JP2004135823A - Medical guide wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical guide wire smoothly inserted into a curved part in the medical guide wire formed by joining two metal wires having different materials. <P>SOLUTION: An insertion part 2 is composed of a metal wire having superior deformability and an introduction part 3 is composed of a metal wire having superior torque transmission performance. A joining member 4 is wound around the outer circumference of the joining part between the insertion part 2 and the introduction part 3 into a coil shape. <P>COPYRIGHT: (C)2004,JPO

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 required tube") requiring treatment or examination. In particular, the present invention relates to a joining structure of the two metal wires in a medical guidewire in which an insertion portion and an introduction portion are made of metal wires having different performances.
[0002]
[Prior art]
An important performance as a medical guidewire is that it can be smoothly inserted into a treatment tube required by manual operation, and a 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, as medical technology advances, in order to be applicable to complicated bifurcated blood vessels, medical guidewires have more adaptability of the insertion section and torque transmission of the introduction section. There is a need for further improvement.
[0004]
As a medical guide wire suitable for the above purpose, the insertion portion is constituted by an insertion member using a Ti-Ni-based alloy having good morphological adaptability, and the introduction portion is formed of a stainless steel introduction member excellent in torque transmission. And joining these two members by covering them with a tubular joining member.
[0005]
Therefore, a conventional medical guidewire will be described with reference to FIG. In FIG. 3, reference numeral 11 denotes a medical guidewire. The medical guidewire 11 includes an insertion member 12 made of a Ti—Ni-based alloy and an introduction member 13 made of stainless steel. The tubular joining member 14 is covered.
[0006]
The technology related to the present invention was originally developed by the inventor, and the present invention was also completed based on the inventor's original thinking. Absent.
[0007]
[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]
At this time, if a rotational motion is given to the guide wire 11, the tubular joining member 14 cannot be smoothly bent along the shape of the bent portion 15a due to poor flexibility, and as a result, 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. .
[0009]
Further, when joining two metal wires made of different materials using a tubular joining member to form a guide wire, as shown in FIG. 5, the joining ends of the insertion member 12 and the introduction member 13 are simply butted to be joined. It has been found through experiments that the guide wire 11 is easily broken at the abutting portion 16 when a bending force is applied to the guide wire 11.
[0010]
The present invention has been made in view of the above-mentioned problems of the related art, and an object of the present invention is to provide a medical guide wire formed by joining two metal wires having different materials to a bent portion. An object of the present invention is to provide a medical guidewire that allows smooth insertion. It is another object of the present invention to provide a medical guidewire having improved joining strength and high bending strength.
[0011]
[Means for Solving the Problems]
Means for Solving the Problems In order to achieve the above object, the present invention employs a medical guide wire having a configuration in which a joining member is wound in a coil shape around an outer periphery of a joining portion between an insertion portion and an introduction portion made of metal wires of different materials. Thereby, the flexibility of the joining member can be improved, and the joining member can be smoothly inserted into the bent portion.
[0012]
That is, in the medical guidewire of the present invention, the insertion portion is formed of a metal wire having excellent morphological adaptability, the introduction portion is formed of a metal wire having excellent torque transmission, and the insertion portion is joined to the introduction portion. In a medical guidewire in which a joining member is covered on a portion, a joining member is wound around an outer periphery of a joining portion between an insertion portion and an introduction portion in a coil shape.
[0013]
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.
[0014]
As described above, according to the present invention, since the joining member is coiled around the outer periphery of the joining portion between the insertion portion and the introduction portion, the coil-like joining member is deformed to freely correspond to the shape of the bent portion. Therefore, the bending performance of the guide wire is improved, and the guide wire can be smoothly inserted into the bent portion. In this regard, as the joining member, it is preferable to use a coil spring having excellent bending performance. For example, silicon manganese steel, manganese chrome steel, chromium vanadium steel, silicon chrome steel, etc. can be used. Steel wires (SUS304-WPA, SUS304-WPB, SUS302-WPA, SUS302-WPB, SUS316-WPA) are particularly preferable because of their excellent corrosion resistance.
[0015]
Further, in the medical guide wire of the present invention, a cut is formed at the joining end of the two metal wires, and after the joining member is wound around the joining portion in a coil shape, the coil-shaped joining member is reduced in diameter. A method in which the coil-shaped joining member is cut into the cut to fix the joining member and the joining end portion is preferable because it is a simple operation without skill. As the diameter reduction method, rolling, caulking, swaging, or the like can be employed.
[0016]
Further, in the medical guide wire of the present invention, the two metal wires are superposed at the joint end, and if the two metal wires are formed on inclined surfaces that can abut each other at the superposed portion, the joining area increases. Thereby, the adhesiveness of the joint is improved, and the bending strength can be improved.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a joint portion of a medical guidewire as one embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a bent state when the guidewire is inserted into a blood vessel.
[0018]
In FIG. 1, reference numeral 1 denotes a medical guidewire. In the guidewire 1, the insertion portion 2 is made of a metal wire of a Ti—Ni-based alloy having good shape adaptability, and the introduction portion 3 is excellent in torque transmission. The insertion portion 2 and the introduction portion 3 are joined by a coil-shaped joining member 4.
[0019]
