At present, decisions regarding insulin dosing are made by the patient with intermittent support from their medical team. Even with glucose sensor augmented insulin pump therapy (SAPT), representing the most advanced technology currently available, there are emotional and intellectual demands placed upon the patient with the most well-educated, intelligent and diligent patients often unable to perfectly match insulin delivery with their varying requirements. SAPT does improve glycaemia in comparison with insulin pump therapy alone though a significant proportion of patients will still not meet target HbA1c (<7.0%). A Closed Loop (CL) system whereby a computerised algorithm reviews continuous glucose information to determine a T1D patient's insulin requirements and controls insulin delivery will potentially have a major impact upon acute and chronic complications of diabetes as well as upon their quality of life. Overnight glycaemic control, without the added challenge of meals, physical activity and stress, is a realistic initial application of CL in clinical practice.