JP2002336360A - Medical guide wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical guide wire in which bending flexibility in the far end part of a guide wire is sufficient, the inserting and passing characteristics of the guide wire into a meandering blood vessel are improved, production is facilitated, working accuracy is high, productivity is improved and costs are reduced. SOLUTION: A medical guide wire 2 has a wire main body 4 having a far end side smaller diameter portion 6 of a thin outer diameter in comparison with a close end side large diameter portion and a coil spring 12 mounted around the circumference of the far end side small diameter portion 6 on the wire main body 4. The coil spring 12 has a radiation contrast wire 12a wound in the shape of coil and a radiation non-contrast wire 12b wound in the shape of coil. The coil-like terminal part of the radiation contrast wire 12a and the coil-like terminal part of the radiation non-contrast wire 12b are brought into contact and jointed on the side face along the winding direction of a coil-like winding unit for each of the wires.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical guidewire for guiding a medical device such as a catheter used for treatment or examination to a predetermined position in a body cavity such as a blood vessel.

[0002]

2. Description of the Related Art In some cases, a catheter must be inserted to a predetermined position in a blood vessel for treatment or examination.
A catheter is generally excellent in flexibility, and it is difficult to push a catheter alone to a predetermined position inside a blood vessel. Therefore, it is common practice to insert a guide wire into a blood vessel in advance and guide the catheter to a predetermined position in the blood vessel along the guide wire.

[0003] A guide wire must be inserted into a tortuous blood vessel so as not to damage the inner wall of the blood vessel. When the tip of the guide wire is located in an arterial blood vessel near the heart, the tip of the guide wire is
In many cases, a portion that is bent to R = 20 mm or less is passed. In this case, if permanent deformation is caused, it is difficult to feed the material beyond that. Therefore, the guide wire is
In particular, it is important that the tip portion has excellent flexibility.

Therefore, as a conventional guide wire, the outer diameter of the guide wire at the distal end portion is made smaller than that of the other portions, and a coil spring is mounted on the outer periphery of the distal end portion to improve the flexibility of the distal end portion. A guide wire aiming at the above has been proposed.

[0005] Usually, since the coil spring is made of metal such as stainless steel, the coil spring has low contrast with respect to radiation such as X-rays. However, there is a strong demand to know the position of the distal end of the guidewire accurately by radiography. Therefore, a guide wire including a coil spring in which a part of a wire constituting the coil spring is formed of a radiopaque material has been proposed.

For example, in Japanese Patent Application Laid-Open No. 9-38210, a guide having a coil spring in which a radiopaque wire and a radiolucent wire are butted and welded, the wire is drawn in a reduced diameter, and the wire is wound in a coil shape. Wire has been proposed.

However, in such a coil spring, the portion used as the coil spring after the diameter-reducing wire drawing is only in the vicinity of the joining portion between the radiopaque wire and the radiolucent wire, and both end portions are made of material. It is wasteful and costly. Also, it is difficult to wire-draw to a uniform wire diameter, resulting in poor working accuracy and poor productivity.

Further, as shown in Japanese Patent Application Laid-Open No. 10-43307, the ends of the radiopaque coil and the radiolucent coil are engaged with each other over a plurality of winding portions, and the portions are brazed and joined. Guidewires with coil springs are also known. However, in a guide wire having such a coil spring, a brazed joint portion becomes hard, and in that portion,
There is a possibility that the bending flexibility of the guide wire is impaired, and the insertion and passage characteristics of the guide wire into a meandering blood vessel are deteriorated.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a sufficient bending flexibility at a distal end portion of a guide wire, so that the guide wire can be inserted into a meandering blood vessel. It is an object of the present invention to provide a low-cost medical guidewire which is excellent in quality, easy to manufacture, high in processing accuracy, and excellent in productivity.

