Feasibility of a New Medtronic Experimental Automated Insulin Delivery (Artificial Pancreas) System

The purpose of this research study is to demonstrate feasibility and to generate initial data to evaluate safety, user acceptance and system efficacy of the Novel Medtronic Experimental Automated Insulin Delivery (NMX-AID) system in adults with type 1 diabetes. The NMX-AID system includes a Medtronic 780G insulin pump with updated software, a factory-calibrated ‘DS5’ continuous glucose sensor, and an extended wear infusion set. A sequential before and after study design will be undertaken in four stages, with data analysis occurring to compare data between stages. User perception of the technology will be assessed at the end of Run-in and at the end of each study stage with a validated questionnaire (Insulin Delivery System Rating Questionnaire-Short Form). Continuous glucose sensor data and insulin delivery data will be collected from the study devices throughout the study and monitored for safety and for adherence by the study staff/diabetes educators. A semi-structured interview to assess participants’ perceptions of NMX-AID will be implemented at the end of the study. Participation in this research will occur over approximately 12-16 weeks. Fifteen participants with type 1 diabetes, with at least three months experience with the Minimed 780G will be recruited. Following informed consent, a baseline clinical history will be obtained, and physical examination performed. Adjustment of all device settings may occur throughout all study stages. Device education and review will be performed by accredited diabetes nurse educators. The schedule of the four stages is as follows, with further details regarding study visits provided thereafter: Run-in: Participants will commence a three-to-four-week run-in using an updated Medtronic 780g system (BLE2.0 Advanced Hybrid Closed-loop (HCL) system), with user-initiated meal boluses performed 15 minutes prior to eating. The last 14 days of Run-in prior to Stage 1 will serve as baseline glucose control reference. Run-in will last a minimum of three weeks and will not exceed four weeks. The duration of this stage will be dependent on achieving stable device data for the final 2 weeks of the stage, as determined by the investigators. Stage 1: Progression to stage 1 will begin immediately following run-in. All participants will be provided with the NMX-AID system and educated in its use, which will occur in small groups of ~4 people. They will use the device after activating the PumpStart function, enabling immediate AID activation and will announce all meals or snacks by initiating a bolus of insulin approximately 15 minutes before any food. Stage 1 will last a minimum of three weeks and will not exceed four weeks. The duration of this stage will be dependent on achieving stable device data for the final 2 weeks of the stage, as determined by the investigators. Stage 2: Progression to stage 2 will begin immediately following stage 1. All participants will use the NMX-AID system as a full closed loop system where meals will be unannounced (they will be requested not to bolus for any meals) though they will be permitted to correct elevated glucose readings and modify the AID target in preparation for exercise. Stage 2 will last a minimum of three weeks and will not exceed four weeks. The duration of this stage will be dependent on achieving stable device data for the final 2 weeks of the stage, as determined by the investigators. Stage 3: Progression to stage 3 will begin immediately following stage 2. All participants will continue to use the NMX-AID system and will be advised to bolus as they see fit. Stage 3 will last a minimum of three weeks and will not exceed four weeks. The duration of this stage will be dependent on achieving stable device data for the final 2 weeks of the stage, as determined by the investigators. The study will require five study visits, with a minimum of 3 face-to-face visits and 2 visits which may occur remotely. The initial visit will be face-to-face and involve screening and provision of BLE2 devices, and will last approximately 2 hours. After enrollment, participants will be screened with demographic data recorded and a clinical history and physical examination will be performed. Carbohydrate counting knowledge will be reviewed. Guidelines will be provided for correction of hyperglycaemia. Blood will be collected for HbA1c and electrolytes. Participants with Minimed 780G experience who have passed screening will be provided with and educated in the use of the BLE2 system (insulin pumps and sensors) and extended wear insulin infusion sets (EWIS). They will commence Run-in which will last three to four weeks. During Run-in participants will be asked to bolus / administer rapid acting insulin approximately 15 minutes prior to each meal (announced meal-time insulin). The second visit will also be face-to-face, will take approximately 4-6 hours and will involve commencement of Stage 1. All BLE2 insulin pumps and sensors will be collected from participants. Questionnaires will be administered to all participants. All participants will be provided with and trained in the use of NMX-AID pumps and associated sensors. All will be advised to continue to announce meals with an insulin bolus for the 3-4 week duration of Stage 1. The third visit can occur remotely, will last approximately 30mins and will involve commencement of Stage 2. Questionnaires will be administered to all participants. Participants will continue the use of NMX-AID devices but will be advised not to bolus for meals nor for corrections for the 3-4 week duration of Stage 2. The fourth visit can also occur remotely, will take approximately 30mins and will involve commencement of Stage 3. Questionnaires will be administered to all participants. Participants will continue the use of NMX-AID devices but will be able to decide if a pre-meal bolus is required or not for the 3-4 week duration of Stage 3. The fifth and final visit will involve the End-of Study Visit, will take approximately 4-6 hours and will occur face-to-face. Questionnaires will be administered. All study devices will be collected. The participants will return to their usual care after their own device settings have been reviewed. Semi-Structured interviews will be conducted. A blood sample will be collected for measurement of HbA1c.