Estimation of individually adapted control parameters for an artificial beta cell.

For optimum long-term glycemic regulation using a miniaturized artificial beta cell it is indispensible to estimate control parameters suited to the individual requirements of each diabetic patient. To solve this problem, a strategy has been developed which is based on engineering optimum-control theory with a model involving glucose and insulin interactions. The model considers physiologically relevant unit processes like endogenous glucose production, insulin-independent glucose uptake from its apparent distribution space, insulin-dependent glucose utilization, glucose-dependent insulin supply, and insulin catabolism. The assumed model structure is validated by results obtained in experimentally diabetic dogs using partition analysis. The individual parameter values of the model are obtained by a digital computer procedure based on a simple test which involves a bolus injection of glucose + insulin when a constant basal insulin dose is being administered in the diabetic in whom normoglycemia was re-established before the test. The method presented is recommended for future use in all cases where an optimized insulin regimen is to be worked out.