[0010]

In order to achieve the above object, a medical guidewire according to a first aspect of the present invention comprises:
A medical guidewire having a wire body and a coil spring attached to an outer periphery on a distal end side of the wire body, wherein the coil spring has a radiographic wire rod wound in a coil shape, and a coil-shaped radiographic wire. The coiled end of the radiographic contrast wire and the coiled end of the radiographic non-contrast wire have side surfaces along the winding direction of the coiled winding unit of each wire. It is characterized in that it is contacted and joined.

[0011] Preferably, the coiled end of the radiographic contrast wire and the coiled end of the non-radiography radiographic wire are:
Each wire has a length of one turn or less, more preferably 0.1 to 1 turn, along the winding direction of the coil-shaped winding unit, and is contacted and joined on each side surface.

[0012] A medical guidewire according to a second aspect of the present invention is a medical guidewire having a wire main body and a coil spring mounted on an outer periphery of a distal end side of the wire main body. A coil spring, a radiographic contrast wire wound in a coil shape, a radiographic non-contrast wire wound in a coil shape, and a joining member having a melting point lower than the melting point of the radiographic contrast wire and the melting point of the non-radiographic contrast wire. Having, the coiled end of the radiographic contrast wire, and the coiled end of the non-radiation contrast wire, via the joining member,
It is characterized in that the wires are joined at the side surfaces along the winding direction of the coiled winding unit. Preferably, the joining member is joined midway in the axial direction at a distal end of the wire body.

[0013] A medical guidewire according to a third aspect of the present invention is a medical guidewire having a wire main body and a coil spring mounted on an outer periphery on a distal end side of the wire main body. A coil spring has a radiographic contrast wire wound in a coil shape, and a radiographic non-contrast wire wound in a coil shape, a coiled end of the radiographic contrast wire, and a coiled end of the radiographic non-contrast wire. However, it is characterized in that the respective wires are joined at the side surfaces along the winding direction of the coil-shaped winding unit via an adhesive.

As the adhesive, a cyanoacrylate-based instant adhesive, an epoxy-based adhesive, an ethylene copolymer-based adhesive, a hot melt adhesive, a phenol-based adhesive, a nylon-based adhesive and the like are used.

[0015] A medical guidewire according to a fourth aspect of the present invention is a medical guidewire having a wire main body and a coil spring mounted on an outer periphery of a distal end side of the wire main body. A coil spring has a radiographic contrast wire wound in a coil shape, and a radiographic non-contrast wire wound in a coil shape, a coiled end of the radiographic contrast wire, and a coiled end of the radiographic non-contrast wire. However, it is characterized in that the bonding material that forms a solid solution with both wires is bonded on the side surfaces along the winding direction of the coil-shaped winding unit of each wire.

For example, the bonding material forming a solid solution of a stainless alloy and a platinum alloy is not particularly limited.
Nickel, palladium, cobalt, platinum and the like are exemplified. Further, the bonding material may be coated on at least the outer periphery of any of the coil ends. Examples of means for coating include plating, sputtering, thermal spraying, vapor deposition, and the like. Further, the bonding material may be provided as a linear member.

Means for contacting and joining the side surfaces of the coiled ends with or without a joining member (including a joining material) include spot welding or laser welding (spot laser welding). Are included). When spot welding is used, it is preferable to perform spot welding at a plurality of positions along the winding direction of the coiled unit of each wire. For example, spot welding is preferably performed at 2 to 10 positions, more preferably 4 to 8 positions, per one turn of the coiled winding unit.

The axial length of the joining member is preferably 10 to 200 μm, more preferably 50 to 100 μm.
It is. The outer and inner diameters of the joining member are comparable to the outer and inner diameters of the coiled end.

Preferably, the melting point of the joining member is lower than the melting point of the material forming the distal end of the wire body. Further, it is preferable that the joining member is joined at the same time in the axial direction of the small diameter portion on the distal end side by spot welding or laser welding for connecting the coiled end to the joining member.

