Analysis and Control of the Current Distribution under Circular Dispersive Electrodes

An idealized model for a circular electrosurgical dispersive electrode is analyzed by solving Laplace's equation for the potential distribution. The resulting analytical solution shows the origin of the perimetrical burn problem, and, simultaneously, points the way toward improved electrode designs. One possible improved electrode design, a segmented circular electrode in which the annular segments are connected to the RF generator through a series of current-leveling resistors, is proposed and discussed. Extensions of this concept and future areas for research are also discussed.