This work presents a compartmental model for delivery of drugs under anesthesia and an advanced model based control algorithm for insulin delivery for Type I diabetes. The model for anesthesia involves choice of three drugs isoflurane, dopamine and sodium nitroprusside, which allows simultaneous regulation of mean arterial pressure and unconsciousness of the patients. A number of dynamic simulations are carried out to validate the model. For Type I diabetes, a parametric programming approach is used to obtain the optimal insulin infusion rate as an explicit function of the state of the patient and the regions in the space of the state of patient where these functions are valid. These explicit functions allow the implementation of blood glucose control on a simple computational software and hardware platform. (c) 2005 Elsevier Ltd. All rights reserved.