A surgical access device has a surgical retractor having a noncompliant outer ring with an annular axis, an inner ring, and a sleeve coupling the outer ring to the inner ring. The noncompliant outer ring is adapted to roll over itself around the annular axis to roll the sleeve around the outer ring to...http://www.google.fr/patents/US8109873?utm_source=gb-gplus-shareBrevet US8109873 - Surgical retractor with gel pad
