A Novel Framework for Realistic 3D Skin Modeling and its Exposure to Millimeter Waves

Millimeter wave (MMW) technology is increasingly used in telecommunications and medical applications, necessitating a deeper understanding of its interaction with human tissue, particularly skin. The limited penetration depth of MMWs makes the skin the primary site of energy absorption, requiring detailed dosimetric analysis. Traditional skin models often assume planar, layered structures, neglecting the natural undulating geometry of the epidermis and dermis. This study introduces a novel methodological framework for constructing realistic three-dimensional (3D) human skin models using Optical Coherence Tomography (OCT) and Ultrasound (US) imaging. The framework involves three key steps: (1) OCT and US image acquisition, (2) image segmentation and processing, and (3) synthesis of processed data to generate high-fidelity 3D skin models. Three anatomical sites—the volar forearm, hypothenar region, and fingertip—were selected for model development, representing variations in skin roughness and layer composition. The dielectric properties of the skin and subcutaneous layers were incorporated into finite-difference time-domain (FDTD) simulations at 27.5 GHz to evaluate the impact of skin roughness on electromagnetic field distribution. Our results demonstrate that the natural undulations of the dermoepidermal junction and air-skin interface significantly affect MMW energy absorption patterns. The roughness of these interfaces varies across anatomical sites, influencing local electric field distributions and leading to deviations from predictions based on planar models. The findings suggest that incorporating realistic skin geometries enhances dosimetric accuracy, which is critical for both safety assessments and optimizing MMW-based medical applications. This study provides an approach for individualized MMW dosimetry and underscores the importance of considering anatomical variations in electromagnetic exposure assessments. The framework was additionally extended to a nodular basal cell carcinoma case, revealing marginal changes in local field and SAR distributions and a moderate increase in reflected power compared to healthy skin.