PT Unknown
AU Jerbic, K
TI Computational Multiscale Models for Microdosimetric Investigations of Skin Tissues under Electromagnetic Exposure
PD 06
PY 2024
DI 10.17185/duepublico/81973
LA en
DE Bioelectromagnetics; Skin Modeling; Tissue Modeling; Cell Modeling; Electromagnetic Exposure; Multiscale Modeling; Microdosimetry
AB As ambitious projects such as Industry 4.0 and the Internet of Things evolve, the consequent drive towards next-generation telecommunication standards (i.e., 5G) implies increasing exposure to electromagnetic (EM) radiation at higher frequencies (2.5 - 6 GHz and 24 - 52 GHz) compared to those currently implemented (600 MHz up to 2.5 GHz, i.e., 2G-4G). This frequency shift brings into focus the absorption of EM energy in the outermost millimeters of the body, and especially in the skin. This highlights the need for both a reevaluation of current exposure guidelines and for refined methodological approaches that allow the dedicated assessment of EM absorption in tissue microstructures down to the cellular level in order to determine precisely where in the subcellular structure EM energy is converted to heat. In response to this challenge, the research presented here introduced scale-back projection, a top-down, multiscale approach that accounts for the intricate interplay between tissue morphology, histochemical composition, and EM absorption at the cellular level. For this approach to be effectively applied, a tailored material description that is adapted to the specific tissue anatomy was required. To this end, a hierarchical bottom-up model of the epidermis was developed, offering a coherent representation of material properties at both macroscopic and microscopic scales. Central to the epidermal model is its detailed representation of the life cycle of keratinocytes, modeling the differentiation of epidermal cells across 24 cell layers by capturing changes in cell geometry, internal structure, and histochemical composition. Scale-back projection allows a deeper exploration into EM exposure within individual cell microvolumes, precisely quantifying EM absorption relative to the specific location of individual epidermal cells. Using this innovative approach reveals a surprisingly high level of variability of EM fields induced in the cellular microstructure of such cells by up to 71 %, and exposure values which are up to 45 % higher than previously predicted by conventional dosimetric studies considering skin exposure on only a macroscopic scale. By providing more accurate exposure profiles across the epidermis, scale-back projection not only offers a detailed exposure map, but also emerges as a promising tool to complement and enhance conventional multiphysics simulation techniques currently used in EM dosimetry.
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