In the present invention, the term "radiation-contrast wire" means a wire made of a material which can be contrasted by radiation such as X-rays, and is not particularly limited. For example, platinum, a platinum alloy, gold, tantalum, tungsten, Iridium and the like are exemplified. In addition, a radiographic non-contrast wire is an X-ray intensity of a normal diagnostic X-ray apparatus which is higher than that of gold or platinum.
This means a wire having a low line absorbance and cannot be imaged with diagnostic X-rays, and is not particularly limited, and examples thereof include stainless steel alloy, copper, aluminum, and chromium copper.

[0021]

According to the medical guidewire of the present invention, the guidewire of the present invention is superior in bending flexibility and tortuous as compared with a conventional guidewire in which the coiled ends are entangled and joined by brazing. It has excellent characteristics of inserting and passing a guide wire into a blood vessel.

In the medical guidewire according to the present invention, at the time of its manufacture, the coiled ends may be welded at a plurality of positions along the circumferential direction by laser spot welding or the like. Therefore, the present invention can provide a low-cost medical guidewire that is easy to manufacture, has high processing accuracy, and is excellent in productivity.

In particular, in the medical guide wire according to the second aspect of the present invention, a radiographic contrast wire, a joining member, and a non-radiological contrast wire are mounted on the outer periphery of the small diameter portion on the distal end side of the wire body. By performing the above-mentioned welding in the state, the following operation is achieved. That is, by the spot welding or the laser welding for connecting the coiled end to the joining member, the coil spring is joined at the same time in the axial direction of the distal end side small diameter portion. In that case, a welding or brazing joining step for joining the coil spring to the small diameter portion on the distal end side of the wire main body is not required separately,
The number of manufacturing steps can be reduced.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments shown in the drawings. FIG. 1 is a partial sectional view of a medical guidewire according to one embodiment of the present invention, FIG. 2 is an enlarged partial perspective view of the coil spring shown in FIG. 1, and FIG.
3 (B) is a schematic explanatory view taken along the line IIIB-IIIB shown in FIG. 3 (A), and FIG.
FIG. 5 is a schematic diagram showing an example of use of the guide wire shown in FIG.
FIG. 5A is a partial cross-sectional view of a coil spring used in a guide wire according to another embodiment of the present invention, and FIG.
FIG. 6 is a schematic explanatory view along the line VB-VB shown in FIG.
(A) and FIG. 6 (B) are partial perspective views of a medical guidewire according to another embodiment of the present invention.

First Embodiment As shown in FIG. 1, a medical guidewire 2 according to an embodiment of the present invention has a small diameter at the distal end having a smaller outer diameter than a large diameter portion at the proximal end. It has a wire body 4 with a portion 6.
The wire body 4 is integrally formed of a wire having a substantially circular cross section, and is tapered toward the distal-end-side small-diameter portion 6. The material of the wire body 4 is not particularly limited, but may be stainless steel (for example, SUS316, SUS316).
304), metals such as gold, platinum, aluminum, tungsten, tantalum or alloys thereof,
In the present embodiment, it is made of stainless steel.

The total length of the wire main body 4 varies depending on the purpose of use and is not particularly limited.
It is about 0 cm. The distal end side small diameter portion 6 of the wire body 4
A coil spring 12 is mounted on the outer periphery of the coil. The axial length L0 of the coil spring 12 is, for example, 5 to 5.
It is about 50 cm. The outer diameter of the large diameter portion on the proximal end side of the wire body 4 is not particularly limited, but may be 0.10 to 0.1.
It is about 90 mm. The outer diameter of the distal-end-side small-diameter portion 6 is not particularly limited, but is preferably about 1/5 to 1/2 the outer diameter of the proximal-end-side large-diameter portion.

The distal end side small diameter portion 6 of the wire body 4
A ball or hemispherical ball portion 10 is joined to the tip of. The ball portion 10 is a portion for smoothing the distal end portion of the guide wire 2 and preventing the inner wall of the body cavity from being damaged when the guide wire 2 is inserted into a body cavity such as a blood vessel. It becomes a distal end side stopper. The ball portion 10 is made of, for example, a metal such as tin, silver, and gold, and is joined to the distal end of the distal-end-side small-diameter portion 6 by means such as welding or brazing. The outer diameter of the ball portion 10 is preferably about 0.5 to 2 times the outer diameter of the large diameter portion on the proximal end side of the wire body 4.

