Guidewire

Abstract

The invention provides a guidewire, which can make sure bonding strength between a coil and a core shaft containing tungsten having bad wettability with brazing metal, and can enhance torque transmission performance. The guidewire (1) includes a core shaft (2) and a coil body (3) that covers the core shaft (2). The guidewire also includes a tip portion, an intermediate fixing portion, and a proximal-end fixing portion that fix the core shaft (2) and the coil body (3) to each other. The coil body (3) includes a single core wire formed of a tungsten wire and a single side wire formed of a stainless steel wire. The side wire is wound around the core wire so as to cover the outer periphery of the core wire.

Description

technical field [0001] The present invention relates to guide wires. Background technique [0002] Conventionally, various guide wires have been proposed for insertion into tubular organs such as blood vessels, alimentary canals, and urinary catheters, or tissues in the body to guide medical devices to target sites. [0003] For example, with regard to the guide wire described in Patent Document 1, the distal coil is formed in a helical spring form by twisting a plurality of wires, and the proximal coil is formed in a helical spring form by a single wire, thereby realizing the front end of the guide wire. Both softness and torque transmission are taken into account. [0004] In addition, the coil wire of the guide wire described in Patent Document 2 is formed of a first wire and a second wire, the front end portion of the first wire is made of a radiation-opaque material, and the other part is made of a radiation-transmissive high-elastic material. The entire second wire i...

AI Technical Summary

Problems solved by technology

[0009] However, since the guide wire described in Patent Document 1 includes a distal end coil with low bending rigidity formed by twisting a plurality of wires, and a proximal coil formed by winding a single wire, it has the problem of easily generating a distal end. Due to the difference in rigidity between the front and back of the joint between the coil and the proximal coil, the joint becomes a starting point of stress concentration when torque is transmitted from the proximal end of the guide wire to the distal end, and the torque at the proximal end of the guide wire cannot be fully controlled. to the tip of the guidewire

[0010] In addition, although the guide wire described in Cited Document 2 uses tungsten for the coil wire, tungsten is a metal with poor wettability with metal solder, so it is a material that is difficult to braze, and because it is a metal with a high melting point, it is It is a material that is difficult to weld with other parts, so the bonding of the second wire made of tungsten and the first wire, and the bonding of the coil wire containing tungsten and the core wire cannot be performed sufficiently, and there is a danger of the coil wire detaching from the core wire

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