Abstract: A method determines an analyte concentration in a sample including the analyte and a substance. The method includes providing an absorption spectrum of the sample. The absorption spectrum has an absorption baseline. The method further includes shifting the absorption spectrum so that the absorption baseline approximately equals a selected absorption value in a selected absorption wavelength range. The method further includes subtracting a substance contribution from the absorption spectrum. Thus, the method provides a corrected absorption spectrum substantially free of a contribution from the substance.

Abstract: A method calibrates a monitor that comprises a non-invasive blood constituent monitor and a traditional measurement system. The non-invasive blood constituent monitor includes a thermal gradient inducing element an analyzer window. A traditional monitor output representing a property of a blood constituent is generated by the traditional measurement system. A non-invasive monitor output representing the property of the whole blood constituent is generated by the non-invasive constituent monitor. The traditional monitor output and the non-invasive monitor output are compared to estimate an amount of error. The non-invasive monitor output is corrected by the amount of error.

Abstract: A method of determining the analyte concentration of a test sample is described. A temperature gradient is introduced in the test sample and infrared radiation detectors measure radiation at selected analyte absorbance peak and reference wavelengths. Reference and analytical signals are detected. In the presence of the selected analyte, parameter differences between reference and analytical signals are detectable. These parameter differences, having a relationship to analyte concentration, are measured, correlated, and processed to determine analyte concentration in the test sample. Accuracy is enhanced by inducing a periodically modulated temperature gradient in the test sample. The analytical and reference signals may be measured continuously and the parameter difference integrated over the measurement period to determine analyte concentration.

Abstract: A solid-state spectrometer for the non-invasive generation and capture of thermal gradient spectra from human or animal tissue. The spectrometer includes an infrared transmissive thermal mass window for inducing a transient temperature gradient in the tissue by means of conductive heat transfer with the tissue, and cooling means in operative combination with the thermal mass window for cooling the thermal mass window. Also provided is an infrared sensor means for detecting infrared emissions emanating from the tissue as the transient temperature gradient progresses into the tissue, and for providing output signals proportional to the detected infrared emissions. Data capture means is provided for sampling the output signals received from the infrared sensor means as the transient temperature gradient progresses into the tissue.

Abstract: A solid-state device for the non-invasive generation and capture of thermal gradient spectra from sample tissue. The device includes an infrared transmissive layered window assembly, a means for inducing a thermal gradient in sample tissues. Also provided is an infrared radiation detector for detecting infrared emissions emanating from the tissue as the transient temperature gradient progresses into the sample tissues. The sensor provides output signals proportional to the detected infrared emissions. A data capture means is provided for the sampling of output signals received from the infrared radiation detector as the induced temperature gradient progresses into the sample tissue.

Abstract: A method uses spectroscopy to determine an analyte concentration in a sample. The method includes producing an absorbance spectrum of the sample. The method further includes shifting the absorbance spectrum to zero in a wavelength region. The method further includes subtracting a water or other substance contribution from the absorbance spectrum.

Abstract: A method and apparatus of determining the analyte concentration of a test sample is described. A temperature gradient is introduced in the test sample and infrared radiation detectors measure radiation at selected analyte absorbance peak and reference wavelengths. The modulation of the temperature gradient is controlled by a surface temperature modulation. A transfer function is determined that relates the surface temperature modulation to the modulation of the measured infrared radiation. Reference and analytical signals are detected. In the presence of the selected analyte, phase and magnitude differences in the transfer function are detected. These phase and magnitude differences, having a relationship to analyte concentration, are measured, correlated, and processed to determine analyte concentration in the test sample.

Abstract: A method of determining the analyte concentration of a test sample is described. A temperature gradient is introduced in the test sample and infrared radiation detectors measure radiation at selected analyte absorbance peak and reference wavelengths. Reference and analytical signals are detected. In the presence of the selected analyte, parameter differences between reference and analytical signals are detectable. These parameter differences, having a relationship to analyte concentration, are measured, correlated, and processed to determine analyte concentration in the test sample. Accuracy is enhanced by inducing a periodically modulated temperature gradient in the test sample. The analytical and reference signals may be measured continuously and the parameter difference integrated over the measurement period to determine analyte concentration.

Abstract: A reagentless whole-blood analyte detection system that is capable of being deployed near a patient has a source capable of emitting a beam of radiation that includes a spectral band. The whole-blood system also has a detector in an optical path of the beam. The whole-blood system also has a housing that is configured to house the source and the detector. The whole-blood system also has a sample element that is situated in the optical path of the beam. The sample element has a sample cell and a sample cell wall that does not eliminate transmittance of the beam of radiation in the spectral band.

Abstract: A reagentless whole-blood analyte detection system that is capable of being deployed near a patient has a source capable of emitting a beam of radiation that includes a spectral band. The whole-blood system also has a detector in an optical path of the beam. The whole-blood system also has a housing that is configured to house the source and the detector. The whole-blood system also has a sample element that is situated in the optical path of the beam. The sample element has a sample cell and a sample cell wall that does not eliminate transmittance of the beam of radiation in the spectral band.

Abstract: A method of determining the analyte concentration of a test sample is described. A temperature gradient is introduced in the test sample and infrared radiation detectors measure radiation at selected analyte absorbance peak and reference wavelengths. Reference and analytical signals are detected. In the presence of the selected analyte, parameter differences between reference and analytical signals are detectable. These parameter differences, having a relationship to analyte concentration, are measured, correlated, and processed to determine analyte concentration in the test sample. Accuracy is enhanced by inducing a periodically modulated temperature gradient in the test sample. The analytical and reference signals may be measured continuously and the parameter difference integrated over the measurement period to determine analyte concentration.

