Feasibility of Outpatient 24-Hour Closed-Loop Insulin Delivery

Studies using outpatient closed-loop insulin delivery for type 1 diabetes have recently been published (1–5). We conducted a 5-day outpatient feasibility study comparing hybrid closed-loop (HCL) to sensor-augmented pump therapy with low-glucose suspend (SAPT + LGS) in eight patients with type 1 diabetes using an open-label randomized crossover trial design (ACTRN12614001005640). We used the Medtronic HCL system: MiniMed insulin pump, MiniMed Enlite II glucose sensor, MiniMed MiniLink REAL-time sensor, MiniMed Translator, and an Android mobile device with the algorithm (proportional integrative derivate with insulin feedback and additional safety parameters—primarily being an upper limit of allowable insulin delivery). Multiple algorithm parameters were individualized according to total daily insulin requirements in the preceding 48 h. Meals were announced by entering a capillary glucose value and meal carbohydrate content, for which bolus insulin was delivered according to the patient’s unique carbohydrate ratio. The Android mobile device sent data via the Internet, …