Connecting theory to the signal dynamics of interferometric diffuse correlation spectroscopy (Conference Presentation)

2019 ◽  
Author(s):  
Mitchell B. Robinson ◽  
Stefan A. Carp ◽  
Davide Tamborini ◽  
David A. Boas ◽  
Maria A. Franceschini
Keyword(s):  
Correlation Spectroscopy ◽  
Diffuse Correlation Spectroscopy

Double layer estimation of flow changes using diffuse correlation spectroscopy

2009 ◽  
Author(s):  
Louis Gagnon ◽  
Michèle Desjardins ◽  
Louis Bherer ◽  
Frédéric Lesage
Keyword(s):  
Double Layer ◽  
Correlation Spectroscopy ◽  
Diffuse Correlation Spectroscopy ◽  
Flow Changes

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.

scholarly journals Investigation of diffuse correlation spectroscopy in multi-layered media including the human head

2008 ◽  
Vol 16 (20) ◽  
pp. 15514 ◽  
Author(s):  
Louis Gagnon ◽  
Michèle Desjardins ◽  
Julien Jehanne-Lacasse ◽  
Louis Bherer ◽  
Frédéric Lesage
Keyword(s):  
Layered Media ◽  
Human Head ◽  
Correlation Spectroscopy ◽  
Diffuse Correlation Spectroscopy

scholarly journals Evaluation of Local Skeletal Muscle Blood Flow in Manipulative Therapy by Diffuse Correlation Spectroscopy

2022 ◽  
Vol 9 ◽  
Author(s):  
Yasuhiro Matsuda ◽  
Mikie Nakabayashi ◽  
Tatsuya Suzuki ◽  
Sinan Zhang ◽  
Masashi Ichinose ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Skeletal Muscle ◽  
Blood Flow ◽  
Muscle Blood Flow ◽  
Nervous Activity ◽  
Correlation Spectroscopy ◽  
Autonomic Nervous Activity ◽  
Local Blood Flow ◽  
Diffuse Correlation Spectroscopy ◽  
Manipulative Therapy

Manipulative therapy (MT) is applied to motor organs through a therapist’s hands. Although MT has been utilized in various medical treatments based on its potential role for increasing the blood flow to the local muscle, a quantitative validation of local muscle blood flow in MT remains challenging due to the lack of appropriate bedside evaluation techniques. Therefore, we investigated changes in the local blood flow to the muscle undergoing MT by employing diffuse correlation spectroscopy, a portable and emerging optical measurement technology that non-invasively measures blood flow in deep tissues. This study investigated the changes in blood flow, heart rate, blood pressure, and autonomic nervous activity in the trapezius muscle through MT application in 30 volunteers without neck and shoulder injury. Five minutes of MT significantly increased the median local blood flow relative to that of the pre-MT period (p &lt; 0.05). The post-MT local blood flow increase was significantly higher in the MT condition than in the control condition, where participants remained still without receiving MT for the same time (p &lt; 0.05). However, MT did not affect the heart rate, blood pressure, or cardiac autonomic nervous activity. The post-MT increase in muscle blood flow was significantly higher in the participants with muscle stiffness in the neck and shoulder regions than in those without (p &lt; 0.05). These results suggest that MT could increase the local blood flow to the target skeletal muscle, with minimal effects on systemic circulatory function.

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.

Non-invasive estimation of intracranial pressure by fast diffuse correlation spectroscopy: a multi-center study

2021 ◽  
Author(s):  
Jonas B. Fischer ◽  
Susanna Tagliabue ◽  
Federica Maruccia ◽  
Amelia Jiménez-Sánchez ◽  
Eashani Sathialingam ◽  
...  
Keyword(s):  
Intracranial Pressure ◽  
Correlation Spectroscopy ◽  
Diffuse Correlation Spectroscopy ◽  
Non Invasive ◽  
Multi Center Study ◽  
Center Study
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