Patent ID: 6028311
Filing Date: 2000-02-22
Classification: A61B,G01N

Abstract:
An apparatus for determining the concentration of a constituent of interest in a sample which has transmittance, emittance, or reflectance in a selected region of the spectrum comprising:illumination means which generates a plurality of beams of illuminating radiation in a selected region of the spectrum;coding means for placing an identifiable, distinct code on each of said plurality of beams of radiation;means for individually limiting the wavelength of each of said plurality of beams such that each beam is limited in wavelength to a distinct portion of said selected region of said spectrum, whereby at least one of said beams covers a broadband spectral region;transmission means for transmitting said coded beams to illuminate said sample;detection means for detecting the intensity of radiation transmitted, emitted, or reflected by said sample, said detection means including at least one broad band detector and decoding means for identifying the code on each of said coded beams, said detection means generating output signals which are functions of the information carried by each coded beam; andanalysis means for converting said output signals into a measure of said concentration of said constituent of interest in said sample;wherein said analysis means generates a response which is an analog of a location in an n-dimensional colorimetric space, where n is equal to, or less than, the number of beams used to illuminate said sample.