Real-Time hypoglycemia prediction suite using continuous glucose monitoring: a safety net for the artificial pancreas.
OBJECTIVE
The purpose of this study was to develop an advanced algorithm that detects pending hypoglycemia and then suspends basal insulin delivery. This approach can provide a solution to the problem of nocturnal hypoglycemia, a major concern of patients with diabetes.


METHODS
This real-time hypoglycemia prediction algorithm (HPA) combines five individual algorithms, all based on continuous glucose monitoring 1-min data. A predictive alarm is issued by a voting algorithm when a hypoglycemic event is predicted to occur in the next 35 min. The HPA system was developed using data derived from 21 Navigator studies that assessed Navigator function over 24 h in children with type 1 diabetes. We confirmed the function of the HPA using a separate dataset from 22 admissions of type 1 diabetic subjects. During these admissions, hypoglycemia was induced by gradual increases in the basal insulin infusion rate up to 180% from the subject's own baseline infusion rate. RESULTS Using a prediction horizon of 35 min, a glucose threshold of 80 mg/dl, and a voting threshold of three of five algorithms to predict hypoglycemia (defined as a FreeStyle plasma glucose readings <60 mg/dl), the HPA predicted 91% of the hypoglycemic events. When four of five algorithms were required to be positive, then 82% of the events were predicted.


CONCLUSIONS
The HPA will enable automated insulin-pump suspension in response to a pending event that has been detected prior to severe immediate complications.
Dassau
Eyal
E
Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California, USA. dassau@engineering.ucsb.edu
Cameron
Fraser
F
Lee
Hyunjin
H
Bequette
B Wayne
BW
Zisser
Howard
H
Jovanovic
Lois
L
Chase
H Peter
HP
Wilson
Darrell M
DM
Buckingham
Bruce A
BA
Doyle
Francis J
FJ
D000293:Adolescent; D001786:Blood Glucose / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000188:drug therapy; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000097:blood* / Q000188:drug therapy; D007332:Insulin Infusion Systems; D008297:Male; D019397:Pancreas, Artificial; D011237:Predictive Value of Tests
D001786:Blood Glucose