초록 ▼

A method is provided for building improved calibration models or for improving modifications to these models or validation of the models used in the non-invasive spectroscopic measurement of an analyte or attribute of tissue. The method uses a matched reference sample and measurement of that sample

A method is provided for building improved calibration models or for improving modifications to these models or validation of the models used in the non-invasive spectroscopic measurement of an analyte or attribute of tissue. The method uses a matched reference sample and measurement of that sample to ensure that the correct relationship between the spectra and analyte is made during the model building, modification or calibration process. A matched reference sample is one in which the analyte of interest or attribute of interest in the reference sample is representative of the analyte or attribute at the site being non-invasively sampled or the agreement between the reference concentration and the non-invasively sampled concentration is clinically significant.

대표청구항 ▼

What is claimed is: 1. A method for performing modifications to calibration models in the non-invasive spectroscopic measurement of an analyte or attribute of tissue, the method comprising the steps of: providing a means for irradiating tissue with infrared energy; providing an output element, the

What is claimed is: 1. A method for performing modifications to calibration models in the non-invasive spectroscopic measurement of an analyte or attribute of tissue, the method comprising the steps of: providing a means for irradiating tissue with infrared energy; providing an output element, the output element operatively connected to a means for measuring a spectrum; irradiating tissue with the infrared energy so that there is absorption of at least a portion of the infrared energy in the tissue; collecting at least a portion of the infrared energy exiting the tissue through the output element and measuring the resulting spectrum; collecting at least one matched reference sample that is assayed to determine at least one reference value of the analyte or attribute of tissue; and using the at least one reference value with the spectral measurement to perform a modification to the calibration model; wherein the matched reference sample is a fluid taken from a tissue compartment that is kinetically matched to the tissue which is irradiated. 2. The method of claim 1, wherein the matched reference sample is interstitial fluid. 3. The method of claim 1, wherein the matched reference sample is bulk fluid in the tissue. 4. The method of claim 1, wherein the matched reference sample is fluid obtained from a limb. 5. The method of claim 1, wherein the matched reference sample is lancet blood obtained from a forearm. 6. The method of claim 1, wherein the matched reference sample is a fluid taken from a tissue compartment that is spatially matched to the tissue which is irradiated. 7. The method of claim 1, wherein site-to-site variations are reduced through multiple collection of matched reference samples of the tissue over a sufficient area. 8. The method of claim 7, where the area optically sampled and the area used for procurement of multiple matched reference samples are nominally similar. 9. A method for performing subject specific modifications in the non-invasive spectroscopic measurement of an analyte or attribute of tissue, the method comprising the steps of: providing a means for irradiating tissue with infrared energy; providing an output element, the output element operatively connected to a means for measuring a spectrum; irradiating tissue with the infrared energy so that there is absorption of at least a portion of the infrared energy in the tissue; collecting at least a portion of the infrared energy exiting the tissue through the output element and measuring the resulting spectrum; collecting reference samples that are kinetically matched to the irradiated tissue and assaying the reference samples for the analyte or attribute of tissue; and using the assayed reference samples with the spectral measurements to perform a subject-specific modification. 10. A method for building a calibration model for the non-invasive spectroscopic measurement of an analyte or attribute of tissue, the method comprising the steps of: providing a means for irradiating tissue with infrared energy; providing an output element, the output element operatively connected to a means for measuring optical information; irradiating tissue with the infrared energy so that there is absorption of at least a portion of the infrared energy in the tissue; collecting at least a portion of the infrared energy exiting the tissue through the output element and measuring a resulting spectrum; collecting matched reference samples and assaying the matched reference samples for the analyte or attribute of tissue; and using the reference sample measurements along with the infrared measurements to build a multivariate calibration model; wherein the matched reference sample is a fluid taken from a tissue compartment that is kinetically matched to the tissue which is irradiated. 11. The method of claim 10, wherein the matched reference sample is interstitial fluid. 