The effect of gelled-pad design on the performance of electrosurgical dispersive electrodes

A two-dimensional model of a simplified configuration of the gelled-pad electrode applied to human tissue was developed. As a consequence of the boundary discontinuity near the edge of the pad, the model predicted high peripheral and low central surface temperature rises. By comparison with base conditions, increased gelled-pad area and gel electrical resistivity and decreased initial pad temperature reduce the temperature rise across the pad surface. Temperature distributions measured on the thighs of human subjects were shown to have similar characteristics to those predicted by the model. Even though three-dimensional and blood flow effects were not considered, the model is satisfactory for evaluating the effect of electrode design changes on thermal performance.