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Category Archives: sfNIRS2024-Session-3
Su-066-Comparison of clinical cerebral oximeter and time resolved near infrared spectroscopy during the onset of cardiopulmonary bypass in neonatal cardiac surgery
Widely utilized clinical cerebral oximeters are based on continuous wave near infrared spectroscopy (CW-NIRS) due to the simplicity of the optoelectronics despite of the well-known limitations imposed by the physics of photon propagation in tissues. Time-resolved spectroscopy (TRS) overcomes the shortcomings with added complexity and cost. We compared CW-NIRS and TRS during cardiopulmonary bypass initiation period of neonatal cardiac surgery (n=9). By analyzing late photons in TRS, we obtain a better estimation of the brain hemodynamics. CW-NIRS and TRS correlate well (R=0.94-0.99) but with a poor concordance and a prominent non-linear relationship. Continue reading
Su-071-AI-driven large-scale and automated neuroimaging and fNIRS data analysis pipeline using mega-datasets on NeuroJSON.io
We present a proof-of-concept that allows a user to use natural-language instructions to query, retrieve rich neuroimaging datasets hosted on NeuroJSON.io and build data analysis pipelines for large-scale fNIRS data processing. User prompts are converted to machine-actionable commands using a large language model (LLM). We show automated anatomical scan segmentation, 3-D mesh generation and mesh-based Monte Carlo simulations, but this framework can readily be expanded to other types of analyses. Continue reading
Su-072-Neural specificity for live dyadic face processing: Preliminary TMS and fNIRS findings
The goal of this investigation is to understand the integrated neurophysiological components associated with live and interactive social processes such as mutual face gaze. Functional near infrared spectroscopy, fNIRS, provides the imaging method of choice by enabling the acquisition of images during live and natural interactions. Transcranial magnetic stimulation, TMS, provides a method of choice for causal evidence of underlying neural correlates. We present preliminary data of TMS stimulation applied to fNIRS findings to test the hypothesis that right supramarginal gyrus, SMG, is specialized for live face gaze. Continue reading
Su-074-High-density speckle contrast optical tomography system for in vivo imaging of deep tissue blood flow
A high-density speckle contrast optical tomography system is introduced for in vivo cerebral blood tomography of the adult head. Continue reading
Su-077-Establishing a neural metabolism resource trade-off account of mental capacity limits: a BNIRS study
We used broadband-NIRS (BNIRS) to measure oxidation states of cytochrome-c-oxidase (oxCCO)- an intracellular marker of neural metabolism, during a visual perception task in which we also assessed task unrelated thoughts (TUTs). We hypothesized that increased demands on visual perception (high perceptual load) will reduce the level of metabolism in medial-prefrontal-cortex (mPFC) associated with TUTs, compared to low perceptual load due to shared capacity limits. Our findings indicated that increased perceptual load results in reduced TUTs-related oxCCO levels in mPFC. These results demonstrate how BNIRS can be used to test neurobiological accounts of attention and capacity limits in cognition. Continue reading
Su-081-Spatial global component filter vs short channel regression for removing non-cortical component of fNIRS
Non-cortical components can be prominent in fNIRS recordings. These components can be related to blood pressure or respiratory activity and should be removed to measure reliable neural activity or functional connectivity. Here we compare two methods for removing non-cortical components, spatial global component filtering (GCR) and short channel regression (SCR). SCR requires short channel signal acquisition with high signal-to-noise ratio (SNR) and only SNR/(1+SNR) of non-cortical component can be removed. GCR requires large channel coverage and will reduce activity that has large spatial extent. Both methods should be used in appropriate manner. Continue reading
Su-055-Experimental performance comparison of speckle contrast optical spectroscopy against diffuse correlation spectroscopy in the context of human cerebral blood flow monitoring
Speckle contrast optical spectroscopy (SCOS) is an emerging camera-based technique that can measure human cerebral blood flow (CBF) noninvasively, like the state-of-the-art technique of diffuse correlation spectroscopy (DCS). There is a lack of comparison studies between SCOS and DCS at longer (i.e. >20 mm) source-detector separations (SDS’s) that afford sufficient sensitivity to the adult human brain. We validated SCOS blood flow index (BFi) values against DCS at longer SDS’s and found SCOS contrast-to-noise ratio (CNR) to be >10x higher than DCS in phantoms. Results from concurrent SCOS and DCS human CBF measurements will also be presented. Continue reading
Su-058-Whole Head High Density fNIRS for Complex Scene Analysis
We propose using high-density (HD) functional Near-Infrared Spectroscopy (fNIRS) for whole-head brain imaging during complex scene analysis (CSA) in naturalistic settings. Our experiment involves ecologically valid "cocktail party" scenarios where participants focus on audiovisual stimuli in both overt and covert contexts. This approach allows analysis of cortical activity patterns and decoding of attended spatial locations, with potential applications in enhancing brain-computer interface technologies for hearing aids. This method addresses the limitations of fMRI and EEG by enabling more natural human subject behavior and improved spatial resolution. Continue reading
Su-063-Posture effects in monitoring fNIRS responses: a pilot study
This work is aimed to investigate the effect of posture changes on task-based estimation of cortical activity and propose a novel method to account them in fNIRS statistical analysis. Five healthy young adults performed a motor task in both sitting and standing conditions revealing: i) a common variation of physiological spectral components derived from fNIRS data; ii) an improvement in estimating non-significant cortical areas with respect to task conditions. Overall, these preliminary results suggest the importance of characterizing posture interference with fNIRS when considering the progress towards fNIRS monitoring in freely moving environment. Continue reading
Su-065-Comprehensive physiological, neuromonitoring and neuroimaging approach in an animal model of cardiopulmonary bypass and circulatory arrest
We introduce a comprehensive approach combining extensive physiological monitoring and biomarker collection, continuous neuromonitoring, advanced neuroimaging and a wide range of surgical conditions in a piglet model of cardiopulmonary bypass and circulatory arrest. Continue reading