Experimental prediction of wavelength dependence of optical path length for optical intrinsic signal analysis

In this study, we proposed a new method to experimentally estimate the wavelength dependence of the optical path lengths from multi-spectral images of the exposed cortex. The proposed method was applied to the path length correction for the multi-spectral measurements of the concentration changes in oxy-haemoglobin (oxy-Hb) and deoxy-haemoglobin (deoxy-Hb) in the cortical tissue of guinea pigs during auditory stimulation