Hybrid Closed-Loop Control With Smart Prandial Insulin Dosing in Type 1 Diabetes

Inclusion Criteria: 1. Age ≥12 and \<18 years old at time of consent 2. Clinical diagnosis, based on investigator assessment, of T1D for at least one year 3. Currently using insulin for at least six months 4. Currently using an insulin pump for at least three months 5. Currently using a CGM system for at least three months 6. Having at least 75% of CGM data over the previous four weeks 7. Using insulin parameters such as carbohydrate ratio and correction factors consistently on their pump in order to dose insulin for meals or corrections 8. Access to internet and willingness to upload data during the study as needed 9. For females, not currently known to be pregnant or breastfeeding 10. A negative urine pregnancy test will be required for all females of childbearing potential 11. Willingness to suspend use of any personal CGM for the duration of the clinical trial once the study CGM is in use 12. Willingness to switch to lispro (Humalog) or aspart (Novolog) if not using already, and to use no other insulin besides lispro (Humalog) or aspart (Novolog) during the study 13. Total daily insulin dose (TDD) of at least 10 U/day 14. Willingness not to start any non-insulin glucose-lowering agent during the course of the trial (including metformin, GLP-1 agonists, pramlintide, DPP-4 inhibitors, biguanides, sulfonylureas and naturaceuticals) 15. Willingness to eat at least 40 grams of carbohydrates per meal 16. An understanding and willingness to follow the protocol and signed informed consent 17. Participants and parent/legal guardians will be proficient in reading and writing in English 18. Willingness to comply with COVID-19 precautions as defined by the study team 19. Having completed a COVID-19 vaccination with an FDA-approved COVID-19 vaccine at least two weeks before the first study admission, and willing to provide a copy of the COVID-19 vaccination card Exclusion Criteria: 1. Hemoglobin A1c \<5% or \>10% if measured at screening or available from historical medical report performed within the last 6 months; in absence of a valid HbA1c measurement, average blood glucose estimated from CGM data to be approximately between 100 and 240 mg/dL 2. History of diabetic ketoacidosis (DKA) in the 6 months prior to enrollment 3. Severe hypoglycemia resulting in seizure or loss of consciousness in the 6 months prior to enrollment 4. Pregnancy or intent to become pregnant during the trial 5. Currently breastfeeding or planning to breastfeed 6. Currently being treated for a seizure disorder 7. Planned surgery during study duration 8. History of cardiac arrhythmia (except for benign premature atrial contractions and benign premature ventricular contractions which are permitted) 9. Treatment with any non-insulin glucose-lowering agent (metformin, GLP-1 agonists, pramlintide, DPP-4 inhibitors, SGLT-2 inhibitors, biguanides, sulfonylureas and naturaceuticals) 10. A known medical condition that in the judgment of the investigator might interfere with the completion of the protocol. 11. Use of an insulin delivery mechanism that is not downloadable by the participant or study team 12. Known contact with COVID-positive individual within 14 days of any study admission without negative follow-up COVID-19 Polymerase Chain Reaction (PCR) test performed 3-5 days after the date of exposure 13. Symptoms of COVID-19 (e.g., fever, shortness of breath, unexpected loss of taste or smell) developed within 14 days of any study admission 14. A positive COVID-19 test within 14 days of any study admission or during study admission participation 15. Not being fully vaccinated at the time of the first camp admission (according to Center for Disease Control (CDC) guidelines a person is intended to be fully vaccinated after two weeks from either the second dose of the Pfizer or Moderna vaccine, or the single dose of the Johnson \& Johnson vaccine)