Resting heart rate is a key indicator of cardiovascular health and tracking how it drifts over weeks and months can identify early signs of illness or declining fitness. Measuring it reliably day after day, however, usually requires a wearable device such as a smartwatch or chest strap, and many of the people who would benefit most may never own one. Methods that read the pulse from facial video offer an alternative, but researchers have tested them only in small, controlled settings, and their accuracy drops sharply for people with darker skin tones.
Compared with a medical electrocardiogram, their PHRM system kept its error below the 10% industry standard for all three skin-tone groups, outperforming 15 existing methods. The authors further show that, by pooling many brief readings across the day, the system estimates a person’s daily resting heart rate to within fewer than five beats per minute of a wearable tracker, and that this value tracks known cardiovascular risk factors such as obesity and low fitness.
