The invention is directed towards a bladeless obturator (18) for wedging through muscle fiber layers (41, 43, 45) to safely cut through to the abdominal cavity (32) in order to apply a cannula (12). The invention comprises a bladeless obturator (18) having a rectangular tip (63) that is twisted radially....http://www.google.de/patents/US20050107816?utm_source=gb-gplus-sharePatent US20050107816 - Bladeless obturator