The joining member 4 is made of stainless steel wire for spring of SUS304-WPA in order to provide excellent flexibility, but may be made of the above-mentioned spring steel material. In order to improve the flexibility, the actual diameter of the joining member is preferably smaller. For example, the actual diameter of the joining member 4 (outer diameter of the joining member) is preferably 1.0 mm or less. On the other hand, in order to secure a certain joining strength, the actual diameter of the joining member 4 is preferably set to 0.1 mm or more. The cross section of the joining member 4 may be any shape such as a square, a rectangle, a circle, an ellipse, and a trapezoid, but from the viewpoint of securing the adhesion, the guide wire is preferably a rectangle, an ellipse, or a trapezoid. This is preferable because the area in contact with is large. When the joining member 4 is wound in a coil shape around the outer periphery of the joining portion between the insertion portion 2 and the introduction portion 3, the joining member 4 may be wound so that the joining members are in close contact with each other, or spirally wound with a certain pitch. Is also good. It is preferable that the winding angle θ of the joining member 4 (the deviation angle with respect to the diametrical direction D of the guide wire 1) is 0 ° <θ ≦ 45 °. 0 ° means perpendicular to the longitudinal direction of the guidewire 1, and if the winding angle θ is too large, the joining state becomes unstable.
[0020]
A plurality of cuts 2a and 3a are formed at the joint end between the insertion section 2 and the introduction section 3, respectively. After the joining member 4 is wound around the outer periphery of the joining portion between the insertion portion 2 and the introduction portion 3 in a coil shape, the diameter of the coiled joining member 4 is reduced. Thereby, a part of the inner surface of the joining member 4 bites into the cuts 2a and 3a. Thus, the joining member 4 is firmly fixed to the joining end of the insertion section 2 and the introduction section 3. The locking portion C is formed by this diameter reduction processing. The shape and size of the cuts 2a and 3a are not particularly limited, and may be semicircular or triangular. In short, the cuts 2a and 3a may have any shape as long as the engaging portion C having a fixed size is formed.
[0021]
As described above, since the joining member 4 is wound in a coil shape around the outer periphery of the joining section between the insertion section 2 and the introduction section 3, the medical guidewire 1 is inserted into the blood vessel 5 as shown in FIG. At this time, when the joining member 4 approaches the bent portion 5a of the blood vessel 5, the coiled joining member 4 is freely deformed to correspond to the shape of the bent portion 5a of the blood vessel 5, so that the insertion can be performed smoothly.
[0022]
An overlapped portion L is formed at the joint end between the insertion portion 2 and the introduction portion 3, and this overlapped portion L has no irregularities such that the joint end surface 2 b of the insertion portion 2 and the joint end surface 3 b of the introduction portion 3 overlap each other. It is formed on an inclined surface. Therefore, the diameter of the metal wire is gradually reduced at the joining end between the insertion section 2 and the introduction section 3 to increase flexibility, and the flexibility of the junction between the insertion section 2 and the introduction section 3 is improved. In addition, due to the increase in the bonding area due to the formation of the overlapping portion L on the inclined surface, the adhesion of the bonding portion is improved, and a bonding structure with extremely small slippage can be obtained.
[0023]
Furthermore, since the overlapping portion L is formed at the joint end between the insertion portion 2 and the introduction portion 3 and the locking portion C is formed at the crimping surface between the joining end and the joining member 4, the overlapping portion L bends. The proof stress is exhibited, and the anchor effect is exhibited by the locking portion C. This anchor effect not only improves the bonding strength but also improves the bending strength. As a result, the bending strength and the joint strength at the joint become extremely large.
[0024]
【The invention's effect】
Since the medical guidewire of the present invention is configured as described above, the following effects can be obtained.
(1) According to the first aspect of the present invention, since the joining member for joining the insertion portion and the introduction portion is wound in a coil shape around the outer periphery of the joining portion, the joining portion of the guide wire is bent at a bent portion such as a blood vessel. When this occurs, the coil-shaped joining member is freely deformed according to the shape of the bent portion, and can be bent according to the shape of the bent portion such as a blood vessel, thereby improving the bending performance of the guide wire.
(2) According to the second aspect of the present invention, after the joining member is wound in a coil shape around the outer periphery of the joining portion, the coil-shaped joining member is reduced in diameter, so that the notch formed at the joining end portion of both metal wires. Since the coil-shaped joining member is cut into the joint member and the joining end portion is fixed, the joining member can be firmly fixed to the joining end portion of both metal wires by a simple operation. In addition, there is also an effect that the bending strength and the joining strength are improved by the locking portion formed by the diameter reduction processing.
(3) According to the third aspect of the present invention, the two metal wires are superposed at the joining end, and the two metal wires are formed on the inclined surfaces that can contact each other at the superposed portion, so that the bending strength is reduced. As the size increases, the bonding area increases, the adhesion of the bonding portion improves, and a bonding structure with extremely small slippage can be obtained.
(4) According to the invention described in claim 4, a medical guidewire having particularly excellent flexibility can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a joint portion of a medical guidewire as one embodiment of the present invention.
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]
DESCRIPTION OF SYMBOLS 1 ... Medical guidewire 2 ... Insertion part 2a ... Incision 2b ... Junction end face 3 ... Introduction part 3a ... Cut 3b ... Junction end face 4 ... Joining member 5 ... Vessel 5a ... Bend part C of blood vessel ... Locking part L ... Polymerization part

Claims (4)

The insertion part is made of a metal wire excellent in form adaptability, the introduction part is made of a metal wire excellent in torque transmission, and the joining part between the insertion part and the introduction part is covered with a joining member. A medical guidewire, wherein a joining member is wound in a coil shape around an outer periphery of a joining portion between an insertion portion and an introduction portion. A notch is formed at the joining end of both metal wires, and after the joining member is wound in a coil shape around the outer periphery of the joining portion, the coil-like joining member is cut into the notch by reducing the diameter of the coil-like joining member. 2. The medical guidewire according to claim 1, wherein the joining member and the joining end are fixed. 3. The medical guidewire according to claim 1, wherein the two metal wires are superposed at a joint end, and the two metal wires are formed on inclined surfaces that can contact each other at the superposed portion. 4. The medical guidewire according to claim 1, wherein the joining member is a coil spring.

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