title: Model-Free Machine Learning in Biomedicine: Feasibility Study in Type 1 Diabetes.
abstract: Although reinforcement learning (RL) is suitable for highly uncertain systems, the applicability of this class of algorithms to medical treatment may be limited by the patient variability which dictates individualised tuning for their usually multiple algorithmic parameters. This study explores the feasibility of RL in the framework of artificial pancreas development for type 1 diabetes (T1D). In this approach, an Actor-Critic (AC) learning algorithm is designed and developed for the optimisation of insulin infusion for personalised glucose regulation. AC optimises the daily basal insulin rate and insulin:carbohydrate ratio for each patient, on the basis of his/her measured glucose profile. Automatic, personalised tuning of AC is based on the estimation of information transfer (IT) from insulin to glucose signals. Insulin-to-glucose IT is linked to patient-specific characteristics related to total daily insulin needs and insulin sensitivity (SI). The AC algorithm is evaluated using an FDA-accepted T1D simulator on a large patient database under a complex meal protocol, meal uncertainty and diurnal SI variation. The results showed that 95.66% of time was spent in normoglycaemia in the presence of meal uncertainty and 93.02% when meal uncertainty and SI variation were simultaneously considered. The time spent in hypoglycaemia was 0.27% in both cases. The novel tuning method reduced the risk of severe hypoglycaemia, especially in patients with low SI.
authors.affiliation: Diabetes Technology Research Group, ARTORG Center for Biomedical Engineering Research, University of Bern, Murtenstrasse 50, 3008 Bern, Switzerland.
authors.forename: Elena
authors.initials: E
authors.lastname: Daskalaki
authors.affiliation: Division of Endocrinology, Diabetes and Clinical Nutrition, Bern University Hospital "Inselspital", 3010 Bern, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Diem
authors.affiliation: Diabetes Technology Research Group, ARTORG Center for Biomedical Engineering Research, University of Bern, Murtenstrasse 50, 3008 Bern, Switzerland.|Division of Endocrinology, Diabetes and Clinical Nutrition, Bern University Hospital "Inselspital", 3010 Bern, Switzerland.
authors.forename: Stavroula G
authors.initials: SG
authors.lastname: Mougiakakou
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D035843:Biomedical Research; D001786:Blood Glucose / Q000032:analysis; D002648:Child; D015331:Cohort Studies; D003198:Computer Simulation; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000150:complications / Q000628:therapy*; D005240:Feasibility Studies; D006801:Humans; D006943:Hyperglycemia / Q000150:complications; D007328:Insulin / Q000097:blood; D000069550:Machine Learning; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D007328:Insulin