Method and cassette for delivering intravenous drugs

A disposable cassette for mixing and delivering an intravenous drug in a vial to a patient, the cassette comprising:

• a liquid inlet for connection to a liquid supply;
• a first vial spike;
• a second vial spike;
• a chamber having a variable volume;
• a liquid outlet for providing the intravenous drug in mixed, liquid form to the patient, the liquid outlet, the variable-volume chamber, the first and second vial spikes, and the liquid inlet being in fluid communication with each other;
• and
• a valve mechanism, which may be actuated to control flow between the liquid outlet, the variable-volume chamber, the vial receptacles and the liquid inlet.

A disposable cassette comprising:

• a liquid inlet for receiving an IV solution;
• a vial inlet for receiving a vial containing a medication;
• an outlet for providing to a patient the medication mixed with the IV solution;
• and
• an outlet free-flow-prevention valve which, when the cassette is removed from a control unit which actuates the valve is permanently closed to prevent flow through the outlet.

A method of delivering a dose of medication to a patient, the method comprising the steps of:

• providing 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;
• moving a first volume of medication from the supply through the manifold to the chamber;
• delivering the first volume of medication from the chamber to the patient;
• moving a second volume of medication from the supply through the manifold towards the chamber;
• urging air from the vent through the manifold to force substantially all the medication from the manifold into the chamber;
• and
• delivering the second volume of medication from the chamber to the patient.