Patent ID: 7632361

Claim:
A guidewire device for use in medical procedures within a body of a human or other animal, the device comprising: an elongate guidewire body formed of a single-crystal hyperelastic alloy of copper, aluminum, and a metal selected from the group consisting of Ni, Fe, Co, and Mn having a crystalline phase change transition temperature that is below body temperature, having an austenite crystalline phase at temperatures above the phase change transition temperature and a martensite crystalline phase at temperatures below the phase change transition temperature, so that the elongate body is deformable at a constant force at recoverable strain of at least 9% at body temperature, with a very narrow loading-unloading hysteresis, a recovery which is completely repeatable and complete and a very low yield strength when martensitic, wherein the device is sized for insertion into the body and has an exposed outer surface of single-crystal alloy that is substantially free of micro- or nano-crystals, further wherein the guidewire comprises one portion having a given diameter and an other portion, the other portion having a diameter that is less than the given diameter sufficient to enable the other portion responsive to a given stress to flex through a greater degree than when the one portion is flexed responsive to the given stress.