Blood glucose control by intermittent loop closure in the basal mode: computer simulation studies with a diabetic model
A semiclosed loop, bedside insulin infusion system using a simple basal infusion algorithm consisting of a linear transition between two insulin delivery rates as blood glucose (BG) increases has been developed. A theoretical study using computer simulation has now been undertaken to examine the effect of BG sampling frequency and algorithm parameters on BG control. A model for BG control by exogenous insulin in the individual with diabetes was developed from a model for healthy subjects and from clinical data in the literature. Results of computer simulation using this model showed a decrease in BG stability as the sampling interval increased from 1 to 4 h. Simulations also showed a decrease in BG stability as the sensitivity of the control algorithm increased. Choice of an appropriate basal control algorithm involved a compromise between stability, sampling interval, and metabolic control. We conclude that satisfactory metabolic control can be obtained using intermittent BG sampling in the basal state; sampling at intervals of 3 h combined with a basal control algorithm whereby insulin delivery rate increases linearly from 0.5 to 2.5 U/h over the BG range 2-12 mmol/L appears suitable for most diabetic persons. Three-hour sampling offers a good compromise between degree of metabolic control and clinical effort involved.
|Authors||Furler, S. M.;Kraegen, E. W.;Smallwood, R. H.;Chisholm, D. J. :|
|Responsible Garvan Author|
|Publisher Name||DIABETES CARE|
|URL link to publisher's version||http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=4075940|