Clinical Evaluation of a Personalized Artificial Pancreas

Abstract

OBJECTIVEAn artificial pancreas (AP) that automatically regulates blood glucose would greatly improve the lives of individuals with diabetes. Such a device would prevent hypo- and hyperglycemia along with associated long- and short-term complications as well as ease some of the day-to-day burden of frequent blood glucose measurements and insulin administration.RESEARCH DESIGN AND METHODSWe conducted a pilot clinical trial evaluating an individualized, fully automated AP using commercial devices. Two trials (n = 22, nsubjects = 17) were conducted using a multiparametric formulation of model predictive control and an insulin-on-board algorithm such that the control algorithm, or “brain,” can be embedded on a chip as part of a future mobile device. The protocol evaluated the control algorithm for three main challenges: 1) normalizing glycemia from various initial glucose levels, 2) maintaining euglycemia, and 3) overcoming an unannounced meal of 30 ± 5 g carbohydrates.RESULTSInitial glucose values ranged from 84–251 mg/dL. Blood glucose was kept in the near-normal range (80–180 mg/dL) for an average of 70% of the trial time. The low and high blood glucose indices were 0.34 and 5.1, respectively.CONCLUSIONSThese encouraging short-term results reveal the ability of a control algorithm tailored to an individual’s glucose characteristics to successfully regulate glycemia, even when faced with unannounced meals or initial hyperglycemia. To our knowledge, this represents the first truly fully automated multiparametric model predictive control algorithm with insulin-on-board that does not rely on user intervention to regulate blood glucose in individuals with type 1 diabetes.

Embedded Control in Wearable Medical Devices: Application to the Artificial Pancreas

“…The AP system architecture has been clinically evaluated for three potential configurations, based on the hardware platform where the controller was implemented, specifically: computer/laptop [7,[16][17][18], tablet [8,19,20] and smartphone [21]. In this study, we examine two possible AP hardware configurations; we refer to them as Configuration A and Configuration B.…”

“…Hence, mp-MPC is regarded as a potential alternative for low-power hardware implementations [75,76]. The idea of an explicit MPC-based AP system has been proposed in [16,77,78] with simplified computational models.…”

Artificial Pancreas Using a Personalized Rule-Based Controller Achieves Overnight Normoglycemia in Patients with Type 1 Diabetes

“…We hypothesized that our algorithm proposing a microbolus every 5 min, mimicking the physiological pulsatile insulin secretion, 27,28 could contribute to insulin action optimization and favor stability. This pulsatile administration is different than the strategy used in other CL studies, [7][8][9]13,15,29 in which a change in the insulin delivery rate is made so insulin is distributed throughout the actuation period.…”

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

“…16,17 Meanwhile, improvements of MPC algorithms incorporating safety components (insulin on board constraint) led, in a short term pilot evaluation, to overcoming small unannounced meals without postprandial hypoglycemia. 18 In a pilot experiment, another team showed that the regulation of blood glucose was feasible in a closed-loop system without any meal announcement. 19 Another team reported that their MPC controller was at least as effective as conventional therapy in managing rises in blood glucose following breakfast.…”