CALIBRATION PROBLEMS OF SUBCUTANEOUS GLUCOSENSORS WHEN APPLIED IN-SITU IN MAN

Continuous glucose monitoring is the conditio sine qua non to achieve total automation in glucose-controlled insulin-delivery. Several types of glucosensors have been designed according to the enzyme-amperometr ic method to measure the glucose in different human compartments. Howe ver, problems such as long-term stability and calibration prevent this technique being put into practice. A feasible method is needed to cal ibrate the glucosensor and at the same time should be accepted by the patients. To achieve calibration we determined the absolute tissue glu cose, as well as the microdialysis recovery in-vivo, in healthy subjec ts under normal conditions and during a hyperglycaemic clamp by applyi ng a device based on the recirculation of phosphate buffer saline in a microdialysis probe implanted in the s.c. adipose tissue. The first e xperiments carried out were promising and encouraging, but further inv estigations are still needed to favour an ideal ''before implantation, all in-vitro'' method to calibrate a s.c. glucosensor.