Fig. 6From: Time-trend analysis of the center frequency of the intrinsic mode function from the Hilbert–Huang transform of electroencephalography during general anesthesia: a retrospective observational studyRelationship between BIS and HHT_IF. Each of the 20 patients had 50 data points during emergence from anesthesia and each data point is indicated by a dot, giving a total of 1000 points. The predicted mean and 68% credible interval for Gaussian process regression are depicted in blueBack to article page