In vivo lactate measurement in human tissue by near-infrared diffuse reflectance spectroscopy

摘要

We have evaluated the potential of near-infrared spectroscopy(NIRS)as a technique for in vivo measurement of fatigue during exercise in humans.By using 2D correlation spectroscopy,lactate was identified as the primary specie that was monitored by the in vivo measurements.Estimates and calibration of the lactate concentration by NIRS was made using partial least squares(PLS)regression analysis and leave-N-out cross-validation on second derivative spectra.Regression analysis provided a correlation coefficient of 0.74 and a standard error of cross-validation(SECV)of 2.21 mmol/1.To study the parameters that impact the spectra baseline and the correlation between the calculated model and the data,lactate spectra were referenced against a baseline spectrum for each individual.For the referenced data,a correlation coefficient of 0.97 and a standard error of cross-validation of 0.76 mmol/1 between the enzymatic assay and the NIRS technique were found.The results suggest that NIRS may provide a valuable tool to assess in vivo physiological status for both research and clinical needs.