Temperature elevation during medical diathermy

Two types of applicators, an inductive applicator and capacitive electrodes, are used to compute the temperature elevation during the treatment of the shoulder, hip and spine in a numerical male model (NORMAN). The used thermal model is based on the Pennes Equation and has been extended by additional thermoregulatory mechanism. The blood flow and metabolic rate are elevated as a function of the local tissue temperature. Furthermore, the blood temperature is elevated by the absorbed power. On the skin/air boundary the heat transfer has been accounted for, by means of radiation and convection, as well as by the insensible loss of water and sweating. Simulations are performed for a varying electrode to skin distance of up to 4 cm, a maximum recommended output power of 400 W and an exposure time of 20min.