JP7580905B2 - Guidewire and method of manufacturing same - Google Patents

Description

The present invention relates to a guidewire used when inserting a catheter or the like into a predetermined position in a human tissue, such as a tubular organ of the human body, such as the bile duct, pancreatic duct, blood vessel, ureter, or trachea, or a body cavity, and a method for manufacturing the same.

For some time now, catheters have been inserted into tubular organs of the human body, such as the bile duct, pancreatic duct, blood vessels, ureter, and trachea, to inject medicinal fluids, balloon catheters to expand blocked tubular organs, and stents to be placed. When carrying out these procedures, a guidewire is first inserted into the tubular organ and brought to a predetermined position, and then a catheter, balloon catheter, or tube holding a stent is moved along its outer circumference.

That is, the guidewire is inserted into the tubular organ prior to the catheter, etc., but at the branching point where the tubular organ branches, it is necessary to select a specific branching vessel. In this case, the proximal side of the guidewire is rotated, the torque is transmitted to the tip of the guidewire, and the tip of the guidewire is directed toward the desired branching vessel, after which the guidewire is inserted. For this reason, torque transmission is important for transmitting torque from the proximal side of the guidewire to the tip of the guidewire.

As an example of such a guidewire with improved torque transmission, the following Patent Document 1 describes a medical guidewire with a double coil structure having an inner coil arranged on the outer periphery of the distal end of the core shaft and an outer coil arranged on the outer periphery of the inner coil. The base ends of the inner coil and the outer coil are fixed to the outer periphery of the core shaft by brazing or the like, while the distal ends of the inner coil and the outer coil are fixed to the very tip of the core shaft via hemispherical distal tips.

Patent No. 5004256

In the medical guidewire of Patent Document 1, the distal ends of the inner coil and outer coil are connected via a distal tip, but because the two coils are separate, when torque is applied from the proximal side of the guidewire, it is difficult to make the two coils interact with each other, which tends to make it difficult to improve torque transmission.

Therefore, the object of the present invention is to provide a guidewire and a method for manufacturing the same that can improve torque transmission.

In order to achieve the above object, one of the present inventions is a guidewire having a core wire and a coil member attached to the outer periphery of the core wire, the coil member having at least a first coil portion arranged on the outer periphery of the core wire and a second coil portion arranged on the outside of the first coil portion, the second coil portion being folded back and extending from a folded portion located on one end side of the first coil portion toward the other end side of the first coil portion and being arranged so as to overlap the outside of the first coil portion, the first coil portion, the second coil portion, and the folded portion being formed from the same continuous wire material.

On the other hand, another aspect of the present invention is a method for manufacturing a guidewire having an extension portion, which includes a first step of winding a wire around the outer periphery of the reduced diameter portion of a core bar having a base portion and a reduced diameter portion that is smaller in diameter than the base portion to form the first coil portion, a second step of folding back the wire at one end side of the first coil portion to form the folded portion, and wrapping the wire around the outside of the first coil portion toward the other end side of the first coil portion to form the second coil portion, and a third step of winding the wire around the outer periphery of the base portion of the core bar to form the extension portion.

According to the present invention, the first coil portion and the second coil portion are formed from the same continuous wire, and the second coil portion is arranged so as to overlap the outside of the first coil portion via the folded portion, so that it is possible to improve torque transmission when the guidewire is rotated (twisted) at the base end (hand side) to change the direction of the tip of the guidewire.

1 is a side view showing a first embodiment of a guide wire according to the present invention. FIG. FIG. 2 is a cross-sectional view of the guidewire. 5A and 5B show other shapes of the coil member constituting the guidewire, where FIG. 5A is a side view of a first other shape, and FIG. 5B is a side view of a second other shape. 1A shows one embodiment of a method for manufacturing a guidewire according to the present invention, where (a) is an explanatory diagram showing a first step, (b) is an explanatory diagram showing a second step, and (c) is an explanatory diagram showing a third step. FIG. 11 is a side view showing a second embodiment of a guidewire according to the present invention. FIG. 2 is a cross-sectional view of the guidewire. FIG. 11 is a cross-sectional view showing a third embodiment of a guidewire according to the present invention. FIG. 11 is a cross-sectional view showing a fourth embodiment of a guidewire according to the present invention. FIG. 13 is a cross-sectional view showing a fifth embodiment of a guidewire according to the present invention.

