Análisis de la incidencia de una fuente radiactiva en un bisturí bipolar para resección de carcinomas en tejido ex vivo

Abstract

The aim of this work was to analyse the incidence of a radioactive source in a bipolar scalpel for resection of carcinomas in ex vivo tissue using the COMSOL MULTIPHYSICS simulator (version 5.4 free). The procedure was to heat the bipolar scalpel with a potential differential obtained from the radioactive source to the two electrodes, considering that it will work with Strontium 90 for voltage estimation, a Geiger tube was used to fulfil the function of sending an electric current to the anode of the tube, reflected as low voltage pulses, being amplified by a voltage converter to receive an input voltage and provide an increased output voltage, through this system values of 50, 55, 60, 65 and 70 Volts were obtained. Finally, a simulation was performed for each voltage by a thermoelectric process to release thermal energy using the finite element method. The results showed that the heat distribution generated for each case did not show a coagulation zone between each electrode, since the scalpel had a monopolar behaviour creating a coagulation zone at the ends of each electrode that grows to the middle of each one, having a maximum symmetry of 0.9 mm and 1.9 mm in lateral diameter and depth at 60 V, causing clots due to the exposed temperature and avoiding the visibility of superficial carcinomas in the ex vivo tissue. It was therefore concluded that this procedure is not feasible to create a symmetrical coagulation zone between the tips of each electrode and increases irreversible thermal damage to possibly healthy tissue. It is recommended to create a larger section for the coolant in the electrode structure, so that a rapid thermal equilibration process can be performed without causing monopolar behaviour.