APPARATUS FOR MEASUREMENT OF ANALYTE CONCENTRATION

摘要

Apparatus for measuring an analyte such as glucose comprises heated ribbon as an IR source (1) outputting IR light in two opposed directions, an ATR waveguide (4) , having a surface for forming an interface with a body region such as skin, hollow waveguide collimators (2) and (5) , and detectors (3) and (6) for each for measurement and reference wavelength bands outputting an optical absorbance d for the measurement band and an optical absorbance c for the reference band, and producing a time dependant output of the concentration g of said analyte calculated as where A and b/a are constants for a given set of conditions of use, and b and a corresponding to measures d and c respectively, but are determined with water rather than said body region in contact with said optical waveguide surface. Collimator (5) and detector (6) view the waveguide (4) at an adjustable angle a. The effect of temperature on the measurement is compensated for by a reading obtained from a temperature sensor (8) . A final value for g is obtained by applying a predictive algorithm to measurements taken at time intervals .