Monte Carlo simulations combined with experimental measurements: a new possibility of study of the light distribution in fat emulsions

摘要

MCML1.2.2-2000 code was used to simulate light distribution in Lipovenos~? 10% (Lp) layers with various thicknesses illuminated by red laser. Light fluence distribution at the layer bottom and fluence profile along a plane distant 5.5 mm from the laser beam were calculated. The results show that the light transmitted to the bottom of the sample has a Gaussian distribution with widths that increase linearly with the thickness. Also, the maximum light intensity and the total fluence transmitted across the sample have exponential decay behavior with thickness. An experiment has been carried out, acquiring, with a CCD camera, pictures of light transmitted and scattered at 90° from a cuvette containing different quantities of Lp, illuminated from the top with He-Ne laser. The experimental results show that the maximum intensity of transmitted light has an asymptotic exponential behavior with the sample thickness, very similar to the simulation. Gaussian curves fitted to the experimental results have widths similar to the simulated ones. The simulated light profile at 5.5 mm from the incidence plane is very similar to the variation of scattered light intensity with depth. We conclude that images of illuminated tissue combined with MCS can contribute with evaluation of light distribution inside tissue.