Near Infrared Spectroscopy
Near Infrared Spectroscopy (NIRS) is a well-established noninvasive optical technique that monitors changes in concentration of the tissue chromophores, such as oxyhemoglobin (O
2Hb), deoxyhemoglobin (HHb), total hemoglobin (THb), cytochrome c oxidase (CCO) and water (H
2O), in real time. In spatially resolved configuration, NIRS can measure the value of oxygenation in the tissue.
The feasibility of NIRS in monitoring the pattern of skeletal muscle chromophore changes during rest, exercise and ischemia is reported by different investigators. NIRS has contributed new knowledge related to muscle physiology at a basic science level, is widely used as a measure of performance in exercise science and also to monitor muscle hypoxia and ischemia in sports medicine. The non-invasive nature of the transcutaneous NIRS interface, and the ability to monitor continuously even during physical movement and active exercise provide an important means of measuring oxygenation and hemodynamics in muscle tissue in health and disease.