A novel glucose control strategy for intensive care unit applications

For patients in intensive care units (ICUs), control of their blood glucose level is an important factor in reducing serious complications and mortality. Standard protocols for glucose control in ICU have been based on infrequent glucose measurements, look-up tables to determine the appropriate insulin infusion rates, and bedside administration of the insulin infusion by ICU staff. In this paper a new automatic control strategy is proposed based on frequent glucose measurements and a self-tuning control technique. During a short initial time period when manual glucose control is performed using a standard protocol, a simple dynamic model is identified using recursive least squares. Then an adaptive PID controller is tuned, based on the model parameters, and the controller is turned on. A simulation study based on a physiological model of glucose-insulin dynamics demonstrates that the proposed control strategy performs better than the standard protocols for insulin infusion.