Abstract

An intravenous flow control system includes a programmed microprocessor which receives information from a drop sensor and varies the adjustment of a clamp to control the infusion rate. The system accepts total dose and infusion duration, or dose rate and time information keyed in by the user, and periodically develops a target rate, based on the amount of infusate already delivered, such target rate being calculated to correct the actual delivered dose to that determined by the user keyed data. The target rate differs from the programmed rate by an amount equal to the programmed rate times an adjustment factor. In a preferred embodiment a series of tolerance bands corresponding to delivered volume errors are defined, with the adjustment factor a constant in each tolerance band. For high rate discrepancies, slewing is used to correct the clamp adjustment. Inability to attain the target rate before the delivery of a threshold volume of fluid triggers an alarm. Further alarms are provided for high and low drip rates, streaming, and for deviation of the total volume outside of a progressively defined maximum tolerance band. Control rate and time data are entered by the user through a menu-driven keyboard, in response to displayed messages, thus requiring only INCREASE, DECREASE and SELECT keys.