Wade-Dahl-Till valve

== English == === Etymology === Developed in 1960-62 by hydraulic engineer Stanley Wade, author Roald Dahl, and neurosurgeon Kenneth Till, after Roald Dahl's son Theo was severely injured. === Noun === Wade-Dahl-Till valve (plural Wade-Dahl-Till valves) A kind of cerebral shunt using two metal discs, each in a restrictive housing at the end of a tube, opened and closed by the pressure of fluid. ==== Synonyms ==== Wade-Dahl-Till shunt WDT