Researchers have developed a method that uses the camera on a person's smartphone or computer to take their pulse and respiration signal from a real-time video of their face. The development comes at a time when telehealth has become a critical way for doctors to provide health care while minimising in-person contact during Covid-19.

The University of Washington-led team's system uses machine learning to capture subtle changes in how light reflects off a person's face, which is correlated with changing blood flow. Then it converts these changes into both pulse and respiration rate. The researchers presented the system in December at the Neural Information Processing Systems conference. Now the team is proposing a better system to measure these physiological signals.