Optical Scattering Properties of Fat Emulsions Determined by Diffuse Reflectance Spectroscopy and Monte Carlo Simulations

Abstract: To estimate the propagation of light in tissue-like optical phantoms (fat emulsions), this thesis utilized the diffuse reflectance spectroscopy in combination with Monte Carlo simulations. A method for determining the two-parametric Gegenbauer-kernal phase function was utilized in order to accurately describe the diffuse reflectance from poly-dispersive scattering optical phantoms with small source-detector separations. The method includes the spectral collimated transmission, spatially resolved diffuse reflectance spectra (SRDR) and the inverse technique of matching spectra from Monte Carlo simulations to those measured. An absolute calibration method using polystyrene micro-spheres was utilized to estimate the relation between simulated and measured SRDR intensities. The phase function parameters were comparable with previous studies and were able to model measured spectra with good accuracy. Significant differences between the phase functions for homogenized milk and the nutritive fat emulsions were found.