Assessment of an Automatic Closed-loop Insulin Delivery System

The overall aim of this research proposal is to determine the safety, feasibility and efficacy of an automatic closed-loop insulin delivery system.

This study will be completed in two parts. The initial part of this study will be an inpatient evaluation of the system with the primary goal of assessing safety and feasibility. This will involve 8 subjects with type 1 diabetes, aged 14 - 40 years, admitted for up to 60 hour. Plasma glucose levels will be collected hourly and tested by YSI (YSI 2300, Yellow Springs Instrument). These studies will be performed at Stanford University and will include group sporting activities to mimic the diabetes camp environment. Capillary blood glucose testing will be performed every 2-3 hours before meals, snacks, exercise, and prebed by subjects with research staff supervision during the day and at 00:00, 03:00 and 07:00 by research staff. These data will be reviewed by the DSMB before proceeding to camp studies. The second part of this study will be to test the efficacy of the system during diabetes summer camps. We will test the system in subjects with type 1 diabetes, aged 14-40 years, attending diabetes camp. There will be 20 subjects recruited, with 10 subjects randomized to the control arm Medtronic 530G system with threshold suspend (control group) and 10 subjects randomized to the automatic closed-loop insulin delivery (intervention group). Capillary blood glucose testing will be performed every 2-3 hours before meals, snacks, exercise and prebed by subjects with research staff supervision and at 00:00, 03:00 and 07:00 by research staff. The primary aim of this study is to generate preliminary data of system safety and efficacy in a closely supervised environment that challenges glucose control.