Local thermal effect of power-on setting on monopolar coagulation: a three-dimensional electrothermal coupled finite element study.

A three-dimensional (3-D) electrothermal coupled finite element (FE) model was used to simulate and analyze the effects of the electrosurgical power-on setting on the temperature distribution and thermal damage in biological tissue during coagulation. The discussed parameters include the power-on-off durations, contact distance between the electrosurgical blade and tissue surface, and inclination angle of the blade during cutting. The results indicate that under the condition of a constant input electrical energy, the maximal temperature decreased when the power-on time was shortened and the power-off (pause) duration was increased. The two contact distances between the blade and tissue (0 and 0.25 mm) did not show a significant temperature difference; however, the tissue temperature increased with increasing blade inclination angle. We concluded that using a normal cut angle and set at a multiple shorter-time power-on with intermittent power-off operation procedure can reduce the risk of thermal damage during monopolar electrosurgery.