Motion artifact reduction in photoplethysmographic signals using singular value decomposition

Artifact free photoplethysmographic (PPG) signals, obtained with red and infrared (IR) optical sources and detectors are necessary for non-invasive estimation of oxygen saturation (SpO(2)) in arterial blood. Movement of a patient corrupts the PPGs with motion artifacts, resulting in large errors in the computation of SpO(2). This paper presents a novel singular value decomposition (SVD) based method to reduce motion artifacts from corrupted PPG signals. Test results on a prototype incorporating the proposed SVD technique show that stable and reliable SpO(2) measurement is achieved even when PPGs are distorted by motion artifacts, thus establishing the efficacy of the proposed method.