Evaluating the sedative effect of TCI propofol on PSI digitized brain power in surgery of two groups (Objective 2) Discussing common Ce, Cp indexes and PSI concentrations for titrations and clinical reliability To reach 70 ≤PSI≤ 80 and OAA / S = 3, the average Ce concentration of group I (1.25 ± 0.21) is lower than the average Ce concentration of group II (1.69 ± 0.30) with p <0.001.