Controller for a dual drug delivery system

Abstract

A system for controlling the flow of intravenous fluids to a patient provides for the sequential administration of two different intravenous fluids at independently preselected drop rates. The system includes a primary administration set associated with a first fluid container, a secondary administration set associated with a second fluid container, and a controller having a control valve operatively associated with both administration sets to control the fluid flow rate through the particular administration set in use. The system further comprises a connector means in the primary administration set, upstream from the control valve, for joining the secondary administration set to the primary administration set. A one-way valve, disposed in the primary administration set upstream from the connector means, prevents fluid flow through the one-way valve whenever hydrostatic pressure in the secondary set is greater than the hydrostatic pressure in the primary set. Drop sensors, operatively associated with drip chambers in each of the administration sets, are electrically connected with the controller to monitor and sense whether there is fluid flow in the particular system. The controller also includes a pinching device which is activated to pinch IV tubing in the secondary set when the controller either senses no flow rate through the secondary set or senses a sufficient flow rate in the primary set. This pinching action causes an instantaneous reversal of the hydrostatic pressure differential at the one-way valve and permits immediate fluid flow from the first fluid container at a controlled rate through the primary administration set to the patient.