Does smartphone photoplethysmography and heart-rate chest strap provide valid measurements of heart-rate variability compared to electrocardiography in healthy subjects?
Smartphone PPG and heart-rate chest straps provide valid and highly correlated measurements of heart-rate variability compared to standard ECG.
PURPOSE: To establish the validity of smartphone photoplethysmography (PPG) and heart-rate sensor in the measurement of heart-rate variability (HRV). METHODS: 29 healthy subjects were measured at rest during 5 min of guided breathing and normal breathing using smartphone PPG, a heart-rate chest strap, and electrocardiography (ECG). The root mean sum of the squared differences between R-R intervals (rMSSD) was determined from each device. RESULTS: Compared to ECG, the technical error of estimate (TEE) was acceptable for all conditions (average TEE CV% 90% CI = 6.35 5.13; 8.5). When assessed as a standardized difference, all differences were deemed "trivial" (average standard difference 90% CI = 0.10 0.08; 0.13). Both PPG- and heart-rate-sensor-derived measures had almost perfect correlations with ECG (R = 1.00 0.99; 1.00). CONCLUSION: Both PPG and heart-rate sensors provide an acceptable agreement for the measurement of rMSSD when compared with ECG. Smartphone PPG technology may be a preferred method of HRV data collection for athletes due to its practicality and ease of use in the field.
Plews et al. (Tue,) studied this question.