The paediGAV, GAV and ShuntAssistant valves are designed to alter resistance to CSF flow through the shunt in response to changes in body position. As the body moves from the reclining position to the upright position a ball valve responds to gravity by closing. As pressure builds proximal to this valve it will reopened when a set pressure is reached. The GAV and paediGAV valves also contain a pressure differential valve proximal to the gravity activated valve while the ShuntAssistant is meant to be used with a separate, fixed or adjustable pressure differential valve.
Valve Opening Pressures