Simulation of the Temperature Distribution with High-Frequency Electrosurgical Heating

Abstract

In the given study, an algorithm for solving the two-dimensional stationary heat conduction problem in a two-phase medium (electrode – biological tissue) is developed with boundary conditions of the first and second types. In the study, the unequal distribution of alternating current in these conducting media (so-called skin-effect) is taken into account. In Cartesian coordinate system a geometrical model of a two-phase medium consisting of rectangular copper electrode and rectangular sample of biological tissue is considered. A model of such kind allowed us to reduce the problem to a plane-parallel case. A numerical experiment is implemented in MATLAB environment, using the finite difference method. To solve the problem of heat transfer, the electromagnetic problem is solved in the first place. As a result, the temperature distribution in a two-phase medium cooled by physiological saline during the flow of high-frequency current is simulated. The model showed that the surfaces of the electrodes and the biological tissue in contact with them do not overheat, and the maximal temperature value lies in the depth of the tissue. This model can be used to study thermal processes during high-frequency surgical intrusion with a tool having rectangular electrodes, in a wide frequency range.