One embodiment of the guidewire according to the present invention will be described below with reference to the drawings. Figures 1 to 3 show a first embodiment of the guidewire according to the present invention.

As shown in FIG. 1, the guidewire 10 of this embodiment has a core wire 20 that extends to a predetermined length and a coil member 30 that is attached to the outer periphery of the core wire 20.

The core wire 20 is a round wire with a circular cross section, and has a base 21 that extends a predetermined length with a constant outer diameter, and a tip 23 that is provided on the tip side of the base 21 and has a smaller diameter than the base 21. The tip 23 has a tapered shape that gradually reduces in diameter as it extends from the tip of the base 21 toward the tip of the core wire. The very tip of the tip 23 of the core wire 20 is the tip 23a (the distal end furthest from the hand of the guidewire operator), and the very base end of the base 21 is the base end 21a (the proximal end closest to the hand of the guidewire operator).

The tip portion 23 may have a shape that has, for example, a tapered portion that extends from the tip of the base portion toward the tip of the core wire while gradually reducing in diameter, and a thin-diameter portion that extends linearly from the tip of the tapered portion with a constant outer diameter, or a stepped shape in which the diameter gradually reduces toward the tip of the core wire, and is not particularly limited.

The core wire 20 may be made of superelastic alloys such as Ni-Ti alloys, Ni-Ti-X (X = Fe, Cu, V, Co, Cr, Mn, Nb, etc.) alloys, Cu-Zn-X (X = Al, Fe, etc.) alloys, stainless steel, piano wire, etc. Alternatively, X-ray impermeable metals such as W, Pt, Ti, Pd, Rh, Au, Ag, Bi, Ta, and alloys thereof may be used.

As shown in FIG. 2, the coil member 30 has a multiple coil structure having at least a first coil section 40 arranged on the outer periphery of the core wire 20 and a second coil section 50 arranged outside the first coil section 40. The coil member 30 of this embodiment has a double coil structure consisting of the first coil section 40 and the second coil section 50. However, one or more coil sections may be arranged further outside the second coil section 50, and there is no particular limitation (a triple coil structure will be described in the fourth and fifth embodiments below).

The second coil section 50 is folded back and extends toward the other end 43 of the first coil section 40 via a folded portion R located on one end 41 side of the first coil section 40, and is arranged so as to overlap the outside of the first coil section 40, and the first coil section 40, the second coil section 50, and the folded portion R are formed from the same continuous wire material W. Note that since the first coil section 40 and the second coil section 50 are folded back via the folded portion R, the winding directions of the wire material W in each coil section 40, 50 are opposite to each other.

The wire W for continuously and integrally forming the coil member 30 may be made of superelastic alloys such as Ni-Ti alloys, Ni-Ti-X (X = Fe, Cu, V, Co, Cr, Mn, Nb, etc.) alloys, Cu-Zn-X (X = Al, Fe, etc.) alloys, stainless steel, piano wire, etc. Alternatively, radiopaque metals such as W, Pt, Ti, Pd, Rh, Au, Ag, Bi, Ta, and alloys thereof may be used.

As shown in FIG. 2, the first coil portion 40 in this embodiment is formed by winding a wire W having a circular cross section, and is arranged on the outer periphery of the tip portion 23 of the core wire 20. The first coil portion 40 in this embodiment has a tightly wound structure in which the wire W is wound so as to be in close contact with each other over the entire length from one end 41 to the other end 43. The first coil portion 40 has one end 41 arranged on the tip 23a side of the tip portion 23 of the core wire 20, and the other end 43 arranged at a location closer to the base 21 of the tip portion 23 of the core wire 20. The one end 41 and the other end 43 of the first coil 40 may be arranged in the opposite direction to the above arrangement. That is, the one end 41 of the first coil portion 40 may be arranged at a location closer to the base of the tip portion 23 of the core wire 20, and the other end of the first coil portion 40 may be arranged on the tip 23a side of the tip portion 23 of the core wire 20.

