On the origin of skin burns and neuromuscular electrical stimulation as a consequence of electrosurgical procedures

Abstract

PurposeDC burns and undesirable electrostimulation are problems related to electrosurgical procedures. Although some causes of these problems are known, the prime mechanism of its energy generation during electrosurgeries is not. DC burns occur in the patient’s skin in the area where the passive conductive plate is placed, especially in the presence of coupling gel and electrical DC components, while electrostimulation needs low-frequency components, both of them supposedly non-existent in electrosurgical procedures. This work investigates in detail some processes in the sparking gap that lead to the generation of electrosurgical asymmetries that explain these problems.MethodsThe experiments were carried out in DC, studying the onset of spark that illustrates the asymmetries noted in AC cycles. As a replacement for organic tissue, we used chayote (Sechium edule) and pork (Sus scrofa domesticus).ResultsThe electrical sparks do not occur equally in both directions considered between active electrode and passive metal plate, introducing electrical asymmetries. Asymmetries were quantified in discharges between metal electrodes with different geometries and between metal electrodes and organic tissue. For small gaps, the relative air humidity influences the breakdown voltage without eliminating the asymmetry.ConclusionBy studying the DC electrosurgical spark, it was possible to quantify the electrical asymmetries and qualify their causes. Since the asymmetry is the cause of undesirable DC burns and neuromuscular electrostimulation, and the conformity process does not take into account the sparking phenomena, the certification process at this class of equipment must change.