An Adaptive Controller for Closed-Loop Management of Blood Pressure in Seriously Ill Patients

An adaptive control strategy is described which has been used for closed-loop computer control of blood pressure in patients in the Intensive Care and Cardiac Surgical Units of the Royal Melbourne Hospital. The initial development and testing of the control algorithm was done by simulation using computer facilities in the Intensive Care Unit. Adaptation to patient variability utilizes a model reference strategy. Control is based on readings of mean arterial pressure obtained from a standard patient monitor unit and implemented by controlling the infusion rate of a volumetric infusion pump. Patient data are displayed graphically on a VDU during control and stored on disk for subsequent postcontrol display and analysis by the medical staff. Clinical trials have indicated that the system is robust and can maintain effective control following sudden large variations in the patient's blood pressure.