This German and Swiss team of investigators used an algorithm they developed to measure heart rate (HR). Detection of the steepest slope of every pulse wave is combined and correlated to an optimized pulse wave pattern. In 68 subjects, the pulse curves were recorded as video signals with a Apple iPhone 4S and simultaneously by ECG. The smartphone-measured HR proved extremely consistent (R > 0.99) with ECGs. Most standard linear HRV parameters also showed high correlations of R ≥ 0.90. Overall, HR and HRV captured by smartphone as video signals with the algorithm proved accurate for preclinical cardiac screening.
Calculation of heart rate (correlation > 0.99 to ECG) and HRV indices (correlation > 0.9 to ECG) with Preventicus algorithm based on smartphone camera derived pulse wave analysis has ECG-comparable accuracy.
N. Koenig, A. Seeck et al. Validation of a New Heart Rate Measurement Algorithm for Fingertip Recording of Video Signals with Smartphones. Telemed J E Health. 2016 Aug;22(8):631-6.