This is a single arm study comprised of a series of feasibility studies.

Feasibility Study Part 2 (i.e. Feasibility 2): Feasibility 2 is the focus of the current version of the study protocol.

This study will include 2 separate Cohorts of individuals, based on the algorithms being studied:

Cohort A: The main purpose of this cohort is to test the Digital Twin insulin delivery algorithm adaptation

Cohort C: The main purpose of this cohort is to test a meal prediction algorithm

Inclusion Criteria:

General Inclusion Criteria

1. Subject is age 2-80 years at time of Visit 1. Note: See staged enrollment reference for adult and pediatric subjects in the Study Design section

2. Subject has a clinical diagnosis of type 1 diabetes.

   1. Subjects 7 years of age and older: Diagnosed at least 1 year prior to Visit 1
   2. Subjects 2-6 years of age: Diagnosed at least 3 months prior to Visit 1

   Study-specific inclusion criteria

3. Subject must have a minimum daily insulin requirement (Total Daily Dose) of greater than or equal to 8 units.

4. If subject has a history of hypothyroidism, must have at least 1 documented normal thyroid-stimulating hormone (TSH) on historical labs within 12 months of Visit 1. A subject without a history of hyperthyroidism is not expected to have a TSH test

5. Subjects and their parent(s)/guardian(s) must have Internet access , a computer system that meets the requirements for uploading the study pump and Smartphone that meets study requirements.

6. Subject must have a companion or caregiver available at night for the duration of the study period who resides (or will live) in in the same building (or home). This requirement may be verified by subject report at screening visit.

7. If subject has celiac disease, it has been adequately treated as determined by the investigator.

8. Subjects and their parent(s)/guardian(s) are willing to take one of the following insulins and can financially support the use of either of the 2 insulin preparations throughout the course of the study (i.e. co-payments for insulin with insurance or able to pay full amount)

   • Humalog™* (insulin lispro injection)
   • NovoLog™* (insulin aspart)

Exclusion Criteria:

1. Subject has a history of 1 or more episodes of severe hypoglycemia, which resulted in any the following during the last 1 year prior to Visit 1

   1. Medical assistance (i.e. Paramedics, Emergency Room (ER) or Hospitalization)
   2. Coma
   3. Seizures

2. Subject is unable to tolerate tape adhesive in the area of sensor placement.

3. Subject has any unresolved adverse skin condition in the area of sensor placement (e.g., psoriasis, dermatitis herpetiformis, rash, Staphylococcus infection).

4. Women of child-bearing potential who have a positive pregnancy test at Visit 1 or plan to become pregnant during the course of the study

5. Females who are sexually active and able to conceive will be excluded if they are not using an effective method of contraception and do not agree to continue using an effective method of contraception for the duration of the study as determined by investigator.

6. Subject has a cardiovascular condition which the Study Investigator determines should exclude the subject, e.g. ventricular rhythm disturbance, hypertrophic cardiomyopathy, recent myocardial infarction in the last year prior to Visit 1.

7. Subject is being treated for hyperthyroidism at time of Visit 1.

8. Subject has a diagnosis of adrenal insufficiency.

9. Subject has had Diabetic Ketoacidosis (DKA) within 1 year prior to Visit 1.

10. Subject has taken any oral, injectable, or intravenous (IV) glucocorticoids within 8 weeks from time of visit 1, or plans to take any oral, injectable, or IV glucocorticoids during the course of the study.

11. Subject is actively participating in an investigational study (e.g., drug or device) wherein he/she has received treatment from an investigational study (drug or device) in the last 2 weeks prior to Visit 1. Please note participation in observational study is acceptable.

12. Subject has been hospitalized or has visited the ER in the 6 months prior to Visit 1 resulting in a primary diagnosis of uncontrolled diabetes.

13. Subject is currently abusing illicit drugs.

14. Subject is currently abusing alcohol.

15. Subject is using pramlintide (Symlin), DPP-4 inhibitor, liraglutide (Victoza or other GLP-1 agonists), metformin, canagliflozin (Invokana or other SGLT2 inhibitors) at time of Visit 1.

16. Subject has a history of visual impairment which would not allow subject to participate in the study and perform all study procedures safely, as determined by the investigator.

17. Subject has elective surgery planned that requires general anesthesia during the course of the study.

18. Subject diagnosed with current eating disorder such as anorexia or bulimia.

19. Subject has been diagnosed with chronic kidney disease that results in chronic anemia.

20. Subject is on dialysis.

21. Subject has serum creatinine of >2 mg/dL, as confirmed through historical labs within 1 year prior to Visit 1.

22. Subject is a member the research staff involved with the study.

Individual subjects were participating in Feasibility 2 for approximately 3.5 months.

Investigators were instructed to monitor the subjects throughout the course of the study for the occurrence of an adverse event. Adverse events were to be documented in the subject study file and reported to the sponsor on an eCRF. Medtronic study Monitors conducted study site visits and monitored subject source documents to reconcile reported adverse events and for possible detection of additional adverse events.