ABSTRACT
The physics of near-infrared (NIR) spectroscopy is favorable for biological applications, especially for in situ measurements. The low absorptivities inherent in NIR allow the radiation to penetrate deeper, resulting in longer pathlengths. The sources are more intense, giving more radiation to work with; detectors are more sensitive and nearly noise-free, giving a more precise and accurate spectrum, This detector and lamp combination has the advantage of being sensitive to minute differences at very low light fluxes. The physical realities allow for measurements through tissue, muscle, fat, and body fluids with great precision. Fiber-optic probes complete the picture and make NIR spectroscopy a technique adaptable to any lab or clinic.
