Patent ID: 7279004

Claim:
An expandable medical device comprising: a plurality of elongated beams, the plurality of elongated beams joined together to form a substantially cylindrical device which is expandable from a first diameter to a second diameter, each beam defining a beam width in the circumferential direction of the cylindrical device; a plurality of ductile hinges connecting the plurality of beams together in the substantially cylindrical device, each hinge defining a hinge width in the circumferential direction of the cylindrical device, wherein the hinge width is smaller than the beam width such that as the device is expanded from the first diameter to the second diameter the ductile hinges experience plastic deformation while the beams are not plastically deformed, the ductile hinges being asymmetrically configured to reach a predetermined strain level upon a first percentage of expansion from an initial dimension and to reach the predetermined strain level upon a second percentage of compression from said initial dimension, wherein the first percentage is larger than the second percentage; wherein the ductile hinges have a first side surface placed in tension during compression of the device and a second side surface placed in tension during expansion of the device, wherein the first side surface is smaller than the second side surface; and wherein a transition between the cross sectional area of the elongated beams orthogonal to the beam length and the cross sectional area of the ductile hinges orthogonal to the hinge length is an abrupt transition on both circumferential sides of the beams.