Accurate wideband measurement of human body absorption cross section in reverberation chamber: A morphological parameters study from 1 GHz to 18 GHz

The human body absorption cross section (ACS) is important in the non-ionized dosimetry, indoor channel modelling, design of electrical biomedical devices, etc. In order to find the relations between morphological parameters and the human body ACS, we developed new measurement techniques which can obtain human body ACS quickly and accurately. Empirical models were inducted from the accurate measurement results, which enables the human body ACS to be quickly evaluated from the morphological parameters.
Our researches include the following parts.
First, the new measurement techniques which can give ACS result accurately had been validated by measuring the ACS of a sphere model with known structure and material in the reverberation chamber (RC). The measurement result matches very well with the analytical solution of the sphere ACS.
After the new measurement techniques had been validated, measurements on the human body ACS of 48 subjects were performed to find its relation to morphological parameters. A strong linear correlation between the ACS and the body surface area (BSA) was found above 6 GHz and a linear equation was inducted. No strong linear correlations between the ACS and all morphological parameters were found below 6 GHz, therefore, the coordinate of several markers on the ACS curve were correlated to the morphological parameters to evaluate the ACS below 6 GHz.

At last, due to the similarities between the measured ACS and the ACS given by multilayer analytical model, a numerical method that can calculate the ACS of object with arbitrary shape was given. The numerical method was specially optimized for calculating the object with multiple thin surface layers, and its accuracy was demonstrated by solving the ACS of a 2D multilayer cylinder, of which the ACS can be solved analytically. The numerical result matches well with the analytical solution.