Fig. 4: Evaluation in long-term daily life scenario.
From: Monitoring long-term cardiac activity with contactless radio frequency signals
a Overnight radar signals. The radar signals throughout the night were collected when the subject was sleeping. b Comparison of real-time inter-beat interval (RT-IBI) error. RF-HRV achieves a 34.1 ms median RT-IBI error, while mmHRV and V2iFi achieve 164.6 ms and 147.9 ms median RT-IBI error, respectively. c Comparison of root mean square of the successive differences (RMSSD) error. RF-HRV achieves a 62.2 ms median RMSSD error, while mmHRV and V2iFi achieve 635.3 ms and 571.2 ms median RMSSD error, respectively. d Comparison of standard deviation of all normal R-R intervals (SDRR) error. RF-HRV achieves a 38.8 ms median SDRR error, while mmHRV and V2iFi achieve 421.1 ms and 382.3 ms median SDRR error, respectively. e Comparison of proportion of N-N intervals exceed 50 ms (pNN50) error. RF-HRV achieves a 10.7% pNN50 error, while mmHRV and V2iFi achieve 48.1% and 43.3% median pNN50 error, respectively. f–i The cumulative distribution function (CDF) plots of RT-IBI error, RMSSD error, SDRR error, and pNN50 error. n = 5 nights data in box plots of (b-i). Square, mean; minima, smallest non-outlier value; maxima, largest non-outlier value; center line, median; box bounds, upper and lower quartiles; whiskers, 1.5  × interquartile range, in box plots of (b-e).
