An improved surgical retraction apparatus (and corresponding method of operation) includes a plurality of rigid retraction members disposed about a central axis that move radially with respect to the central axis between a closed state and an open state. In the closed state, the retraction members form...http://www.google.co.uk/patents/US20050165281?utm_source=gb-gplus-sharePatent US20050165281 - Surgical retractor apparatus for use with a surgical port
