Development of Algorithms for a Hypoglycemic Prevention Alarm: Closed Loop Study

Inclusion Criteria: 1. Age 18 years or older, 2. Type 1 diabetes for at least 1 year 3. Current user of the MiniMed Paradigm Real-Time Revel system and Sof-sensor glucose sensor 4. Hemoglobin A1c level of \< 8.0%, 5. Home computer with access to the Internet, 6. At least one CGMglucose value \< 70 mg/dL during the most recent 15 nights of CGM glucose data. 7. Not pregnant or planning to become pregnant Exclusion Criteria: The exclusion criteria for this study is the following: 1. The presence of a significant medical disorder that in the judgment of the investigator will affect the wearing of the sensors or the completion of any aspect of the protocol 2. The presence of any of the following diseases: * Asthma if treated with systemic or inhaled corticosteroids in the last 6 months * Cystic fibrosis * Angina (recurrent heart pain) * Past heart attack or coronary artery (heart vessel) disease * Past stroke or impairment of blood flow to the brain * Other major illness that in the judgment of the investigator might interfere with the completion of the protocol Adequately treated thyroid disease and celiac disease do not exclude subjects from enrollment 3. Inpatient psychiatric treatment in the past 6 months for either the subject or the subject's primary care giver (i.e., parent or guardian) 4. Current use of oral/inhaled glucocorticoids or other medications, which in the judgment of the investigator would be a contraindication to participation in the study 5. Severe hypoglycemic event, as described as a seizure, loss of consciousness, severe neurological impairment, or neurological impairment suggestive of hypoglycemia and requiring an emergency department visit or hospitalization within 18 months of enrollment.