RecruitingDevice studyNon-Invasive ICP Monitoring StudyMeasuring the pressure inside the skull, which is called intracranial pressure, is important to treat severe neurological illness. Currently, measuring intracranial pressure requires doctors to place an invasive pressure monitor. Recently, a non-invasive intracranial pressure monitor has been developed. This monitor has a tiny pin that is placed on the head which measures the tiny movements of the skull every time the heart beats. This produces a waveform that looks very similar to an invasive intracranial pressure waveform. However, we don't know enough about how the non-invasive device to make it clinically useful yet.