In this embodiment, the wire has a circular cross section, but it may have, for example, an angular cross section. The wire diameter of the wire W is preferably 0.03 to 0.10 mm, and more preferably 0.05 to 0.08 mm.

Furthermore, as shown in FIG. 2, the inner diameter of the first coil portion 40 is constant from one end 41 to the other end 43, and is larger than the outer diameter of the tip 23a side of the tip portion 23 of the core wire 20. Therefore, when the first coil portion 40 is arranged on the outer periphery of the tip portion 23 of the core wire 20, a predetermined gap is formed between the inner periphery of one end 41 of the first coil portion 40 and the outer periphery of the tip portion 23 of the core wire 20.

The outer diameter D1 of the first coil portion 40 is preferably 0.12 to 0.26 mm, and more preferably 0.16 to 0.22 mm. Furthermore, the axial length L1 of the first coil portion 40 (the distance from one end 41 to the other end 43) is preferably 25 to 100 mm, and more preferably 50 to 75 mm.

On the other hand, the second coil section 50 extends from one end 41 of the first coil section 40 via a folded section R formed by folding the wire W back toward the other end 43 of the first coil section 40, and is positioned so as to overlap the outside of the first coil section 40.

As shown in FIG. 2, the folded portion R provides an essential folded portion for overlapping and arranging the second coil portion 50 on the outside of the first coil portion 40 when integrally forming the first coil portion 40 and the second coil portion 50 from a single continuous wire W, and has a structure including one end 41 of the first coil portion 40 and one end 51 of the second coil portion 50. In addition, this folded portion R is disposed on the tip 23a side of the tip portion 23 of the core wire 20.

Furthermore, one end 41 of the first coil section 40 on the folded-back portion R side and one end 51 of the second coil section 50 on the folded-back portion R side are structured so that one of them protrudes in the axial direction compared to the other. In this embodiment, one end 41 of the first coil section 40 protrudes in the axial direction toward the tip 23a of the core wire 20 relative to one end 51 of the second coil section 50. Also, here, one end 41 of the first coil section 40 protrudes toward the tip 23a of the core wire 20 relative to one end 51 of the second coil section 50 by an amount of protrusion approximately equal to the radius of the wire W, and the first coil section 40 and the second coil section 50 have a double coil structure in which they are misaligned by half a pitch.

In addition, one end 51 of the second coil section 50 may protrude toward the tip 23a of the core wire 20 relative to one end 41 of the first coil section 40, and further, one end 41 of the first coil section 40 and one end 51 of the second coil section 50 may be aligned in the axial direction of the core wire 20 (at the same axial location).

In addition, in this embodiment, as described above, since the first coil section 40 and the second coil section 50 have a double coil structure with a half-pitch position shift, a portion of the wire W forming the second coil section 50 enters and abuts between the wires W, W forming the first coil section 40, as shown in the partially enlarged view of Figure 2.

Furthermore, the second coil portion 50 extends a predetermined length from one end 51 forming the folded portion R toward the other end 43 of the first coil portion 40, and extends beyond the other end 43 toward the base end 21a of the core wire 20, and has an extension portion 55 in which only the second coil portion 50 is disposed alone. As shown in FIG. 2, the extension portion 55 in this embodiment is formed with an inner diameter D2' that is the same as the inner diameter of the second coil portion 50, and the inner diameter D2' of the extension portion 55 is set to be larger than the inner diameter D1' of the first coil portion 40. As described above, the coil member 30 in this embodiment has a shape in which the second coil portion 50 extends longer than the first coil portion 40, but it is not particularly limited even if the first coil portion extends longer than the second coil portion, or the first coil portion and the second coil portion extend the same length (these will be described in the embodiment described later).

