Simultaneous Measurement and Responsive Treatment - Part 2

Inclusion Criteria Part A: * Males and females ≥ 18 years of age. * Clinical diagnosis of type 1 diabetes for at least 12 months. The diagnosis of type 1 diabetes is based on the investigator's judgment; C peptide level and antibody determinations are not needed. * Undergoing multiple daily injection or continuous subcutaneous insulin infusion therapy for at least 3 months. Those using an automated insulin delivery system can also participate. * Total daily insulin dose (TDD) between 30 and 100 IU. Inclusion Criteria Part B: * Males and females ≥ 18 years of age. * Clinical diagnosis of type 1 diabetes for at least 12 months. The diagnosis of type 1 diabetes is based on the investigator's judgment; C peptide level and antibody determinations are not needed. * Undergoing continuous subcutaneous insulin infusion therapy for at least 3 months. Those using an automated insulin delivery system can also participate. * Totally daily insulin dose (TDD) between 30 and 100 IU. Exclusion Criteria (A and B): * Serious medical illness likely to interfere with study participation or with the ability to complete the trial by the judgment of the investigator. * Failure to comply with the study protocol or with the team's recommendations. * Current or recent use of any anti-hyperglycemic agent other than insulin (≤ one month for GLP1-RA, ≤ one week for all others). * Female participants of childbearing potential who are pregnant, breastfeeding, or unwilling to use effective contraception during the study. Pregnancy will be verified by urine dipstick testing at the time of admission visit. * Severe hypoglycemic episode within one month of admission. * Severe diabetic ketoacidosis episode within one month of admission. * Clinically significant nephropathy, neuropathy or retinopathy as judged by the investigator. * Recent (\<6 months) acute macrovascular event e.g., acute coronary syndrome or cardiac surgery. * Other serious medical illness likely to interfere with study participation or with the ability to complete the trial by the judgment of the investigator. * Current or ≤ one month use of supraphysiological doses of systemic glucocorticoids * Pronounced lipohypertrophy in the abdominal subcutaneous adipose tissue, which may impair sensor function or insulin infusion. * Insufficient abdominal surface area to support the wearing of three DPP systems in Part A.