JP2004283198A - Joining structure of guide wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joining structure of a guide wire capable of smoothly performing insertion to a bend part without the influence of the bend angle of the guide wire in the guide wire composed by joining two metallic wires of different materials. <P>SOLUTION: An insertion part 2 is constituted of the metallic wire excellent in form adaptability, and an introduction part 3 is constituted of the metal wire excellent in torque transmission property. A tapered opening part 4 is provided on the center part of an end face on the side of the introduction part 3 of the insertion part 2, a tapered tip part 5 is formed at the tip part of the introduction part 3, and the tapered tip part 5 of the introduction part 3 is fitted into the tapered opening part 4 of the insertion part 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a medical guide wire (referred to as a medical guide wire used for guiding a thin tubular catheter introduced into a blood vessel, a digestive tract, a trachea, and other body cavities (hereinafter referred to as a "treatment tube requiring treatment") requiring treatment or examination. In particular, the present invention relates to a joining structure of the two metal wires in a guide wire in which the insertion portion and the introduction portion are made of metal wires having different performances.
[0002]
[Prior art]
The important performance as a guide wire is that it can be smoothly inserted into the treatment tube required by manual operation, and the catheter can be accurately guided and introduced to a target site. For this reason, the guide wire has a form adaptability that allows the insertion portion to correspond to a complicated meandering tube requiring meandering and to be inserted without damaging the inner wall of the tube requiring treatment, and has an introduction portion following the insertion portion. It is required to have a torque transmitting property for accurately transmitting torque to the insertion portion even with a delicate operation amount at hand.
[0003]
And today, with the development of medical technology, in order to be able to apply to complicated branch vessels, the guide wire has further improved the form adaptability of the insertion part and the torque transmission of the introduction part. Is required.
[0004]
As a guide wire suitable for the above-mentioned purpose, the insertion portion is constituted by an insertion member using a superelastic material such as a Ti-Ni-based alloy having good morphological adaptability, and the introduction portion is made of stainless steel having excellent torque transmission property. There has been proposed a structure in which a high-rigidity introduction member such as a piano wire is used, and both members are covered with a tubular joining member and joined (for example, see Patent Document 1).
[0005]
Therefore, a conventional guide wire disclosed in Patent Document 1 will be described with reference to FIG. In FIG. 3, reference numeral 11 denotes a guide wire. The guide wire 11 includes an insertion member 12 made of a Ti—Ni alloy and an introduction member 13 made of high-tensile stainless steel for a spring. The tubular joining member 14 is covered.
[0006]
[Patent Document 1]
JP-A-4-9162
[Problems to be solved by the invention]
As shown in FIG. 3, in the guide wire in which two metal wires made of different materials are joined, the insertion portion has excellent morphological adaptability, and the introduction portion following the insertion portion has excellent torque transmission. As shown in FIG. 4, if the tubular joint member 14 of the guide wire 11 approaches the bent portion 15a of the blood vessel 15 while the guide wire 11 is being inserted into the blood vessel 15, the tubular joint member 14 is in a bent state.
[0008]
The insertion member 12 is made of a highly flexible (low rigidity and hardly plastically deformed) material for advancing a guide wire in a meandering blood vessel or a thin blood vessel, and the introduction member 13 is at hand. Since it is made of a material having high rigidity in order to provide a function of reliably transmitting the operation to the distal end insertion portion, there is a difference in the amount of transmission torque between the insertion member 12 and the introduction member 13. Therefore, even if the guide wire 11 is rotated while being bent, the amount of torque transmitted from the introduction member 13 to the insertion member 12 varies depending on the difference in the bending angle of the guide wire 11. For example, when the guide wire 11 is close to a straight line, the operation at hand is almost accurately transmitted from the introduction member 13 to the insertion member 12, but as shown in FIG. If it is inclined at a certain angle, it becomes difficult to transmit the operation at hand from the introduction member 13 to the insertion member 12. That is, even if the introduction member 13 is rotated at hand to try to follow the bent portion 15a of the blood vessel 15, the insertion member 12 cannot be operated at will, and the bent state as shown in FIG. 4 may not be realized. .
[0009]
As described above, the conventional guide wire has a problem that the flexibility differs depending on the state (bending angle) of the guide wire. As a result, the tubular joint member 14 cannot be smoothly bent along the shape of the bent portion 15a, and there is an inconvenience that the tubular joining member 14 is damaged or the guide wire 11 is disconnected. An attempt was made to improve the bendability of the tubular joining member 14 by shortening the length of the tubular joining member 14, but in this case, the joining strength was reduced, and it was found that this was not practical. .
