Frequency selection in frequency domain diffuse optical spectroscopy

Frequency domain diffuse optical spectroscopy (FD-DOS) is a non-invasive technique used to determine the optical absorption and reduced scattering coefficients of biological tissue. Incident light is modulated at radio frequencies and the amplitude and phase shift induced by tissue are analyzed. Here, we evaluate different modulation frequency selection schemes using simulated data. We used noise-free data to evaluate the inverse model, and noisy data using instrument-specific noise models. We found that careful tuning of the inversion algorithm parameters is required to achieve good results and adding modulation frequencies can sometimes result in worse performance depending on the instrument.