In Vivo Glucose Measurement Using Fine Needle Type Amperometric Glucose Sensor

Fine needle type glucose sensors having outer membrane layers of heparin and urokinase were prepared.   Glucose sensor properties were evaluated by in vitro measurement in phosphate buffer solution and horse serum, and in vivo measurement using the veins of rabbit. Glucose sensors were implanted using cannula and the blood glucose levels were influenced by the injection of glucose and insulin. Definite glucose was hardly observed at the days of implantation, while clear response was obtained after several days. This may due to the recovery from the damage of blood vessel received on the process of sensor implantation. Good correlation between in vitro blood glucose levels was obtained at especially low glucose level.  Clear glucose sensor response was obtained even after 10 days of implantation. The formation on thrombus was not observed on the surface of sensor implanted for 10 days.  This indicate that the glucose sensor with outer membrane of heparin and urokinase have excellent biocompatibility.