Open-loop glucose control: Automatic IOB-based super-bolus feature for commercial insulin pumps

Area of Science:

• Biomedical Engineering
• Metabolic Disease Research
• Artificial Pancreas Technology

Background:

• Type 1 Diabetes Mellitus (T1DM) management often relies on open-loop insulin pump therapy.
• Closed-loop systems show promise but widespread adoption is limited.
• Conventional bolus dosing lacks dynamic adjustment based on insulin activity.

Purpose of the Study:

• To present an automatic insulin bolus shaping method using insulin-on-board (IOB) as an alternative to conventional dosing.
• To develop a super-bolus (SB) strategy for improved glycemic control in T1DM.
• To avoid detrimental transients associated with manual or pre-calculated insulin adjustments.

Main Methods:

• A two-compartment IOB dynamic model was employed to generate the super-bolus (SB).
• Insulin-on-board (IOB) levels and duration of insulin action (DIA) were used to compute SB parameters.
• The system automatically re-establishes basal insulin delivery once IOB returns to baseline levels.

Main Results:

• In-silico trials on 30 patients demonstrated improved glycemic control with automatic SB versus standard treatment.
• Significant increases in time spent in euglycemia were observed for both 75g and 100g meal scenarios.
• A notable reduction in time spent in hypoglycemia was achieved across all tested scenarios.

Conclusions:

• Automatic IOB-based SB shows potential for superior performance compared to standard T1DM treatments.
• The method is particularly effective for managing high-carbohydrate, high-glycemic index meals.
• This approach effectively reduces glucose excursions and minimizes hypoglycemia risk.