Estimation of Whole-Body Averaged SARs in Human Models for Far-Field Exposures in Whole- Body Resonance and GHz Frequency Regions

The purpose of the present study is to propose a scheme to estimate whole-body averaged specific absorption rate (WBA-SAR) in the whole-body resonance and GHz frequency regions. The motivation is that WBA-SARs in the child models in these frequency regions have been reported to approach to the basic restrictions in the international guidelines/standards. In the resonance frequency region, we proposed a formula to estimate WBA-SAR based on the antenna theory. The variability of WBA-SAR in the child models was given using the formula. The computational uncertainty in the WBA-SAR using the formula may be up to several percents especially due to the model inhomogeneity. The variability of the WBA-SAR due to model shape or Kaup index was found to be 30%. In the GHz region, we proposed a homogeneous ellipsoid having the electrical constants of muscle for a conservative WBA-SAR estimation. The applicability of that model was confirmed considering the infant model with different Kaup indexes. The variability of WBA-SAR with different Kaup indexes was shown to be 15%.