Patient description: The patient is a 24-year-old man who has had type 1 diabetes for 11 years. He presents to the emergency room with hyperglycemia and concern for possible diabetic ketoacidosis after not taking his insulin for 3 days. The patient reports that he is currently homeless and has lost his supply of insulin, syringes, glucometer, and glucose testing supplies. The patient states that at the time of his initial diagnosis with type 1 diabetes he was hospitalized with a glucose value >1000 mg/dL. At the time, he was experiencing polyuria, polydipsia, and polyphagia. He reports that he has been on insulin since the time of his diagnosis, and he has never been prescribed oral agents for diabetes management. Most recently, he has been using insulin glargine 55 units once daily, and insulin aspart sliding scale 3 times daily. The patient has had previous episodes of diabetic ketoacidosis, for which he was hospitalized. With this episode of hyperglycemia, he is not experiencing any nausea, vomiting, or abdominal discomfort, and he appears well. His lab studies showed: A1c: 11.3% Creatinine: 0.9 mg/dL with eGFR >60 mL/min Aspartate aminotransferase (AST): 17 U/L Alanine aminotransferase (ALT): 14 U/L Beta-hydroxybutyrate: 0.1 mmol/L Bicarbonate: 25 mEq/L Anion

Clinical trial eligibility criteria: eligible ages (years): 15.0-55.0,  Type 1 Diabetes 1 1. Clinical diagnosis of type 1 diabetes for at least 12 months 2. Daily insulin therapy for at least 12 months 3. Age between 15.0 to 55.0 years of age 4. Use of an insulin pump for at least 3 months 5. Current use of continuous glucose monitoring with Dexcom sensor 6. Subject comprehends English 7. Females of childbearing potential must use an adequate method of contraception and have a negative pregnancy test 8. Total daily insulin requirement ≥ 0.3 units/kg/day 9. A1C between 7.0 and 10% 3.2  Diabetic ketoacidosis in the past 6 months 2. Hypoglycemic seizure or loss of consciousness in the past 6 months 3. Hypoglycemia unawareness as defined by no recognition of hypoglycemia until the glucose is <60 mg/dL and no adrenergic symptoms at glucose of 60 mg/dL (shakiness, palpitations, diaphoresis). Subjects will also be administered the Clark questionnaire for hypoglycemia unawareness. If they have a score ≥ 4, they are excluded from the study 4. Subjects requiring an intermediate or long-acting insulin (such as NPH, detemir or glargine) 5. Subjects using other anti-diabetic medications other than insulin (oral or injectable) at the time of enrollment. Any prior use of other anti-diabetic medications must be washed out for at least 8 weeks prior to enrollment. 6. Current use of other medications, which in the judgment of the investigator would be a contraindication to participation in the study 7. Subject has a medical disorder that in the judgment of the investigator will affect completion of any aspect of the protocol 8. Subject is currently participating in another investigational device or drug study within 30 days or 5-half lives of the drug. 9. Subject has a history of any cardiac or vascular disorder including, but not limited to, myocardial infarction, unstable angina, coronary artery bypass surgery, coronary artery stenting, transient ischemic attack, cerebrovascular accident, angina, congestive heart failure, arrhythmia or thromboembolic disease 10. An EKG will be obtained on subjects who are ≥ 45 years of age, or who have had a 20 year history of diabetes and are ≥ 30 years of age. Subjects will be excluded if they have an abnormal EKG consistent with coronary artery disease or increased risk of malignant arrhythmia including, but not limited to, evidence of active ischemia, prior myocardial infarction, proximal LAD critical stenosis (Wellen's sign), prolonged QT interval (> 440 ms). Non-specific ST segment and T wave changes are not grounds for in the absence of symptoms or history of heart disease. 11. Subject has a history of hepatic disease 12. Subject has renal failure on dialysis 13. Systolic blood pressure > 160 mmHg on screening visit 14. Diastolic blood pressure > 90 mmHg on screening visit 15. Subjects with inadequately treated thyroid disease or celiac disease 16. Subject has a neurologic disorder that in the judgment of the investigator will affect completion of the protocol 17. Subject has received inpatient psychiatric treatment in the past 6 months 18. Subject consumes more than an average of 4 standard alcoholic drinks/day in the last 30 days 19. Subject has an active skin condition that would affect sensor placement 20. Subject is unable to avoid acetaminophen for the duration of the study 21. Subject consuming less than 100g of carbohydrates daily