This functional near-infrared spectroscopy sensor can be used to estimate the oxygen saturation level on the blood and extract heart rate.
The fNIRS (functional near-infrared spectroscopy) sensor is an easy-to-use sensor which uses two emitting LEDs, one in the red region and the other in the infrared region of the spectrum, to measure the red and infrared light reflectance in the cortical tissue. It provides a non-intrusive and non-invasive method to estimate the local oxygen saturation level in the blood to derive information about the activity of the perfused tissue, for example, to measure and track the activity of a specific brain region by measuring variations in oxygen saturation levels. The reflected light of each one of these LEDs is absorbed by a photodiode and then this current is converted into a digital value that is sent via SPI. Additionally, the acquired sensor data can be used to extract heart rate information. This sensor has been developed in cooperation with the R&D company Charles River Analytics to provide a new miniaturized fNIRS sensor allowing acquisitions of high-quality data in brain activity-tracking applications while keeping the costs at a fraction of current systems’ costs.