Diffuse Reflectance Spectroscopy For Obtaining Physiological Parameters Of Skin

Reflectance spectroscopy is a non- invasive method for obtaining skin physiological parameters, such as melanin, hemoglobin, and oxygen saturation. All of these parameters can help to diagnose skin diseases or evaluate aesthetic efficacy. However, most of the reflectance spectroscopy is developed based on simplified models, such as Beer-Lambert Law and diffusion theory. This thesis focuses on obtaining skin physiological parameters using diffuse reflectance spectroscopy.The main research contents and conclusions are listed below:(1) A fiber reflectance spectroscopy based on the two- layered skin model and Monte Carlo simulation was developed for obtaining the physiological parameters of skin, s uch as melanin volume fraction, blood volume fraction and oxygen saturation(2) Human experiments were conducted to verify the validity of the physiological parameters obtained by the established fiber reflectance spectroscopy. The extracted melanin volume fraction indicated good coincidence with the values measured by a commercial probe, and the correlation coefficient between them was 0.97. The blood volume fraction and oxygen saturation were in agreement with physiological changes during forearm venous occlusion and ischemia experiment, and hot compress experiment.(3) Build a hyperspectral imaging system for monitoring the distribution of the oxygen saturation in mouse dorsal skin. The validity of the oxygen saturation calculated by the hyperspectral ana lyzing method based on Beer-Lambert Law was evaluated using computer simulating calculation.In conclusion, this work provided a much more accurate fiber reflectance spectroscopy to obtain the physiological parameters of the skin tissue. And in the future, this technique has the potential to be used in hyperspectral imaging of skin, and become a new technique for diagnosis of skin diseases and follow-up of curative effect.