Passive heart-rate monitoring during smartphone use in everyday life https://medicalxpress.com/news/2026-06-smartphone-heart-potentially-health-billions.html Unlocking smartphones can measure heart rate, potentially enabling health monitoring for billions of people https://www.nature.com/articles/s41586-026-10507-6 A machine-learning system has been developed that can monitor heart rate using facial video clips that are captured passively by the user-facing camera during everyday smartphone use. The system meets industry accuracy standards for heart-rate measurement and is as accurate as wearable technology for measuring daily resting heart rate