Assessment of Flow in Cerebrospinal Fluid Shunts With a Wireless Thermal Anisotropy Measurement Device, Phase B

Patients with an existing implanted ventriculoperitoneal (VP) shunt and who are experiencing shunt malfunction symptoms will be recruited by the clinical investigators at each investigational site in accordance with the inclusion and exclusion criteria. Assessment of shunt flow will be performed non-invasively with the study device; physician and clinical staff will be blinded to the device result. Standard-of-care assessment of shunt function will be performed and surgical intervention will occur based on the judgement of the treating neurosurgeon without the use of study device data. This trial will evaluate the ability of the study device to identify shunt malfunctions.