The influence of boundary conditions on the accuracy of diffusion theory in time-resolved reflectance spectroscopy of biological tissues.

The applicability of diffusion theory for the determination of tissue optical properties from time-resolved reflectance spectroscopy is investigated. Analytical expressions from diffusion theory using the three most commonly assumed boundary conditions at the air-tissue interface are compared with time-resolved Monte Carlo simulations and measurements on tissue phantoms. The effects of the choice of the boundary conditions on the accuracy of the findings for the optical parameters are quantified, and criteria for accurate curve-fitting algorithms are developed.