title: A closed-loop artificial pancreas using a proportional integral derivative with double phase lead controller based on a new nonlinear model of glucose metabolism.
abstract: BACKGROUND
  Most closed-loop insulin delivery systems rely on model-based controllers to control the blood glucose (BG) level. Simple models of glucose metabolism, which allow easy design of the control law, are limited in their parametric identification from raw data. New control models and controllers issued from them are needed.
  
  
  METHODS
  A proportional integral derivative with double phase lead controller was proposed. Its design was based on a linearization of a new nonlinear control model of the glucose-insulin system in type 1 diabetes mellitus (T1DM) patients validated with the University of Virginia/Padova T1DM metabolic simulator. A 36 h scenario, including six unannounced meals, was tested in nine virtual adults. A previous trial database has been used to compare the performance of our controller with their previous results. The scenario was repeated 25 times for each adult in order to take continuous glucose monitoring noise into account. The primary outcome was the time BG levels were in target (70-180 mg/dl).
  
  
  RESULTS
  Blood glucose values were in the target range for 77% of the time and below 50 mg/dl and above 250 mg/dl for 0.8% and 0.3% of the time, respectively. The low blood glucose index and high blood glucose index were 1.65 and 3.33, respectively.
  
  
  CONCLUSIONS
  The linear controller presented, based on the linearization of a new easily identifiable nonlinear model, achieves good glucose control with low exposure to hypoglycemia and hyperglycemia.
authors.affiliation: Supelec/I.E.T.R., Avenue de la Boulaie, Cesson-Sévigné Cedex, France. ilham.benabbes@supelec.fr
authors.forename: Ilham Ben
authors.initials: IB
authors.lastname: Abbes
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Richard
authors.forename: Marie-Anne
authors.initials: MA
authors.lastname: Lefebvre
authors.forename: Isabelle
authors.initials: I
authors.lastname: Guilhem
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Poirier
mesh_terms: D000465:Algorithms; D001786:Blood Glucose / Q000032:analysis*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D004867:Equipment Design; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007332:Insulin Infusion Systems; D019397:Pancreas, Artificial; D014584:User-Computer Interface
chemical_list: D001786:Blood Glucose; D005947:Glucose