Figure 3.

Determination of the wake-sleep transition based on GSR signals and validation with EEG signals. (A) EEG spectrogram measured on the forehead that differentiates the transition between awake and sleep (top), band-pass filtered GSR data measured on the wrist (middle), and RMS data from the filtered GSR for determination of sleeping (bottom). (B) Signal processing method of GSR data and sleep estimation process based on the RMS threshold. (C) Optimization of the threshold values to determine the sleeping transition in comparison with the EEG data.