A surgical device is described. The surgical device may comprise a rotatable cutter configured to cut tissue for insertion of a cannula, and a first driver configured to be driven by a motor arrangement and to rotate the cutter. The surgical device may further include, for example, the cannula, at least...http://www.google.se/patents/US7905897?utm_source=gb-gplus-sharePatent US7905897 - Trocar device
