A piggyback IV administration system uses a solenoid actuated sequence valve to control the flow of fluid from a pair of IV fluid sources to the inlet of an IV pump or controller. The sequence valve pinches off a first tube while allowing fluid to flow through the second tube and then, in response to...http://www.google.de/patents/US4714463?utm_source=gb-gplus-sharePatent US4714463 - Sequence valve for piggyback IV administration with tube reversal prevention