[0010]
Further, as shown in FIG. 3, when the joining ends of the insertion member 12 and the introduction member 13 are simply joined to each other and joined, when a bending force is applied to the guide wire 11, as shown in FIG. It was found by experiment that it was easily broken.
[0011]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the related art, and an object of the present invention is to provide a guide wire formed by joining two metal wires made of different materials. An object of the present invention is to provide a guide wire joining structure that can be smoothly inserted into a bent portion without being affected.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a tapered opening so that the diameter gradually decreases inward from the center of the end surface of the insertion member on the introduction member side, and one of the introduction members is provided. By tapering the end portion into a shape adapted to the tapered opening to form a tapered tip, and inserting the tapered tip of the introduction member into the tapered opening of the insertion member. By adopting a structure in which the insertion member and the introduction member are joined, a drop in rigidity between the introduction member and the insertion member is reduced, and the rigidity changes smoothly from the introduction member to the insertion member. Can be transmitted almost accurately from the introduction member to the insertion member.
[0013]
That is, in the guide wire joining structure of the present invention, the insertion portion is formed by an insertion member made of a metal wire having good form adaptability, and the introduction portion is formed by an introduction member made of a metal wire having excellent torque transmission. The guide wire has a structure in which the insertion portion and the introduction portion are joined together, and a tapered opening is provided so that the diameter gradually decreases inward from the center of the end surface of the insertion member on the introduction member side. One end of the introduction member is tapered so as to have a shape adapted to the tapered opening to form a tapered tip, and the tapered tip of the introduction member is tapered to the tapered opening of the insertion member. It is characterized in that the insertion member and the introduction member are joined by being inserted into the section.
[0014]
Morphological adaptability means the ability to easily insert into a complicated bifurcated blood vessel without damaging the inner wall. Torque transmissibility accurately transmits a delicate hand operation amount to the tip (insertion part). In other words, superior torque transmission means that transmittable torque and torsional rigidity are high.
[0015]
As described above, according to the present invention, one end of the introduction member is tapered so as to gradually decrease in diameter toward the tip to form a tapered tip, and the tapered tip of the introduction member is formed. By adopting a structure that is inserted into the tapered opening of the insertion member, a sudden change in rigidity between the introduction member and the insertion member is eliminated, and the rigidity gradually changes from the introduction member to the insertion member, Smooth bendability near the joint between the introduction member and the insertion member, as if operating a fishing rod, transmitting the rotation operation at hand to the insertion member almost exactly, and the difference in the bending angle of the guide wire The guide wire can be freely bent according to the shape of the bent portion without being affected by the above, and can be smoothly inserted into the bent portion.
[0016]
In order to improve the joining between the introduction member and the insertion member, an adhesive is applied to the inner surface of the tapered opening of the insertion member or the tapered tip of the introduction member, so that the tapered opening and the tapered tip are Preferably, the parts are adhered with an adhesive. For example, an epoxy-based adhesive having heat resistance at high temperatures is preferably used as the adhesive.
[0017]
In addition, by adding a brazing material to the outer periphery of the joint between the introduction member and the insertion member and brazing the same, it is also possible to secure a favorable joint between the introduction member and the insertion member. As the brazing material, lead-free solder or the like is preferably used. It is not always necessary to use the bonding with the adhesive and the brazing with the brazing material together, and if a predetermined bonding strength can be obtained, only one of the bonding means can be used.
[0018]
As a means for providing a tapered opening in the end surface of the insertion member on the introduction member side, electric discharge machining can be adopted.
[0019]
The diameter and depth of the tapered opening also depend on the diameter of the insertion member, but if the area of the opening is too large, the strength of the insertion member will be significantly reduced and it will not withstand use. In order to ensure the strength of the insertion member, it is preferable that the entrance diameter of the tapered opening is 0.1 to 0.2 mm, and the hole is formed in the center of the end surface of the insertion member on the introduction member side, and the depth of the opening ( The length from the entrance of the opening to the tip) is preferably 2.0 to 3.0 mm, and the tip diameter of the tapered opening is preferably about 0.05 mm.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. 1 (a) and 1 (b) are cross-sectional views showing a state before and after joining of a joining portion of a guide wire according to an embodiment of the present invention, and FIG. 2 shows a bent state when the guide wire is inserted into a blood vessel. FIG.
