Assessment of absorbed power density and temperature rise for nonplanar body model under electromagnetic exposure above 6 GHz

TL;DR

This study evaluates absorbed power density and temperature increase in nonplanar body models exposed to electromagnetic waves above 6 GHz, introducing a new correction method for heat convection in bioheat calculations.

Contribution

A novel, easily implementable compensation method for heat convection correction in bioheat models was developed and validated.

Findings

Heating factors depend on frequency and curvature.

Differences among APD schemes are small for large radii and high frequencies.

The proposed method improves accuracy without needing boundary normal directions.

Abstract

The averaged absorbed power density (APD) and temperature rise in body models with nonplanar surfaces were computed for electromagnetic exposure above 6 GHz. Different calculation schemes for the averaged APD were investigated. Additionally, a novel compensation method for correcting the heat convection rate on the air/skin interface in voxel human models was proposed and validated. The compensation method can be easily incorporated into bioheat calculations and does not require information regarding the normal direction of the boundary voxels, in contrast to a previously proposed method. The APD and temperature rise were evaluated using models of a two-dimensional cylinder and a three-dimensional partial forearm. The heating factor, which was defined as the ratio of the temperature rise to the APD, was calculated using different APD averaging schemes. Our computational results revealed different frequency and curvature dependences. For body models with curvature radii of >30 mm and at frequencies of >20 GHz, the differences in the heating factors among the APD schemes were small.