The present invention provides apparatuses and methods to safely and economically deliver infusion fluid to a patient during a medical procedure. The infusion fluid may be a sedative, analgesic, amnestic or other pharmaceutical agent (drug) for alleviating a patient's pain and anxiety before, during and/or after a medical or surgical procedure. In general the apparatus comprises a microprocessor-based controller that receives inputs from a plurality of physiological monitors attached to a patient. The system controller processes the data from the physiological monitors and based upon a fluid infusion algorithm delivers infusion fluid to a patient. The physiological monitors monitor the patient throughout the course of the procedure and depending upon the health of the patient, drug delivery may be adjusted to optimize the procedure while ensuring the patient's health is maintained. Functionality detectors such as an occlusion sensor, air-in-line sensor and a fluid detection sensor alert a clinician to such hazards as a pressure build up in the infusion line, air-bubbles in the infusion line, and the absence of fluid in the infusion line.