Analysis of light absorption with variation of epidermis thickness in human skin model using Monte Carlo simulation

Abstract

The sensitivity of the oxygenation detection using non-invasive light visible and near infrared range during muscle activation is clinically important. Monte Carlo simulations have been performed to determine light propagation based on epidermal thickness of human skin model. All perimeters such as absorption coefficient, scattering coefficient and anisotropy factor of the five layers samples in the visible spectral range from 600 to 900 nm was determined in this paper. In order to assess the predictability of our simulations, we evaluate their accuracy by comparing results from the model with actual skin measured data. The parameters was estimated using root-mean-squared error of less than 5% for epidermal thickness from (0.001 to 0.2) cm of human skin model under the visible part of the spectrum. The change in optical density is significantly decreased and the linearity of measurement characteristics is clearly distorted by the presence of a larger thickness layer of epidermis about maximum 0.2 cm. Thus, suitable modelling of light propagation passing through epidermis layer in a human muscle is important for quantitative near-infrared spectroscopy and optical imaging for muscle activation studies.