Flow metering apparatus for a fluid infusion system

摘要

Metering apparatus for controlling the flow of fluid through a fluid infusion system at an operator-designated rate includes a single-use cassette having a syringe-type pump in the flow system. The cassette is removably mounted on actuator apparatus which drives the syringe plunger through alternate fill and pump modes to advance fluid through the system. To provide compensation for the lack of flow in the system during fill strokes, the plunger is advanced at a higher compensation rate for first and second portions of the pump stroke immediately preceding and immediately following each fill stroke, with the pump stroke advancing at the designated rate therebetween. This results in an average flow rate which corresponds to the designated rate. By making the first and second compensations of equal duration, the effect of the fill cycles on the regularity of the average flow rate is minimized.