Measuring Brain Signals in Real-Time: fNIRS in BCI

What is fNIRS-BCI?

Brain-Computer Interfaces (BCI) are systems that use brain activity measured by different neuroimaging techniques to control external devices, such as computers. Functional Near-Infrared Spectroscopy (fNIRS) is commonly applied in BCIs, as it is completely portable, relatively easy to use, robust to motion, and provides good spatial resolution. This makes fNIRS particularly suitable for BCI applications in both clinical and daily-life settings.

Neurorehabilitation

fNIRS-BCI is frequently used in clinical contexts, especially due to its portability, ease of use, and comfort. In neurorehabilitation, fNIRS-BCI can rebuild motor or cognitive functions and promote neuroplasticity in patients with neurological disorders such as stroke or Parkinson’s Disease.

Study examples: Kamavuako et al. used the OxyMon to measure prefrontal activity during overt and covert speech, achieving high classification accuracy — indicating fNIRS-BCI holds potential for speech detection in patients with neuromuscular disorders such as locked-in syndrome. Asadi et al. tested fNIRS-BCI in motor imagery tasks using the Brite, achieving classification accuracy of 89.12%.

Neurofeedback

By monitoring brain activity, fNIRS can be used in neurofeedback applications to train self-regulation of brain function in real-time, improving cognitive or motor functions and emotional regulation.

Study examples: Park assessed VR-based cognitive training combined with fNIRS neurofeedback (OctaMon) to enhance cognition in elderly patients with mild cognitive impairment, achieving significantly increased prefrontal activity. Zheng et al. proposed a randomized study protocol combining fNIRS neurofeedback with VR to improve executive function in children with ADHD.

fNIRS-BCI in Daily Life

fNIRS-BCI also holds potential outside clinical settings — for detecting mental workload, evaluating media content, and other daily-life applications. Liang et al. used the OctaMon to investigate neural responses to horror movies, while Dolmans et al. achieved 0.985 classification accuracy of mental workload using multimodal deep learning combining fNIRS measured with the Brite.

Artinis Solutions for fNIRS-BCI

Artinis offers a range of portable, wireless, lightweight fNIRS devices for fNIRS-BCI research:

• Brite: Most versatile device, measuring brain activity from any cortical region with 27 channels — ideal for fNIRS-BCI applications
• Brite Frontal: Dedicated headband for complete frontal cortex coverage, enabling quick setup within minutes
• MediBrite: Modified for safe clinical research use, the only European medical portable NIRS device per MDR (EU)
• Brite Lite: Compact 8-channel device in a completely wearable and wireless setup

Both OxySoft and Brite Connect support Lab Streaming Layer (LSL) for real-time data streaming and synchronization with other measurement streams — essential for BCI applications.