System for controlling flow through a line during intravenous drug delivery

A system for delivering a dose of medication to a patient, the system comprising:

• a cassette having
• a variable-volume chamber having an inlet leading from a medication supply and an outlet leading to the patient,
• a manifold providing fluid communication between the medication supply and the chamber,
• an air vent in fluid communication with the manifold,
• an outlet valve controlling flow out of the chamber,
• an inlet valve controlling flow between the chamber and the manifold, and
• an air valve controlling flow between the air vent and the manifold;
• and
• a control unit having
• a device for inducing change in the volume of the chamber,
• an apparatus for actuating the outlet valve, the inlet valve and the air valve, and
• a controller for controlling the volume-changing device and the valve-actuating apparatus to move fluid back and forth between the supply and the chamber while delivering medication to the patient.

A system for delivering a dose of medication to a patient, the system comprising:

• a variable-volume chamber having an inlet leading from a medication supply and an outlet leading to the patient,
• a manifold providing fluid communication between the medication supply and the chamber,
• an air vent in fluid communication with the manifold,
• an outlet valve controlling flow out of the chamber,
• an inlet valve controlling flow between the chamber and the manifold, and
• an air valve controlling flow between the air vent and the manifold;
• and
• a control unit having
• a device for inducing change in the volume of the chamber,
• an apparatus for actuating the outlet valve, the inlet valve and the air valve, and
• a controller for controlling the volume-changing device and the valve-actuating apparatus to move fluid back and forth between the supply and the chamber while delivering medication to the patient.