An expandable tissue supporting device of the present invention employs
ductile hinges at selected points in the expandable device. When
expansion forces are applied to the device as a whole, the ductile hinges
concentrate expansion stresses and strains in small well defined areas.
The expandable medical device including ductile hinges provides the
advantages of low expansion force requirements, relatively thick walls
which are radio-opaque, improved crimping properties, high crush
strength, reduced elastic recoil after implantation, and control of
strain to a desired level. The expandable tissue supporting device
includes a plurality of elongated beams arranged in a cylindrical device
and connected together by a plurality of ductile hinges. Although many
ductile hinge configurations are possible, the ductile hinges preferably
have a substantially constant hinge cross sectional area which is smaller
than a beam cross sectional area such that as the device is expanded from
a first diameter to a second diameter, the ductile hinges experience
plastic deformation while the beams are not plastically deformed.