Fluid delivery control and monitoring apparatus for a medication infusion system

A fluid delivery monitoring and control apparatus for use in a medical infusion system employing a disposable fluid pathway and cassette, which cassette contains a plurality of fluid channels, each of which includes a positive displacement pump having a piston mounted for reciprocating movement within a chamber and respective intake and outlet valves for controlling fluid flow through said chamber, the apparatus comprising:

• drive means for coupling to a cassette in association with a selected fluid channel including means for actuating said piston and said intake and outlet valves in a controlled sequence;
• encoding means coupled to the drive means for providing signals indicative of home position and rate of movement of said drive means;
• means for receiving rate command signals defining a desired rate of fluid flow through an associated cassette;
• means for ascertaining fluid flow rate from rate of movement signals and from cassette indicia indicating piston stroke volume and generating feedback signals indicative of sensed flow rate;
• and
• means for combining the rate command signals with said feedback signals to develop signals for controlling the drive means.