 Patients admitted to the ICU may have delayed awakening after their critical illness has resolved. Though most either are due to metabolic causes or delayed elimination of sedative medications, more serious pathologies such as intracranial hemorrhage, ischemic stroke, and vasogenic edema may also be the cause of coma. These pathologies all result in increases in intracranial pressure ICP with cerebral edema. At this stage, the usual workup includes brain CT scans, MRI or EEG. These tests require transporting the patient from the ICU to the Radiology department, a process that may not be possible for an unstable, critically ill patient. Identifying elevated intracranial pressure elevations have so far, relied on invasive monitoring techniques requiring placement of an intracranial or intraventricular catheter. 