In the present invention, a surgical trocar is adapted to inductively couple electrosurgical energy to specially adapted cordless electrosurgical instruments. In one embodiment of the present invention, an electrosurgical trocar includes a cannula, an inductive electrosurgical adapter and a locking connector...http://www.google.se/patents/US6117132?utm_source=gb-gplus-sharePatent US6117132 - Inductively coupled electrosurgical trocar
