Improved accuracy of brain oxygen metabolism measurements using multi-distance diffuse correlation spectroscopy and near infrared spectroscopy together with a Monte Carlo light transport model (Conference Presentation)

2017 ◽  
Author(s):  
Stefan A. Carp ◽  
David A. Boas ◽  
Juliette J. Selb
Keyword(s):  
Monte Carlo ◽  
Near Infrared ◽  
Transport Model ◽  
Oxygen Metabolism ◽  
Correlation Spectroscopy ◽  
Light Transport ◽  
Diffuse Correlation Spectroscopy ◽  
Brain Oxygen ◽  
Improved Accuracy ◽  
Brain Oxygen Metabolism

scholarly journals Portable Near-Infrared Technologies and Devices for Noninvasive Assessment of Tissue Hemodynamics

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Lin Hou ◽  
Yinqiu Liu ◽  
Lixia Qian ◽  
Yucong Zheng ◽  
Jinnan Gao ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Measurement ◽  
Near Infrared ◽  
Tissue Oxygenation ◽  
Oxygen Metabolism ◽  
Correlation Spectroscopy ◽  
Tissue Blood Flow ◽  
Diffuse Optical Spectroscopy ◽  
Diffuse Correlation Spectroscopy ◽  
Custom Made

Tissue hemodynamics, including the blood flow, oxygenation, and oxygen metabolism, are closely associated with many diseases. As one of the portable optical technologies to explore human physiology and assist in healthcare, near-infrared diffuse optical spectroscopy (NIRS) for tissue oxygenation measurement has been developed for four decades. In recent years, a dynamic NIRS technology, namely, diffuse correlation spectroscopy (DCS), has been emerging as a portable tool for tissue blood flow measurement. In this article, we briefly describe the basic principle and algorithms for static NIRS and dynamic NIRS (i.e., DCS). Then, we elaborate on the NIRS instrumentation, either commercially available or custom-made, as well as their applications to physiological studies and clinic. The extension of NIRS/DCS from spectroscopy to imaging was depicted, followed by introductions of advanced algorithms that were recently proposed. The future prospective of the NIRS/DCS and their feasibilities for routine utilization in hospital is finally discussed.

scholarly journals Non-invasive optical neuromonitoring of the temperature-dependence of cerebral oxygen metabolism during deep hypothermic cardiopulmonary bypass in neonatal swine

2018 ◽  
Vol 40 (1) ◽  
pp. 187-203 ◽  
Author(s):  
Tiffany S Ko ◽  
Constantine D Mavroudis ◽  
Wesley B Baker ◽  
Vincent C Morano ◽  
Kobina Mensah-Brown ◽  
...  
Keyword(s):  
Cardiac Surgery ◽  
Cardiopulmonary Bypass ◽  
Temperature Response ◽  
Oxygen Metabolism ◽  
Correlation Spectroscopy ◽  
Neurological Injury ◽  
Diffuse Correlation Spectroscopy ◽  
Non Invasive ◽  
Neuroprotective Strategy ◽  
Subject Variability

Management of deep hypothermic (DH) cardiopulmonary bypass (CPB), a critical neuroprotective strategy, currently relies on non-invasive temperature to guide cerebral metabolic suppression during complex cardiac surgery in neonates. Considerable inter-subject variability in temperature response and residual metabolism may contribute to the persisting risk for postoperative neurological injury. To characterize and mitigate this variability, we assess the sufficiency of conventional nasopharyngeal temperature (NPT) guidance, and in the process, validate combined non-invasive frequency-domain diffuse optical spectroscopy (FD-DOS) and diffuse correlation spectroscopy (DCS) for direct measurement of cerebral metabolic rate of oxygen ( CMRO2). During CPB, n = 8 neonatal swine underwent cooling from normothermia to 18℃, sustained DH perfusion for 40 min, and then rewarming to simulate cardiac surgery. Continuous non-invasive and invasive measurements of intracranial temperature (ICT) and CMRO2 were acquired. Significant hysteresis ( p < 0.001) between cooling and rewarming periods in the NPT versus ICT and NPT versus CMRO2 relationships were found. Resolution of this hysteresis in the ICT versus CMRO2 relationship identified a crucial insufficiency of conventional NPT guidance. Non-invasive CMRO2 temperature coefficients with respect to NPT ( Q10 = 2.0) and ICT ( Q10 = 2.5) are consistent with previous reports and provide further validation of FD-DOS/DCS CMRO2 monitoring during DH CPB to optimize management.

