Wearable, Integrated EEG-fNIRS Technologies: A Review

Sensors (Basel). 2021 Sep 12;21(18):6106. doi: 10.3390/s21186106.


There has been considerable interest in applying electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) simultaneously for multimodal assessment of brain function. EEG-fNIRS can provide a comprehensive picture of brain electrical and hemodynamic function and has been applied across various fields of brain science. The development of wearable, mechanically and electrically integrated EEG-fNIRS technology is a critical next step in the evolution of this field. A suitable system design could significantly increase the data/image quality, the wearability, patient/subject comfort, and capability for long-term monitoring. Here, we present a concise, yet comprehensive, review of the progress that has been made toward achieving a wearable, integrated EEG-fNIRS system. Significant marks of progress include the development of both discrete component-based and microchip-based EEG-fNIRS technologies; modular systems; miniaturized, lightweight form factors; wireless capabilities; and shared analogue-to-digital converter (ADC) architecture between fNIRS and EEG data acquisitions. In describing the attributes, advantages, and disadvantages of current technologies, this review aims to provide a roadmap toward the next generation of wearable, integrated EEG-fNIRS systems.

Keywords: EEG; diffuse optical tomography; fNIRS; integrated; multimodal; wearable.

Publication types

  • Review

MeSH terms

  • Brain
  • Electroencephalography
  • Hemodynamics
  • Humans
  • Spectroscopy, Near-Infrared*
  • Wearable Electronic Devices*