A review on functional near-infrared spectroscopy and application in stroke rehabilitation

Functional near-infrared spectroscopy (fNIRS) has gained great interest as a noninvasive modality to study the changes in cerebral hemodynamics related to brain activity. The unique and beneficial characteristics of fNIRS allow ecologically effective investigations of all ages and conditions in more realistic and clinical environments. In this review, we provide a comprehensive description of fNIRS basics, analytical method developments and applications in stroke rehabilitation. We first review various new methods for the time-series processing and functional analysis of fNIRS data. Then, we review the fNIRS-based application in clinical research for stroke rehabilitation and highlight the exciting developments based on fNIRS. Finally, we discuss the possible technical limitations of the implementation of fNIRS and provide suggestions from different aspects for practical application.