NUMERICAL EVALUATION OF SPECIFIC ABSORPTION RATE IN HUMAN HEAD AND TORSO FOR WEARABLE WIRELESS DEVICES IN UNDERGROUND...

The radiofrequency field levels may increase in confined environments, such as underground mines, due to reflections from inner boundaries (walls and arches). This study investigated the specific absorption rate (SAR) in the head and torso of a miner wearing a wireless device in underground mine scenarios. Two high-resolution voxel models were used to analyse the effects of a tunnel structure, a metal arch and a safety helmet at 2.4 GHz and 868 MHz. The results indicated that the SAR increase is modest for all simulated underground mine scenarios and was maximum in the presence of a metal arch. At 868 MHz, some observed that the SAR was greater in deep tissues of the head and torso as compared to SAR at 2.4 GHz. Also, the torso is a better site for mounting wearable devices on the body to mitigate exposure.