Analysis of photon transport and detectability in skin tissue through Monte Carlo simulation of photosensitization-mediated fluorescence and singlet oxygen luminescence

BACKGROUND: Transport of photons that enter and exit biological tissue is strongly influenced by optical property of biological tissue. In situ collection and detection of photons can also be strongly influenced by the configuration of photodetector. OBJECTIVE: luminescence in skin tissue model. METHODS: luminescence (1270 nm) were analyzed using a simplified proportional model to assess relative changes in signal generation and collection. Detection performance of excitation-detection confocal mode and fiber optic bundle reflection mode were analyzed. RESULTS: signals. Confocal approach provided substantially higher detection efficiency but strong dependence on axial alignment and pinhole size. The signal collection efficiency of fiber bundle probes of symmetric circular configuration was higher than that of linear configurations, but the linear configurations could provide depth-dependent signals. CONCLUSION: luminescence is strongly regulated by the combined effects of skin structure and optical property as well as the geometric configurations of photon collection apparatus.