There have been reports in the past of using thermal cameras to demonstrate flow in the tubing as a surrogate of proper shunt function. This was shown to have almost 90% accuracy at determining proper functioning but required expensive equipment that was not universally available. There is now smart phone based thermal camera technology (Flir One: http://www.flir.com/flirone/) that could make this technique widely available for health care use. The goal of the study is to determine if this device can demonstrate flow in the distal tubing of a VP shunt.

Inclusion Criteria:

• Patients with known VP shunt
• Status of shunt function known.
• Patients with well healed wounds (no immediately post op patients)

Exclusion Criteria:

• Patients in urgent need of shunt revision
• Age less than 18

Adult patients with VP shunts at the University of Pennsylvania, Department of Neurosurgery