A system and method for processing photoplethysmography (PPG) signals in a vehicle. The system and method include receiving a PPG waveform signal from an optical sensor. The system and method also include processing a PPG measurement signal based on the PPG waveform signal. The system and method additionally include receiving a noise waveform signal from at least one of: a seat assembly sensor, a vehicle sensor, and a vehicle system. Additionally, the system and method include processing a motion artifacts measurement signal based on the noise waveform signal. The system and method further include processing a refined PPG signal to suppress the motion artifacts measurement signal from the PPG measurement signal.