The tip 23a of the core wire 20, one end 41 of the first coil section 40, one end 51 of the second coil section 50, and the folded portion R consisting of one ends 41, 51 of both coil sections 40, 50 are fixed to each other via a rounded head 35 made of a fixing material such as metal solder or adhesive. At this time, the fixing material is attached to the axial tip side of one end 41 of the first coil section 40 that constitutes the folded portion R and to the axial tip side of one end 51 of the second coil section 50. The fixing material that forms the head 35 also enters the gap between the inner circumference of one end 41 of the first coil section 40 and the outer circumference of the tip section 23 of the core wire 20, and the one end 41 of the first coil section 40 that constitutes the folded portion R is fixed at a location near the tip 23a of the tip section 23 of the core wire 20. That is, the folded portion R is fixed to the core wire 20.

The above-mentioned fastening material for fastening the coil member 30 to the core wire 20 may be, for example, a brazing material such as Sn or Ag brazing, but other materials such as, for example, ultraviolet-curing acrylate resin, silicone adhesive, modified silicone adhesive, epoxy resin adhesive, acrylate adhesive, urethane resin adhesive, etc. may also be used.

Furthermore, the other end 43 of the first coil section 40 is fixed to the tip 23 of the core wire 20 at a location near the base 21 via a fixing section 45 made of the above-mentioned fixing material. The other end 53 side of the second coil section 50, i.e., the other end 53 side of the extension section 55 located on the other end 23a side of the core wire 20, is fixed to the tip 23 of the core wire 20 at a location near the base 21 via a fixing section 57 made of the above-mentioned fixing material. In this way, the coil member 30 in this embodiment is attached to the outer periphery of the core wire 20 via multiple fixing sections 45, 57 and the head 35. Note that the coil member may be fixed to the core wire 20 at a predetermined location in the middle of the axial direction, in addition to both ends of both coil sections 40, 50.

In addition, in this embodiment, the second coil section 50, like the first coil section 40, has a tightly wound structure in which the wires W are wound so as to be in close contact with each other over the entire length from one end 51 to the other end 53. However, both coil sections 40, 50 may be loosely wound with a predetermined gap between the wires W, or may have a portion of the axial direction that is tightly wound or loosely wound, and are not particularly limited.

Figure 3 illustrates such coil members of other shapes. In the coil member 30A of Figure 3(a), the range from one end 41 of the first coil section 40 to just before the other end 43 is a densely wound section M, and the range from the end of this densely wound section M closer to the other end 43 to the other end 43 is a loosely wound section S. In addition, the axially intermediate section of the second coil section 50 is a densely wound section M, and loosely wound sections S, S are provided at both axial end sections. Furthermore, the second coil section 50 extends longer than the first coil section 40.

On the other hand, in the coil member 30B of FIG. 3(b), the range from one end 41 of the first coil section 40 to just before the other end 43 is the densely wound portion M, and the range from the end of the densely wound portion M closer to the other end 43 to the other end 43 is the sparsely wound portion. Also, the range from one end 51 of the second coil section 50 to just before the other end 53 is the densely wound portion M, and the range from the end of the densely wound portion M closer to the other end 53 to the other end 53 is the sparsely wound portion S. Furthermore, the first coil section 40 extends longer than the second coil section 50.

In addition, since the coil members 30A and B as described above have a loosely wound portion S, it is easier for a fastening material such as metal brazing material to penetrate between the wires W, W that make up this loosely wound portion S, which has the advantage of increasing the attachment strength of the coil member to the core wire 20.

The outer diameter D2 of the second coil portion 50 is preferably 0.18 to 0.46 mm, and more preferably 0.26 to 0.38 mm. Furthermore, the axial length L2 (the distance from one end 51 to the other end 53) of the second coil portion 50 is preferably 50 to 500 mm, and more preferably 100 to 300 mm.

