Guide wire

Abstract

A guide wire includes a first wire disposed on the distal side, and a second wire disposed on the proximal side and made from a material having an elastic modulus larger than that of the first wire. The first wire and the second wire are joined to each other by welding. The second wire has, in the vicinity of the welded portion, a small cross-sectional area portion having a cross-sectional area smaller than that of a proximal end portion of the first wire. The outer diameter of the small cross-sectional area portion is gradually reduced in the direction toward the distal end. The first wire may be made from a superelastic alloy, whereas the second wire may be made from a stainless steel. The first wire and the second wire may be welded to each other by a butt resistance welding process. Since the change in rigidity of the guide wire becomes smooth in the longitudinal direction, the operationality and kink resistance of the guide wire are improved.

Description

[0001] This application is a divisional of prior application Ser. No. 10 / 635,716 filed on Aug. 7, 2003, the entire content of which is incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a guide wire, particularly to a guide wire used to guide a catheter in a body lumen such as a blood vessel. [0004] 2. Description of the Related Art [0005] Guide wires are used to guide a catheter in treatment of cites at which open surgeries are difficult or which require minimally invasiveness to the body, for example, PTCA (Percutaneous Transluminal Coronary Angioplasty), or in examination such as cardio-angiography. A guide wire used in the PTCA procedure is inserted, with the distal end projecting from the distal end of a balloon catheter, into the vicinity of a target angiostenosis portion together with the balloon catheter, and is operated to guide the distal end portion of the balloon catheter to the target ang...

AI Technical Summary

Benefits of technology

[0009] An object of the present invention is to provide a guide wire capable of making the change in rigidity smooth in the longitudinal direction of the guide wire, thereby improving the operationality and kink resistance of the guide wire.

Problems solved by technology

The guide wire including such a core member, however, has an inconvenience that the distal end portion of the guide wire becomes lower in flexibility.

In this way, it has been regarded as difficult to satisfy both requirements associated with the flexibility and operationality by using a core member made from a single material.

Such a guide wire, however, has a problem that the control of the flexibility of the distal end portion by heat-treatment has a limitation.

For example, even if it is successful to obtain a sufficient flexibility of the distal end portion of the alloy wire, it may often fail to obtain a sufficient rigidity on the proximal side of the alloy wire.

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