Table 3.
Turn onset detection using both orientation and angular velocity thresholds, with various IMU positions in within-subject and subject-independent crossvalidation. CD = correct detection, PLD = premature/late detection, FN = false negatives, FP = false positive, DIFF = mean difference between detected and reference onset.
| CD (%) | PLD (%) | FN (%) | FP (%) | DIFF (ms) | ||
|---|---|---|---|---|---|---|
| within-subject | head | 63.6 | 27.8 | 0.8 | 7.7 | −204 |
| upper back | 87.4 | 10.4 | 2.2 | 4.8 | 69 | |
| lower back | 83.4 | 15.5 | 1.1 | 8.1 | −5 | |
| thigh | 73.5 | 25.1 | 1.3 | 10.1 | 80 | |
| shank | 68.9 | 30.7 | 0.2 | 9.4 | −40 | |
| foot | 66.5 | 29.0 | 4.4 | 25.7 | 74 | |
|
| ||||||
| subject-independent | head | 63.6 | 33.3 | 3.1 | 12.5 | −210 |
| upper back | 74.5 | 22.3 | 3.2 | 12.9 | 108 | |
| lower back | 77.3 | 21.9 | 0.8 | 8.1 | 56 | |
| thigh | 61.3 | 37.5 | 1.2 | 6.3 | 25 | |
| shank | 54.8 | 44.7 | 0.4 | 7.1 | −42 | |
| foot | 45.6 | 50.0 | 4.4 | 21.4 | −78 | |