In addition, radiopaque markers may be provided on the first coil section 40 and the second coil section 50 that constitute the coil member 30. Such radiopaque markers may be provided on the core wire 20 side. Furthermore, a resin layer may be applied to the outer periphery of the coil member 30. This resin layer may cover not only the coil member 30 but also the entire guidewire, including the core wire 20.

Next, we will explain one embodiment of a method for manufacturing the guidewire of the present invention for manufacturing the guidewire of the above embodiment (guidewire 10 having an extension portion 55).

As shown in FIG. 4, the manufacturing method of this guidewire includes a first step (see FIG. 4(a)) of winding a wire W around the outer circumference of the narrowed diameter portion 5 of the core bar 1, which has a base portion 3 and a narrowed diameter portion 5 that is narrower than the base portion 3, to form a first coil portion 40; a second step (see FIG. 4(b)) of folding back the wire W at one end 41 of the first coil portion 40 to form a folded portion R and wrapping the wire W around the outside of the first coil portion 40 toward the other end 43 of the first coil portion 40 to form a second coil portion 50; and a third step (see FIG. 4(c)) of wrapping the wire W around the outer circumference of the base portion 3 of the core bar 1 to form an extension portion 55.

More specifically, the core 1 in this manufacturing method has a base 3 that extends with a constant outer diameter, and a reduced diameter portion 5 that extends from one end of the base 3 with a constant outer diameter smaller than that of the base 3. In this embodiment, since a part of the wire W that forms the second coil portion 50 enters and abuts between the wires W, W that form the first coil portion 40 (see the partially enlarged view in Figure 2), the outer diameter of the base 3 is formed with an outer diameter slightly smaller than the outer diameter of the wire W wound around the outer periphery of the reduced diameter portion 5 (an outer diameter that matches the inner diameter of the wire W in the state in which the second coil portion 50 is formed) (see Figure 4 (b)).

Then, as shown by the arrow F1 in FIG. 4(a), the wire W is wound from the other end 5b of the reduced diameter portion 5 toward the one end 5a, and wound up to the one end 5a of the reduced diameter portion 5 of the core bar 1, thereby forming the first coil portion 40 (this is the first step).

Then, the wire W is folded back at one end 41 of the first coil section 40 and wound around the outside of the first coil section 40 toward the other end 43 of the first coil section 40, as shown by arrow F2 in FIG. 4. Then, the second coil section 50 overlaps the outside of the first coil section 40 without any gaps, forming a double coil shape. The wire W is further wound up to the other end 5b of the reduced diameter section 5 of the core 1, thereby forming the second coil section 50 except for the extension section 55 (this is the second process).

Then, the wire W is wound around the outer circumference of the base 3 of the core 1 until it reaches the other end 3a of the base 3 of the core 1, thereby forming an extension portion 55 that extends beyond the other end 43 of the first coil portion 40 (this is the third step).

After the first to third steps, the core wire 1 is pulled out from the coil member 30, and the coil member 30 is placed on the outer periphery of the tip portion 23 of the core wire 20. As described above, the coil member 30 is attached to the outer periphery of the core wire 20 via the multiple fixing portions 45, 57 and the head portion 35, thereby manufacturing the guide wire 10 as shown in Figures 1 and 2.

In this way, the manufacturing method of this guidewire includes the above-mentioned first, second, and third steps, so that the first coil portion 40, the folded portion R, and the second coil portion 50 can be continuously and integrally formed from a single wire W, and the second coil portion 50 can be provided with an extension portion 55 having an inner diameter D2' larger than the inner diameter D1' of the first coil portion 40.

Next, we will explain how to use the guidewire of the present invention, which has the above structure.

The guidewire 10 in this embodiment can be used, for example, to place a catheter or place a stent in a predetermined position in various tubular organs such as blood vessels, bile ducts, pancreatic ducts, ureters, and tracheas, or in human tissue such as body cavities, and there is no particular limitation on the location of use.

