Medical Utility of NIR Monitoring

Clinical monitoring instruments that utilize near-infrared light are valuable tools for medical doctors allowing them to monitor oxygenation and hemodynamics including blood flow. The main principle of the techniques is the absorption of near-infrared light by hemoglobin. Measuring intensity changes of light traveling through biological tissue enables tracking tissue oxygenation due to the difference in the absorption spectra of oxygenated and deoxygenated hemoglobin. The two main techniques are pulse oximetry, which is standardly used in the clinic to measure oxygen saturation of the arterial compartment of the circulatory system, and near-infrared spectroscopy, which is mostly applied to monitor cerebral oxygenation. This real-time and noninvasive tracking of the oxygen supply to tissue has the potential to prevent poor outcome by detecting stroke, hemorrhage, and other pathological hemodynamic events and can be found both in adult and pediatric intensive care units. Near-infrared instruments can also be used to monitor blood flow and obtain 3-D images of brain or other tissues.