Non invasive and real time analysis of skin pigmentation and cutaneous hemoglobin oxygenation: An experimental and theoretical approach

Abstract

In this work we present a technique for examining human skin, based on the in vivo measurement of diffuse reflectance spectra in the visible and near-infrared ranges of the electromagnetic spectrum for non-invasive characterisation of haemoglobin oxygenation and pigmentation in skin. Spectra were measured by means of a fiber optic probe, and they were analyzed using an analytical model, based on the Kubelka–Munk theory of scattering and absorption within inhomogeneous materials. To evaluate the utility of the model, skin sites with variable melanin content were studied on individuals with different skin types or with pathological skin conditions. The results of the analysis indicated that it is possible to obtain quantitative information about main skin pigments, as well as basic information regarding the scattering properties of the skin. In addition to quantification of haemoglobin and melanin, qualitative information on the redox state of the blood may also be obtained. The proposed analytical model could be a helpful tool to monitor and evaluate the variations in the biological skin tissue data and its medical conditions