@article {328, title = {Online adjustable linear parameter-varying controller for artificial pancreas systems}, journal = {Biomedical Signal Processing and Control}, volume = {86}, year = {2023}, pages = {105164}, abstract = {

The purpose of this article is to present a non-hybrid fully closed-loop controller for the Artificial Pancreas (AP) problem focused on long-term clinical trials and home-use applications. It includes physical activity (PA) and unannounced meals. The controller is based on a robust gain-scheduled algorithm with a Linear Parameter-Varying (LPV) structure. It takes into account the time-varying dynamics of the problem by adapting itself in real-time according to measured glucose levels, and allows online fine-tuning during tests and periodic evaluations without the need of a controller redesign. The proposed fully parameterized LPV control adds several features to our previous results, accounts for the main perturbations of the AP problem and simplifies its implementation. To help in the parameter fine-tuning, a methodology based on clinical information is proposed. In-silico tests show that the achieved performance is similar or better than our previous Automatic Regulation of Glucose (ARG) algorithm, tested in two clinical trials, with the addition of the features mentioned before.

}, keywords = {Artificial pancreas, Diabetes type 1, insulin-on-board, LPV control}, issn = {1746-8094}, doi = {https://doi.org/10.1016/j.bspc.2023.105164}, url = {https://www.sciencedirect.com/science/article/pii/S1746809423005979}, author = {Bianchi, Fernando D. and S{\'a}nchez-Pe{\~n}a, Ricardo S. and Garelli, Fabricio} } @article {242, title = {Artificial pancreas clinical trials: Moving towards closed-loop control using insulin-on-board constraints}, journal = {Biomedical Signal Processing and Control}, volume = {45}, year = {2018}, pages = {1 - 9}, abstract = {

Abstract Artificial pancreas (AP) systems for people with type 1 diabetes (T1DM) combine the use of a smart insulin pump with a Continuous Glucose Monitor (CGM) and a control algorithm to improve the regulation of glycaemia. Based on the extensive clinical evidence provided by the main research groups in the area, a hybrid control algorithm combining insulin meal boluses and glucose feedback action has been recently approved. However, this sort of algorithms should be refined especially during the postprandial period. In turn, fully closed-loop control strategies have to be further developed. In either case, intensive in vivo validation is necessary to ensure the viability of the proposed strategy as an effective method to treat \{T1DM\} patients. In this paper, a safety layer called \{SAFE\} loop [1] is reformulated to be employed during clinical trials in two different ways: the time enable mode to gradually activate the closed-loop control after an insulin meal bolus in hybrid configurations; and the amplitude enable mode to activate the full closed-loop control as long as the insulin infusion does not exceed the conventional therapy to a given extent. The \{SAFE\} module decides the activation of the controller as a function of a constraint on the insulin on board (IOB). In the case of the Time Enable, this results in the use of a constant restriction on the IOB, whereas in the amplitude enable it results in the use of a time-varying {\.I}OB\} constraint. Both operation modes are evaluated in silico using broadly accepted high-order models and the results contrasted with the ones obtained without the \{SAFE\} protection.

}, keywords = {insulin-on-board}, issn = {1746-8094}, doi = {https://doi.org/10.1016/j.bspc.2018.05.009}, url = {https://www.sciencedirect.com/science/article/pii/S1746809418301113}, author = {Fushimi, Emilia and Rosales, Nicol{\'a}s and De Battista, Hern{\'a}n and Garelli, Fabricio} } @article {50, title = {Safety Auxiliary Feedback Element for the Artificial Pancreas in Type 1 Diabetes}, journal = {Biomedical Engineering, IEEE Transactions on}, volume = {60}, year = {2013}, month = {Aug}, pages = {2113-2122}, abstract = {

The artificial pancreas aims at the automatic delivery of insulin for glycemic control in patients with type 1 diabetes, i.e., closed-loop glucose control. One of the challenges of the artificial pancreas is to avoid controller overreaction leading to hypoglycemia, especially in the late postprandial period. In this study, an original proposal based on sliding mode reference conditioning ideas is presented as a way to reduce hypoglycemia events induced by a closed-loop glucose controller. The method is inspired in the intuitive advantages of two-step constrained control algorithms. It acts on the glucose reference sent to the main controller shaping it so as to avoid violating given constraints on the insulin-on-board. Some distinctive features of the proposed strategy are that 1) it provides a safety layer which can be adjusted according to medical criteria; 2) it can be added to closed-loop controllers of any nature; 3) it is robust against sensor failures and overestimated prandial insulin doses; and 4) it can handle nonlinear models. The method is evaluated in silico with the ten adult patients available in the FDA-accepted UVA simulator.

}, keywords = {Absorption, Artificial, artificial organs, Artificial pancreas, Biological, Blood Glucose Self-Monitoring, closed loop systems, closed-loop glucose control, Computer Simulation, Computer-Assisted, Diabetes, Diabetes Mellitus, diseases, drug delivery systems, Drug Therapy, drugs, Equipment Safety, FDA-accepted UVA simulator, feedback, glucose control, glycemic control, Humans, hypoglycemia, insulin, insulin-on-board, medical control systems, Models, Pancreas, Physiological, postprandial period, Proposals, reference conditioning, Robustness, safety, safety auxiliary feedback element, sliding mode (SM), sliding mode reference conditioning, Sugar, two-step constrained control algorithms, Type 1, type 1 diabetes}, issn = {0018-9294}, doi = {10.1109/TBME.2013.2247602}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6463437}, author = {Revert, Ana and Garelli, Fabricio and Pic{\'o}, Jes{\'u}s and De Battista, Hern{\'a}n and Rossetti, Paolo and Veh{\'\i}, Josep and Bondia, Jorge} }