Quantification and influence of skin chromophores for remote detection of anemic conditions

Current standards for diagnosing and monitoring anemia are relatively invasive. The superficial symptoms of this condition are due to an underlying deficiency of red blood cells (RBC) or erythrocytes, and hemoglobin in the blood. This results in an inadequate supply of oxygen to the body's tissues. For point-of-care diagnostic systems, remote determination of blood conditions will depend on an understanding of the interaction of light with hemoglobin. However, the skin acts as the first barrier for this detection. In this study, we pursue the possibility of detecting anemic conditions from the perfused blood in the dermis using optical models and Monte Carlo (MC) methods. The skin is composed of two primary layers, the epidermis and the dermis. The avascular epidermis absorbs light due to its primary chromophore, melanin. Subsequently, the absorption in the dermis layer is quantified by hematocrit and hemoglobin concentrations. Two-layer models of the human skin are set up and optical properties are assigned to these models. The optical variability across these models are defined by six melanin (epidermis) and two erythrocytes (dermis) concentrations. The twelve combinations of optical properties are assessed at six wavelengths of interest in the Virtual Tissue Simulator (VTS) environment. The chosen wavelengths range across the visible and near-infrared spectrum, which is a known and important diagnostic window for biological tissues. In this study, we explore the variability of light interactions for healthy and anemic blood conditions quantified in the dermis while accounting for variable melanin concentrations in the epidermis.