The outer peripheral surface of the wire main body 4 may be integrally coated with a biocompatible coating film. Examples of the biocompatible coating film include, but are not particularly limited to, ordinary polymers used for medical purposes, such as olefins such as polyethylene, nitrogen-containing polymers such as polyimide and polyamide, and siloxane polymers. Further, the coating film is not limited to the polymer, and may be an inorganic coating film such as silicon carbide, carbon such as pyrolite carbon and diamond-like carbon.

In the present embodiment, the coil spring 12
Is composed of a radiographic contrast wire 12a wound in a coil shape and a radiographic non-contrast wire wire 12b wound in a coil shape, and these are axially joined at a joint portion 14. The radiological contrast wire 12a is located on the distal end side of the wire 2 with respect to the radiological non-contrast wire 12b. The axial length L1 of the radiographic wire 12a is preferably 10 to 50 mm.
It is about.

The outer diameter of the coil spring 12 is not particularly limited, but is preferably equal to or less than the outer diameter of the ball portion 10.

The wire diameter of the radiopaque wire 12a and the wire diameter of the radiopaque non-contrast wire 12b may be the same or different. However, in the present embodiment, the wire diameter is the same, and the wire diameter is preferably 20 mm. To 150 μm, more preferably 50 to 1
It is in the range of 00 μm.

The material of the radiographic wire 12a is not particularly limited, but may be platinum, a platinum alloy (for example, Pt / Ir = 9).
3/7), gold, gold-copper alloy, tungsten, tantalum, and other materials having good X-ray contrast properties. The material of the radiation non-contrast wire 12b is not particularly limited, but stainless steel (for example, SUS316, SUS304) or the like is mainly used, and is a material that is inferior in X-ray contrast property to the radiation contrast wire 12a.

As shown in FIG. 2 and FIG. 3, at the joint 14 of the coil spring 12, the coiled end of the radiologically contrasting wire 12a and the coiled end of the non-radiologically contrasting wire 12b are connected to the respective wires 12a, 12a. The coil 12b is directly contacted and joined along the winding direction over about one turn or less (in FIG. 2, 1/4 turn or less) of the coiled winding unit. In order to directly contact and join along the winding direction, in the present embodiment, as shown in FIG.
2b over about one turn of the coiled winding unit,
Spot laser welding is performed at a plurality of zero locations to form a welded portion 16.

The specific conditions of the spot laser welding are not particularly limited, but the following conditions are exemplified. As the laser, a YAG laser is used, and a laser beam condensed to a diameter of 50 μm by an optical system is used. The pulse width of the laser is about 10 ⁻³ seconds, the number of pulses is 10 PPS (pulse / sec), and the output is 10 W.

The medical guidewire 2 according to the present embodiment is more excellent in bending flexibility than a conventional guidewire in which the coiled ends are entangled and brazed and joined. Therefore, as shown in FIG. 4, for example, when the guide wire 2 is inserted from the aorta 22 at the base of the foot to the coronary artery of the heart 20, a blood vessel having a strongly bent portion near the distal end of the wire is used. It can be easily inserted into the inside.

In the guide wire 2 of the present embodiment,
At the time of the manufacture, the portions between the coiled ends may be welded at a plurality of positions along the circumferential direction by laser spot welding. Therefore, in this embodiment, manufacture is easy,
A low-cost medical guidewire 2 with high processing accuracy and excellent productivity can be provided.

Second Embodiment A medical guidewire according to the present embodiment is a modification of the medical guidewire 2 according to the first embodiment, and FIG.
As shown in (A) and FIG. 5 (B), only the part of the coil spring 112 is different, and the others have the same configuration, and the description of the common parts is partially omitted.

