Närvivalude

Närvivalude, also known as near-infrared spectroscopy (NIRS), is a non-invasive optical imaging technique used to measure changes in blood oxygenation levels in the brain. It operates on the principle that different wavelengths of light are absorbed by different substances, allowing for the determination of oxygenation levels. Near-infrared light, which has a wavelength between 700 and 1100 nanometers, is used because it can penetrate the skull and reach the brain tissue.

NIRS is commonly used in research and clinical settings to study brain function and monitor brain activity. It is particularly useful in situations where other imaging techniques, such as functional magnetic resonance imaging (fMRI), are not feasible or appropriate. For example, NIRS can be used to monitor brain activity in patients with metal implants or claustrophobia, as it does not require the use of a magnetic field or a confined space.

The technique involves placing optical probes on the scalp, which emit and detect near-infrared light. The changes in light absorption are then used to calculate the concentration of oxygenated and deoxygenated hemoglobin in the brain tissue. This information can be used to infer brain activity and function, as oxygenation levels are closely linked to neural activity.

NIRS has several advantages over other brain imaging techniques. It is relatively inexpensive, portable, and can be used in real-time. It also has a high temporal resolution, allowing for the detection of rapid changes in brain activity. However, it has a lower spatial resolution compared to other techniques, which can limit its ability to pinpoint the exact location of brain activity.

In summary, närvivalude, or NIRS, is a non-invasive optical imaging technique used to measure brain oxygenation levels. It has applications in research and clinical settings, offering advantages such as portability, real-time monitoring, and compatibility with patients who cannot undergo other imaging techniques. However, its lower spatial resolution is a limitation that researchers and clinicians must consider.