 -RL-TIVA: Propofol, ketamine and sufentanil PKS administration will be done via a three way stop cock connected directly to the IV catheter to minimize dead space volume. PKS solution will contain total of 50ml. Propofol 10mgml, Ketamine 1mgml will be omitted in subsequent preparations after first 50ml, Sufentanil 0.25 mcg-ml. Drug will be administered using a Harvard 33 syringe pump The Harvard 33 Syringe pump has been used in human trials in prior study at Stanford that is pending publication. This pump will be connected via a RS 232 interface to the study computer running RL reinforcement learning control software. This software platform collects real time vital signs and BIS values and steer the target controlled infusion pumps and the closed-loop controllers. 