Abstract: A method calibrates a monitor that comprises a non-invasive blood constituent monitor and a traditional measurement system. The non-invasive blood constituent monitor includes a thermal gradient inducing element an analyzer window. A traditional monitor output representing a property of a blood constituent is generated by the traditional measurement system. A non-invasive monitor output representing the property of the whole blood constituent is generated by the non-invasive constituent monitor. The traditional monitor output and the non-invasive monitor output are compared to estimate an amount of error. The non-invasive monitor output is corrected by the amount of error.

Abstract: A calibration standard for calibrating a thermal gradient spectrometer. The calibration standard is a structure having a particular glucose concentration which a thermal gradient spectrometer reads for determining whether the spectrometer is in calibration. The structure of the calibration standard properly mimics the physiology of human tissue. A number of such standards, each containing a different concentration of glucose are provided in kit form with a thermal gradient spectrometer for use in calibrating the spectrometer. The spectrometer is provided with a display and internal circuitry for performing self-calibrating adjustments and a communications port for electronically coupling to a remote computer and database for supplying external calibration commands to said spectrometer.

Abstract: A solid-state spectrometer for the non-invasive generation and capture of thermal gradient spectra from human or animal tissue. The spectrometer includes an infrared transmissive thermal mass window for inducing a transient temperature gradient in the tissue by means of conductive heat transfer with the tissue, and a cooling element in operative combination with the thermal mass window for cooling the thermal mass window. Also provided is an infrared sensor for detecting infrared emissions emanating from the tissue as the transient temperature gradient progresses into the tissue, and for providing output signals proportional to the detected infrared emissions. A data capture element is provided for sampling the output signals received from the infrared sensor as the transient temperature gradient progresses into the tissue.

Abstract: A method of determining the analyte concentration of a test sample is described. A temperature gradient is introduced in the test sample and infrared radiation detectors measure radiation at selected analyte absorbance peak and reference wavelengths. Reference and analytical signals are detected. In the presence of the selected analyte, parameter differences between reference and analytical signals are detectable. These parameter differences, having a relationship to analyte concentration, are measured, correlated, and processed to determine analyte concentration in the test sample. Accuracy is enhanced by inducing a periodically modulated temperature gradient in the test sample. The analytical and reference signals may be measured continuously and the parameter difference integrated over the measurement period to determine analyte concentration.

Abstract: A spectrometer for the non-invasive generation and capture of thermal gradient spectra from human or animal tissue. The spectrometer includes an infrared transmissive thermal mass for inducing a transient temperature gradient in the tissue by means of conductive heat transfer with the tissue, and cooling means in operative combination with the thermal mass for cooling the thermal mass. Also provided is an infrared sensor means for detecting infrared emissions emanating from the tissue as the transient temperature gradient progresses into the tissue, and for providing output signals proportional to the detected infrared emissions. Data capture means is provided for sampling the output signals received from the infrared sensor means as the transient temperature gradient progresses into the tissue.

Abstract: Spectrometric methodology for non-invasively obtaining optical spectra from heterogeneous material for the identification and quantification of constituent compounds. There is provided a transient or steady state subsurface thermal gradient spectroscopic methodology for obtaining in vivo optical spectra relating to the concentration of n analytes at depths to around 330 microns in human tissue, and for determining that concentration from the spectra. The methodology is employable on a wide variety of spectrometric devices, and enables: a real time determination of both surface and reference intensities; a fast, efficient calibration of the spectrometric device; and results in the provision of an analytical parameter which avoids the measurement of the optical path length to enable the extremely accurate calculation of a ratio of concentrations of n analytes in the system under analysis.

Abstract: A noninvasive infrared spectrometer which includes an infrared detector system for measuring the intensity, wavelength, and time varying nature of infrared energy emanating from deep layers within a body. Before detection, the energy emanating from deep within the body passes through layers of that body in the presence of a natural or induced thermal gradient. The measured infrared energy is processed into an absorption spectra and then into a concentration of at least one constituent of the body which concentration may be strongly dependent on the depth into the body. In one embodiment the temperature gradient is induced by chilling the surface of the body to provide a clearer indication of the infrared absorption levels of the deeper constituents. Other embodiments describe the sequential or simultaneous heating and cooling of the heterogenous body to induce and capture the transient infrared absorption spectral information.

Abstract: Spectrometric methodology for non-invasively obtaining optical spectra from heterogeneous material for the identification and quantification of constituent compounds. There is provided a transient or steady state subsurface thermal gradient spectroscopic methodology for obtaining in vivo optical spectra relating to the concentration of .eta. analytes at depths to around 330 microns in human tissue, and for determining that concentration from the spectra. The methodology is employable on a wide variety of spectrometric devices, and enables: a real time determination of both surface and reference intensities; a fast, efficient calibration of the spectrometric device; and results in the provision of an analytical parameter which avoids the measurement of the optical path length to enable the extremely accurate calculation of a ratio of concentrations of .eta. analytes in the system under analysis.

Abstract: A method and apparatus for monitoring glucose, ethyl alcohol and other blood constituents in a noninvasive manner. The measurements are made by monitoring infrared absorption of the desired blood constituent in the long infrared wavelength range where the blood constituent has a strong and distinguishable absorption spectrum. The long wavelength infrared energy emitted by the person as heat is monitored and the infrared absorption of particular constituents in the blood (such as glucose or blood alcohol) is measured at characteristic infrared absorption wavelengths for those constituents. The measurements are preferably synchronized with systole and diastole of the cardiac cycle so that the signal contribution caused by veins and tissues (which do not pulse) may be cancelled when a ratio of the detected signals is taken.