PROBLEM TO BE SOLVED: To provide a medical guide wire which is formed by inserting a core wire having a reduced diameter into an outside coil formed of wires of different kinds of metals, and constituted of outside first coil and outside second coil, capable of solving such technical problems that the outside coil formed by integrally joining wires of different kinds of metals, cannot draw a uniform arc when it is bent and deformed at a front part and a rear part of an integrally joined boundary part, and rotation transmission performance to a distal end side accompanying the reduced diameter of the core wire and piercing performance of a lesion part have to be improved.SOLUTION: Initial tension is made to act on dense winding parts of an outside first coil and an outside second coil, and torsional stress by the initial tension is set to be in a fixed range, so that, when the coil is bent and deformed at the front part and the rear part of a boundary part, a uniform arc can be drawn. In addition, a distal end part of the core wire has a concatenated truncated-cone structure satisfying a certain relational expression, in which truncated cones are concatenated, and thus, torsional moment to the distal end side is increased and piercing performance at an obstructed lesion part can be improved.SELECTED DRAWING: Figure 6COPYRIGHT: (C)2017,JPO&INPIT【課題】外側第1コイルと外側第2コイルとの異種金属の線材から成る外側コイル内へ細径の芯線を貫挿して成る医療用ガイドワイヤであって、異種金属の線材を一体接合して成る外側コイルは、一体接合した境界部の前後で屈曲変形させた場合に均一な円弧を描くことはできず、又、芯線の細径化に伴う先端側への回転伝達性能と病変部の穿孔性能を向上させる為の技術課題が存在する。【解決手段】外側第1コイルと外側第2コイルの密巻きに初張力を作用させ、初張力によるねじり応力を一定範囲とすることにより、境界部の前後で屈曲変形させた場合に均一な円弧を描くことができ、又、芯線先端部は截頭円錐体を連接した一定の関係式を満たす連接截頭円錐体構造とすることにより、先端側へのねじりモーメントを増大させて閉塞病変部での穿孔性能を向上させることができる。【選択図】図6
