Аннотация:The direct problem of noninvasive optical biomedical diagnostics based on laser probing is considered. Light propagation in tissue is described by the radiative transfer equation. A grid algorithm using an analytical representation of the non-scattered radiation and a semi-analytical method for calculating the single scattered radiation intensity is presented. The direct solution of the radiative transfer equation is compared with the experimental data, Monte-Carlo simulation results and the diffusion approximation solution. The proposed algorithm has advantages in terms of accuracy and lower calculation time.