Figure 5.

Control-to-range vs open-loop glycemic regulation under perturbed meals and perturbed insulin sensitivity. Closed-loop control starts at 13:00. Insulin sensitivity is 25% higher than nominal. The first two meals are greater than nominal, which counterbalances the reduction in insulin sensitivity and helps open-loop control maintain glycemia within the range. Nevertheless, it cannot avoid a severe hypoglycemia after the third meal, which is smaller than nominal and delayed by 30 minutes. The joint action of the RCM and SSM achieves effective glycemic regulation. In particular, when risk for hypoglycemia is detected on three occasions, the SSM prevents possible hypoglycemia.