Assessment of the Efficacy of the Artificial Pancreas Combined With a Qualitative Meal Size Estimation to Control Postprandial Glucose Levels

Every 10 minutes, the glucose levels as measured by the sensor will be transferred automatically to a LG Google Nexus Smartphone that the algorithm is running on, which will calculate the recommended doses and will send them wirelessly to the infusion pump.

Tandem Diabetes Care

Dexcom G6

Aspart or lispro will be infused with the infusion pump

Participants will be required to enter an estimate of the carbohydrate content of their meal into the phone. Insulin boluses will be calculated based on grams of carbohydrates and participant's insulin-to-carbohydrate ratio. Carbohydrate-matching full prandial bolus will be given 5 to 10 minutes before the meal.

A pre-meal partial prandial bolus will be given 5-10 minutes before the meal. The partial bolus will be based on the estimated meal size (small, regular, large and extra-large). The closed-loop system will give the remaining insulin needed based on the sensor readings. For this strategy, meal size will be defined as: small as any meal less than 30g, regular meal as any meal between 30g and 60g CHO, large meal as any meal between 60g and 90g CHO, extra-large meal for anything above 90g CHO.

Glucose levels will be regulated by the single-hormone closed-loop system for 3 consecutive weeks.

60 minute exercise will be started one hour after the meal time.

60 minute exercise will be started two hours after meal time

Meal bolus reduction of 33% at meal time and exercise announcement (increased target glucose from 6 to 9mmolL) to the CLS algorithm