Non-invasive non-spectrophotometric infrared measurement of blood analyte concentrations

A method of measuring the concentration of a constituent of interest in a sample which has absorbance or reflectance in a selected region of the spectrum comprising the steps of:

• illuminating said sample with a plurality of beams of radiation, each of said beams being limited in wavelength to a distinct portion of said selected spectral region, with each of said distinct spectral portions having at least partial overlap in wavelength with the distinct spectral portion of at least one other of said beams, each of said beams also having an identifiable code associated therewith which is distinct from the code of any other of said beams;
• detecting transmitted or reflected radiation from said sample;
• decoding said identifiable code from each of said beams to generate a signal indicative of said detected radiation;
• and
• analyzing said signals to measure the concentration of said constituent of interest.

An apparatus for determining the concentration of a constituent of interest in a sample which has absorbance or reflectance in a selected region of the spectrum comprising:

• a plurality of LED's each of which generate a beam of radiation in a selected region of the spectrum, each of said beams having at least partial overlap in wavelength with at least one other of said beams;
• coding means for placing a separate and identifiable, distinct code on each of said beams of radiation;
• transmission means for transmitting said coded beams to illuminate said sample;
• a sample chamber for confining said sample during illumination;
• detection means for detecting the intensity of radiation transmitted or reflected by said sample, said detection means including decoding means for identifying the code on each of said coded beams, said detection means generating an output signal which is a function of the information carried by each coded beam;
• and
• analysis means for converting said output signal into a measure of said concentration of said constituent of interest in said sample.

A method of measuring the concentration of a constituent of interest in a sample which has absorbance or reflectance in a selected region of the spectrum comprising the steps of:

• illuminating said sample with a plurality of beams of radiation, each of said beams being generated by LED's which are limited in wavelength to a distinct portion of said selected spectral region, with each of said distinct spectral portions having at least partial overlap in wavelength with the distinct spectral portion of at least one other of said beams, each of said beams also having an identifiable code associated therewith which is distinct from the code of any other of said beams;
• detecting transmitted or reflected radiation from said sample;
• decoding said identifiable code from each of said beams to generate a signal indicative of said detected radiation from each of said beams;
• and
• analyzing said signals to measure the concentration of said constituent of interest.

An apparatus for performing colorimetry or an analog of colorimetry using absorption or reflectance of radiation in a selected portion of the spectrum comprising:

• radiation generation means generating a plurality of broad wavelength beams of radiation in said selected region of the spectrum;
• coding means for producing a distinct, identifiable code associated with each of said beams;
• optical filtering means in the form of a plurality of broad bandpass filters, each said filter having a spectral transmission centered about a separate portion of said selected radiation, the spectral transmission for each filter partially overlapping that of at least one other filter;
• detection means differentially responsive to said coded beams, said response being in the form of an output signal which is a function of the information carried by said coded beams;
• and
• analysis means for converting said output into the colorimetry or analog of colorimetry values.

A method for performing colorimetry or an analog of colorimetry using transmission or reflectance measurements comprising the steps of:

• illuminating a sample with a plurality of beams of radiation, each of said beams being centered about a different portion of a selected region of the spectrum and partially overlapping spectrally with the portion of at least one other beam;
• detecting transmitted or reflected radiation from said sample;
• generating at least one signal corresponding to said detected radiation;
• and
• analyzing said signal to convert it to the colorimetry or analog of a colorimetry value;
• wherein each of said beams is distinguishably coded with an identifying code prior to impinging on the sample and is decoded subsequent to impinging on the detector.

An apparatus for performing colorimetry or an analog of colorimetry using absorption or reflectance of radiation in a selected portion of the spectrum comprising:

• a plurality of LED's each emitting a broad wavelength beam of radiation in said selected region of the spectrum, the spectral emission for each LED partially overlapping that of at least one other LED;
• coding means for producing a distinct, identifiable code associated with each of said beams;
• detection means differentially responsive to said coded beams, said response being in the form of an output signal which is a function of the information carried by said coded beams;
• and
• analysis means for converting said output into the colorimetry or analog of colorimetry values.

An apparatus for determining the concentration of a constituent of interest in a sample which has absorbance or reflectance in a selected region of the spectrum comprising:

• radiation generating means which generates a beam of broad spectrum radiation;
• coding means for placing a distinct, identifiable frequency of modulation on each of the wavelengths in said beam of radiation;
• transmission means for transmitting said coded beams to illuminate said sample;
• a sample chamber for confining said sample during illumination;
• detection means for detecting the intensity of radiation transmitted or reflected by said sample, said detection means including filtering means for electronically filtering said reflected or transmitted radiation, said filtering means comprising a plurality of electrical broad bandpass filters each having a frequency transmission centered about a selected portion of the frequencies of modulation of the wavelengths, each of said selected portions transmitted by said electronic broad bandpass filters having at least a partial overlap with the portion of the selected region for at least one other electronic broad bandpass filter, said detection means generating an output signal which is a function of the information carried by said coded wavelengths;
• and
• analysis means for converting said output signal into a measure of said concentration of said constituent of interest in said sample.