| Number of crackles per breath (Cr/breath) |
The total number of crackles per breath as detected by the computer |
| Number of crackles per breath per quadrant (top left, top right, bottom left, bottom right) |
These 4 features count the total number of crackles observed in each quadrant of the chest. Together they add up to the total number of crackles per breath |
| Percentage differences between crackle quadrants (6 total) |
Calculated from the 4 features described above, these features represent a comparison between quadrants. Each percentage is a pairwise comparison of all 6 possible combinations of quadrants |
| Maximum distances (x,y,z) |
Distances between crackles in 3-dimensional space. There are separate features for x, y, and z planes. One feature also records a maximum distance across all 3 dimensions |
| Channel distances |
These features are similar to those described above, except that they are defined based upon which channel microphone picked up the crackle. Distances are defined accordingly |
