Introducing contactless assessment of heart rate variability using high speed video camera

Heart rate variability (HRV) was shown instrumental in assessing the balance of Autonomous Nervous System (ANS). Recent studies demonstrated potential in measuring heart rate using a web cam however existing contactless approaches have limited resolution to satisfy requirements of HRV analysis. In the present article, we propose an approach to measure HRV using contactless methodology based in high-speed camera which addresses this limitation. In this study we estimated precision of contactless estimation of SDNN which is one of the most frequently used HRV parameters. The main goals of this study were (1) to compare between short-term ECG-based standard deviation of RR intervals (SDNN) and short-term image-based standard deviation of RR intervals (iSDNN) (2) to estimate feasibility of using iSDNN as a proxy of SDNN. Correlation analysis in healthy volunteers demonstrated the potential of using iSDDN to estimate SDNN. The results showed a meaningful correspondence between SDNN and iSDNN with correlation coefficients ranging from 0.6 to 1.0. A contactless methodology to monitor ANS balance can be implemented using high speed camera. Based on the initial evaluation the proposed approach has potential for continuous contactless monitoring of stress reactions in a variety of settings. Further assessment of the proposed approach is warranted in larger sample of diverse group of participants.