SAR AND INDUCED CURRENT DISTRIBUTIONS FOR OPERATOR EXPOSURE TO RF DIELECTRIC SEALERS

The finite-difference time-domain method is used to calculate local, layer-averaged, and whole-body-averaged specific absorption rates (SAR's) and induced current distributions in a 16-tissue, anatomically based, 5628-cell model of a human to assess operator exposure to RF sealers. Industrially relevant shapes and dimensions of commonly used RF dielectric heaters using parallel-plate and bar-type electrodes are considered. Realistic postures of the human operators are used for the calculations, including extended arms to simulate working conditions or an operator sitting on a wooden or metallic stool. Due to the high-intensity leakage fields in proximity to the RF applicators, some of the highest induced currents and SAR's are calculated for the hands and the ankles and in the sitting position, the knees. Steps should therefore be taken either to reduce the leakage fields or shield the hands and the knees if it is necessary for them to be in high leakage field regions.