Wearable, Integrated EEG–fNIRS Technologies: A Review

• Published in: Sensors (Basel, Switzerland) Vol. 21; no. 18; p. 6106
• Main Authors: Uchitel, Julie, Vidal-Rosas, Ernesto E., Cooper, Robert J., Zhao, Hubin
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 12.09.2021; MDPI
• Subjects: diffuse optical tomography; EEG; Electrodes; Electroencephalography; fNIRS; integrated; Laboratories; Light emitting diodes; Medical imaging; multimodal; Review; Search strategies; Spectrum analysis; wearable
• ISSN: 1424-8220; 1424-8220
• 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.