Abstract: A device and method are provided for use with a non-invasive optical measurement system, such as a thermal gradient spectrometer for improved determination of analyte concentrations within living tissue. In a preferred embodiment, a site selector is secured to a patient's forearm thereby isolating a measurement site on the patient's skin for determination of blood glucose levels. The site selector attaches to a thermal mass window of the spectrometer and thus forms an interface between the patient's skin and the thermal mass window. When the spectrometer must be temporarily removed from the patient's skin, such as to allow the patient mobility, the site selector is left secured to the forearm so as to maintain a consistent measurement site on the skin. When the spectrometer is later reattached to the patient, the site selector will again form an interface between the gradient spectrometer and the same location of skin as before.

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 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 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: The present invention comprises a system and method for detecting multiple wavelength bands of infrared radiation. The present invention incorporates an optical concentrator or "optical funnel" to increase the energy density on the detection elements and discrete filters mounted in the funnels and a mounting structure for individual detector elements. An apparatus in accordance with the present invention is an advance over conventional infrared detector assemblies in several areas. The apparatus in accordance with the present invention provides a unified means for mounting detectors, optical concentrators and infrared filters. It also provides an efficient means for electrical connection to the detector elements. The present invention provides a mounting structure for the detectors bonding them directly to the body of the optical funnel and passing light into them from the "backside" of the detector elements.