OPTICALLY SIMILAR REFERENCE SAMPLES AND RELATED METHODS FOR MULTIVARIATE CALIBRATION MODELS USED IN OPTICAL SPECTROSCOPY

摘要

Systems and methods for establishing and/or maintaining the prediction capability over time of a multivariate calibration model designed for quantitative optical spectroscopic measurement of attributes or analytes in bodily tissues, bodily fluids or other biological samples, which are particularly useful when the spectral absorbance of the attribute or analyte is small relative to the background. The present invention provides an optically similar reference sample to capture the characteristics of instrument and environmental variation and to reduce the effect of such variation of the measurement capability of the model. The optically similar reference is preferably stable over time and is designed such that its optic al properties are sufficiently matched to the sample of interest that instrumen t and environmental variations are captured in the same manner in both the tes t sample of interest and the optically similar reference sample. The optically similar reference sample max include one or more physical components which a re spectroscopically measured in a manner which closely mimics the spectroscopi c measurement of the test sample of interest. Spectral similarity may also be achieved by using alternative components with spectral characteristics simil ar to the components contained in thetest sample of interest.