Evaluation of Water Measurement Techniques for Human Skin by Dielectric Spectroscopy and Confocal Raman Spectroscopy (original) (raw)

We compared experimental results of confocal Raman microscope and Time Domain Reflectometry (TDR) measurements using a coaxial electrode with a flat-end termination for water content distribution in the depth direction of the human skin. The TDR method suggests an average value of water contents in depth direction from the skin surface to a certain depth. On the other hand, the confocal Raman microscope offers a value of the water content at each depth of the skin. The difference between water contents thus obtained by the both methods was well described by the quadratic expression of the depth from the skin surface. The water content in the skin detected by the electric field from the coaxial electrode on the skin surface used in TDR method decays in proportion to the square of the depth from the contact surface. It is expected that TDR measurements with the flat-end electrode thus characterized in the present study make it possible to offer newer simple experimental techniques to evaluate human skin. Key word: Time Domain Reflectometry, Confocal Raman Spectroscopy, human skin, water content