Muscle Oximetry in Sports Science: An Updated Systematic Review

Sports Medicine, Journal Year: 2024, Volume and Issue: 54(4), P. 975 - 996

Published: Feb. 12, 2024

Abstract Background In the last 5 years since our systematic review, a significant number of articles have been published on technical aspects muscle near-infrared spectroscopy (NIRS), interpretation signals and benefits using NIRS technique to measure physiological status muscles determine workload working muscles. Objectives Considering consistent studies application oximetry in sports science over years, objectives this updated review were highlight applications assessment skeletal oxidative performance activities emphasize how technology has applied exercise training years. addition, some recent instrumental developments will be briefly summarized. Methods Preferred Reporting Items for Systematic Reviews guidelines followed fashion search, appraise synthesize existing literature topic. Electronic databases such as Scopus, MEDLINE/PubMed SPORTDiscus searched from March 2017 up 2023. Potential inclusions screened against eligibility criteria relating recreationally trained elite athletes, with or without programmes, who must assessed variables monitored by commercial oximeters instrumentation. Results Of identified records, 191 regrouping 3435 participants, met criteria. This highlighted key findings 37 domains sport activities. Overall, information can used meaningful marker capacity become one primary monitoring tools practice conjunction with, comparison heart rate mechanical power indices diverse contexts across different types interventions. Conclusions Although feasibility success use is well documented, there still need further development overcome current limitations. Longitudinal are urgently needed strengthen science.

Language: Английский

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Advances in Dynamic Light Scattering Imaging of Blood Flow

Laser & Photonics Review, Journal Year: 2023, Volume and Issue: 18(2)

Published: Nov. 27, 2023

Abstract Dynamic light scattering (DLS) is a well known experimental approach uniquely suited for the characterization of small particles undergoing Brownian motion in randomly inhomogeneous turbid medium, including water suspension, polymers solutions, cells cultures, and so on. DLS based on illuminating medium with coherent laser further analyzes intensity fluctuations caused by particles. The DLS‐based spin‐off derivative techniques, such Doppler flowmetry (LDF), diffusing wave spectroscopy (DWS), speckle contrast imaging (LSCI), optical coherence tomography (DOCT), are exploited widely non‐invasive blood flow brain, skin, muscles, other biological tissues. recent advancements technologies frame their application brain monitoring, skin perfusion measurements, micro‐circulation overviewed. fundamentals, breakthrough potential, practical findings revealed studies, limitations challenges as movement artifacts, non‐ergodicity, overcoming high properties studied also discussed. It concluded that continued research technological will pave way new exciting developments insights into diagnostic imaging.

Language: Английский

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Validation of the Openwater wearable optical system: cerebral hemodynamic monitoring during a breath-hold maneuver

Neurophotonics, Journal Year: 2024, Volume and Issue: 11(01)

Published: March 8, 2024

SignificanceBedside cerebral blood flow (CBF) monitoring has the potential to inform and improve care for acute neurologic diseases, but technical challenges limit use of existing techniques in clinical practice.AimHere, we validate Openwater optical system, a novel wearable headset that uses laser speckle contrast monitor microvascular hemodynamics.ApproachWe monitored 25 healthy adults with system concurrent transcranial Doppler (TCD) while performing breath-hold maneuver increase CBF. Relative (rBF) was derived from changes contrast, relative volume (rBV) average intensity.ResultsA strong correlation observed between beat-to-beat rBF TCD-measured velocity (CBFv), R=0.79; slope linear fit indicates good agreement, 0.87 (95% CI: 0.83 −0.92). Beat-to-beat rBV CBFv were also strongly correlated, R=0.72, as expected two variables not proportional; smaller than changes, 0.18 0.17 0.19). Further, agreement found waveform morphology related metrics.ConclusionsThis first vivo validation highlights its hemodynamic monitor, additional is needed disease states.

