Table 3.
Similarity measures of HRVs and PRVs obtained from simultaneous ECG and PPG (averaged over SELECTED 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: SELECTED Subjects (Mean ± SD) | ||||
|---|---|---|---|---|---|---|
| NoMove | Light | Tap | Arm | Breath | ||
| RRMSE (%) | PDA | 2.9 ± 1.6 | 2.6 ± 1.7 | 13.8 ± 5.6 ¶ | 11.1 ± 4.2 | 4.8 ± 3.8 |
| AMPD | 3.4 ± 2.1 | 2.5 ± 1.5 | 13.1 ± 6.1 ¶ | 10.7 ± 3.9 ¶ | 9.2 ± 8.3 | |
| SSF | 3.6 ± 2.2 | 2.7 ± 1.8 | 16.1 ± 4.8 | 11.9 ± 4.1 | 5.4 ± 4.2 | |
| RRMSEar (%) | PDA | 2.9 ± 1.0 | 3.3 ± 1.5 | 12.3 ± 4.9 ¶ | 9.8 ± 3.8 | 3.9 ± 2.4 |
| AMPD | 3.1 ± 1.3 | 3.1 ± 1.4 | 11.7 ± 5.4 | 9.7 ± 3.8 | 7.5 ± 6.3 | |
| SSF | 3.3 ± 1.3 | 3.1 ± 1.4 | 14.3 ± 4.2 | 10.3 ± 4.0 | 3.9 ± 2.0 | |
| DTWp | PDA | 3.8 ± 2.1 | 4.5 ± 2.6 | 30.5 ± 11.2 ¶ | 21.7 ± 8.6 | 12.2 ± 7.6 |
| AMPD | 3.5 ± 1.6 | 4.5 ± 2.5 | 23.0 ± 8.8 ¶ | 21.4 ± 8.7 | 13.1 ± 8.7 | |
| SSF | 4.7 ± 3.1 | 4.9 ± 3.0 | 37.4 ± 13.6 | 22.4 ± 9.2 | 12.5 ± 7.9 | |
| DTWs | PDA | 3.3 ± 1.3 | 3.7 ± 1.5 | 25.4 ± 9.4 | 17.4 ± 6.2 ¶ | 10.5 ± 6.3 |
| AMPD | 3.6 ± 1.6 | 3.7 ± 1.5 | 21.3 ± 8.3 #,¶ | 16.9 ± 6.0 ¶ | 11.0 ± 6.8 | |
| SSF | 3.9 ± 2.0 | 4.1 ± 2.0 | 30.9 ± 11.2 | 18.1 ± 6.5 | 10.4 ± 6.1 | |
| r | PDA | 0.96 ± 0.05 | 0.95 ± 0.06 | 0.64 ± 0.2 | 0.78 ± 0.15 | 0.92 ± 0.11 |
| AMPD | 0.96 ± 0.05 | 0.96 ± 0.05 | 0.66 ± 0.16 | 0.79 ± 0.14 | 0.92 ± 0.09 | |
| SSF | 0.95 ± 0.05 | 0.95 ± 0.07 | 0.63 ± 0.19 | 0.77 ± 0.14 * | 0.91 ± 0.12 | |