As shown in FIG. 5 (A), the coil spring 112 is used for the radiographic wire 1 wound in a coil shape.
12a and a non-contrast radiographic wire 112 wound in a coil shape
b and a ring-shaped joining member 11 arranged in the middle of these
5, which are joined in the axial direction at the joining portion 114.

The length L3 in the axial direction of the joining member 115 is preferably shorter than the size of the spot laser welded portion 116, specifically, 0.05 to 0.5 mm. The outer diameter and inner diameter of the joining member 115
a and 112b are comparable to the outer and inner diameters of the coiled ends.

The joining member 115 is made of, for example, pure platinum, nickel, cobalt, palladium, iridium, etc., is lower than the melting point of the material forming each of the wires 112a and 112b, and forms the distal end side small diameter portion 6. It is composed of a material having a melting point lower than the melting point of. Each wire rod 112
The materials and sizes of a and 112b are the same as those of the wires 12a and 12b shown in FIGS.

In the manufacture of the guide wire of this embodiment, the outer periphery of the joining member 115 is welded at a plurality of positions along the circumferential direction by laser spot welding. Therefore, the coiled ends of the wires 112a and 112b are simultaneously welded to both shaft end surfaces of the joining member 115. This is because the axial length of the joining member 115 is shorter than the size of the welding portion 116.

Further, in the present embodiment, the above-described welding is carried out in a state where the radiographic contrast wire 112a, the joining member 115, and the radiographic non-contrast wire 112b are mounted on the outer periphery of the small diameter portion 6 on the distal end side of the wire main body. Performs the following operation. That is, by the laser spot welding for connecting the coiled end portion to the joining member 115, the coil spring 112 is joined at the same time in the middle of the distal end side small diameter portion 6 in the axial direction. Therefore, in the present embodiment, the coil spring 112 is connected to the distal end side small diameter portion 6 of the wire main body.
This eliminates the necessity of a separate welding or brazing step for joining to the substrate, thereby reducing the number of manufacturing steps.

Third Embodiment As shown in FIG. 6 (A), a medical guidewire according to the present embodiment is a modification of the medical guidewire 2 according to the first embodiment, and is connected to a coil spring. Part 214
Are different from each other, and the others have the same configuration, and the description of the common parts is partially omitted.

As shown in FIG. 6 (A), the coil spring is a radiographic wire 212a wound in a coil shape.
And a non-contrast radiographic wire 212b wound in a coil shape. At the joint 214, the wire is joined by the instant adhesive 215 on the side surfaces along the winding direction of the coiled winding unit of each wire. is there. As the instant adhesive 215, for example, a cyanoacrylate-based instant adhesive is used.

The length of the joining portion 214 is preferably not more than one turn, more preferably 0.1 to 1 turn, along the winding direction of the coiled winding unit. Other configurations are the same as those of the first embodiment.
This is the same as the embodiment, and has the same effect.

Fourth Embodiment As shown in FIG. 6B, the medical guidewire according to the present embodiment is a modification of the medical guidewire 2 according to the first embodiment, and is connected to a coil spring. Part 314
Are different from each other, and the others have the same configuration, and the description of the common parts is partially omitted.

As shown in FIG. 6 (B), the coil spring is a radiographic wire 312a wound in a coil shape.
And a non-contrast-enhanced radiological wire 312b wound in a coil shape, and at a joint 314, a coiled winding unit of each wire through a bonding material 315 that forms a solid solution with both wires. It is joined on the side along the direction. As the bonding material 315, for example, nickel, cobalt, palladium, or iridium is used.
The outer periphery of the joining end of 2a or 312b is previously coated and formed. The joining material 315 is made into a solid solution by laser welding or the like as in the first embodiment, and joins the joining ends of the wires 312a or 312b.

The length of the joining portion 314 is preferably not more than one turn, more preferably 0.1 to 1 turn, along the winding direction of the coiled winding unit. Other configurations are the same as those of the first embodiment.
This is the same as the embodiment, and has the same effect.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the present invention.

