Real-Time Non-invasive Assessment of Cerebral Hemodynamics With Diffuse Optical Spectroscopies in a Neuro Intensive Care Unit: An Observational Case Study DOI Creative Commons
Rodrigo M. Forti, Marilise Katsurayama,

Julien Menko

et al.

Frontiers in Medicine, Journal Year: 2020, Volume and Issue: 7

Published: April 28, 2020

Prevention of secondary damage is an important goal in the treatment severe neurological conditions, such as major head trauma or stroke. However, there currently a lack non-invasive methods for monitoring cerebral physiology. Diffuse optical have been proposed inexpensive, bedside monitor capable providing neurophysiology information neurocritical patients. reliability technique to provide accurate longitudinal measurement during clinical evolution patient remains largely unaddressed. Here, we report on translation hybrid diffuse system combining frequency domain spectroscopy (FD-DOS) and correlation (DCS) real-time physiology neuro intensive care unit (neuro-ICU). More specifically, present case study admitted with high-grade aneurysmal subarachnoid hemorrhage, who was monitored throughout hospitalization. We show that neurophysiological parameters measured by optics at are consistent all different stages following its brain lesion. These data support DOS/DCS useful biomarker neuro-ICU, particularly locations where other resources limited.

Language: Английский

Muscle Oximetry in Sports Science: A Systematic Review DOI
Stéphane Perrey, Marco Ferrari

Sports Medicine, Journal Year: 2017, Volume and Issue: 48(3), P. 597 - 616

Published: Nov. 25, 2017

Language: Английский

Citations

189
Reactive hyperemia: a review of methods, mechanisms, and considerations DOI Open Access
Ryan Rosenberry, Michael D. Nelson

AJP Regulatory Integrative and Comparative Physiology, Journal Year: 2020, Volume and Issue: 318(3), P. R605 - R618

Published: Feb. 5, 2020

Reactive hyperemia is a well-established technique for noninvasive assessment of peripheral microvascular function and predictor all-cause cardiovascular morbidity mortality. In its simplest form, reactive represents the magnitude limb reperfusion following brief period ischemia induced by arterial occlusion. Over past two decades, investigators have employed variety methods, including brachial artery velocity Doppler ultrasound, tissue near-infrared spectroscopy, distension venous occlusion plethysmography, tonometry, to measure hyperemia. Regardless used hyperemia, blunted believed reflect impaired function. With advent several technological advancements, together with an increased interest in microcirculation, becoming more common as research tool widely across multiple disciplines. this mind, we sought review various methodologies commonly assess current mechanistic pathways contribute on methodological considerations.

Language: Английский

Citations

158
Continuous non-invasive optical monitoring of cerebral blood flow and oxidative metabolism after acute brain injury DOI Open Access
Wesley B. Baker, Ramani Balu,

Lian He

et al.

Journal of Cerebral Blood Flow & Metabolism, Journal Year: 2019, Volume and Issue: 39(8), P. 1469 - 1485

Published: May 14, 2019

Rapid detection of ischemic conditions at the bedside can improve treatment acute brain injury. In this observational study 11 critically ill brain-injured adults, we employed a monitoring approach that interleaves time-resolved near-infrared spectroscopy (TR-NIRS) measurements cerebral oxygen saturation and extraction fraction (OEF) with diffuse correlation (DCS) measurement blood flow (CBF). Using approach, demonstrate clinical promise non-invasive, continuous optical changes in CBF metabolic rate (CMRO 2 ). addition, CMRO measures were compared to invasive tissue tension (PbtO ), thermal diffusion flowmetry CBF, microdialysis obtained concurrently. The information successfully distinguished between ischemic, hypermetabolic, hyperemic arose spontaneously during patient care. Moreover, pressor-induced mean arterial pressure enabled assessment autoregulation. total, findings suggest hybrid non-invasive neurometabolic monitor (NNOM) facilitate adverse physiological injured patients are otherwise difficult measure conventional techniques.

Language: Английский

Citations

79
Effects of exercise training on calf muscle oxygen extraction and blood flow in patients with peripheral artery disease DOI Open Access
Wesley B. Baker, Zhe Li,

Steven S. Schenkel

et al.

