Shedding light on the brain with near-infrared spectroscopy

Abstract

In 1977 it was first shown that light in the near-infrared region of the spectrum penetrates biological materials sufficiently to measure changes in cerebral oxygenation, a completely non-invasive technique.1 Since then, near-infrared spectroscopy (NIRS) has been used to monitor oxyhaemoglobin, deoxyhaemoglobin, blood volume and cytochrome oxidase for a variety of clinical and research applications.