Quantitative modeling of light propagation in optically turbid media, the design of optical instrumentation for medical imaging, the development of novel near-infrared spectroscopy and imaging techniques for medical diagnostics, and a number of applications on animal models and human subjects. Specific applications are aimed at functional imaging of the brain, optical characterization of peripheral nerve stimulation, diffuse optical mammography, hemodynamic monitoring of skeletal muscles, and quantitative tissue oximetry.