Laser diode applications in a continuous blood glucose sensor

Animas Corporation is developing a long-term (>5 years), implantable optical, blood glucose sensor based on near-infrared absorption spectroscopy. While the glucose sensing R & D community tends to over promise results to the general public without convincing scientific evidence due to the business potential for the sensing market, Animas would like to present solid data showing robust glucose calibration and prediction. In vitro data from whole blood in more than 500 patients, with various medical histories, shows an excellent correlation (R-2=0.94) between glucose concentrations determined using sensor prediction and traditional fingerstick measurement. The numbers of outliers identified in the thousands of measurements from the 500 patient population are less than 1 %. Better than 13 mg/dl accuracy was achieved in dogs in in-vivo testing. Glucose data showing excellent tracking between measurements with the Animas sensor and a Hemocue glucometer will be presented. One of the technical challenges of developing the Animas. implantable sensor is to fabricate laser diodes that have stable emission spectra, especially for those that emit in wavelength above 2 pm. Requirements for various kinds of diode light sources will be discussed.