Author(s)

N. Nessler, W. Reischer & M. Salchner

Abstract

Neutral electrodes (grounding plates used in electrosurgical operations) were tested with thermo cameras in volunteer experiments. These experiments are difficult to perform and expensive. A new test device swaroTEST with a measuring board \“electronic skin” simulates the relevant electrical features of human skin to replace volunteer experiments. This device consists of a three dimensional resistor network representing the electric features of the skin and muscle tissue, and a temperature sensing array (one transistor for each cm²) to measure the resultant temperature increase after a standardized current load (700 mA hf current during 60 s, proposed in the relevant AAMI HF-18 standard). The comparison of test results with thermo camera images of volunteer experiments showed a sufficient coincidence, which proves the applicability of this test device to replace volunteer experiments. Keywords: electronic skin, electrosurgery, neutral electrode. 1 Introduction Neutral electrodes (dispersive electrodes, grounding plates) are safety relevant accessories in electrosurgery and must be tested according to AAMI HF 18 standard. A neutral electrode in contradiction to the active electrode (electrical knife) must not heat the patient’s skin in excess of 6°C during the hf-current pass. One test method is a volunteer experiment under standardized conditions (AAMI) with a thermo camera to measure the temperature increase on the skin under the neutral electrode. This method is laborious (10 volunteers for one significant test!), time consuming and expensive (thermo camera, clinical environment) and cannot be used routinely for quality tests. The result of a typical volunteer experiment is shown in fig. 1. As usual the higher temperatures are displayed in yellow to red, cooler sites are green to blue.

Keywords

electronic skin, electrosurgery, neutral electrode.