Journal of Applied Physiology, Journal Year: 2017, Volume and Issue: 123(6), P. 1599 - 1609

Published: Oct. 5, 2017

We employed near-infrared optical techniques, diffuse correlation spectroscopy (DCS), and frequency-domain (FD-NIRS) to test the hypothesis that supervised exercise training increases skeletal muscle microvascular blood flow oxygen extraction in patients with peripheral artery disease (PAD) who experience claudication. PAD ( n = 64) were randomly assigned control groups. Patients group received 3 mo of training. Calf optically monitored before, during, after performance a graded treadmill protocol at baseline both Additionally, measurements ankle-brachial index (ABI) peak walking time (PWT) maximal claudication made during each patient visit. Supervised was found increase calf levels by 29% (13%, 50%) 8% (1%, 12%), respectively [ P < 0.001; median (25th percentile, 75th percentile)]. These improvements across population significantly higher than corresponding changes 0.004). Exercise also increased PWT 49% (18%, 101%) 0.01). However, within statistical error, ABI, resting extraction, recovery half-time for hemoglobin\myoglobin desaturation following cessation not altered The concurrent monitoring hybrid DCS/FD-NIRS instrument revealed enhanced oxidative metabolism physical activity from training, which could be an underlying mechanism observed improvement PWT. NEW & NOTEWORTHY report on noninvasive dynamics before/during/after tracked effects 3-mo improved ability activity.

Language: Английский

Citations

61
Noninvasive continuous optical monitoring of absolute cerebral blood flow in critically ill adults DOI Creative Commons

Lian He,

Wesley B. Baker, Daniel Milej

et al.

Neurophotonics, Journal Year: 2018, Volume and Issue: 5(04), P. 1 - 1

Published: Nov. 23, 2018

We investigate a scheme for noninvasive continuous monitoring of absolute cerebral blood flow (CBF) in adult human patients based on combination time-resolved dynamic contrast-enhanced near-infrared spectroscopy (DCE-NIRS) and diffuse correlation (DCS) with semi-infinite head model photon propogation. Continuous CBF is obtained via calibration the DCS index (BFI) by intermittent intravenous injections optical contrast agent indocyanine green. A coefficient (γ) thus determined, permitting conversion BFI to units at all other times. study acute brain injury (N = 7) carried out ascertain stability γ. The patient-averaged across multiple days was good agreement between two coefficients measured different times during single found. 1.24 × 109 ( mL / 100 g min ) cm2 s applied previously from similar brain-injured patients; this case, underestimated compared XeCT, an effect we show primarily due use homogeneous models head.

Language: Английский

Citations

58
Improved accuracy of cerebral blood flow quantification in the presence of systemic physiology cross-talk using multi-layer Monte Carlo modeling DOI Creative Commons
Melissa M. Wu, Suk‐Tak Chan,

Dibbyan Mazumder

et al.

Neurophotonics, Journal Year: 2021, Volume and Issue: 8(01)

Published: Jan. 1, 2021

Significance: Contamination of diffuse correlation spectroscopy (DCS) measurements cerebral blood flow (CBF) due to systemic physiology remains a significant challenge in the clinical translation DCS for neuromonitoring. Tunable, multi-layer Monte Carlo-based (MC) light transport models have potential remove extracerebral cross-talk index ( CBFi ) estimates. Aim: We explore effectiveness MC recovering accurate changes presence strong variations during hypercapnia maneuver. Approach: Multi-layer slab and head-like realistic (curved) geometries were used run simulations photon propagation through head. The simulation data post-processed into with variable thicknesses fit multi-distance intensity autocorrelation estimate timecourses. results values from set human subject sessions compared estimated using semi-infinite analytical model, as commonly field. Results: Group averages indicate gradual increase following different temporal profile versus expected rapid CBF response. Optimized models, guided by several intrinsic criteria pressure modulation maneuver, able more effectively separate scalp influence than fitting, which assumed homogeneous medium. Three-layer performed better two-layer ones; curved achieved largely similar results, though closer physiological layer thicknesses. Conclusion: Three-layer, adjustable can be useful separating distinct brain flow. Pressure modulation, along reasonable estimates parameters, help direct choice appropriate models.

