Hydrocephalus is a neurological condition that can result from trauma, hemorrhage, cancer, and infection. To control the intracranial pressure (ICP) a shunt is implanted to drain the cerebro-spinal fluid (CSF). We are working to develop an implantable pressure sensor. When the ICP is too high it will open a valve to relieve the ICP. When the ICP is too low, it will close the valve.