Estimation of Whole-Body Average SAR in Human Models Due to Plane-Wave Exposure at Resonance Frequency

This study proposes an equation for estimating whole-body average specific absorption rate (WBSAR) in human body models for plane-wave exposure at whole-body resonance frequency. This study is important because the WBSAR takes maximal at this frequency and approaches the basic restrictions in the international guidelines/standards for human protection. Therefore, the variability of the WBSAR at this frequency has attracted a great deal of attention. First, the dominant factors influencing the resonance frequency of the human body models are investigated for plane-wave exposures. An equation for estimating the WBSAR at the resonance frequency is then proposed based on an analogy to an antenna. This equation can estimate the WBSAR with the body mass index of the human body only for a given incident power density. The uncertainty of the WBSAR estimated with the proposed equation is approximately 10%, which is mainly attributed to the electrical constants of tissue, including the inhomogeneity of the human body model. The variability of the WBSAR due to the body shape was found to be 30% for humans of the same age.