A comparison of clinical control strategies for the hyperglycemia of injury and illness

The performances of several closed-loop algorithms for the automated regulation of blood glucose in an intensive care unit are compared in simulation studies. A nonlinear compartmental model with 15 distinct sets of patient parameter values is used to mimic the difficulties faced by an ICU treating many patients with different insulin sensitivities. A major advantage to the classical PID strategy is that the tuning parameters are a clear function of sample time, whereas other published strategies are specific to a given sample time. It is difficult to regulate extreme patients (extremely low or high insulin sensitivities) with any of the controllers with fixed-parameter control laws.