Table 2.
A full list of features used for the classification of ED segments: S ALL denotes all data (source signal) in a segment; S NS denotes data in the nondetected (as a sharp or SW) block only within the segment. Some features are paired (e.g., numbers 9 and 21), which can be calculated for sharps and SWs independently.
| Feature number | Description |
|---|---|
| 1 | Standard deviation of amplitude for S ALL |
|
| |
| 2, 14 | Number of detected waveforms |
|
| |
| 3, 15 | Median wave-width of detected waveforms∗ |
|
| |
| 4, 16 | Median amplitude of detected waveforms |
|
| |
| 5, 17 | Mean kurtosis of detected waveforms∗ |
|
| |
| 6, 18 | Mean ratio of amplitude to wave-width of detected waveforms∗ |
|
| |
| 7, 19 | Standard deviation of amplitude for S NS |
|
| |
| 8, 20 | Feature 8 = feature 1/feature 7 Feature 20 = feature 1/feature 19 |
|
| |
| 9, 21 | Feature 9 = feature 4/feature 7 Feature 21 = feature 16/feature 19 |
|
| |
| 10, 22 | Max(S ALL) − min(S ALL) |
|
| |
| 11, 23 | Max(S NS) − min(S NS) |
|
| |
| 12, 24 | Feature 12 = feature 4/feature 11 Feature 24 = feature 16/feature 23 |
|
| |
| 13, 25 | Mean skewness of detected waveforms∗ |
|
| |
| 26 | Mean distance from a SW to its closest and preceding sharp |
|
| |
| 27 | Ratio of detected waveform types: SW to sharp |
∗Basic features (wave-width, amplitude, kurtosis, amplitude to wave-width ratio, and skewness) were calculated from each detected waveform first, and their median/mean was taken as the features for the classification.