A glucose biosensor includes a plurality of optical fibers configured for placement within the ear canal. A first optical fiber emits light into the ear canal. A plurality of other optical fibers capture and transmit the reflected light back to the glucose biosensor. A plurality of photodetectors are configured in the glucose biosensor to detect the reflected light from the plurality of optical fibers. The glucose biosensor processes the detected light from each photodetector to determine a glucose level measurement. In an embodiment, the glucose biosensor also obtains a second glucose level measurement using another method and determines a calibration for the first glucose level measurement using the second glucose level measurement.
