Development of a Wearable fNIRS System for Non-invasive Cerebral Oxygenation Monitoring

Abstract

Near-infrared spectroscopy (NIRS) is a non-invasive method extensively employed to observe real-time data regarding tissue oxygenation levels, hemodynamics, and metabolic activity. By utilizing infrared light to penetrate biological tissue and analyzing the absorption and scattering of light, NIRS offers critical insights into oxygen saturation and blood flow dynamics. This paper details the design and development of a cost-effective, wearable, multichannel functional NIRS (fNIRS) device for measuring regional cerebral oxygen saturation (∆rSO₂) across the prefrontal (fp1, fp2, f7, f8) and frontal (f3, f4) cortex regions. The device integrates optodes with four infrared wavelengths (660, 750, 850, and 880 nm) mounted on a flexible printed circuit board (PCB), ensuring optimal orthogonal contact with the skin and enhancing light penetration for improved signal strength. To validate the device’s performance, a forearm occlusion experiment was conducted, and the results were compared against a standard cerebral oximeter device. Results indicated a Mean Absolute Error of 0.83% in ∆rSO₂ and a Mean Percentage Error of 0.89%. The findings confirm the system’s capability for accurate, real-time cerebral oxygenation monitoring, highlighting its potential for clinical and research applications where affordability, portability, and reliability are essential. ## Citation

@inproceedings{soni_development_2025,
    address = {Warsaw University of Technology, Poland},
    title = {Development of a {Wearable} {fNIRS} {System} for {Non}-invasive {Cerebral} {Oxygenation} {Monitoring}},
    copyright = {All rights reserved},
    author = {Soni, Shreyash and Chand, Kulbhushan and Chowdhury, Shubhajit Roy},
    year = {2025},
    note = {In Press}}