US Patent 7070604 RF electrosurgically-activated cutter

A novel cutter instrument uses radiofrequency (RF) electrosurgery and RF energy to achieve the desired cutting action with minimum of mechanical force, thereby reducing the risk of tissue damage due to excessive mechanical cutting action. Preferably, a cutter head of the instrument comprises an outer tube of electrically-insulating material with an aperture into which is telescoped an inner electrically-conductive tube. When the working or leading end of the latter is reciprocated across the aperture in the outer tube while RF electrosurgical currents are applied to the inner tube, the cutting action of tissue entering the aperture takes place primarily via the RF electrosurgical currents.