Patent ID: 8652199

Claim:
A stent having an autonomic function, comprising a Ti—Ni based shape memory alloy of a thin long cylindrical shape or a wire shape, wherein the stent has a first part and a second part that is different from the first part in a lengthwise direction, wherein the first part comprises a center portion of the stent in the lengthwise direction and the second part comprises two end portions of the stent outside the first part, wherein the stent has a parent phase region at the first part and a martensite region at the two end portions of the second part before or at a time of placement of the stent in a lumen, wherein the stent has been subjected to different processes by which different strains are applied at the first part and at the second part, wherein the stent has a maximum expanding force at the first part which depends on a state of phase or a shape recovery temperature at the first part, and wherein each of the center portion and the two end portions are subjected to a shape memory treatment so that the stent has the thin cylindrical shape or the wire shape in which the two end portions and the center portion have identical diameters after balloon expansion.