Language: Английский

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Comparing the performance potential of speckle contrast optical spectroscopy and diffuse correlation spectroscopy for cerebral blood flow monitoring using Monte Carlo simulations in realistic head geometries

Neurophotonics, Journal Year: 2024, Volume and Issue: 11(01)

Published: Jan. 27, 2024

SignificanceThe non-invasive measurement of cerebral blood flow based on diffuse optical techniques has seen increased interest as a research tool for perfusion monitoring in critical care and functional brain imaging. Diffuse correlation spectroscopy (DCS) speckle contrast (SCOS) are two such that measure complementary aspects the fluctuating intensity signal, with DCS quantifying temporal fluctuations signal SCOS spatial blurring pattern. With increasing use these techniques, thorough comparison would inform new adopters benefits each technique.AimWe systematically evaluate performance flow.ApproachMonte Carlo simulations dynamic light scattering an MRI-derived head model were performed. For both SCOS, estimates sensitivity to changes, coefficient variation measured flow, contrast-to-noise ratio calculated. By varying data collection between methods, we investigated different strategies, including altering number modes per detector, integration time/fitting time measurement, laser source delivery strategy.ResultsThrough across metrics simulated detectors having realistic noise properties, determine several guiding principles optimization report over range properties tissue geometries. We find outperforms terms ideal case here but note requires careful experimental calibrations ensure accurate measurements flow.ConclusionWe provide design by which development systems their flow.

Language: Английский

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Dynamic Light Scattering in Biomedical Applications: feature issue introduction

Biomedical Optics Express, Journal Year: 2024, Volume and Issue: 15(5), P. 2890 - 2890

Published: April 3, 2024

The feature Issue on "Dynamic Light Scattering in Biomedical Applications" presents a compilation of research breakthroughs and technological advancements that have shaped the field biophotonics, particularly non-invasive exploration biological tissues. Highlighting significance dynamic light scattering (DLS) alongside techniques like laser Doppler flowmetry (LDF), diffusing wave spectroscopy (DWS), speckle contrast imaging (LSCI), this issue underscores versatile applications these methods capturing intricate dynamics microcirculatory blood flow across various Contributions explore developments fluorescence tomography, integration machine learning for data processing, enhancements microscopy cancer detection, novel approaches optical biophysics, among others. Innovations featured include high-resolution tomography system deep imaging, rapid estimation technique real-time tissue perfusion use convolutional neural networks efficient mapping. Additionally, studies delve into impact skin strain spectral reflectance, sensitivity cerebral measurement techniques, potential photobiomodulation enhancing brain function. This not only showcases latest theoretical experimental strides DLS-based but also anticipates continued evolution modalities groundbreaking disease diagnosis, monitoring, marking pivotal contribution to biomedical optics.

Language: Английский

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Correlating Stroke Risk with Non-Invasive Cerebrovascular Perfusion Dynamics using a Portable Speckle Contrast Optical Spectroscopy Laser Device

Biomedical Optics Express, Journal Year: 2024, Volume and Issue: 15(10), P. 6083 - 6083

Published: Sept. 11, 2024

Stroke poses a significant global health threat, with millions affected annually, leading to substantial morbidity and mortality. Current stroke risk assessment for the general population relies on markers such as demographics, blood tests, comorbidities. A minimally invasive, clinically scalable, cost-effective way directly measure cerebral flow presents an opportunity. This opportunity has potential positively impact effective prevention intervention. Physiological changes in cerebrovascular system, particularly response hypercapnia hypoxia during voluntary breath-holding can offer insights into assessment. However, existing methods measuring perfusion reserves, volume changes, are limited by either invasiveness or impracticality. Herein we propose non-invasive transcranial approach using speckle contrast optical spectroscopy (SCOS) non-invasively monitor regional brain breath-holding. Our study, conducted 50 individuals classified two groups (low-risk higher-risk stroke), shows differences dynamic between groups, providing physiological quantification paradigm. Given its cost-effectiveness, scalability, portability, simplicity, this laser-centric tool early diagnosis treatment of population.

Language: Английский

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Compact and cost-effective laser-powered speckle contrast optical spectroscopy fiber-free device for measuring cerebral blood flow

Journal of Biomedical Optics, Journal Year: 2024, Volume and Issue: 29(06)

Published: May 31, 2024

SignificanceIn the realm of cerebrovascular monitoring, primary metrics typically include blood pressure, which influences cerebral flow (CBF) and is contingent upon vessel radius. Measuring CBF noninvasively poses a persistent challenge, primarily attributed to difficulty accessing obtaining signal from brain.AimOur study aims introduce compact speckle contrast optical spectroscopy device for noninvasive measurements at long source-to-detector distances, offering cost-effectiveness, scalability while tracking (BF) with remarkable sensitivity temporal resolution.ApproachThe wearable sensor module consists solely laser diode board camera. It can be easily placed on subject's head measure BF sampling rate 80 Hz.ResultsCompared single-fiber-based version, proposed achieved gain about 70 times, showed superior stability, reproducibility, signal-to-noise ratio measuring distances. The distributed in multiple configurations around head.ConclusionsGiven its scalability, simplicity, this laser-centric tool offers significant potential advancing monitoring technologies.

