23may be formed over the entire core shaft40. The marker portions20,21,22, and23are assumed to be drawn with one pattern. However, the marker portions20,21,22, and23may have a plurality of types of patterns. In this case, the marker portions20,21,22, and23may have a mode in which the pattern changes continuously, or may have a different pattern for each predetermined zone. The marker portions20,21,22, and23may be cut somewhere in the core shaft40and drawn at a plurality of locations. For example, in the marker portions20,21,22, and23, 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.

Second Modification

FIG. 8illustrates a guide wire1D which is a modification of the first to fourth embodiments. The guide wire1D includes a coating film14, and the coating film14includes a marker portion24. An outer surface of the marker portion24is of arc shape and is recessed toward the inside of the core shaft40in the radial direction, e.g., has a convex shape toward the inside of the core shaft40in the radial direction. Therefore, the thickness Hm of the portion of the coating film14where the marker portion24is represented on the outer surface is not substantially constant in the stretching direction of the core shaft40. In the case ofFIG. 8, the thickness of the end portion of the marker portion24is a maximum value of the thickness of the portion of the coating film14where the marker portion24is represented on the outer surface. In the marker portions20,21,22, and23according to the first to fourth embodiments, in the longitudinal section of the core shaft40, similarly to the marker portion24, the outer surface of the marker portions20,21,22, and23may be recessed toward the inside of the core shaft40in the radial direction. As long as the outer surface of the marker portions20,21,22, and23do not protrude outward in the radial direction of the core shaft40from the outer surface of the resin portion30, the outer surface of the marker portions20,21,22, and23may be recessed outward in the radial direction of the core shaft40.

Third Modification

The guide wires1,1A,1B, and1C of the first to fourth embodiments are assumed to include the coil body50at the distal end. However, it is not required that the guide wires1,1A,1B, and1C include the coil body50. In this case, the coating films10,11,12, and13may be provided at the distal end portion of the core shaft40.

Although the aspects have been described based on the embodiments and the modifications, the embodiments of the above-described aspects are for facilitating understanding of the aspects, and do not limit the aspects. The aspects can be modified and improved without departing from the spirit of the aspects and the scope of the claims, and equivalent aspects are included in the aspects. Further, unless a technical feature is described as essential in the present specification, it may be omitted as appropriate.

DESCRIPTION OF REFERENCE NUMERALS