Near-infrared spectroscopy has been widely employed in biophotonics to study and quantify the optical properties of biological tissues. Unlike steady-state approaches, time-resolved spectroscopic techniques enable optical absorption and scattering properties of the medium to be separated, allowing for quantitation of depth-dependent absolute tissue optical properties. However, robust analysis of time-resolved signals requires careful consideration of calibration techniques and computational models. Here, we consider the effect of the time window employed when fitting a diffusion theory model to Monte-Carlo simulations. Next, we describe the impact of the temporal position of the instrument response function (IRF) in recovery of the optical properties. Finally, we discuss a technique to analyze time-resolved measurements without knowledge of the timescale of the IRF or the time-resolved measurement by fitting the relative shape of the photons’ distribution time-of-flight (DTOF).
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