Readily operable catheter guide wire using shape memory alloy with pseudo elasticity.

摘要

A catheter guide wire (10) comprises a solid core wire (11) of a Ti-Ni shape memory alloy and an outer jacket (12) covering the core wire. In order to provide a plasticity to one end portion of the core wire, at least one end portion is made of a 45.0-51.0 at% Ni-0.5-5.0 at% Fe-Ti shape memory alloy and is heat treated at 400-500 <o>C. The end portion is provided with a pseudo elasticity at a temperature about 37 <o> and a plasticity at a temperature below 80 <o>C. Alternatively, the end portion may be made of a 50.3-52.0 at% Ni-Ti alloy and is heat treated at a temperature of 700 <o>C. In order to improve operability of the catheter guide wire, the remaining portion other than the end portion is made of provided with a comparatively high rigidity by a usual Ti-Ni shape memory alloy which is not heat treated. Alternatively, the remaining portion is covered with an inorganic layer.