[0050]

As described above, according to the present invention, the guide wire has sufficient bending flexibility at the distal end thereof, and has excellent characteristics of inserting and passing the guide wire into a tortuous blood vessel. It is possible to provide a low-cost medical guidewire that is easy to manufacture, has high processing accuracy, and is excellent in productivity.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a medical guidewire according to one embodiment of the present invention.

FIG. 2 is an enlarged partial perspective view of the coil spring shown in FIG.

3 (A) is a partial cross-sectional view of the coil spring shown in FIG. 1, and FIG. 3 (B) is a IIIB-III shown in FIG. 3 (A).
It is a schematic explanatory drawing which follows the B line.

FIG. 4 is a schematic view showing an example of use of the guide wire shown in FIG.

5A is a partial cross-sectional view of a coil spring used in a guide wire according to another embodiment of the present invention, and FIG. 5B is a schematic view taken along line VB-VB shown in FIG. 5A. FIG.

FIG. 6A and FIG. 6B are partial perspective views of a medical guidewire according to another embodiment of the present invention.

[Explanation of symbols]

2 Medical guide wire 4 Wire main body 6 Salt end side small diameter portion 10 Ball portion 12, 112 Coil spring 12a, 112a, 212a, 312a Radiation-contrast wire 12b, 112b, 212b, 312b Non-radiography Wire rods 14, 114, 214, 314 joining part 16, 116 welding part 115 joining member 215 instantaneous adhesive 315 joining substance

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Seiji Shimura 3-12-20 Honcho, Toda City, Saitama F-term (reference) 4C167 AA29 BB16 BB26 BB43 BB52 CC08

Claims (6)

[Claims] 1. A medical guidewire comprising: a wire main body; and a coil spring mounted on an outer periphery of a distal end side of the wire main body, wherein the coil spring is a radiographic wire wound in a coil shape. And a non-contrast radiological wire wound in a coil shape, wherein the coiled end of the radiographic contrast wire and the coiled end of the non-contrast radiological wire are wound in a coiled winding unit of each wire. A medical guidewire, wherein the medical guidewire is in contact with and joined to a side surface in a direction. 2. A coiled end of the radiographic wire,
The coiled end portion of the non-contrast-enhanced radiological wire is characterized by being contacted and joined on each side by a length of one turn or less along a winding direction of a coiled winding unit of each wire. The medical guidewire according to claim 1, wherein 3. A medical guidewire comprising: a wire main body; and a coil spring mounted on an outer periphery on a distal end side of the wire main body, wherein the coil spring is a radiographic wire rod wound in a coil shape. And a non-contrast radiological wire wound in a coil shape, and a joining member having a melting point lower than the melting point of the radiographic wire and the melting point of the non-contrast radiographic wire, and a coiled end of the radiographic wire. And a coil-shaped end portion of a non-contrast radiographic wire, which is joined on the side surface along the winding direction of the coil-shaped winding unit of each wire via the joining member. . 4. The medical guidewire according to claim 3, wherein the joining member is joined at an intermediate position in the axial direction at a distal end of the wire main body. 5. A medical guidewire comprising: a wire main body; and a coil spring mounted on an outer periphery of a distal end side of the wire main body, wherein the coil spring is wound in a coil shape. And a non-contrast radiographic wire wound in a coil shape. The coil-shaped end of the radiographic wire and the coiled end of the non-contrast radiographic wire are each formed of a coil-shaped wire with an adhesive. A medical guidewire which is joined at a side surface along a winding direction of a winding unit. 6. A medical guidewire comprising: a wire main body; and a coil spring attached to an outer periphery of a distal end side of the wire main body, wherein the coil spring is wound in a coil shape. And a non-contrast radiographic wire wound in a coil shape, wherein the coiled end of the radiographic wire and the coiled end of the non-contrast radiological wire are a bonding material that forms a solid solution with both wires. A medical guidewire characterized in that side surfaces are joined along a winding direction of a coiled winding unit of each wire.