Table 2.
Similarity measures of HRVs and PRVs obtained from simultaneous ECG and PPG (averaged over ALL subjects): RRMSE—relative RMSE before AR modeling, RRMSEar—relative RMSE after AR modeling, DTWp—Dynamic Time Warping before entire post-processing, DTWs—Dynamic Time Warping after outliers correction, r—Pearson’s correlation coefficient after entire post-processing. The symbols #, *, or ¶ indicate that a given value is statistically smaller than for PDA, AMPD, and SSF, respectively, verified with the Student’s t-test at the 5% significance level.
| Measure | PRV Algorithm | Experiments: ALL Subjects (Mean ± SD) | ||||
|---|---|---|---|---|---|---|
| NoMove | Light | Tap | Arm | Breath | ||
| RRMSE (%) | PDA | 2.9 ± 1.6 | 2.6 ± 1.7 | 22.5 ± 11.2 | 17.7 ± 10.3 | 24.4 ± 22.0 |
| AMPD | 3.4 ± 2.1 | 2.5 ± 1.5 | 23.4 ± 12.8 | 20.0 ± 13.3 | 26.9 ± 23.7 | |
| SSF | 3.6 ± 2.2 | 2.7 ± 1.8 | 22.9 ± 9.6 | 18.4 ± 10.4 | 23.7 ± 21.2 | |
| RRMSEar (%) | PDA | 2.9 ± 1.0 | 3.3 ± 1.5 | 21.5 ± 11.3 | 15.9 ± 9.5 | 23.4 ± 21.1 |
| AMPD | 3.1 ± 1.3 | 3.1 ± 1.4 | 22.1 ± 12.6 | 18.9 ± 12.9 | 26.2 ± 23.0 | |
| SSF | 3.3 ± 1.3 | 3.1 ± 1.4 | 21.5 ± 9.8 | 16.0 ± 9.2 | 22.9 ± 20.6 | |
| DTWp | PDA | 3.8 ± 2.1 | 4.5 ± 2.6 | 38.9 ± 14.8 | 32.5 ± 18.3 | 28.2 ± 21.8 |
| AMPD | 3.5 ± 1.6 | 4.5 ± 2.5 | 37.5 ± 19.2 | 32.7 ± 18.8 | 31.0 ± 24.3 | |
| SSF | 4.7 ± 3.1 | 4.9 ± 3.0 | 42.2 ± 13.3 | 32.3 ± 17.5 | 29.4 ± 22.9 | |
| DTWs | PDA | 3.3 ± 1.3 | 3.7 ± 1.5 | 36.2 ± 15.8 | 24.8 ± 12.9 | 23.7 ± 18.2 |
| AMPD | 3.6 ± 1.6 | 3.7 ± 1.5 | 34.8 ± 17.7 | 25.4 ± 14.0 | 24.5 ± 18.7 | |
| SSF | 3.9 ± 2.0 | 4.1 ± 2.0 | 37.5 ± 13.0 | 25.8 ± 13.4 | 23.4 ± 17.9 | |
| r | PDA | 0.96 ± 0.05 | 0.95 ± 0.06 | 0.66 ± 0.16 | 0.75 ± 0.15 *,¶ | 0.87 ± 0.15 |
| AMPD | 0.96 ± 0.05 | 0.96 ± 0.05 | 0.67 ± 0.14 | 0.77 ± 0.13 | 0.87 ± 0.18 | |
| SSF | 0.95 ± 0.05 | 0.95 ± 0.07 | 0.65 ± 0.16 | 0.74 ± 0.15 *,# | 0.85 ± 0.19 | |