Switched LPV glucose control with insulin-on-board limitation in type 1 diabetes.

PATRICIO COLMEGNA; FABRICIO GARELLI; HERNÁN DE BATTISTA; RICARDO SANCHEZ PEÑA

Milano

Conferencia; 9th International Conference on Advanced Technologies & Treatments for Diabetes; 2016

ATTD

Background and AimsIn this work, a closed loop algorithm which combines two different control strategies is presented. A Linear Parameter-Varying (LPV) controller and the so-called Safety Auxiliary Feedback Element (SAFE) are joined to allow designing more aggressive controllers that are able to reduce postprandial hyperglycemia without increasing the risk of hypoglycemia.MethodFirst, a switched Linear Parameter-Varying (LPV) controller with different switching regions related to hyper- and euglycemia situations is designed, providing stability and performance guarantees. In [2], its closed loop performance has been successfully tested with unannounced meals on the UVA/Padova metabolic simulator. Then, the SAFE procedure presented in [1] is added. This mechanism is based on sliding mode concepts as a way to reduce hypoglycemia events, which could be induced by the previous controller. To this end, it adapts the controller´s gain to avoid violating given constraints on the insulin-on-board (IOB). In this way, it provides a safety layer that can be adjusted according to medical criteria and is robust against sensor failures and over-estimated prandial insulin doses.ResultsAn example that shows the effectiveness of the combination of both the switched LPV controller and the SAFE algorithm is illustrated in the figure below.