Language: Английский

Citations

39
Noninvasive hemoglobin sensing and imaging: optical tools for disease diagnosis DOI Creative Commons

Michaela Taylor-Williams,

Graham Spicer, Gemma Bale

et al.

Journal of Biomedical Optics, Journal Year: 2022, Volume and Issue: 27(08)

Published: Aug. 1, 2022

Significance: Measurement and imaging of hemoglobin oxygenation are used extensively in the detection diagnosis disease; however, applied instruments vary widely their depth imaging, spatiotemporal resolution, sensitivity, accuracy, complexity, physical size, cost. The wide variation available instrumentation can make it challenging for end users to select appropriate tools application understand relative limitations different methods.Aim: We aim provide a systematic overview field sensing.Approach: reviewed sensing methods analyze oxygenation, including pulse oximetry, spectral reflectance diffuse optical spectroscopic coherence tomography, photoacoustic correlation spectroscopy.Results: compared contrasted ability determine biomarkers such as while considering factors that influence practical application.Conclusions: highlight key current state-of-the-art suggestions routes advance clinical use interpretation information.

Language: Английский

Citations

28
Portable, high speed blood flow measurements enabled by long wavelength, interferometric diffuse correlation spectroscopy (LW-iDCS) DOI Creative Commons
Mitchell B. Robinson, Marco Renna, Nisan Ozana

et al.

Scientific Reports, Journal Year: 2023, Volume and Issue: 13(1)

Published: May 31, 2023

Diffuse correlation spectroscopy (DCS) is an optical technique that can be used to characterize blood flow in tissue. The measurement of cerebral hemodynamics has arisen as a promising use case for DCS, though traditional implementations DCS exhibit suboptimal signal-to-noise ratio (SNR) and sensitivity make robust measurements adults. In this work, we present long wavelength, interferometric (LW-iDCS), which combines the longer illumination wavelength (1064 nm), multi-speckle, detection, improve both SNR. Through direct comparison with based on superconducting nanowire single photon detectors, demonstrate approximate 5× improvement SNR over channel LW-DCS measured signals human subjects. We show equivalence extracted between LW-iDCS, feasibility LW-iDCS at 100 Hz source-detector separation 3.5 cm. This performance potential enable unlock novel cases diffuse spectroscopy.

Language: Английский

Citations

15
A comprehensive overview of diffuse correlation spectroscopy: theoretical framework, recent advances in hardware, analysis, and applications DOI Creative Commons
Quan Wang, Mingliang Pan, Lucas Kreiß

et al.

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

Citations

4
Interferometric diffuse correlation spectroscopy improves measurements at long source–detector separation and low photon count rate DOI Creative Commons
Mitchell B. Robinson, David A. Boas, Sava Sakadžić

et al.

Journal of Biomedical Optics, Journal Year: 2020, Volume and Issue: 25(09)

Published: Sept. 30, 2020

Significance: The use of diffuse correlation spectroscopy (DCS) has shown efficacy in research studies as a technique capable noninvasively monitoring blood flow tissue with applications neuromonitoring, exercise science, and breast cancer management. ability DCS to resolve these tissues is related the optical sensitivity signal-to-noise ratio (SNR) measurements, which some cases, particularly adult cerebral inadequate significant portion population. Improvements SNR could allow for greater clinical translation this technique. Aim: Interferometric (iDCS) was characterized compared traditional homodyne determine possible benefits utilizing heterodyne detection. Approach: An iDCS system constructed by modifying fused fiber couplers create Mach–Zehnder interferometer. Comparisons between detection were performed using an intralipid phantom at two extended source–detector separations (2.4, 3.6 cm), different photon count rates, range reference arm power levels. Characterization signal mixing theory. Precision estimation diffusion coefficient autocorrelation curve measurement conditions that mimicked what would be seen vivo. Results: mixture signals present function found agree derived theory resulted accurate phantom. Improvement up ∼2 × 80% reduction variability fit observed all cases increased power. Conclusions: potential improve characterization separations, enhancing depth SNR.

Language: Английский

Citations

28