When in use, the guidewire 10 is inserted from the tip side (coil member 30 side) into the tubular organ and pushed in until it reaches the desired location. At that time, the desired branch tube may be selected at the branching point of the tubular organ. In this case, the base end side (hand side) of the guidewire 10 is rotated at the branching point to select the desired branch tube.

2, the first coil section 40 and the second coil section 50 are formed from the same continuous wire W, and the second coil section 50 is arranged so as to overlap the outside of the first coil section 40 via the folded section R. This improves torque transmission when the guidewire 10 is rotated (twisted) at the base end to change the direction of the tip of the guidewire 10. That is, the torque applied to the base end 21a of the core wire 20 is transmitted to the first coil section 40, the folded section R, and the second coil section 50 on the outer periphery of the core wire 20. However, since the first coil section 40, the second coil section 50, and the folded section R are integrally formed from a single wire W, the torque from the base end of the core wire is transmitted smoothly to both coil sections 40 and 50, and the two coil sections 40 and 50 are easily allowed to interact with each other, compared to a structure in which the folded sections are separate, and as a result, the torque transmission can be improved.

When the inner coil and outer coil, which are separate from each other, are fixed to the core shaft via brazing, as in the medical guidewire of Patent Document 1, if the brazing of the inner coil and outer coil is insufficient or defective, there is a risk of reduced torque transmission. In contrast, in this guidewire 10, as described above, the two coil sections 40, 50 are integrally formed via the folded portion R, so brazing the two coil sections 40, 50 together is not necessary in the first place, and any resulting reduction in torque transmission can be reliably prevented.

In addition, in this embodiment, as shown in FIG. 2, the folded portion R is fixed to the core wire 20 (here, the fixing material forming the head 35 enters the gap between the inner circumference of one end 41 of the first coil portion 40 and the outer circumference of the tip portion 23 of the core wire 20, so that one end 41 of the first coil portion 40 and one end 51 of the second coil portion 50 constituting the folded portion R are fixed to the core wire 20). Therefore, when the guidewire 10 is rotated, the torque from the core wire 20 is directly transmitted to the folded portion R, thereby further improving torque transmission.

Furthermore, in this embodiment, as shown in FIG. 2, the folded portion R is disposed on the tip 23a side of the core wire 20. Therefore, the torque generated when the guidewire 10 is rotated on the base end side can be easily transmitted from the base end 21a side to the tip 23a side of the core wire 20, thereby further improving torque transmission.

In addition, in this embodiment, as shown in FIG. 2, one end 41 of the first coil section 40 on the folded portion R side and one end 51 of the second coil section 50 on the folded portion R side are structured so that one of them protrudes in the axial direction compared to the other. In other words, the one end 41 of the first coil section 40 on the folded portion R side and the one end 51 of the second coil section 50 on the folded portion R side are configured to be shifted in the axial direction, so that when a fixing agent such as metal solder or adhesive is applied to the folded portion R to attach the coil member 30 to the outer periphery of the core wire 20, it is possible to easily apply them, and the attachment strength of the coil member 30 to the core wire 20 can be increased, and the coil member 30 can be made less likely to be misaligned with respect to the core wire 20.

Furthermore, in this embodiment, the second coil section 50 has an extension section 55 that extends beyond the other end 43 of the first coil section 40 and is formed by disposing only the second coil section 50, and the inner diameter D2' of this extension section 55 is set to be larger than the inner diameter D1' of the first coil section 40 (see FIG. 2). Therefore, the stiffness of the coil member 30 can be changed relatively smoothly from its base end side to its tip end side, making it less likely to kink, and it is also possible to make it difficult for a step to occur between the coil member 30 and the core wire 20, so that the surface of the guidewire 10 can be formed smoothly and it can be smoothly inserted into various tubular organs, body cavities, etc.

Figures 5 and 6 show a second embodiment of the guidewire according to the present invention. Note that parts that are substantially the same as those in the previous embodiment are given the same reference numerals and their description is omitted.

