Posture related in-vitro characterization of a flow regulated MEMS CSF valve

A Review of Passive Constant Flow Regulators for Microfluidic Applications

“…Dynamic simulations based on electrical equivalent networks are particularly useful during the design phase to determine the behavior of the passive flow regulator. For a complex system such as the hydrocephalus flow control valve, the model can be further refined by the introduction of experimental data [28].…”

Design and Characterization of an Adjustable Passive Flow Regulator and Application to External CSF Drainage

“…A variation of pressure moves a flexible element of the device to induce a change in the fluidic path cross-section or length. The flexible element can be a silicon membrane [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ], an elastomeric membrane [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ], a silicone tube [ 24 ], a thin flap [ 25 , 26 , 27 , 28 ], or a moving piston [ 29 , 30 ].…”

“…Several implantable passive flow-controlled valves have been considered for the drainage of cerebrospinal fluid (CSF) from the brain ventricles toward the peritoneum cavity for the treatment of hydrocephalus [ 7 , 13 , 22 , 23 , 24 , 29 , 31 , 32 , 33 ]. The single flow-control valve available on the market is the OSVII™ (Integra Life Science, Princeton, NJ, USA).…”

“…An alternative to account for individual-to-individual variability in CSF production rate and cerebrovascular fluctuations is the implementation of the specific fluidic profile that should allow better control of intracranial pressure (ICP) [ 32 ]. A MEMS-based passive flow-regulating valve has been designed to evaluate this solution [ 13 ]. The device consists of a flexible membrane with holes and facing pillars that form valves that close progressively as the pressure increases.…”

“…Numerical simulations have been performed to obtain the targeted flow profile. MEMS technology offers numerous advantages in terms of manufacturing cost, repeatability, and reliability, but the small dimensions of the fluid pathway make the device sensitive to contamination and prone to clogging [ 13 ].…”