Eliminating motion artifacts in PPG

In this study, independent component analysis was employed to separate the independent components (i.e., PPG signals and noise) from the raw signals with motion artifacts. Subsequently, independent components containing PPG signals were selected and the locations of the PPG signal components on the frequency spectrum were analyzed. Next, the raw signals passed through a multi-bandpass filter specifically designed for this study to eliminate motion artifacts. For the experiment, motion artifacts were created using four types of finger movements: vertical finger movement, horizontal finger movement, rapid finger shaking, and random finger shaking. The study results included an independent component analysis of the independent components, the waveforms of the filtered PPG signals in the time and frequency domains, and the heart rate measurements.