Validation of Frontal EEG to Formal Polysomnography in the ICU

Group 1: Healthy Subjects in Sleep Lab: Inclusion Criteria * Age 18 or older * Scheduled for a standard of care polysomnography lasting at least 8 hours for any condition Exclusion Criteria * Patient/Legally Authorized Representative declines consent Group 2: ICU patient, not sedated, not ventilated Inclusion Criteria * Age 18 or older * Anticipated to stay in intensive care unit overnight (minimum 8 hours) * Glasgow Coma Scale score of 13 or great Exclusion Criteria: * Intubated with endotracheal tube * Sedated (includes sedative drugs such as propofol, Dexmedetomidine, versed infusion above 2mg/hr, ketamine infusion above 0.2 mg/kg/hr). Group 3: ICU patient, sedated and ventilated Inclusion Criteria: * Age 18 or older * Anticipated to stay in the intensive care unit overnight (minimum 8 hours) * Intubated, sedated, and ventilated Exclusion Criteria: * Presence of traumatic brain injury * Planned extubation in next 8 hours * Scheduled to leave the intensive care unit for any reason in the next 8 hours * Anticipated life expectancy of less than 24 hours * Electroencephalogram monitoring (current or scheduled in the next 8 hours) * Hemodynamic instability (defined as: (i) mean arterial pressure \<60mmHg for \>20 minutes with efforts to raise it or (ii) \>2 liter fluid administered in 2h after operating room and anticipating on-going needs for fluid resuscitation or (iii) ICU MD determination of "atypical and profound hemodynamic instability" or (iv) PI determination after evaluation. * Refractory hypoxemia - defined as Saturation \<88% on Sp02 despite efforts to increase it * Hemorrhage - defined as \>500cc chest tube output in 2h and anticipated need of more than 2 units of packed red blood cells in immediate post op period. This does NOT include cell-saver.