Wearable Functional Near-Infrared (FNIR) Technology and Its Applications in Naturalistic Conditions | Biomedgrid

Wearable functional near-infrared technology (fNIR) is a noninvasive neuroimaging technology that is affordable, low cost, and user-friendly, making it a promising technology to study how our brain works in naturalistic conditions. A practical user-friendly fNIR device that allows naturalistic use (e.g., home-use) can open unprecedented opportunities with health, psychologic, political/economic, and physiologic impacts. Wearable fNIR devices impose additional requirements compared to laboratory-based fNIR systems, including size, weight, and motion/ambient artifacts, without sacrificing key performance. Furthermore, to ensure user-friendliness, special attentions to cost, power, connectivity, flexibility to adapt to various applications, and comfort have to be properly considered. This manuscript reviews wearable fNIR in naturalistic conditions, covering reported applications and technologies developed to enable fNIR wearability. We also highlight some of the remaining challenges of current wearable fNIR devices including the limited number of optodes. uncorrected artifacts and noise, and the need for user alignment and manual event recording