[0021]
In FIG. 1A, reference numeral 1 denotes a guide wire, and the guide wire 1 is configured such that the insertion portion 2 is made of a metal wire having a diameter of 0.25 to 0.40 mm of a Ti—Ni-based alloy having good conformability to a shape, The introduction portion 3 is made of a metal wire of SUS304 having a diameter of 0.25 to 0.40 mm and excellent in torque transmission. At the center of the end surface on the side where the metal wire of the Ti—Ni alloy constituting the insertion portion 2 faces the introduction portion 3, a tapered opening 4 whose diameter gradually decreases inward is formed by electric discharge machining. Is formed. The entrance diameter D of the tapered opening 4 is 0.12 to 0.30 mm, the tip diameter d of the tapered opening 4 is 0.10 to 0.28 mm, and the depth L of the tapered opening 4 is 1 to 10 mm. is there.
[0022]
A tapered tip 5 is formed by tapering the tip of the SUS304 metal wire constituting the introduction portion 3 so as to gradually decrease in diameter toward the tip so as to have a shape adapted to the tapered opening 4. are doing. The diameter of the taper start point 6 of the tapered tip 5 is 0.25 to 0.40 mm, the diameter of the tip 7 is 0.10 to 0.30 mm, and the length M of the tapered tip 5 is 10 to 100 mm.
[0023]
As shown in FIG. 1B, an adhesive 8 is applied to the tapered tip 5 of the introduction section 3, and is charged into the tapered opening 4 of the insertion section 2 to form the tapered opening 4 and the tapered opening 4. The tip 5 was adhered and a brazing material (silver brazing) 9 was applied, and the insertion portion 2 and the introduction portion 3 were brazed. It is not always necessary to use the adhesive and the brazing material together, and the insertion section 2 and the introduction section 3 can be joined by only one of the bonding means.
[0024]
As described above, since the joint structure is such that the tapered tip portion 5 of the introduction portion 3 is inserted into the tapered opening portion 4 of the insertion portion 2, the guide wire 1 is inserted into the blood vessel 15 as shown in FIG. When the robot reaches the bent portion 15a of the blood vessel 15, the torque generated by the rotation operation at hand is smoothly transmitted from the introduction portion 3 to the insertion portion 2 through the tapered joint portion 10, and the blood vessel 15 is bent. Since the guidewire 1 can be bent freely according to the shape of the portion 15a, it can be smoothly inserted into a meandering blood vessel.
[0025]
【The invention's effect】
Since the guide wire bonding structure of the present invention is configured as described above, the following effects can be obtained.
[0026]
According to the first aspect of the present invention, it is possible to provide a guide wire bonding structure that can be smoothly inserted into a bent portion without being affected by the bending angle of the guide wire. In particular, the use of the guide wire having the joint structure of the present invention has a remarkable effect that the burden on the doctor in medical practice can be reduced and the affected part can be prevented from being damaged.
[0027]
According to the second and third aspects of the present invention, a more reliable joining structure can be provided.
[Brief description of the drawings]
FIG. 1A is a cross-sectional view showing a state before joining a joining portion of a guide wire according to an embodiment of the present invention, and FIG. 1B is a sectional view of the joining portion.
FIG. 2 is a cross-sectional view showing a bent state when the guide wire of FIG. 1 is inserted into a blood vessel.
FIG. 3 is a cross-sectional view of a joint portion of a conventional guide wire.
FIG. 4 is a cross-sectional view showing a bent state when a conventional guide wire is inserted into a blood vessel.
FIG. 5 is a cross-sectional view showing a bent state when a bending stress is applied to a conventional guide wire.
[Explanation of symbols]
1, 11 guide wire 2, 12 insertion part 3, 13 introduction part 4 tapered opening part 5 tapered tip part 8 adhesive 9 brazing material 10 tapered joining part 14 tubular joining member 15 ... Vessel 15a ... Bend of blood vessel

Claims (3)

The insertion part is formed of an insertion member made of a metal wire having good conformability, and the introduction part is formed of an introduction member made of a metal wire having excellent torque transmission properties. In the structure, a tapered opening is provided so that the diameter gradually decreases inward from the center of the end surface on the introduction member side of the insertion member, and one end of the introduction member is tapered. The tapered end is formed by tapering so as to have a shape conforming to the opening, and the tapered end of the introduction member is inserted into the tapered opening of the insertion member to introduce the insertion member. A joining structure of a guide wire, wherein members are joined. 2. The guidewire joining structure according to claim 1, wherein the tapered opening of the insertion member and the tapered tip of the introduction member are bonded with an adhesive. The guidewire joining structure according to claim 1 or 2, wherein the insertion member and the introduction member are brazed by adding a brazing material to the outer periphery of the joint between the insertion member and the introduction member.

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