US Patent 7393358 Stent delivery system

A medical device comprises a catheter, a retractable sheath, and a rolling membrane. The catheter includes a catheter shaft about which a stent in a reduced diameter configuration may be disposed. A stent retaining region of the sheath is disposed about the stent to retain the stent in the reduced diameter state prior to delivery. The rolling membrane is engaged to a portion of the sheath at an engagement region. The rolling membrane is positioned between the catheter shaft and the sheath and prior to retraction of the sheath the rolling membrane is disposed about at least a proximal section of the stent and is rollingly retracted therefrom when the sheath is retracted to deliver the stent.