Perioperative closed-loop control of analgesia in humans

Summary form only given. We present a new paradigm for intraoperative closed-loop control of analgesia in humans. The infusion rate of the opiate alfentanil is the manipulated variable which is administered intravenously through a Computer Controlled Infusion Pump (CCIP). The two regulated outputs are the patient´s Mean Arterial Pressure (MAP) and the drug concentration in the plasma. Maintaining MAP within acceptable ranges improves the patient´s reactions to surgical stimulation. Tracking plasma concentrations enables anesthesiologists to titrate analgesic administration to other qualitative signs of inadequate analgesia. An explicit Model Predictive Controller (MPC) was designed to achieve the above mentioned goals. The results of clinical tests of the controller on humans are presented and discussed.