Abstract
This paper deals with the light transport, photon trajectory and its radiation in tissue. A model based on Monte Carlo simulation has been implemented in Matlab to get inside into photon interaction with tissue. The project is aimed to non-invasive pulse oximetry measurement of fetal oxygen saturation in the maternal abdomen. One of the fundamental challenges is to ensure a sufficient penetration depth which covers maternal and fetal tissue. This contribution investigates the photon trajectories and analyse the number of photons which stayed in tissue and their radiation distribution. The principle and photon propagation rules, needed for simulation, are presented in this article. Finally the results are compared with literature.