Flow and heat transfer in biological tissue due to electromagnetic near-field exposure effects

Abstract

Electromagnetic fields (EMF) have been a vital part of our daily life over the past decade. Therefore, people are continuously exposed to electromagnetic (EM) sources in their vicinity generated by electronic devices such as those emitted by Wi-Fi, mobile phones, portable wireless router and other wireless services. This study aims to investigate the SAR, fluid flow and heat transfer in biological tissue due to EM near-field exposure. In a tissue model, the effects of distance to an EMF source and tissue permeability on natural convection in the biological tissue are systematically investigated. The specific absorption rate (SAR), fluid flow and the temperature distributions in the tissue during exposure to EM fields are obtained by numerical simulation of EM wave propagation and heat transfer equations. The EM wave propagation is expressed mathematically by Maxwell’s equations. The heat transfer model used in this study is developed based on bioheat model and porous media model. By using the porous media model, the distribution patterns of temperature are quite different from the bioheat model by the strong blood dissipation effect of the porous media model. The exposure distance significantly influences the SAR, velocity field and temperature distribution. Moreover, the tissue permeability also affects the temperature distribution patterns within the tissue. The obtained results may be of assistance in determining exposure limits for the power output of the wireless transmitter, and its distance from the human body. The results can also be used as a guideline to clinical practitioners in EM relates the interaction of the radiated waves with the human body.