The purpose of this study is to use closed-loop systems with the algorithms designed by the University of Virginia and by the Instituto Tecnologico de Buenos Aires (ITBA)/ Universidad Nacional de La Plata (UNLP)/ Universidad Nacional de Quilmes (UNQ) to determine the infusion of insulin in a prolonged period of time in patients with type 1 diabetes mellitus (T1DM).

Aims:

1. To test University of Virginia closed-loop algorithm with meal announcement for 36 hours at our facilities.
2. To test the ability of the closed-loopInstituto Tecnologico de Buenos Aires (ITBA)/ Universidad Nacional de La Plata (UNLP)/ Universidad Nacional de Quilmes (UNQ) algorithm without meal announcement to maintain glucose control for 2 periods of 12 hours

In both cases, the adequate operation of the system will be considered verified if the system works properly at least 80% of the total connection time .

Inclusion Criteria:

• Patient have been diagnosed with T1DM at least two years ago and have been using an insulin pump and a CGM for at least 6 months prior to the trial first visit.
• Patient is >18 and <65 years.
• Patient has HbA1c > 6.5 % and < 10%.
• Woman in premenopausal age agrees to use contraceptive methods.
• Woman in premenopausal age has negative B-HCG in the tests performed in the trial.
• Patient is trained in carbohydrates counting.
• Patient has signed informed consent and has the ability to understand the nature and intent of the study including the ability to comply with study procedures and is willing to keep scheduled visits.

Exclusion Criteria:

• Patient has been hospitalized for diabetic ketoacidosis in the last 12 months.
• Patient has experienced severe hypoglycemia with loss of consciousness in the last 12 months.
• Patient has a history of coronary disease or cardiac failure.
• Patient with uncontrolled arterial hypertension.
• Patient with a condition that makes the researcher believe that it might increase the chance of hypoglycemia.
• Patient has symptoms compatible with an active infectious disease.
• Patient has Cystic Fibrosis.
• Pregnant women, or women with the intention of getting pregnant; women breastfeeding.
• Patient has been hospitalized for psychiatric treatment in the last 6 months.
• Patient with a diagnosis of an adrenal disease.
• Patient has abnormal laboratory values for liver function: transaminase > 2x upper limit of normal.
• Patient has abnormal laboratory values for renal function: GFR < 60 ml/min/1.73m2
• Patient has active gastroparesis.
• Patient is under oncological treatment.
• Patient has taken acetaminophen 72 hours previous to the study.