Relation between brain oxygen metabolism and temperature gradient between brain and bladder

2003 ◽  
pp. 251-253 ◽  
Author(s):  
Atsushi Sakurai ◽  
K. Kinoshita ◽  
T. Atsumi ◽  
T. Moriya ◽  
A. Utagawa ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Oxygen Metabolism ◽  
Brain Oxygen ◽  
Brain Oxygen Metabolism

Impact of Changes in Tissue Optical Properties on Near-Infrared Diffuse Correlation Spectroscopy Measures of Skeletal Muscle Blood Flow

2021 ◽  
Author(s):  
Miles F. Bartlett ◽  
Scott M. Jordan ◽  
Dennis M. Hueber ◽  
Michael D. Nelson
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Optical Properties ◽  
Near Infrared ◽  
Muscle Blood Flow ◽  
Reactive Hyperemia ◽  
Correlation Spectroscopy ◽  
Skeletal Muscle Blood Flow ◽  
Diffuse Correlation Spectroscopy ◽  
Tissue Optical Properties

Near-infrared diffuse correlation spectroscopy (DCS) is increasingly utilized to study relative changes in skeletal muscle blood flow. However, most diffuse correlation spectrometers assume that tissue optical properties- such as absorption (μa) and reduced scattering (μ's) coefficients- remain constant during physiological provocations, which is untrue for skeletal muscle. Here, we interrogate how changes in tissue μa and μ's affect DCS calculations of blood flow index (BFI). We recalculated BFI using raw autocorrelation curves and μa/μ's values recorded during a reactive hyperemia protocol in 16 healthy young individuals. First, we show that incorrectly assuming baseline μa and μ's substantially affects peak BFI and BFI slope when expressed in absolute terms (cm2/s, p<0.01) but these differences are abolished when expressed in relative terms (% baseline). Next, to evaluate the impact of physiologic changes in μa and μ's, we compared peak BFI and BFI slope when μa and μ's were held constant throughout the reactive hyperemia protocol versus integrated from a 3s-rolling average. Regardless of approach, group means for peak BFI and BFI slope did not differ. Group means for peak BFI and BFI slope were also similar following ad absurdum analyses, where we simulated supraphysiologic changes in μa/μ's. In both cases, however, we identified individual cases where peak BFI and BFI slope were indeed affected, with this result being driven by relative changes in μa over μ's. Overall, these results provide support for past reports in which μa/μ's were held constant but also advocate for real-time incorporation of μa and μ's moving forward.

Cerebral Blood Flow of the Neonatal Brain after Hypoxic-Ischemic Injury

2021 ◽  
Author(s):  
Luis Octavio Tierradentro-García ◽  
Sandra Saade-Lemus ◽  
Colbey Freeman ◽  
Matthew Kirschen ◽  
Hao Huang ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Near Infrared ◽  
Imaging Modality ◽  
Brain Perfusion ◽  
Correlation Spectroscopy ◽  
Therapeutic Interventions ◽  
Routine Practice ◽  
Diffuse Correlation Spectroscopy ◽  
Positron Emission

Objective Hypoxic-ischemic encephalopathy (HIE) in infants can have long-term adverse neurodevelopmental effects and markedly reduce quality of life. Both the initial hypoperfusion and the subsequent rapid reperfusion can cause deleterious effects in brain tissue. Cerebral blood flow (CBF) assessment in newborns with HIE can help detect abnormalities in brain perfusion to guide therapy and prognosticate patient outcomes. Study Design The review will provide an overview of the pathophysiological implications of CBF derangements in neonatal HIE, current and emerging techniques for CBF quantification, and the potential to utilize CBF as a physiologic target in managing neonates with acute HIE. Conclusion The alterations of CBF in infants during hypoxia-ischemia have been studied by using different neuroimaging techniques, including nitrous oxide and xenon clearance, transcranial Doppler ultrasonography, contrast-enhanced ultrasound, arterial spin labeling MRI, 18F-FDG positron emission tomography, near-infrared spectroscopy (NIRS), functional NIRS, and diffuse correlation spectroscopy. Consensus is lacking regarding the clinical significance of CBF estimations detected by these different modalities. Heterogeneity in the imaging modality used, regional versus global estimations of CBF, time for the scan, and variables impacting brain perfusion and cohort clinical characteristics should be considered when translating the findings described in the literature to routine practice and implementation of therapeutic interventions. Key Points

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