Robust control of drug infusion with time delays using direct adaptive control: Experimental results

The control of hemodynamic variables, particularly mean arterial pressure (MAP) and cardiac output (CO), is a challenging problem. Due to the complex, nonlinear behavior of the system, a good controller is difficult to design. In addition, there are significant changes in dynamics from one patient to another, and even variations in the patient's response to the drugs as his condition evolves. A robust direct model reference adaptive controller (DMRAC) is developed for such plants with uncertainty in both the time delay elements and in the transfer function coefficients. Further modifications are introduced as well to handle command limiting. The controller developed is then validated with dog experiments. The experiments were conducted on three mongrel dogs, using different drug combinations and different anesthetics.