BACKGROUND/ PURPOSE: The penetration depth of light in diffuse reflectance near-infrared spectroscopy for measuring water content in skin is assessed both from theoretical and experimental points of view. METHODS: The Monte Carlo simulation was implemented to investigate the dependencies of the light penetration depth on a source-detector distance. To compare with the simulation results, an in vivo experiment for water contents of skin was performed introducing two different optical fiber probes. RESULTS: It is found that the minimum separation between a source and detector fibers influences largely the measurement depth. The larger separation leads to a deeper measurement depth at a particular wavelength. The measurement depth is also influenced fairly by the absorption coefficient of the tissue. The larger absorption coefficient results in a shallower measurement depth. CONCLUSION: The correlations between the water contents measured by the optical and capacitance techniques were discussed. The dependencies of the light penetration depth on the source-detector geometry and wavelength are presented.
BACKGROUND/ PURPOSE: The penetration depth of light in diffuse reflectance near-infrared spectroscopy for measuring water content in skin is assessed both from theoretical and experimental points of view. METHODS: The Monte Carlo simulation was implemented to investigate the dependencies of the light penetration depth on a source-detector distance. To compare with the simulation results, an in vivo experiment for water contents of skin was performed introducing two different optical fiber probes. RESULTS: It is found that the minimum separation between a source and detector fibers influences largely the measurement depth. The larger separation leads to a deeper measurement depth at a particular wavelength. The measurement depth is also influenced fairly by the absorption coefficient of the tissue. The larger absorption coefficient results in a shallower measurement depth. CONCLUSION: The correlations between the water contents measured by the optical and capacitance techniques were discussed. The dependencies of the light penetration depth on the source-detector geometry and wavelength are presented.
Authors: Shital Kandel; William Querido; Jessica M Falcon; Hannah M Zlotnick; Ryan C Locke; Brendan Stoeckl; Jay M Patel; Chetan A Patil; Robert L Mauck; Nancy Pleshko Journal: Front Bioeng Biotechnol Date: 2022-08-23