Patent ID: 6312455
Filing Date: 2001-11-06
Classification: A61F,A61L,C22F

Abstract:
A stent for use in a lumen in a human or animal, which has a generally tubular body formed from a superelastic shape memory alloy having an Af temperature less than about 15.degree. C. which has been treated so that it exhibits enhanced elastic properties with a point of inflection in the stress-strain curve on loading, enabling the body to be deformed inwardly to a transversely compressed configuration for insertion into the lumen and then revert towards its initial configuration, into contact with and to support the lumen, the shape memory alloy comprising nickel, titanium and from about 3 at. % to about 20 at. %, based on the weight of the total weight of the alloy composition, of at least one additional element selected from the group consisting of niobium, hafnium, tantalum, tungsten and gold, the ratio of the stress on loading to the stress on unloading at the respective inflection points on the stress-strain curve being at least about 2.5:1.