The purpose of this research, which has been determined as non-significant risk by the central IRB overseeing the study, is to obtain information to help further develop a machine (a medical device) to measure the pressure around the brain from the outside (this pressure is called intracranial pressure or ICP). Monitoring and managing ICP is an important part of care for patients with conditions such as Traumatic Brain Injury (TBI). However, the current way of measuring ICP requires surgery to drill a hole into the skull, and therefore can introduce additional risks such as infections and pain. Recent research has shown it may be possible to measure ICP without needing surgery. This technology is in development, but large amounts of data is required to build these new devices. Through collecting a large database of information from patients who have both the routine surgical device and the research device applied to their head, the research team will work to develop and test an effective and potentially safer way of monitoring patient ICP.