Optimizing spatial specificity and signal quality in fNIRS: an overview of potential challenges and possible options for improving the reliability of real-time applications

Frontiers in Neuroergonomics, Journal Year: 2024, Volume and Issue: 5

Published: June 5, 2024

The optical brain imaging method functional near-infrared spectroscopy (fNIRS) is a promising tool for real-time applications such as neurofeedback and brain-computer interfaces. Its combination of spatial specificity mobility makes it particularly attractive clinical use, both at the bedside in patients' homes. Despite these advantages, optimizing fNIRS use requires careful attention to two key aspects: ensuring good maintaining high signal quality. While detects superficial cortical regions, consistently reliably targeting specific regions interest can be challenging, studies that require repeated measurements. Variations cap placement coupled with limited anatomical information may further reduce this accuracy. Furthermore, important maintain quality contexts ensure they reflect true underlying activity. However, signals are susceptible contamination by cerebral extracerebral systemic noise well motion artifacts. Insufficient preprocessing therefore cause system run on instead aim review article help advance progress fNIRS-based applications. It highlights potential challenges improving quality, discusses possible options overcome challenges, addresses considerations relevant By addressing topics, aims improve planning execution future studies, thereby increasing their reliability repeatability.

Language: Английский

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Functional near-infrared spectroscopy for the assessment and treatment of patients with disorders of consciousness

Frontiers in Neurology, Journal Year: 2025, Volume and Issue: 16

Published: Feb. 3, 2025

Background Advances in neuroimaging have significantly enhanced our understanding of brain function, providing critical insights into the diagnosis and management disorders consciousness (DoC). Functional near-infrared spectroscopy (fNIRS), with its real-time, portable, noninvasive imaging capabilities, has emerged as a promising tool for evaluating functional activity nonrecovery potential DoC patients. This review explores current applications fNIRS research, identifies limitations, proposes future directions to optimize clinical utility. Aim examines application monitoring DoC. Specifically, it investigates value combining brain-computer interfaces (BCIs) closed-loop neuromodulation systems patients DoC, aiming elucidate mechanisms that promote neurological recovery. Methods A systematic analysis was conducted on 155 studies published between January 1993 October 2024, retrieved from Web Science Core Collection database. Results Analysis 21 eligible diseases involving 262 revealed significant findings. The prefrontal cortex most frequently targeted region. proven crucial assessing connectivity activation, facilitating Furthermore, plays pivotal role treatment through techniques such deep stimulation (DBS) spinal cord (SCS). Conclusion As noninvasive, real-time tool, holds promise advancing assessment Despite limitations low spatial resolution need standardized protocols, demonstrated utility residual activity, detecting covert consciousness, therapeutic interventions. In addition levels, offers unique advantages tracking hemodynamic changes associated neuroregulatory treatments, including DBS SCS. By feedback cortical facilitates optimizing strategies supports individualized planning. Continued research addressing technical methodological challenges will further establish an indispensable diagnosis, prognosis,

Language: Английский

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Using preregistration as a tool for transparent fNIRS study design

Neurophotonics, Journal Year: 2023, Volume and Issue: 10(02)

Published: March 8, 2023

The expansion of functional near-infrared spectroscopy (fNIRS) methodology and analysis tools gives rise to various design analytical decisions that researchers have make. Several recent efforts developed guidelines for preprocessing, analyzing, reporting practices. For the planning stage fNIRS studies, similar guidance is desirable. Study preregistration helps transparently document study protocols before conducting study, including materials, methods, analyses, thus, others verify, understand, reproduce a study. Preregistration can thus serve as useful tool transparent, careful, comprehensive design.We aim create guide on steps involved in studies provide template specified studies.The presented has strong focus specific requirements, associated provides examples based continuous-wave (CW) conducted humans. These can, however, be extended other types studies.On step-by-step basis, we walk user through key methodological analysis-related aspects central design. include items CW, task-based but also sections are general importance, an in-depth elaboration sample size planning.Our introduces these open science community, providing with overview specification recommendations planning. As such it used preregister or merely transparent

Language: Английский

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Mobile fNIRS for exploring inter-brain synchrony across generations and time

