Figure 4

" Automatic Insulin Infusion System" (AIIS) for Inpatient Treatment: Simulation of mild positive challenge. "Automatic Insulin Infusion System" (AIIS) for Inpatient Treatment: Simulation of mild positive challenge given by a standard meal containing 50 grams of carbohydrate in a 70-Kg patient with Type-1 Diabetes Mellitus and average hepatic sensitivity (Sh = 0.5). See also fifth row in Table 1. (A) Glycemia [mg × dL^-1]. The arrow shows the start of the mild positive challenge. The black area under the curve shows an overshoot that after reaching a peak at 150 mg × dL^-1, lasts for 30 minutes. The time it takes for the blood glucose to return to a value just below 120 mg × dL^-1 is 90 minutes (T_S = 90 minutes). (B) The insulin infusion rate moves around an average of 1.0 I.U. × h^-1 before the challenge, i.e. around 0.35 I.U. per Kilogram of body weight in a 70-Kg individual, which is the normal basal insulin secretion (see the text). After the challenge, the insulin infusion rises up to 7.0 I.U. × h^-1 during 90 minutes. Please observe that the insulin infusion rate is not a continuous function but a step function representing orders given by the controller to the clinical infusion pumps, whose flow rate has to be adjusted by steps not smaller than 0.1 mL × h^-1 (see "Actuators", part I-D in methods section, above). (C) The estimated serum insulin concentration moves around an average of 20.0 μI.U. × mL^-1 before the challenge, and then rises up to 55 μI.U. × mL^-1 for 90 minutes.