Optical imaging and spectroscopy for the study of the human brain: status report

Neurophotonics, Год журнала: 2022, Номер 9(S2)

Опубликована: Авг. 30, 2022

This report is the second part of a comprehensive two-part series aimed at reviewing an extensive and diverse toolkit novel methods to explore brain health function. While first focused on neurophotonic tools mostly applicable animal studies, here, we highlight optical spectroscopy imaging relevant noninvasive human studies. We outline current state-of-the-art technologies software advances, most recent impact these neuroscience clinical applications, identify areas where innovation needed, provide outlook for future directions.

Язык: Английский

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Continuous non-invasive optical monitoring of cerebral blood flow and oxidative metabolism after acute brain injury

Journal of Cerebral Blood Flow & Metabolism, Год журнала: 2019, Номер 39(8), С. 1469 - 1485

Опубликована: Май 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.

Язык: Английский

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Functional interferometric diffusing wave spectroscopy of the human brain

Science Advances, Год журнала: 2021, Номер 7(20)

Опубликована: Май 12, 2021

Cerebral blood flow (CBF) is essential for brain function, and CBF-related signals can inform us about activity. Yet currently, high-end medical instrumentation needed to perform a CBF measurement in adult humans. Here, we describe functional interferometric diffusing wave spectroscopy (fiDWS), which introduces collects near-infrared light via the scalp, using inexpensive detector arrays rapidly monitor coherent fluctuations that encode index (BFI), surrogate CBF. Compared other optical approaches, fiDWS measures BFI faster deeper while also providing continuous absorption signals. Achieving clear pulsatile waveforms at source-collector separations of 3.5 cm, confirm BFI, not absorption, shows graded hypercapnic response consistent with human cerebrovascular physiology, has better contrast-to-noise ratio than during activation. By high-throughput measurements low cost, will expand access

Язык: Английский

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Complete head cerebral sensitivity mapping for diffuse correlation spectroscopy using subject-specific magnetic resonance imaging models

Biomedical Optics Express, Год журнала: 2022, Номер 13(3), С. 1131 - 1131

Опубликована: Янв. 21, 2022

We characterize cerebral sensitivity across the entire adult human head for diffuse correlation spectroscopy, an optical technique increasingly used bedside perfusion monitoring. Sixteen subject-specific magnetic resonance imaging-derived models were to identify high regions by running Monte Carlo light propagation simulations at over eight hundred uniformly distributed locations on head. Significant spatial variations in sensitivity, consistent subjects, found. also identified correlates of such differences suitable real-time assessment. These can be largely attributed changes extracerebral thickness and should taken into account optimize probe placement experimental settings.

Язык: Английский

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Aneurysmal Subarachnoid Hemorrhage

Neurologic Clinics, Год журнала: 2021, Номер 39(2), С. 419 - 442

Опубликована: Апрель 1, 2021

Язык: Английский

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First-in-clinical application of a time-gated diffuse correlation spectroscopy system at 1064 nm using superconducting nanowire single photon detectors in a neuro intensive care unit

Biomedical Optics Express, Год журнала: 2022, Номер 13(3), С. 1344 - 1344

Опубликована: Янв. 28, 2022

Recently proposed time-gated diffuse correlation spectroscopy (TG-DCS) has significant advantages compared to conventional continuous wave (CW)-DCS, but it is still in an early stage and clinical capability yet be established. The main challenge for TG-DCS the lower signal-to-noise ratio (SNR) when gating deeper traveling late photons. Longer wavelengths, such as 1064 nm have a smaller effective attenuation coefficient higher power threshold humans, which significantly increases SNR. Here, we demonstrate utility of at case study on patient with severe traumatic brain injury admitted neuro-intensive care unit (neuroICU). We showed between (ρ = 0.67) 0.76) gated against invasive thermal diffusion flowmetry. also analyzed high temporal resolution (50 Hz) elucidate pulsatile flow data. Overall, this demonstrates first translation system using superconducting nanowire single-photon detector.

Язык: Английский

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Portable, high speed blood flow measurements enabled by long wavelength, interferometric diffuse correlation spectroscopy (LW-iDCS)

Scientific Reports, Год журнала: 2023, Номер 13(1)

Опубликована: Май 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.

Язык: Английский

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Pilot Study on Dose-Dependent Effects of Transcranial Photobiomodulation on Brain Electrical Oscillations: A Potential Therapeutic Target in Alzheimer’s Disease

Journal of Alzheimer s Disease, Год журнала: 2021, Номер 83(4), С. 1481 - 1498

Опубликована: Июнь 4, 2021

Transcranial photobiomodulation (tPBM) has recently emerged as a potential cognitive enhancement technique and clinical treatment for various neuropsychiatric neurodegenerative disorders by delivering invisible near-infrared light to the scalp increasing energy metabolism in brain.We assessed whether transcranial with modulates cerebral electrical activity through electroencephalogram (EEG) blood flow (CBF).We conducted single-blind, sham-controlled pilot study test effect of continuous (c-tPBM), pulse (p-tPBM), sham (s-tPBM) on EEG oscillations CBF using diffuse correlation spectroscopy (DCS) sample ten healthy subjects [6F/4 M; mean age 28.6±12.9 years]. c-tPBM radiation (NIR) (830 nm; 54.8 mW/cm2; 65.8 J/cm2; 2.3 kJ) p-tPBM 10 Hz; 33%; 21.7 0.8 were delivered concurrently frontal areas four LED clusters. DCS recordings performed weekly before, during, after each tPBM session.c-tPBM significantly boosted gamma (t = 3.02, df 7, p < 0.02) beta 2.91, 0.03) spectral powers eyes-open power 3.61, 6, 0.015) eyes-closed recordings, widespread increase over frontal-central regions. There was no significant compared sham.Our data suggest dose-dependent NIR neuronal activity. Altogether, our findings support neuromodulatory NIR.

Язык: Английский

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Assessment of Cerebral Autoregulation Using Invasive and Noninvasive Methods of Intracranial Pressure Monitoring

Neurocritical Care, Год журнала: 2022, Номер 38(3), С. 591 - 599

Опубликована: Сен. 1, 2022

Язык: Английский

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Time-domain methods for quantifying dynamic cerebral blood flow autoregulation: Review and recommendations. A white paper from the Cerebrovascular Research Network (CARNet)

Journal of Cerebral Blood Flow & Metabolism, Год журнала: 2024, Номер 44(9), С. 1480 - 1514

Опубликована: Апрель 30, 2024

Cerebral Autoregulation (CA) is an important physiological mechanism stabilizing cerebral blood flow (CBF) in response to changes perfusion pressure (CPP). By maintaining adequate, relatively constant supply of flow, CA plays a critical role brain function. Quantifying under different and pathological states crucial for understanding its implications. This knowledge may serve as foundation informed clinical decision-making, particularly cases where become impaired. The quantification functionality typically involves constructing models that capture the relationship between CPP (or arterial pressure) experimental measures CBF. Besides describing normal function, these provide means detect possible deviations from latter. In this context, recent white paper Cerebrovascular Research Network focused on Transfer Function Analysis (TFA), which obtains frequency domain estimates dynamic CA. present paper, we consider use time-domain techniques alternative approach. Due their increased flexibility, methods enable mitigation measurement/physiological noise incorporation nonlinearities time variations dynamics. Here, practical recommendations guidelines support researchers clinicians effectively utilizing study

Язык: Английский

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