The artificial beta cell or closed-loop insulin delivery system expands on the concept of sensor responsive insulin delivery. The closed-loop system differs from conventional pump therapy as the former uses a control algorithm that autonomously and continually increases and decreases the subcutaneous delivery of insulin on the basis of real-time sensor glucose levels. There have been extensive studies in a controlled laboratory setting of a closed system; however, the real challenge sets in when the same device is used by patients at home.
A study published in the New England Journal of Medicine compared closed-loop insulin delivery with sensor augmented pump therapy in 58 patients with type-1 diabetes. The closed-loop system was used day and night by 33 adults and overnight by 25 children and adolescents. Participants used the closed-loop system for a 12 week period and sensor –augmented pump therapy (control) for a similar period.
At the end of the study, it was observed that the closed-loop system, as compared with sensor- augmented pump therapy, improved glucose control, reduced hypoglycemia, and in adults, resulted in a lower glycated hemoglobin level. Hence the extended use of a closed-loop system at home over a period of 12 weeks without close supervision is feasible in adults, children and adolescents with type-1 diabetes.