Closing the loop: Combining insulin pumps and glucose sensors in children with type 1 diabetes mellitus

Tight glycemic control of diabetic patients is associated with a reduction in the risk of microvascular and macrovascular complications, yet with elevated risk of severe episodes of hypoglycemia. The goal of "closing the loop" is to develop an autonomous insulin delivery system attached to a device capable of continuous glucose sensing, thus mimicking the islet beta cells activity and its capability of maintaining normal blood glucose levels and freeing the patient from the need of constant calculations of daily insulin and carbohydrates. The closed loop will protect patients from experiencing glucose excursions, including life-threatening events of hypoglycemia, thus improving glycemic control, reducing the fear from hypoglycemia and improving patients' quality of life. This review focuses on the steps towards closing the loop in the attempts to develop an artificial pancreas and on recent ongoing research and future directions in this field.