Abstract
The artificial beta cell is a Glucose Controlled Insulin (and dextrose) Infusion System
(GCIIS) for maintaining normoglycemia in diabetic conditions and other disturbances
of metabolism. The insulin and dextrose infusion rates are calculated by a microcomputer
according to the static glucose concentration (proportional control) and to its rate
of change (dynamic control). The algorithms controlling the computer can be adapted
to the subjects' requirements. It has already been shown, that the artificial beta
cell is able to maintain blood sugar values in diabetics within physiological ranges
during the course of the day.
In our present study we examined the response of the artificial beta cell using a
100 gm oral glucose load in severe diabetics. The first type of control algorithms
applied effected a rather small initial insulin infusion following OGTT in 8 juvenile
diabetics connected with the artificial beta cell. The glucose responses thus obtained
were similar to latent diabetes. In contrast, when the computer was controlled by
the second type of algorithms with a more responsive dynamic control and a consequently
higher initial insulin infusion, in one diabetic OGTT was fully normalized, whereas
an improvement was achieved in another diabetic patient. Furthermore it was shown
that control algorithms must be varied individually, depending on residual beta cell
function and glucose regulatory mechanisms.
Key words
Glucose Controlled Insulin Infusion System (GCIIS) - Artificial Beta Cell - Artificial
Endocrine Pancreas - Control Algorithms - Continuous Plasma Glucose Measurement -
Oral Glucose Tolerance Test - First Phase Insulin Secretion
1 This study was supported by Landesversicherungsanstalt Württemberg and the "Dotation
Herbert Weishaupt e.V."
2 Research Fellow of Alexander von Humboldt-Foundation
