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): 18.0-65.0,  Diabetes Clinical diagnosis of type 1 diabetes mellitus for ≥1 year. For an individual to be enrolled at least one criterion from each list must be met. 2. for documented hyperglycemia (at least 1 must be met): 1. Fasting glucose ≥ 7 mmol/L [126 mg/dL] confirmed 2. Two-hour OGTT (oral glucose tolerance test) glucose ≥ 11.1 mmol/L [200 mg/dL] - confirmed 3. HbA1c ≥6.5% documented confirmed 4. Random glucose ≥ 11.1 mmol/L [200 mg/dL] with symptoms 5. No data at diagnosis is available but the participant has a convincing history of hyperglycemia consistent with diabetes 3. for requiring insulin at diagnosis (1 must be met): 1. Participant required insulin at diagnosis and continually thereafter 2. Participant did not start insulin at diagnosis but upon investigator review likely needed insulin (significant hyperglycemia that did not respond to oral agents) and did require insulin eventually and used continually 3. Participant did not start insulin at diagnosis but continued to be hyperglycemic, had positive islet cell antibodies consistent with latent autoimmune diabetes in adults (LADA) and did require insulin eventually and used continually 4. Signed informed consent 5. Age ≥18 and ≤65 years old 6. Body mass index between 19 and 35 kg/m2, inclusive 7. HbA1c ≤ 10.0%  Uncontrolled arterial hypertension (diastolic blood pressure > 90 mm Hg and/or systolic blood pressure > 160 mm Hg) 2. Impaired hepatic function measured as alanine aminotransferase or aspartate aminotransferase ≥ three times the upper reference limit 3. Impaired renal function measured as creatinine > 1.2 times above the upper limit of normal 4. Diabetic ketoacidosis in the past 6 months 5. Severe hypoglycemia resulting in a seizure or loss of consciousness in the 6 months prior to enrollment 6. Conditions which may increase the risk of hypoglycemia or conditions of known microvascular (diabetic) complications will be assessed on an individual basis with based on the discretion of the principal investigator. 7. Current use of medications containing > 4000 mg acetaminophen per day. 8. Current use of MAO (monoamine oxidase) inhibitors. 9. Known allergy to eggs 10. Pregnancy, breast-feeding or intention of becoming pregnant 11. Current or recent alcohol or drug abuse by subject history. 12. Blood donation of more than 473 ml within the last 56 days 13. Mental incapacity, unwillingness or language barriers precluding adequate understanding or cooperation 14. Any skin condition that prevents sensor placement on the abdomen (e.g., bad sunburn, pre-existing dermatitis, intertrigo, psoriasis, extensive scarring, cellulitis) 15. Known allergy to medical adhesives, e.g. Tegaderm 16. Hematocrit < 38% (males) and < 36% (females) 17. Potassium < 3.4 mmol/L 18. Active enrollment in another clinical trial