Table 1.

Labels and description of the 23 features used for SVMs and automated scoring of wakefulness and sleep.

Label	Description
SID	Standard deviation of consecutive image difference
SNR _(L/H)	Respiratory signal to noise ratio
K_(L/H)	Kurtosis of raw signal
RFQ_(L/H)	Respiratory frequency
SAC_(L/H)	Standard deviation for autocorrelation of signal
KAC_(L/H)	Kurtosis for autocorrelation of signal
MAC_(L/H)	Mean autocorrelation of signal
K_PSD	Kurtosis of power spectral density
S_PSD	Skewness of power spectral density
MPL1	Mean power spectral density (0.1–1HZ)
MP1-3	Mean power spectral density (1–3HZ)
MP3-5	Mean power spectral density (3–5HZ)
MP5-8	Mean power spectral density (3–5HZ)
MP8-15	Mean power spectral density (8–15HZ)
TPSD	Total Power spectral density
DP2AR_(L/H)	Distance from power spectral density peak in the 1–3 Hz range to the average respiratory peak position (2.1 Hz)

(L/H): denotes whether the raw signal was from the lower analog band pass filter channel (L) or from the higher filter channels (H). Thus, labels with the L/H designation indicate two separate features. Power spectral densities (MPL1, MP1-3, MP5-8, MP8-15, TPSD), kurtosis for power spectral density (K_PSD), and skewness of power spectral density (S_PSD) were derived only from the L channel. SID was obtained from the infrared camera. All other features were obtained from the radar sensor.