As shown in Figs. 5 and 6, the guidewire 10A of the second embodiment has a double coil structure consisting of a first coil section 40 and a second coil section 50, like the guidewire 10 of the first embodiment, but the other end 43 of the first coil section 40 arranged on the outer periphery of the core wire 20 extends longer than the other end 53 of the second coil section 50 arranged on the outer side thereof. As shown in Fig. 6, the other end 53 of the second coil section 50 and the axial middle part of the first coil section 40 are fixed to each other via the fixing section 45 made of the fixing material at the axial middle of the tip section 23 of the core wire 20. The guidewire 10A having such a configuration can also obtain the same effects as the guidewire 10 of the first embodiment.

Figure 7 shows a third embodiment of the guidewire according to the present invention. Note that parts that are essentially the same as those in the previous embodiment are given the same reference numerals and their description is omitted.

As shown in FIG. 7, the guidewire 10B of the third embodiment has a structure in which another coil is connected to the distal end side of the coil member of the guidewire 10 of the first embodiment.

That is, the guide wire 10B has a coil member 30 having a double coil structure consisting of a first coil portion 40 and a second coil portion 50, and a coil member 37 is arranged on the tip 23a side of the tip portion 23 of the core wire 20 from the coil member 30, and is made of a wire W' having a larger diameter than the wire W constituting the coil member 30 and is separate from the coil member 30. One end 37a of the coil member 37 is fixed to the tip 23a of the core wire 20 via a head portion 35 made of the fixing material. The other end 37b of the coil member 37 abuts against one end 51 of the second coil portion 50 of the coil member 30, and the other end 37b of the coil member 37, one end 41 of the first coil portion 40, and one end 51 of the second coil portion 50 are fixed to each other via a fixing portion 47 made of the fixing material in the axial middle of the tip portion 23 of the core wire 20.

The guidewire 10B having such a configuration can achieve the same effect as the guidewire 10 of the first embodiment. In addition to the coil member 30, a separate coil member 37 is provided, so that the axial length of the entire coil member can be extended.

Figure 8 shows a fourth embodiment of the guidewire according to the present invention. Note that parts that are essentially the same as those in the previous embodiment are given the same reference numerals and their description is omitted.

As shown in FIG. 8, the guidewire 10C of the fourth embodiment differs from the first to third embodiments in the structure of the coil member 30. That is, the coil member 30 in the fourth embodiment has a triple coil structure consisting of a first coil section 40 arranged on the outer periphery of the core wire 20, a second coil section 50 arranged on the outside of the first coil section 40, and a third coil section 60 arranged on the outside of the second coil section 50.

In addition, a folded portion R is located on one end 41 of the first coil portion 40 and one end 51 of the second coil portion 50, and a folded portion R is also located on the other end 53 of the second coil portion 50 and the other end 63 of the third coil portion 60. That is, the second coil portion 50 is folded back and extended toward the other end 43 of the first coil portion 40 via the folded portion R located on the one end 41 side of the first coil portion 40, and is arranged so as to overlap the outside of the first coil portion 40, and the third coil portion 60 is folded back and extended toward the one end 51 of the second coil portion 50 via the folded portion R located on the other end 53 side of the second coil portion 50, and is arranged so as to overlap the outside of the second coil portion 50, and the first coil portion 40, the second coil portion 50, the third coil portion 60, and the two folded portions R, R are formed of the same continuous wire W. As shown in FIG. 8, the other end 43 of the first coil section 40, which is disposed on the outer periphery of the core wire 20, extends longer than the other end 53 of the second coil section 50 and the other end 63 of the third coil section 50. Furthermore, the axial middle portion of the first coil section 40, the other end 53 of the second coil section 50, and the other end 63 of the third coil section 60 are fixed to each other at the axial middle of the tip section 23 of the core wire 20 via the fixing section 45 made of the fixing material.