Frontiers in Neuroergonomics, Journal Year: 2024, Volume and Issue: 4

Published: Jan. 2, 2024

While still relatively rare, longitudinal hyperscanning studies are exceptionally valuable for documenting changes in inter-brain synchrony, which may turn underpin how behaviors develop and evolve social settings. The generalizability ecological validity of this experimental approach hinges on the selected imaging technique being mobile–a requirement met by functional near-infrared spectroscopy (fNIRS). fNIRS has most frequently been used to examine development synchrony behavior child-parent dyads. In position paper, we contend that dedicating attention intergenerational stands benefit fields cognitive neuroscience more broadly. We argue is particularly relevant understanding neural mechanisms underpinning dynamics, potentially benchmarking progress psychological interventions, many situated contexts. line with our position, highlight areas research stand be enhanced mobile devices, describe challenges arise from measuring across generations real world, offer potential solutions.

Language: Английский

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Decoding working-memory load during n-Back task performance from high channel fNIRS data

Journal of Neural Engineering, Journal Year: 2024, Volume and Issue: 21(5), P. 056005 - 056005

Published: Aug. 23, 2024

Abstract Objective. Functional near-infrared spectroscopy (fNIRS) can measure neural activity through blood oxygenation changes in the brain a wearable form factor, enabling unique applications for research and outside lab practical occupational settings. fNIRS has proven capable of measuring cognitive states such as mental workload, often using machine learning (ML) based brain–computer interfaces (BCIs). To date, this largely relied on probes with channel counts from under ten to several hundred, although recently new class NIRS devices featuring thousands channels emerged. This poses challenges ML classification, is typically limited by few training trials which results severely under-determined estimation problems. So far, it not well understood how high-resolution data best leveraged BCIs whether state-of-the-art or better performance be achieved. Approach. address these questions, we propose an strategy classify working-memory load that relies spatio-temporal regularization transfer other subjects combination that, our knowledge, been used previous BCIs. The approach interpreted end-to-end generalized linear model allows high degree interpretability channel-level cortical imaging approaches. Main results. We show proposed methodology, possible achieve decoding data. also replicated approaches dataset 43 participants wearing 3198 dual-channel device while performing n -Back task existing methodologies struggle high-channel regime are outperformed pipeline. Significance. Our helps establish viable platform BCI opens headset interpretation.

Language: Английский

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A Graduate Level Personalized Learning Environment in the Field of f-NIRS Signal Processing

Information, Journal Year: 2025, Volume and Issue: 16(3), P. 162 - 162

Published: Feb. 21, 2025

Active student involvement and instruction through experience in everyday contexts are pedagogical approaches suitable to promote inquiry-based learning improve learners’ cognitive skills. Nevertheless, many university postgraduate courses offer lecture-based instructions of theoretical concepts the students; little attention is still devoted design hands-on activities, practical/technical competencies enhance students’ effective understanding concepts. The development a personalized, student-centered environment that encourages teamwork aligns with contemporary push for interdisciplinary education bioengineering fields. This particularly relevant fostering expertise emerging technologies like functional Near-Infrared Spectroscopy (f-NIRS). In this framework, paper reports lab activity bioelectronic engineering and/or biomedical science students focused on analyzing prefrontal cortex activation during memory task, processing f-NIRS signals. pilot activity, conducted at University Palermo (Italy), involved Master’s Ph.D. working teams address challenges experimental design. study combines cutting-edge biosignal detection techniques innovative educational strategies, offering substantial contributions both research. outcomes suggest laboratory, experienced methodical sequence self-directed could considerably boost motivation learn level engagement biosciences.

Language: Английский

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Dynamic Measurement of Flowing Microparticles in Microfluidics Using Pulsed Modulated Digital Holographic Microscopy

Photonics, Journal Year: 2025, Volume and Issue: 12(5), P. 411 - 411

Published: April 24, 2025

We propose a pulsed modulated digital holographic microscopy (PM-DHM) technique for the dynamic measurement of flowing microparticles in microfluidic systems. By digitally tuning pulse width and repetition rate laser source within single-frame exposure, this method enables recording multiple images at different time points single hologram, allowing quantification velocity acceleration. demonstrate feasibility PM-DHM by measuring velocity, acceleration, forces exerted on PMMA microspheres red blood cells chips. Compared to traditional frame-sampling-based imaging methods, has much higher resolution (in range microseconds) that is limited only duration. This demonstrates significant potential high-throughput label-free flow cytometry detection offers promising applications drug development cell analysis.

