Patent ID: 7758628

Claim:
A method of applying a radial force against a surface of a passageway with an expandable device, comprising: providing an expandable device with a plurality of cells comprising a generally longitudinal wave-like first member and a generally longitudinal wave-like second member, at least one cell capable of being expanded between a stable contracted state in which the first and second members are generally in phase and at least one stable expanded state in which the first and second members are generally out of phase; radially expanding the expandable device to expand the plurality of cells to a transition point defining a geometry of the plurality of cells at which no additional force is necessary to further expand the plurality of cells; and permitting the plurality of cells to continue to expand beyond the transition point to the at least one expanded state without the application of additional force so that the expandable device expands against a surface of the passageway; wherein: one of the first and second members substantially retains its shape when the cell transitions from the contracted to the at least one expanded shape.