Near-infrared spectroscopy (NIRS)

Near-Infrared Spectroscopy (NIRS)

Near-infrared spectroscopy (NIRS) is a method that can be used to analyse the oxygen content of the blood and therefore also changes in blood flow.
The basis of near-infrared spectroscopes lies in the fact that biological tissue is only relatively permeable to light from the near-infrared range. Due to its longer wavelengths, this light can penetrate into the outer areas of the brain tissue. When the activity of the brain area changes, the oxygen content of the blood also changes. The red blood pigment haemoglobin is responsible for transporting oxygen in the human body and changes colour depending on whether it has bound oxygen or not. This possible change in colour, caused by the degree of absorption, can be detected by the near-infrared light and recorded as a change in activity in the area of the brain under the detector by means of further conversions.

Further Information:

Caspers, S. / Schnitzler, A. (2023): Medizinische Aspekte. In: Sturma, D. / Lanzerath, D. (Hg.): Bildgebung in den Neurowissenschaften. Medizinische, rechtliche und ethische Aspekte. Ethik in den Biowissenschaften – Sachstandsberichte des DRZE. Bd. 24. Baden-Baden: Verlag Karl Alber, 29–30. (German)

Villringer, A. / Chance, B. (1997): Non-invasive optical spectroscopy and imaging of human brain function. In: Trends Neurosci 20 (10), 435–442. Online Version

Steppan, J. / Hogue, C. W. Jr. (2014): Cerebral and tissue oximetry. In: Best Pract Res Clin Anaesthesiol. 28 (4), 429–39. Online Version

Physikalisch-Technische Bundesanstalt (PTB). Nationales Metrologieinstitut. Funktionelle Bildgebung am Kopf. Zeitaufgelöste Nahinfrarot-Spektroskopie und Bildgebung am Kopf des Erwachsenen. Online Version (German)

Harnisch, L.-O. (2023): Zerebrale Oxymetrie/ Nahinfrarotspektroskopie. In: Harnisch, L.-O. / Mörer, O. / Stephani, C. (Hg.): Nahinfrarotspektroskopie. Technik, Entwicklung, aktueller Einsatz und Ausblick. Berlin: Springer, 95–103. Online Version (German)

Bolkenius, D. / Dumps, C. / Rupprecht, B. (2021): Nahinfrarotspektroskopie. Technik, Entwicklung, aktueller Einsatz und Ausblick. In: Anaesthesist 70, 190–203. Online Version (German)