New technique improves monitoring of cerebral blood flow

Jan. 11, 2023

Monitoring the proper blood supply to the brain is crucial, not only to prevent neurological diseases but also to treat them. The parallel near-infrared interferometric spectroscopy technique, or simply πNIRS, could make life easier for doctors and patients worldwide.

When there is a lack of oxygen and lack of proper blood supply, the death of nerve cells occurs, which can lead to a stroke. To help prevent strokes, a team of neuroscientists led by researchers from The International Centre for Translational Eye Research (ICTER) has developed a technique that can significantly improve the monitoring of cerebral blood flow in vivo. It is described in a paper titled, “Continuous-wave parallel interferometric near-infrared spectroscopy (CW πNIRS) with a fast two-dimensional camera,” which appeared in the journal Biomedical Optics Express.

The team of researchers at ICTER modified interferometric near-infrared spectroscopy (iNIRS), relying on parallel near-infrared interferometric spectroscopy (πNIRS) for multi-channel detection of cerebral blood flow. To achieve this, it was necessary to alter the iNIRS detection system. In πNIRS, the collected optical signals are recorded with a two-dimensional CMOS camera operating at an ultrafast frame rate (~1 MHz). Each pixel in the recorded image sequence effectively becomes an individual detection channel. With this approach, it is possible to obtain similar data as with iNIRS, but much faster.

This improvement translates into greater sensitivity of the system, and accuracy of detection itself. It is possible to detect rapid changes in blood flow related to the activation of neurons, for example, in response to an external stimulus or administered drug. The solution could be helpful for diagnosing CBF-related neuronal disorders, and evaluating the effectiveness of therapeutic approaches for neurodegenerative diseases.

This project will improve rapid, non-invasive systems for human cerebral blood monitoring in vivo. Continuous and non-invasive monitoring of blood flow could help treat significant brain diseases. In addition, quick detection of cerebral blood flow will advance the development of a non-invasive brain-computer interface (BCI) that could help people with disabilities.

Tests have confirmed that the technique used effectively monitors prefrontal cortex activity in vivo. Moreover, it can be further improved thanks to the development of LiDAR technology and ultrafast volumetric imaging of the eye, reducing the cost of CMOS cameras. The data obtained by the πNIRS technique can be applied to the diagnosis of cerebral circulatory disorders, which will facilitate the evaluation of the patient's condition, and allow the prediction of early and long-term treatment results.    

Institute of Physical Chemistry release

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