Clinical analyte determination by infrared spectroscopy

摘要

The present invention comprises methods for minimally invasive and noninvasive analyte determination using infrared spectroscopy. A minimally invasive in vitro method comprises obtaining a volume of a fluid sample. A minimally invasive manner of obtaining the sample includes using a laser to form a micropore on a user's skin. The sample is placed on a plane of an optically clear window, such as by pressing the window against the micropore. Infrared light is directed through the window and the sample at an angle such that the light path is approximately vertical. The resulting spectrum is measured and subjected to multivariate analysis to determine the presence of at least one analyte. A noninvasive in vivo method comprises obtaining a spectral measurement of a sample in conjunction with the arterial pulse measurement. A difference spectrum is determined by subtracting the arterial pulse trough measurement from the peak measurement. The difference spectrum is normalized by dividing by the area of the absolute value of the derivative spectrum. The presence of at least one analyte is determined by applying multivariate analysis to the normalized spectrum.