The Study on how Model Selection Propagates in High Frequency Electromagnetic-Thermal Dosimetry

Abstract

This paper is on the electromagnetic (EM)-thermal dosimetry workflow in GHz frequency range. The hybrid bound- ary element method/finite element method (BEM/FEM) is used to calculate the induced electric field due to exposure to plane EM wave at 0.9 GHz, 1.8 GHz, 3.5 GHz, and 6 GHz. Two simplified human head models are considered, homogeneous one and non-homogeneous one. The output of two EM models is used as input to the thermal model based on Pennes’ bioheat equation solved by means of FEM. The numerical results for the induced electric field, the specific absorption rate, the temperature increase and the heating factor, respectively, are compared point-wise along the propagation axis. By representing the human head with simplified geometry such as a sphere, the influence of geometry on the calculated metrics can be minimized, while focusing on the results along the diameter of the spherical head, the effect of the plane wave polarization can be neglected. As the frequency increases toward the transition frequency of 6 GHz, similar results are obtained with both homogeneous and non-homogeneous models, respectively. The results suggest that if we are interested in the thermal response, the homogeneous EM model of biological tissue might prove sufficient.

Mario Cvetković

Associate Professor | Department of Electrical Engineering Fundamentals

Associate professor at FESB in Split, with a research focus on numerical modeling including finite element and moment methods, computational bioelectromagnetics and heat transfer related phenomena. He is involved in IEEE’s ICES Technical Committee 95, various international projects and is committed to advancing both knowledge and practical applications in electromagnetic safety and biomedical engineering.