Using an Artificial Pancreas System in Older Adult Type 1 Diabetes Mellitus Patients

Inclusion Criteria: * Provide signed and dated informed consent form * Male or female * Age 50-75 years (at least 50% over the age of 65) * T1DM (\>20 years duration) * C-peptide undetectable * HbA1c of \< 8% * Insulin pump therapy * History of frequent hypoglycemia with unawareness (defined as 2 or more episodes of severe hypoglycemia within one year requiring assistance) and 2 or more glucose values \< 54 mg/dL during the week of Continuous Glucose Monitoring (CGM) (iPRO monitor, Medtronic) prior to enrollment * BMI \<27 kg/m2 * Good general health as evidenced by medical history and blood screening * Willing to comply with all study procedures and be available for the duration of the study * Willing to fast for a limited time period on the morning of a clamp study Exclusion Criteria: * Significant diabetic complications (untreated proliferative retinopathy, creatinine ≥1.5 mg/dl, urinary albumin levels 300 mg/day, autonomic neuropathy, painful peripheral neuropathy) * Significant alcohol intake and vegetarian diet since both are known to have an impact on counterregulation and brain metabolism * Any contraindications for MRI scanning, including presence of metallic implants or claustrophobia. * Heavy exercise on a regular basis (i.e. marathon runners) * Known allergic reactions to components of the study product(s) * Treatment with another investigational drug or other intervention * Active infection including hepatitis C, hepatitis B, HIV * Any past or current history of alcohol or substance abuse * Psychiatric or neurological disorders under active treatment * Baseline hemoglobin \< 10.5 g/dL in females, or \< 12.5 g/dL in males. Blood donation within 30 days of the study * History of coagulopathy or medical condition requiring long-term anticoagulant therapy (low-dose aspirin treatment is allowed) * Co-existing cardiac, liver, and kidney disease * Abnormal liver function tests * Women that are on oral contraceptives, post-menopausal, pregnant (as assessed by pregnancy test that will be performed on female participants at reproductive age), or lactating. * Any medical condition or medication that, in the opinion of the investigators, will interfere with the safe completion of the study or study outcomes