Preliminary Evaluation of a New Semi-Closed-Loop Insulin Therapy System Over the Prandial Period in Adult Patients With Type 1 Diabetes

Abstract

There has been considerable progress recently in closed-loop insulin therapy during the interprandial period, and particularly overnight. 1-3 However, closed-loop delivery of insulin therapy during the prandial and postprandial periods remains a real challenge since calculation by the algorithm of inappropriate and excessive delivery commands related to early postprandial elevation of glucose levels exposes patients to a risk of hypoglycemic episodes. 4,5 In addition to the problems of forecasting the inherent glycemic variations associated with meals (inter-and intraindividual variation in carbohydrate digestion), there is the question of the inertia of a closed-loop system, combining the absorption time for subcutaneously administered insulin and the delayed dynamics of interstitial glucose compared to plasma glucose levels. 4,5 Several technological and strategic choices must be made to address control during the prandial period: type of algorithm 545668D STXXX10.

Efficacy of the Diabeloop closed‐loop system to improve glycaemic control in patients with type 1 diabetes exposed to gastronomic dinners or to sustained physical exercise

“…The Diabeloop system is a single‐hormone CL system running an original MPC algorithm reinforced by a decisional matrix, uploaded on an Android smartphone linked to a Dexcom Share AID (Dexcom Inc., San Diego, California) continuous glucose monitoring (CGM) device and a CellNovo insulin patch pump . The Diabeloop system was developed in the framework of the Hovorka non‐linear predictive model . A machine‐learning algorithm continuously re‐estimated the series of 11 model parameters defining “model physiology”.…”

“…9 The Diabeloop system was developed in the framework of the Hovorka non-linear predictive model. 9 A machine-learning algorithm continuously re-estimated the series of 11 model parameters defining "model physiology". Additional input parameters were: weight, meal ratios, compensation factor and basal insulin profile as defined by the diabetologist.…”

“…Tight control of blood glucose (BG) reduces the risk of long‐term complications in type 1 diabetes (T1D), and automated insulin delivery (AID) systems have been proven safe and efficient to reduce BG variability . In particular, the Diabeloop (Paris, France) single‐hormone, closed‐loop (CL) AID device runs an original model predictive control (MPC) algorithm, which has proven safety and efficacy and has been validated in previous studies …”

“…[3][4][5][6][7][8] In particular, the Diabeloop (Paris, France) single-hormone, closed-loop (CL) AID device runs an original model predictive control (MPC) algorithm, which has proven safety and efficacy and has been validated in previous studies. [9][10][11] In "real-life" conditions, daytime meals and postprandial hyperglycaemic excursions are difficult to control, 12,13 as is the BG variability associated with overnight fasting and physical exercise. 14,15 The aim of the present study, therefore, was to compare the Diabeloop CL system with conventional open-loop (OL) devices with regard to their efficacy in glucose control during challenging situations in the dayand night-time, such as eating gastronomic meals and taking part in sustained bouts of physical exercise (the Diabeloop WP6.2 trial).…”

A critical review and analysis of ethical issues associated with the artificial pancreas

“…A first commercial version of the AP was approved by the FDA in September 2016 [7]. Most of the currently developed AP versions are hybrid closed-loop systems: they still require the patient to announce exercise and meals, with or without exact carbohydrate counting [8, 9]. This is partly due to the pharmacokinetics of the available insulins and equilibration between interstitial glucose measured by the continuous glucose monitoring device and actual blood glucose values.…”