Multicomponent blood analysis by near-infrared Raman spectroscopy

We demonstrate the use of Raman spectroscopy to measure the concentration o f many important constituents (analytes) in serum and whole blood samples a t physiological concentration in vitro across a multipatient data set. A ne ar-infrared (830-nm) diode laser generates Raman spectra that contain super positions of Raman signals from different analytes. Calibrations for glucos e, cholesterol, urea, and other analytes are developed by use of partial le ast-squares cross validation. We predict six analytes in serum with signifi cant accuracy in a 66-patient data set, using 60-s spectra. The calibration s are shown to be fairly robust against system drift over the span of seven weeks. In whole blood, a preliminary analysis yields accurate predictions of some of the same analytes and also hematocrit. The results hold promise for potential medical applications. (C) 1999 Optical Society of America OCI S codes: 170.1470, 170.5660.