Optical Spectroscopy of Cerebral Blood Flow for Tissue Interrogation in Ischemic Stroke Diagnosis

ACS Chemical Neuroscience, Journal Year: 2025, Volume and Issue: 16(5), P. 895 - 907

Published: Feb. 20, 2025

Ischemic stroke remains a leading cause of morbidity and mortality worldwide, early diagnosis is critical for improving clinical outcomes. This paper presents an optical design framework combining speckle contrast spectroscopy (SCOS) with multiwavelength reflectance to monitor subtle changes in cerebral blood flow during ischemic events. The research aims enable precise tissue interrogation using high-resolution, low-scatter imaging. Key the system's accuracy 1.55 μm small beam waist, grating density 1300 grooves/mm, 15.53 depth focus. calculated effective focal length 8333.33 enhances resolution 4.07 μm, detection minor properties. We investigate sensitivity various near-infrared wavelengths (660, 785, 800, 976 nm) ischemic-induced changes, particular emphasis on nm wavelength, which demonstrates superior penetration increased variations perfusion ischemia. Optical markers such as spot-size widening, spatial intensity shifts, central decrease are identified reliable indicators Our findings suggest that analysis, particularly range, provides practical, noninvasive approach continuously monitoring strokes. technique indicates potential real-time perfusion, allows continuous, management strokes, patient outcomes decision-making.

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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The Concept of an Innovative System for Monitoring Physiological Parameters Under Extreme Conditions

Electronics, Journal Year: 2025, Volume and Issue: 14(5), P. 889 - 889

Published: Feb. 24, 2025

This study presents a novel, non-invasive system designed to assess the fitness of flight personnel in extreme environments. Existing methods for evaluating pilot readiness lack objectivity, precision, and adaptability dynamic conditions. Our addresses these shortcomings by integrating mobile physiological measurement modules with an aircraft simulator, Lower Body Negative Pressure (LBNP) system, advanced analytical software. It continuously monitors critical parameters, including heart rate, blood pressure, oxygen saturation, respiratory carotid flow, using innovative sensor placements that minimize motion artifacts. approach offers cost-effective efficient alternative traditional centrifuge-based assessments, which are costly physically demanding. Preliminary tests demonstrate system’s stability ability acquire consistent signals despite disturbances. Ongoing validation studies will compare data obtained LBNP simulator centrifuge data, ensuring effectiveness real-world aviation applications.

Language: Английский

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Tetherless miniaturized point detector device for monitoring cortical surface hemodynamics in mice

Journal of Biomedical Optics, Journal Year: 2025, Volume and Issue: 30(S2)

Published: March 19, 2025

SignificanceSeveral miniaturized optical neuroimaging devices for preclinical studies mimicking benchtop instrumentation have been proposed in the past. However, they are generally relatively large, complex, and power-hungry, limiting their usability long-term measurements freely moving animals. Further, there is limited research development of algorithms to analyze signals.AimWe aim develop a cost-effective, easy-to-use intrinsic monitoring system (TinyIOMS) that can be reliably used record spontaneous stimulus-evoked hemodynamic changes further cluster brain states based on features.ApproachWe present design fabrication TinyIOMS (8 mm×13 mm×9 mm3, 1.2 g with battery). A standard camera-based widefield (WFIOS) validate signals. Next, continuously activity 7 h chronically implanted mice. We show up 2 days intermittent recording from an animal. An unsupervised machine learning algorithm signals.ResultsWe observed data comparable WFIOS data. Stimulus-evoked recorded using was distinguishable stimulus magnitude. Using TinyIOMS, we successfully achieved continuous its home cage placed animal housing facility, i.e., outside controlled lab environment. (k-means clustering), grouping into two clusters representing asleep awake accuracy ∼91%. The same then applied 2-day-long dataset, where similar emerged.ConclusionsTinyIOMS applications Results indicate device suitable mice during behavioral synchronized video external stimuli.

Language: Английский

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Exploring non-invasive sexing of early chick embryos in intact eggs using Laser Speckle Contrast Imaging (LSCI) and Deep Neural Network (DNN)

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: April 23, 2025

Abstract The ability to image blood flow in early-stage avian embryos has significant applications developmental biology, drug and vaccine testing, as well determining sex differentiation. In this project, we used our recently developed laser speckle contrast imaging (LSCI) system non-invasively extraembryonic vessels these images attempt early identification of chick embryos. Specifically, captured from 1,251 living chicken between day three four incubation. We then applied deep neural network (DNN) models evaluate whether it is possible differentiate based on vascular patterns. Using ResNetBiT YOLOv5 models, results indicate that differentiation vessel was not achievable with sufficiently high accuracy or statistical significance for practical use. had a five-fold cross-validated average 59%±5% (fold-wise p-value, p ≤ 0.3) at 3 61%±3% (fold-wise, 0.04) 4. 55%±3% 53%±3% 0.5) Our findings suggest using pattern alone inconclusive reliable

Language: Английский

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Automated non-invasive laser speckle imaging of the chick heart rate and extraembryonic blood vessels and their response to nifedipine and amlodipine drugs

Developmental Biology, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 1, 2024

Language: Английский

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Automated non-invasive laser speckle imaging of the chick heart rate and extraembryonic blood vessels and their response to nifedipine and amlodipine drugs

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 27, 2024

Abstract Using our recently developed laser speckle contrast imaging (LSCI) to visualize blood vessels and monitor flow, here we test the utility of chick embryo for drug screening. To this end, examined effects antihypertensive agents Nifedipine Amlodipine, belonging L-type calcium channel antagonist family, on flow visualized noninvasively through intact shell. Guided by live view mode, drugs were injected shell ventral HH16-19 embryos. Our results show a significant reduction in heart rate, vascular size within 5-20 minutes after or Amlodipine injection. For moderate concentrations, these parameters returned initial values 2-3 hours. In contrast, showed rapid rate dynamics at more than ten times higher concentration Nifedipine. These findings that LSCI system can distinguish heart’s response from same family. This serves as proof-of-concept, paving way rapid, cost effective, quantitative screening affect cardiovascular Live noninvasive may also provide insights into development functioning vertebrate heart. Graphical Highlights Non-invasive Laser Speckle Contrast Imaging chorioallantoic membrane (CAM) whole incubated eggs Simultaneous recording images CAM, mode identify size, position, location egg Automated data acquisition analysis Longitudinal quantification impact antagonists, nifedipidine amlodipine embryonic CAM’s number

Language: Английский

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Portable Six-Channel Laser Speckle System for Simultaneous Cerebral Blood Flow and Volume Measurement with Potential Application for Characterization of Brain Injury

medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 1, 2024

Abstract In regional cerebrovascular monitoring, cerebral blood flow (CBF) and volume (CBV) are key metrics. Simultaneous, non-invasive measurement of CBF CBV at different brain locations would advance monitoring pave the way for injury detection, as current diagnostic methods often constrained by high costs, limited sensitivity, reliance on subjective symptom reporting. This study’s aim is to develop a multi-channel optical system measuring regions simultaneously with cost-effective, reliable, scalable capable detecting potential differences in across brain. The based speckle contrast spectroscopy (SCOS) consists laser diodes board cameras which have been both tested investigated safe use human head. Results cohort five healthy subjects indicated that dynamics were synchronized exhibited similar cardiac period waveforms all six channels. As preliminary investigation, we also explored our six-channel physiological sequela injury, involving subject significant structural damage compared another lesser damage. six-point measurements MRI scans, revealing altered closely correlated sites identified MRI.

Language: Английский

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