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A novel method, condensed Monte Carlo simulation, is presented that applies the results of a single Monte Carlo simulation for a given albedo micro(s)/(micro(alpha) & micro(s)) to obtaining results for other albedos; micro(s) and micro(alpha), are the scattering and absorption coefficients, respectively. The method requires only the storage of the number of interactions of each photon with the medium. The reflectance and transmittance of turbid slabs can thus be found from a limited number of condensed Monte Carlo simulations. We can use an inversion procedure to obtain the absorption and scattering coefficients from the total reflectance and total transmittance of slabs. Remitted photon densities from a semi-infinite medium as a function of the distance between the light source and the detector for all albedos can be found even from the results of a single condensed Monte Carlo simulation. The application of similarity rules may reduce further the number of Monte Carlo simulations that are needed to describe the influence of the distribution of scattering angles on the results.

Condensed Monte Carlo simulation results have been used for calculating absorption and reduced scattering coefficients from the literature data on the measured total transmittance and total reflectance of samples of the human skin in vitro. The results of several measuring methods have been compared. We have also estimated the range for absorption coefficients and reduced scattering coefficients at 660 and 940 nm from measured intensities at the skin surface as a function of the distance from the location where the light enters the skin by using condensed Monte Carlo simulations for a homogeneous semi-infinite medium. The in vivo values for the absorption coefficients and the reduced scattering coefficients appear to be much smaller than the values from the in vitro measurements, that have been assumed until now. The discrepancies have been discussed in detail. Our in vivo results are in agreement with other in vivo measurements that are available in the literature.