12. The method of claim 10, wherein the matched reference sample is the bulk fluid in the tissue. 13. The method of claim 10, wherein the matched reference sample is the fluid obtained from a limb. 14. The method of claim 10, wherein the matched reference sample is lancet blood obtained from a forearm. 15. The method of claim 10, wherein the matched reference sample is a fluid from a tissue compartment that is spatially matched to the tissue which is irradiated. 16. The method of claim 10, wherein the area irradiated and the area used for procurement of the matched reference samples of the tissue are nominally similar in size. 17. A noninvasive method for measuring a biological attribute in human tissue of a specific subject comprising the steps of: providing an apparatus for measuring infrared absorption, the apparatus including an energy source emitting infrared energy at multiple wavelengths, an input element, an output element and a spectrum analyzer; coupling the input and output elements to the human tissue; irradiating the tissue through the input element with multiple wavelengths of infrared energy with resulting absorption of at least some of those wavelengths; collecting at least a portion of the non-absorbed infrared energy with the output element followed by determining the intensities of the infrared energy; and predicting the biological attribute of the specific subject utilizing a model, wherein the subject specific prediction method uses one or more previously obtained matched reference samples assayed for the biological attribute and one or more previously obtained spectral measurements from the specific subject, and the matched reference sample is taken from a tissue compartment that is kinetically matched to the tissue which is irradiated. 18. The method of claim 17, wherein the matched reference sample is interstitial fluid. 19. The method of claim 17, wherein the matched reference sample is bulk fluid in the tissue. 20. The method of claim 17, wherein the matched reference sample is fluid obtained from a limb. 21. The method of claim 17, wherein the matched reference sample is lancet blood obtained from a forearm. 22. The method of claim 17, wherein the matched reference sample is a fluid from a tissue compartment tat is spatially matched to the tissue which is irradiated. 23. The method of claim 17, wherein the area irradiated and the area used for procurement of the matched reference sample are nominally similar. 24. A method for validating noninvasive measurement performance in the non-invasive spectroscopic measurement of an analyte or attribute of tissue, the method comprising the steps of: providing a means for irradiating tissue with infrared energy; providing an output element, the output element operatively connected to a means for measuring optical information; irradiating tissue with the infrared energy so that there is absorption of at least a portion of the infrared energy in the tissue; collecting at least a portion of the infrared energy exiting the tissue through the output element and measuring a resulting spectrum; collecting at least one matched reference sample and assaying the sample for the analyte or attribute of tissue; and using the matched reference sample measurement, the spectral measurements and a pre-existing multivariate calibration model to evaluate the non-invasive measurement performance; wherein the matched reference sample is a fluid taken from a tissue compartment that is kinetically matched to the tissue which is irradiated. 25. The method of claim 24, wherein the pie-existing model contains data from multiple subjects. 26. The method of claim 24, wherein the pre-existing model contains data from a single subject. 27. The method of claim 24, wherein the matched reference sample is interstitial fluid. 28. The method of claim 24, wherein the matched reference sample is bulk fluid in the tissue. 29. The method of claim 24, wherein the matched reference sample is fluid obtained from a limb. 30. The method of claim 24, wherein the matched reference sample is lancet blood obtained from a forearm. 31. The method of claim 24, wherein the matched reference sample is a fluid from a tissue compartment that is spatially matched to the tissue which is irradiated. 32. A method for correcting predictions in the non-invasive spectroscopic measurement of an analyte or attribute of tissue, the method comprising the steps of: providing a means for irradiating tissue with infrared energy; providing an output element, the output element operatively connected to a means for measuring a spectrum; irradiating tissue with the infrared energy so that there is absorption of at least a portion of the infrared energy in the tissue; collecting at least a portion of the infrared energy exiting the tissue through the output element and measuring a resulting spectrum; collecting at least one matched reference sample and assaying the sample for the analyte or attribute of tissue; and using the at least one matched reference sample measurement with the spectral measurements to correct future non-invasive analyte predictions; wherein the matched reference sample is a fluid taken from a tissue compartment that is kinetically matched to the tissue which is irradiated.