Optiscan, a privately-held company in Hayward, California, has developed a continuous bedside glucose monitoring system called the OptiScanner. It is currently being developed for use with terminally ill patients.
Unlike the Near-IR approach, Optiscan opted to measure glucose in the middle infrared or Mid-IR range. One big advantage of using this IR region is that there is minimal interference from other molecules like urea. Another is that blackbody radiation can be used, ie, the device can actually use the human body's own inherent radiation, rather than apply an external radiation source.
However, a big problem arises in that Mid-IR waves are largely absorbed by water, which is the major component of blood and interstitial fluid. Another is that because there is no temperature difference between water and glucose beneath the skin, they cannot be differentiated from each other.
Most companies decided to not tackle these difficult problems, but Optiscan believes that after 7 years of work, it has gotten around many of the interference problems. It uses a rapid cooling device on the skin surface which detects glucose in a phase-shift using eight different wavelengths of IR radiation in the 9 to 10 micron range.
In this way, Glucose can be detected very close to the skin surface to a depth of about 200 micrometers. Accuracy appears to be good in very limited testing. Accuracy is reduced by individual variations in black body radiation, skin temperature, cooling speed and other factors. It is not known what adjustment factors will need to be applied, or whether an external meter will be needed to calibrate the device.
Optiscan plans to expand their mid-IR technology by detecting additional analytes within the same blood sample so more information about the condition of a critically ill patient can be gathered.
OptiScan Biomedical Corporation
21021 Corsair Blvd., Hayward, CA 94545
510-342-5800 • firstname.lastname@example.org