The first phase of this study will test the feasibility of initializing the DiAs CTR system in a clinical research center. We will test the procedures that will occur with the camp studies, from consenting the subjects, obtaining morning glucose readings, initializing the sensor in the early afternoon, having some light activity in the evening, a bedtime snack, and initializing the closed-loop system within 30 minutes before they go to bed. We will also test how the system performs using the same calibration and blood glucose monitoring that will be done at camp. In the inpatient study we will mimic some camp activities by having the subjects have 20-30 minutes of aerobic activity in the afternoon and in the evening after dinner. The data from the inpatient studies will be reviewed by the Data Safety Monitoring Board (DSMB) before we proceed with the Phase 2 summer camp studies.