rPPG (Remote Photoplethysmography)

Remote Photoplethysmography (rPPG) is a contactless optical measurement technique that detects blood volume changes beneath the skin using a standard camera. By analyzing subtle color variations in facial video that are invisible to the naked eye, rPPG algorithms can extract physiological signals including heart rate, heart rate variability, respiratory rate, and blood oxygen saturation.

Unlike traditional photoplethysmography (PPG) which requires physical contact with a sensor, rPPG works at a distance using ambient or controlled lighting and a camera. The technology leverages the fact that each heartbeat causes a slight increase in blood volume in the capillaries near the skin surface, producing tiny fluctuations in reflected light that can be captured and processed by computer vision and signal processing algorithms.

rPPG has applications across telehealth, remote patient monitoring, fitness assessment, insurance underwriting, and any scenario where contactless vital signs measurement is valuable. The technology continues to advance with improvements in AI-based signal processing, motion artifact removal, and multi-vital extraction from a single measurement session.