The guidewire 10C having such a configuration can achieve the same effect as the guidewire 10 of the first embodiment. In addition, since the coil member 30 has a triple coil structure, the torque generated when the base end side of the guidewire 10C is rotated can be easily transmitted to the three coil portions 40, 50, and 60 via the two folded portions R, thereby further improving torque transmission.

Figure 9 shows a fifth embodiment of the guidewire according to the present invention. Note that parts that are essentially the same as those in the previous embodiment are given the same reference numerals and their description is omitted.

As shown in FIG. 9, the guidewire 10D of the fifth embodiment has a coil member 30 having a triple coil structure consisting of a first coil section 40, a second coil section 50, and a third coil section 60, as in the fourth embodiment. In addition, the coil sections 40, 50, and 60 extend at approximately the same length so that the other end 43 of the first coil section 40, the other end 53 of the second coil section 50, and the other end 63 of the third coil section 60 are at approximately the same position, and these other ends 43, 53, and 63 are fixed to each other via the fixing section 45 made of the fixing material. In the guidewire 10D having such a configuration, it is possible to obtain the same effect as the guidewire 10 of the first embodiment, and since the coil member 30 has a triple coil structure as in the fourth embodiment, it is possible to further improve the torque transmission.

The present invention is not limited to the above-described embodiment, and various modified embodiments are possible within the scope of the present invention, and such embodiments are also included in the scope of the present invention.

REFERENCE SIGNS LIST 1 Core metal 3 Base portion 5 Reduced diameter portion 10, 10A, 10B, 10C, 10D Guide wire 20 Core wire 21 Base portion 23 Tip portion 30, 30A, 30B Coil member 35 Head portion 40 Second coil portion 41 One end 43 Other end 50 Second coil portion 51 One end 51 Other end 55 Extension portion R Folded portion

Claims (4)

A method for manufacturing a guidewire, comprising the steps of:
The guide wire comprises:
The coil member has a core wire and a coil member disposed and attached to the outer periphery of the core wire.
the coil member has a multiple coil structure including at least a first coil portion disposed on an outer periphery of the core wire and a second coil portion disposed outside the first coil portion,
the second coil portion is folded back and extends toward the other end of the first coil portion via a folded back portion located at one end of the first coil portion, and is disposed so as to overlap the outside of the first coil portion, the first coil portion, the second coil portion, and the folded back portion being formed from the same continuous wire material,
the second coil portion has an extension portion that extends beyond the other end of the first coil portion and in which only the second coil portion is disposed, and an inner diameter of the extension portion is set to be larger than an inner diameter of the first coil portion,
A core bar having a base portion and a reduced diameter portion having a diameter smaller than that of the base portion is used,
a first step of winding a wire around an outer periphery of the reduced diameter portion of the core to form the first coil portion;
a second step of folding back the wire at one end side of the first coil portion to form the folded portion, and winding the wire around the outside of the first coil portion toward the other end side of the first coil portion to form the second coil portion;
a third step of winding the wire around an outer periphery of the base portion of the core metal to form the extension portion, thereby manufacturing the coil member;
a method for manufacturing the guide wire by pulling out the core bar from the coil member, inserting the core wire into the inside of the coil member, disposing the coil member on an outer periphery of the core wire, and attaching the coil member to the outer periphery of the core wire via a fixing portion,
A method for manufacturing a guidewire, characterized in that the first step, the second step, and the third step form the first coil portion, the folded portion, the second coil portion, and the extension portion continuously and integrally using a single wire. The method for manufacturing a guidewire according to claim 1, wherein the folded portion is fixed to the core wire. The method for manufacturing a guidewire according to claim 1 or 2, wherein the folded portion is disposed on the tip side of the core wire. A method for manufacturing a guidewire as described in any one of claims 1 to 3, wherein one end of the first coil portion on the folded portion side and one end of the second coil portion on the folded portion side are such that the one end of either coil portion protrudes in the axial direction relative to the one end of the other coil portion .

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