Fig. 3. Bispectral Index (BIS; ▴) and spectral edge frequency 95 (the frequency below which 95% of the power in the spectrum resides [SEF⁹⁵]; ○) are shown during the change in sevoflurane concentration. Both BIS and SEF⁹⁵decreased by deepening sevoflurane anesthesia. Significant difference between: * 1% and 2% sevoflurane; ** 1% and 3% sevoflurane; # 2% and 3% sevoflurane.