Research on reflective pulse oximetry based on fiber optic spectrometer

Human oxygen saturation detection is based on the Lambert-Beer Law, but since the human body is a strong scattering tissue instead of a homogeneous medium, the influence of scattering need to be considered, which means the basic Lambert-Beer Law is not applicable. In this paper, a fiber optic spectrometer is used to detect the blood oxygen saturation in vivo with reflective method. Based on the dynamic spectrum theory, the concept of equivalent attenuation is proposed, converting the three-dimensional data measured in real time into two-dimensional characteristic spectral data. In spite of the baseline drift and dark noise of the spectrometer, the two-dimensional characteristic spectral data can be corrected by multiple scatter correction, which can eliminate the influence of the scattering and baseline drift, and improve the accuracy of the model building.