MULTIPLE-SCATTERING EFFECTS IN TRANSMISSION OXIMETRY

To develop an algorithm for the spectrophotometric determination of th e oxygen saturation in blood, a model for the transmission of light in a scattering and absorbing medium is developed, taking into account e ffects of multiple scattering. The computed results obtained by a Mont e Carlo simulating program agreed well with those found by experiment. The results were compared with those obtained by the commonly used al gorithm of transmission oximetry (based on Lambert-Beer's law) and it was found that the calibration curves obtained by this method were str ongly dependent on the haematocrit and thickness of the sample. These curves were less reliable the lower the saturation of oxygen.