Patient care using closed-loop computer control

The application of computer control technology to aspects of patient care offers the possibility of relieving medical and nursing staff of some routine management tasks which follow well established and test protocols. There are, however, problems of patient sensitivity, non-linearity and variability which need to be overcome by the system designer before closed-loop control can ensure adequate standards of patient safety and improve on current manual control procedures. The major difficulties facing the control system designer in the medical environment are illustrated by looking at some specific applications of closed-loop computer control to patient care. These are the controlled release of an anaesthetic agent into gases in the patient breathing circuit during surgery, the controlled intravenous infusion of vasoactive drugs to manage blood pressure and controlled infusion of insulin to manage blood glucose levels