The worldwide market for glucose monitoring products is expected to exceed 3 billion dollars by the year 2000. These figures and the revenue potential make development of the non-invasive glucose sensor a most sought after device. But many technological and financial challenges and questions remain. Types of Measurement Techniques Non-invasive glucose monitoring techniques can be grouped as subcutaneous, dermal, epidermal and combined dermal and epidermal glucose measurements. Matrices other than blood under investigation include interstitial fluid, ocular fluids and sweat.
Test sites being explored include finger tips, cuticle, finger web, forearm and ear lobe.
Subcutaneous measurements include microdialysis, wick extraction, and implanted electrochemical or competitive flourescence sensors. Microdialysis is also an investigational dermal and epidermal glucose measurement technique. Epidermal measurements can be obtained via infrared spectroscopy, as well. The light is modified by the tissue after transmission through the target area. An optical signature or fingerprint of the tissue content is produced by the diffuse light that escapes the tissue it has penetrated.