Visualization of induced currents and SAR in human´s head in cellular telecommunications

Although many numerical studies concerning electromagnetic interactions based either on solving an integral equation using the finite-difference time-domain or finite element methods exist, only a few studies calculating heterogeneous realistic models of a human body can be found. High specific absorption rates (SAR) and concomitant "hot spots" may result due to the applied radio frequency (RF) fields. Since parts of the body, such as the brain in the head, are very sensitive to a change of the local temperature, the problems of induced current densities and energy deposition should therefore be treated in detail. A number of mathematical models have been used to estimate potential and current distributions, as well as the impedance of the different parts of the head. In this paper the current density distributions and specific absorption rate are calculated and visualized. To find out the position of high energy deposition as well as their values, we performed a finite element simulation for a heterogeneous model of the human head exposed to a linearly polarized RF magnetic field at 900 MHz. The ease of modeling is established through the variable shape of the elements, which do not have to be the same throughout. Obtained results from this calculation are valid for the exposure of a human head to continuous wave RF electromagnetic energy.