Design of AS-LMS Adaptive filter for reduction of Motion Artifacts in PPG signals

This paper proposes a simple and efficient approach for reducing Motion Artifact (MA) in corrupted PPG (Photo Plethysmo Graphic) Signals based on AS-LMS Adaptive Filter. The performance of pulse oximeters is highly influenced by motion artifact in PPG signals. To generate the noise reference signal for an adaptive filtering process, instead of using any additional hardware such as accelerometer or source-detector pair, it is generated internally from the MA corrupted PPG signal itself. Thus the generated noise signal is applied to AS-LMS adaptive filter for artifact removal. The experimental results proved the efficacy of this scheme, hence it is suitable for present-day oximeters utilizing PPG sensor, which does not require any extra hardware for generating noise reference signal. Keywords— Adaptive filter, oximeter, Photo Plethysmo Graphic (PPG) signal, oxygen saturation, motion artifact (MA).