A device for retracting edges of an incision in a surface to form an opening including: a flexible, tubular skirt having an upper end, a lower end, and a channel therebetween; a ring connected to the lower end of the skirt for maintaining the lower end in an open configuration and defining an exit opening...http://www.google.com.au/patents/US20020183594?utm_source=gb-gplus-sharePatent US20020183594 - Surgical access port
