EVALUATION OF A LONG-RANGE ADAPTIVE PREDICTIVE CONTROLLER FOR COMPUTERIZED DRUG-DELIVERY SYSTEMS

A closed-loop adaptive control system, based on the generalized predic tive control law with a terminal matching condition, has been develope d for computerized drug delivery, The control law is a minimization of the squares of prediction errors over a small future prediction horiz on plus weighted square of the prediction error at steady-state, A con trol-relevant, long-range identification algorithm is used for on-line parameter estimation, Since the control and identification are mutual ly compatible, the system truly satisfies the approximate dual control criterion, The system has been applied to the control of mean arteria l pressure (MAP) by automatic infusion of sodium nitroprusside in the presence of physical and physiological constraints, Experimental evalu ation on six mongrel dogs, in an ethics-approved manner, included setp oint tracking and regulation of MAP in the presence of unpredictable d isturbances, The system was found to be capable of inducing hypotensio n in an average of 2.44 +/- 0.31 min (mean +/- standard error of mean) after probing without any overshoots in mean arterial pressure, The n itroprusside infusion was also free of any ringing. When the subjects were not disturbed, 96.2 % of mean arterial pressure remained within 5 mm Hg of the target pressure, A series of disturbances introduced in the presence and absence of closed-loop control affirms the robustness and effectiveness of this control system.