An Improved Computing Method for Analysing Light Propagation in Biological Tissue
M-X. Sun, M-L. Kang, Y-X. Li and C-P. Zhang
An improved computing method was applied to analysing light propagation in biological tissue irradiated by a finite size photon beam. This method combined diffusion approximation equation and convolution method. We compare the fluence rate and reflectance for semi infinite biological tissue calculated from this modified method with that computed by Monte Carlo simulations and the results show good agreement. The characteristics of fluence rate for different width incident photon beam on semi infinite tissue were revealed by this modified method. Light propagation in two-layered turbid media irradiated by a finite size photon beam is also investigated by this modified method because many parts of the body have a layered tissue structure.
Keywords: Light propagation, biological tissue, finite size photon beam, diffusion approximation (DA), extrapolated boundary condition (EBC), convolution method, Monte Carlo simulation