Automated control of physiological variables and clinical therapy.

Improved transducers and low-cost computational power make the development of on-line systems to control physiological variables and clinical therapy feasible. This review deals only with systems that provide control by the infusion of chemical agents or by changing the concentration of respiratory gases; control provided by electrical stimulation or mechanical means (orthotic and prosthetic devices) are not considered. Applications reviewed include drug dosage planning by computer, insulin infusion, automated anesthesia, control of respiratory variables, and control of blood pressure by vasoactive agents. There is a general need for the development of new sensors for physiological variables, algorithms for adaptive control, and controllable miniature activators for delivering therapeutic agents. Proposed control systems should be thoroughly evaluated in a realistic environment, preferably by comparing them with systems that they were designed to replace.