Recently found this patent on Google Patents - Optical glucose detector https://patents.google.com/patent/US6466807B1/en and Patent: GB2328279 (B) some work of mine from the late 1990s (now that makes me feel old).
A device for the in vivo measurement of the concentration of an analyte in an aqueous solution comprises a transmitter for illuminating a body part with light at a plurality of predetermined wavelengths. A detector receives light from such body part and generates input signals representative of the intensity of received light at each of the predetermined wavelengths, and a computer coupled to the detector generates an output signal representative of the analyte concentration in the body part by analysis of the input signals received from the detector. The detector is adapted to generate input signals representative of the intensity of light received at three discrete wavelengths, and a formula is provided for calculating the output signal on the basis thereof.
Details of some of the other patents that refer to this patent can be found at https://scholar.google.co.uk/scholar?oi=bibs&hl=en&cites=13789974580943020660&as_sdt=5.
It has been interesting to see the way work in this area has developed and diversified. As an example the idea of using the principle we were looking at, changes in the spectrum of water in the Near InfraRed, others have used to reduce the effects of movement on Pulse Oximetry (the clip they put on your finger in hospitals to check the oxygen levels of the blood - https://www.google.com/patents/US7277741. As the ideas of pulse oximetry inspired some the ideas for the glucose detector, it was nice to see it going full circle.
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