IN SITU MONITORING OF MEAN BLOOD OXYGEN SATURATION USING EXTENDED MODIFIED LAMBERT BEER MODEL

摘要

We present the use of Extended Modified Lambert-Beer model for optical monitoring of mean blood oxygen saturation (S_mO_2) via a fitting procedure. This work focuses on the absorption characteristics of hemoglobin derivatives in the wavelength range of 520-600 nm to give the best estimates of S_mO_2. The study of the feasibility of applying this analytic method to skin oximetry is via spectroscopy data collected from fingertips of four healthy volunteers both at rest and during arterial blood occlusion condition. The results revealed a decrease in the mean of mean and standard deviation of S_mO_2 value of fingertips from 94.5 ± 2.19% when volunteers were at rest to 56.76 ± 5.8% during the arterial blood occlusion measurement. The larger variation in the value estimated for blood occlusion condition could be a result of differences in volunteers' physical fitness and hypertension status. These estimated S_mO_2 values agreed reasonably well with the value reported in most of the previous studies. This work concluded that the proposed technique can potentially be used as a complementary technique to clinical assessment of skin grafts and burnt skin.