CURRENT STATUS OF THE GLUCOSE SENSOR

This study gives an overview of glucose sensing strategies for potenti al use in diabetes therapy. The basis for the most commonly used amper ometric glucosensors is the Clark electrode which measures oxygen tens ion. Coupling this sensor with glucose oxidase led to the first specif ic ''biosensor'' for glucose measurement. This sensor has been used fo r more than 20 years in the in vitro artificial pancreas (''Biostator' '). The development of implantable glucose sensors has been hampered b y the disappointing in vivo behavior of these sensors. Alternative glu cose sensing techniques including noninvasive approaches are still exp erimental. Combining the microdialysis technique for continuous sampli ng of subcutaneous extracellular fluid with an in vitro on-line ampero metric glucose oxidase electrode (the ''Ulmer Zuckeruhr'' or ''sugar w atch'' system), permits continuous glucose sensing for 72 hours. Altho ugh there are differences and delays between changes in tissue and blo od glucose concentrations, a complete automated feedback controlled in sulin delivery system is possible if fast acting insulin analogs can c lose the insulin delivery ''feedback loop.''