Language: Английский

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From lab to life: challenges and perspectives of fNIRS for haemodynamic-based neurofeedback in real-world environments

Philosophical Transactions of the Royal Society B Biological Sciences, Journal Year: 2024, Volume and Issue: 379(1915)

Published: Oct. 21, 2024

Neurofeedback allows individuals to monitor and self-regulate their brain activity, potentially improving human function. Beyond the traditional electrophysiological approach using primarily electroencephalography, haemodynamics measured with functional magnetic resonance imaging (fMRI) more recently, near-infrared spectroscopy (fNIRS) have been used (haemodynamic-based neurofeedback), particularly improve spatial specificity of neurofeedback. Over recent years, especially fNIRS has attracted great attention because it offers several advantages over fMRI such as increased user accessibility, cost-effectiveness mobility—the latter being most distinct feature fNIRS. The next logical step would be transfer haemodynamic-based neurofeedback protocols that already proven validated by mobile However, this undertaking is not always easy, since novices may miss important fNIRS-specific methodological challenges. This review aimed at researchers from different fields who seek exploit unique capabilities for It carefully addresses challenges suggestions possible solutions. If raised are addressed further developed, could emerge a useful technique its own application potential—the targeted training activity in real-world environments, thereby significantly expanding scope scalability applications. article part theme issue ‘Neurofeedback: new territories neurocognitive mechanisms endogenous neuromodulation’.

Language: Английский

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The application of fNIRS in studies on occupational workload: a systematic review

Frontiers in Public Health, Journal Year: 2025, Volume and Issue: 13

Published: April 22, 2025

Occupational workload can contribute to significant health problems such as chronic stress, fatigue and burnout. To investigate the underlying mechanisms, it is necessary monitor brain activity in real work environments. Functional near-infrared spectroscopy (fNIRS) a portable, non-invasive neuroimaging method that captures neural correlates of occupational under natural conditions. However, despite its increasing application, comprehensive overview fNIRS-based research this field lacking. Therefore, systematic review examines how fNIRS be utilized workload. Following PRISMA 2020 guidelines, we conducted our by searching Web Science, PubMed, Scopus between November 15, 2023 March 20, 2025. We included all studies published English or German at any date, long they examined healthy adult professionals performing tasks with functional (fNIRS). Extracted data study characteristics, details, signal processing methods, main findings, quality, assessed using JBI Critical Appraisal Tool. 41 studies. Of these, 23 reported increase oxygenated hemoglobin (HbO) concentration connectivity prefrontal cortex (PFC) higher Only five typical office tasks. Nine analyzed differences cortical activation experts novices, showing increased HbO PFC than novices. Regarding methodology, 26 used standardized optode placements, while only 17 applied systemic extracerebral artifact correction. Small sample sizes absence randomized controlled trials limited reliability reproducibility findings. effectively detects provides objective insights into cognitive demands real-world settings. Standardizing placement, harmonizing signal-processing would enhance validity comparability future research. Expanding investigations environments also crucial for understanding daily developing interventions promote employee well-being productivity. Overall, represents promising tool establishing evidence-based workplace promotion strategies across diverse

Language: Английский

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Distinguishing motion artifacts during optical fiber-based in-vivo hemodynamics recordings from brain regions of freely moving rodents

Neurophotonics, Journal Year: 2024, Volume and Issue: 11(S1)

Published: May 24, 2024

SignificanceMotion artifacts in the signals recorded during optical fiber-based measurements can lead to misinterpretation of data. In this work, we address problem in-vivo rodent experiments and develop a motion correction (MAC) algorithm for single-fiber system (SFS) hemodynamics from brains rodents.Aim(i) To distinguish effect SFS signals. (ii) Develop MAC by combining information simulations validate it.ApproachMonte-Carlo (MC) were performed across 450 790 nm identify wavelengths where reflectance is least sensitive blood absorption-based changes. This wavelength region then used quantitative metric measure artifacts, termed dissimilarity (DM). We MC mimic seen experiments. Further, developed mathematical model describing light intensity at various interfaces. Finally, an was formulated validated using simulation experimental data.ResultsWe found that 670 680 relatively less absorption. The standard deviation DM (σDM) relative magnitude cause rapid shifts data be modeled as transmission changes lightpath. observed experiment agreement those obtained simulations. represent extended algorithm. data.ConclusionsWe distinguished vivo hemodynamic monitoring From data, showed shown minimize artifactual variations both

Language: Английский

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