Quantification of tissue chromophore concentration via water-peak measurements in near-infrared spectroscopy

摘要

Abstract: We describe a simple method for measuring the differential pathlength of photons in a scattering medium utilizing the absorption features of water. The method allows quantification of chromophore concentration changes measured by near infrared spectroscopy without the need for time- or frequency-resolved measurements. We present the results of validation experiments performed on tissue phantoms and in-vivo comparisons between the differential path estimates yielded by water absorption and time- resolved measurements. We discus the accuracy of the differential path estimates provided by both the 975 nm and the 840 nm water features, finding that while the 840 nm feature is measured with lower accuracy for a given light flux, it is intrinsically a more accurate differential path estimator. !20