Reduction of Motion Artifact in PPG signal with CDS-LMS Filter

Abstract

This paper presents correlated double sampling least mean squares (CDS-LMS) filter to reduce the motion artifacts of the PPG signal. By using red and green PPG signals as the inputs of the LMS filter, the motion artifacts with the same frequency component as PPG signals can be removed without losing information in PPG. Also, CDS is employed before the LMS filter to remove the effect of ambient light offset. With the proposed CDS-LMS filter, the RMS error in heart-beat interval is reduced by 86.49%, 87.54%, and 89.09% compared to a conventional bandpass filter when the PPG signal is measured during squatting, walking, and running. The mean absolute error in heart rate is 2.59 beats per minute while running.