Precision Insulin-Pump Calibration and Optimal Insulin Delivery to Improve Blood Glucose Levels

The successful management of type-1 diabetes (T1D) and insulin-dependent type-2 diabetes depends on the ability to accurately calibrate bolus and basal insulin doses, and minimize the time spent with high postprandial blood glucose (BG) levels while avoiding dangerously low hypoglycemic excursions. Precise calibration of the insulin pump helps with successful disease management; however, people with T1D may still experience prolonged, potentially damaging BG levels due to postprandial highs. Insulin pumps offer large, currently underexploited degrees of freedom in insulin delivery, which can have a dramatic impact on average postprandial BG levels. Building on existing models of the glucose-insulin system, we first propose a simple, automated, and individualized insulin-pump calibration system based on a series of measures taken before and a few hours after carbohydrate ingestion. We then modulate the shape of pre-meal insulin dosing to explicitly reduce postprandial BG levels while minimizing the likelihood of dangerously low BG. Such an optimal insulin delivery time course can potentially improve postprandial BG levels and rapidly bring BG to the target level. We evaluated our methods in 20 patients over 4 days, with BG levels sampled frequently.