Simultaneous Measurement and Responsive Treatment - Part 2

This research study is testing an investigational dual-port insulin patch pump that integrates a continuous glucose monitor (CGM) in adults with type 1 diabetes. The goal of the study is to better understand how insulin delivery near a CGM sensor affects glucose readings and to collect data to support development of a combined insulin pump and CGM system. People with type 1 diabetes require lifelong insulin therapy. Many use insulin pumps and CGMs, but these systems usually involve wearing multiple devices at different body sites. Managing several devices can increase treatment burden and may contribute to skin irritation, device failures, and challenges with glucose control. This study is conducted in two in-patient parts. In Part A, participants will wear three investigational devices at the same time while glucose levels are closely monitored using laboratory blood tests and a commercial CGM. This part of the study is designed to measure how basal and bolus insulin delivery near the CGM sensor affects sensor accuracy and how quickly the sensor signal recovers after insulin delivery. In Part B, participants will wear one investigational device while trained study staff use CGM information from the integrated sensor to guide insulin delivery recommendations generated by an automated glucose control algorithm. Insulin delivery decisions will be closely supervised, and glucose levels will be frequently monitored. Participants will stay at the clinical research center for short, controlled study visits. Safety will be monitored throughout the study, with predefined procedures for treating low or high blood sugar. The information collected will be used to support further development of an integrated insulin pump and CGM system for people with type 1 diabetes.

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 10 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 (\