Adaptive sum comb filter for PPG signals by using ECG signal as reference

Measured PPG signals can be often affected by noises and motion artefacts. The usual band-pass filter does not remove noises, which are sharing the same frequency band as the signal. The PPG signal AC component fundamental harmonic and all other frequency multiples of the fundamental frequency are extracted by comb filter. The adaptive comb filter has been proposed, which uses ECG signal as reference. Comparative experiments have been carried out.