Nonlinear fitting model for continuous monitoring of mean blood oxygen saturation

We aim to demonstrate the use of Extended Modified Lambert Beer model (EMLB) to detect changes in one's mean blood oxygen saturation (S_mO₂) with different experimental settings. We performed spectroscopy measurement on fingertip and back of the hand of four healthy adults at rest condition, and on the same fingertip after the heat application. The attenuation values given from EMLB are fitted to the experimental reflectance data in the estimation of S_mO₂. The obtained results revealed mean S_mO₂ of 92.6±3.7%, 39.8±6.85% and 102±3.1%, respectively, estimated for measurement on the fingertip and the back of the hand of volunteers at rest, and the heated fingertips. This work concluded that Extended Modified Lambert Beer model can potentially be used to monitor skin oxygenation.