Simulated and experimental studies of temperature elevation around electrosurgical dispersive electrodes.

Abstract

We have developed a three-dimensional computer model for the human thigh to predict temperature rises around electrosurgical dispersive electrodes. It numerically solves Laplace's equation and the heat equation including Joulean heating, conduction, radiation, and convection effects. The simulations show that the current density and temperature rise distributions are nonuniform longitudinaly as well as transversely, which explains the leading edge effect. Results of the temperature distribution from these simulation studies correspond well to those from experimental studies. We discuss the effects of the geometry and size of dispersive electrodes on the temperature rise around the dispersive electrode. We also identify and evaluate the effects of other variables which affect the thermal performance of dispersive electrodes. We suggest ways to improve an existing standard for evaluating dispersive electrodes. Our model is a useful tool for evaluating different dispersive electrodes, predicting their performance under various circumstances, and designing them to be better and safer. We also discuss numerical aspects and limitations of our model, results of using the model to test theoretically superior dispersive electrodes, and ways to overcome these limitations in future research.