Patent ID: 8353945

Claim:
A delivery system for delivering a plurality of prostheses to a treatment site, comprising: a sheath having a proximal end, a distal end, an opening at the distal end, and a passage in communication with the opening, the plurality of prostheses being movably disposed in the passage, and a valve at or near the distal end of the sheath adapted for selectively retaining at least one prosthesis within the passage, wherein the valve comprises an impinger that is selectively moved from a first state in which it does not engage the at least one prosthesis to a second state in which it engages the at least one prosthesis and prevents its relative movement, wherein the impinger is formed of a deformable cylinder having a first diameter in the first state which is larger than an outer diameter of the at least one prosthesis and a second diameter in the second state which is smaller than the first diameter when the impinger is electrically actuated such that the cylinder contacts and engages the at least one prosthesis.