A SPARK COUNTER AS A CONTROL UNIT OF A RADIO-FREQUENCY SURGERY DEVICE

A new approach in radio frequency (rf) electrosurgery for tissue treat ment, is achieved by using a new control method. An external control u nit allows a commonly available rf-generator to automatically supply t he appropriate power for differing tissue types, thus ensuring best cu tting quality. The sparks, generated during the scalpel electrode inte raction with the tissue, appear statistically distributed. The spark r ate depends on various factors and is monotonic with the supplied elec trical power. This allows it to be used as the controlled variable in the cutting process. The ac current passing through the tissue is eval uated by an external control unit using an analyzation algorithm to de termine the number of sparks. The external unit is comprised of a syst em, which measures the spark rate, and a subsequent proportional integ ral (P.I.) controller. The functionality of the control method as well as the electrical circuitry is verified through cuts with different d egrees of carbonization and cuts through tissue heterojunctions.