Sensor and source level δ-oscillation complexity during maintenance and emergence phases of sevoflurane general anesthesia in infants aged 0 to 3.9 months. (A) δ-Oscillation complexity at the sensor level was decreased when comparing anesthesia with emergence. (B) Similar results were observed at the source level. In the box plots, the thick lines represent median values, and whiskers represent 1.5 times the interquartile range. Gray lines indicate individual data. Data comes from n = 20 infants from 100-s epochs. The anesthesia end-tidal sevoflurane was 1.8 to 2.5%, and the emergence end-tidal sevoflurane was 0 to 0.3%. *P < 0.05 using the two-tailed Wilcoxon signed rank test.