Language: Английский

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Portable cerebral blood flow monitor to detect large vessel occlusion in patients with suspected stroke

Journal of NeuroInterventional Surgery, Journal Year: 2024, Volume and Issue: unknown, P. jnis - 021536

Published: March 21, 2024

Early detection of large vessel occlusion (LVO) facilitates triage to an appropriate stroke center reduce treatment times and improve outcomes. Prehospital scales are not sufficiently sensitive, so we investigated the ability portable Openwater optical blood flow monitor detect LVO. Patients were prospectively enrolled at two comprehensive centers during alert evaluation within 24 hours onset with National Institutes Health Stroke Scale (NIHSS) score ≥2. A 70 s bedside scan generated cerebral waveforms based on relative changes in speckle contrast. Anterior circulation LVO was determined by CT angiography. deep learning model trained all patient data using fivefold cross-validation learned discriminative representations from raw contrast waveform data. Receiver operating characteristic (ROC) analysis compared diagnostic performance (ie, detection) prehospital scales. Among 135 patients, 52 (39%) had anterior The median NIHSS 8 (IQR 4-14). instrument 79% sensitivity 84% specificity for rapid arterial (RACE) scale 60% 81% Los Angeles motor (LAMS) 50% specificity. binary classification (high-likelihood vs low-likelihood) area under ROC (AUROC) 0.82 (95% CI 0.75 0.88), which outperformed RACE (AUC 0.70; 95% 0.62 0.78; P=0.04) LAMS 0.65; 0.57 0.73; P=0.002). patients undergoing acute emergency department. These encouraging findings need be validated independent test set environment.

Language: Английский

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A comprehensive overview of diffuse correlation spectroscopy: theoretical framework, recent advances in hardware, analysis, and applications

NeuroImage, Journal Year: 2024, Volume and Issue: 298, P. 120793 - 120793

Published: Aug. 15, 2024

Diffuse correlation spectroscopy (DCS) is a powerful tool for assessing microvascular hemodynamic in deep tissues. Recent advances sensors, lasers, and learning have further boosted the development of new DCS methods. However, newcomers might feel overwhelmed, not only by already-complex theoretical framework but also broad range component options system architectures. To facilitate entry to this exciting field, we present comprehensive review hardware architectures (continuous-wave, frequency-domain, time-domain) summarize corresponding models. Further, discuss applications highly integrated silicon single-photon avalanche diode (SPAD) sensors DCS, compare SPADs with existing other components (lasers, correlators), as well data analysis tools, including learning. Potential medical diagnosis are discussed an outlook future directions provided, offer effective guidance embark on research.

Language: Английский

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Portable six-channel laser speckle system for simultaneous measurement of cerebral blood flow and volume with potential applications in characterization of brain injury

Neurophotonics, Journal Year: 2025, Volume and Issue: 12(01)

Published: Jan. 24, 2025

SignificanceCerebral blood flow (CBF) and cerebral volume (CBV) are key metrics for regional cerebrovascular monitoring. Simultaneous, non-invasive measurement of CBF CBV at different brain locations would advance monitoring pave the way injury detection as current diagnostic methods often constrained by high costs, limited sensitivity, reliance on subjective symptom reporting.AimWe aim to develop a multi-channel optical system measuring regions simultaneously with cost-effective, reliable, scalable capable detecting potential differences in across brain.ApproachThe is based speckle contrast spectroscopy consists laser diodes board cameras, which have been both tested investigated safe use human head. Apart from universal serial bus connection camera, entire system, including its battery power source, integrated into wearable headband powered 9-V batteries.ResultsThe temporal dynamics cohort five healthy subjects were synchronized exhibited similar cardiac period waveforms all six channels. The our six-channel physiological sequelae was explored two subjects, one moderate significant structural damage, where six-point measurements referenced magnetic resonance imaging (MRI) scans.ConclusionsWe viable multi-point instrument CBV. Its cost-effectiveness allows baseline be established prior populations risk injury.

Language: Английский

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