Functional Near-Infrared Spectroscopy

This functional near-infrared spectroscopy sensor can be placed on the forehead and 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 sensor is primarily designed for measurements on the forehead.

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.

  • Adjustable LED intensities
  • Accurate signal acquisition on the forehead
  • Pre-conditioned digital output
  • High signal-to-noise ratio
  • Versatile form-factor
  • Medical-grade raw data output
Dual LED Design 1 red & 1 infrared LED
Red LED wavelength 660nm
Infrared wavelength 950nm
Connector Type UC-E6 (Male)
Detector Sensitivity 400nm-1100nm (max@920nm)
Resolution 16-bit
Sampling Frequency 500Hz
Cable Length 100cm±0.5cm (customizable)

This sensor is not a standalone use sensor and requires the use of a biosignalsplux hub (4 or 8 channel). It can be used with the following biosignalsplux kits and systems for data acquisition:

The development of this sensor is based upon work supported by the United States Army Medical Research and Materiel Command under Contract No. W81XWH-14-C-0018 and United States Air Force under Contract No. FA8650-14-C-6579. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the United States Army Medical Research and Materiel.

J. Xu, J. Slagle, A. Banerjee, B. Bracken, M. Weinger, Use of a Portable Functional Near-Infrared Spectroscopy (fNIRS) System to Examine Team Experience During Crisis Event Managament in Clincial Simulations, in Frontiers in Human Neuroscience, vol. 13, no. 85, pp. 1-14, 2019

B. Bracken, S. Elkin-Frankston, N. Palmon, M. Farry, B. Frederick, A System to Monitor Cognitive workload in Naturalistic High-Motion Environments, in Proc. of the First Int. Symposium on Human Mental Workload, 2019

B. Bracken, P. Amazens, A. Likens, M. Demir, C. Gibbons, Comparison of a Custom Functional Near-Infrared Spectroscopy Sensor, a Peripheral SpO2 Sensor, and a Standard Laboratory Sensor (Biopac) for RR-Interval Assessment, in Proc. of the 11th Int. joint. Conf. on Biomedical Engineering Systems and Technologies, vol. 4: BIOSIGNALS, 2018

B. Bracken, N. Palmon, S. Elkin-Frankston, S. Irvin, M. Jenkins, M. Farry, An Unobtrusive System to Measure, Assess, and Predict Cognitive Workload in Real-World Environments, in Institute for Systems and Technologies of Information (INSTICC), 2017

B. Bracken, N. Palmon, L. Kellog, S. Elkin-Frankston, M. Ferry, A Cross-Domain Approach to Designing an Unobstrusive System to Assess Human State and Predict Upcoming Performance Deficits, in Proc. of the Human Factors and Ergonomics Society of Annual Meeting, vol. 60, no. 1, pp. 707-2016, 2016

Looking for more?

Visit the biosignalsplux publications page for a full list of available publications.

You might also like these