Table 3.
Alertness measurement methods.
| N. | Measurement methods | No. of Included Studies | |
|---|---|---|---|
| 1 | Physiological signal | EEG | (16, 18, 24, 34) |
| HR | (18, 32) | ||
| HRV | (22, 23, 38) | ||
| Eye Movement Characteristics | (19, 21, 33) | ||
| Others | (23, 30, 42) | ||
| 2 | Questionnaire | KSS | (18, 24, 26, 35) |
| MFI | (25, 27), | ||
| POMS | (15, 37–39, 42) | ||
| VAS | (36, 37) | ||
| Others | (3, 20, 21, 23, 26, 28, 29, 31, 34, 36, 39–41) | ||
| 3 | Task performance | (22, 32, 33) | |
| 4 | Vehicle driving characteristics | (21) |
EEG, Electroencephalograph; HR, Heart rate; HRV, Heart rate variability; KSS, Karolinska Sleepiness Scale; MFI, Multi-dimensional fatigue inventory; POMS, Profile of Mood States; VAS, Visual analog scale.