A tissue retractor includes a body having proximal and distal ends. The retractor also includes a retraction device having a head connected to the distal end of the body and defining two opposing openings, a connector movably disposed in the body, and two flexible needles of a shape memory material having...http://www.google.de/patents/US7731655?utm_source=gb-gplus-sharePatent US7731655 - Tissue retractor and method for using the retractor
