Miniaturized Passive Bio-mechanical Valve for Hydrocephalus Treatment

Hydrocephalus is an accumulation of excess pressure in the brain due to malfunction of the fluid drainage system, arachnoid granulations. Standard treatment uses a shunt to drain excess cerebrospinal fluid to the abdomen. Conventional shunts suffer high failure rates over time. To reduce failure, we propose replacing the shunt with a miniaturized valve placed in the intracranial space. Our current prototype uses a duckbill valve design with 1 mm outlet width. The valve leaflets are silicone (PDMS), with the fluid channel defined using photolithography. In bench top pressure vs. flow testing, the silicone duckbill valve achieved the target cracking pressure range of 5 to 15 cmH2O with no cycling degradation or reverse flow leakage. Upcoming studies will monitor long-term degradation and test valve performance in vivo.