Scaling method for efficient Monte Carlo simulation of fluorescence spectra from multi-layered turbid media with oblique illumination and collection geometry

Fluorescence spectroscopy has been explored extensively in biomedicine. To optimize probe geometry used in fluorescence spectroscopy, the Monte Carlo (MC) method is often used to simulate light propagation in tissues. However, the Monte Carlo simulation of fluorescence is often extremely time-consuming, which limits its application in spectral simulations. In this paper, we present a scaling Monte Carlo algorithm for efficient fluorescence simulation with oblique illumination and detection geometries in multi-layered tissue models. Fluorescence simulations are performed on a two-layered skin tissue model using both the traditional MC method and the scaling method. It is demonstrated that the scaling method can achieve a 46-fold improvement in computational time while maintaining a mean absolute percentage error within 3% compared to independent simulations.