Guide wire having distal extremity with adjustable support characteristic and method

摘要

A guide wire having a distal extremity with an adjustable support characteristic comprising a core wire having proximal and distal extremities. The distal extremity has a reduced cross sectional area which is more flexible than the proximal extremity. A tip secured to the distal extremity of the core wire. A sleeve of superelastic material is disposed coaxially on the distal extremity of the core wire. The sleeve is annealed so that it is relatively flexible at a temperature ranging from 20 DEG to 40 DEG C. and becomes progressively stiffer as temperature increases. The core wire conducts electrical energy to the superelastic sleeve to supply heat to the sleeve and extends from the proximal extremity of the core wire to the sleeve to cause the sleeve to become stiffer to thereby increase the stiffness of the distal extremity of the guide wire. A guide wire is provided having a distal extremity with an adjustable support characteristic which varies from a floppy characteristic to a stiff characteristic.