A quantitative and non-contact technique to detect skin water content based on Mueller matrix polarimetry

Water content of stratum corneum has one of the most important biological effects on the physiological function of the skin. Measuring and adjusting the water content can be helpful to understand the physiological state of skin and delay skin aging. However, most existing skin water content analyzers have to contact the skin and the results may be affected by personal usage habits prominently. Mueller matrix polarimetry is sensitive to structural features of tissues. Parameters derived from Mueller matrix can provide the microstructural information quantitatively, such as the sizes of scatterers, the distribution of collagen fibers and so on. In this study, we demonstrate a novel, quantitative, non-contact and in situ technique based on Mueller matrix polarimetry for monitoring the microstructural changes of skin tissues during the process of skin water content reduction. We measure the Mueller matrices of rat skin samples and porcine abdominal skin samples, then analyze the Mueller matrix derived parameters to indicate microstructural changes during the skin water content reduction processes. Comparison between the rat skin samples applied with and without moisturizing cream show that the Mueller matrix derived parameters are potential indicators to reflect the water content of the skin quantitatively. This technique can provide a non-contact detection method and be used to evaluate the change of skin water content when different skin-care cosmetics are used on the skin.