Analytical models for time-domain diffuse correlation spectroscopy for multi-layer and heterogeneous turbid media

Li, Jun; Qiu, Lina; Poon, Chien-Sing; Sunar, Ulaş

doi:10.1364/boe.8.005518

Cited by 18 publications

(13 citation statements)

References 23 publications

(58 reference statements)

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“…Recently, an implementation and theory for time-domain DCS (TD-DCS), or pathlength-resolved DCS, has been developed, aiming at improving the depth sensitivity by discriminating short and long photon pathlengths. [10][11][12] By employing a pulsed laser with a certain coherence length, Sutin et al 10 simultaneously measured the time-of-flight of photons and DCS speckle fluctuations and demonstrated that TD-DCS was able to separate the contribution of photons from shallow and deep layers. Very recently this technique has also been successfully applied to in vivo measurements on human tissues including adult head.…”

Section: Introductionmentioning

confidence: 99%

“…11 At the same time, TD-DCS analytical theory for multilayer and heterogeneous turbid media was also presented. 12 The photon detection of TD-DCS is very similar to time-resolved spectroscopy (TRS) system, except for the detection fibers. TD-DCS uses single mode fiber to ensure detection of light from a single speckle (or a single coherence area).…”

Section: Introductionmentioning

confidence: 99%

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Using a simulation approach to optimize time-domain diffuse correlation spectroscopy measurement on human head

et al. 2018

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Time-domain diffuse correlation spectroscopy (TD-DCS) has been recently proposed to improve detection of deep blood flow dynamics in a biological tissue, such as human brain. To obtain a high sensitive measurement, several experimental parameters such as the source-detector (SD) distance, gate opening time, and width need to be considered and optimized. We use a simulation approach to optimize these parameters based on Monte Carlo computations using a realistic human head model. Two cortical regions are investigated including the frontal and temporal lobes. SD distance ranging from 0 to 45 mm, gate opening time from 400 to 1000 ps, and gate width from 50 to 3000 ps are considered. The goal is to find out the optimal combinations of these parameters by which the higher contrast measurement on the cortical dynamics can be achieved. The simulations show that with an acceptable input power of light, the combinations of SD distance ranging from 0 to 15 mm, gate opening time at 700 to 800 ps, and gate width of 800 ps are optimal for achieving higher contrast measurement on the cortical dynamics. The simulation approach and results are helpful for the optimization of TD-DCS experimental design focused on brain functional detection.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Using a simulation approach to optimize time-domain diffuse correlation spectroscopy measurement on human head

et al. 2018

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“…Our approach differs from previous theoretical works. Recently, Li et al introduced an analytical model for TD-DCS applied to multi-layer heterogeneous turbid samples 26 . In their approach is represented as a product of several negative exponential functions: …”

Section: Introductionmentioning

confidence: 99%

Time-domain diffuse correlation spectroscopy (TD-DCS) for noninvasive, depth-dependent blood flow quantification in human tissue in vivo

Samaei

Sawosz

Kacprzak

et al. 2021

Sci Rep

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Monitoring of human tissue hemodynamics is invaluable in clinics as the proper blood flow regulates cellular-level metabolism. Time-domain diffuse correlation spectroscopy (TD-DCS) enables noninvasive blood flow measurements by analyzing temporal intensity fluctuations of the scattered light. With time-of-flight (TOF) resolution, TD-DCS should decompose the blood flow at different sample depths. For example, in the human head, it allows us to distinguish blood flows in the scalp, skull, or cortex. However, the tissues are typically polydisperse. So photons with a similar TOF can be scattered from structures that move at different speeds. Here, we introduce a novel approach that takes this problem into account and allows us to quantify the TOF-resolved blood flow of human tissue accurately. We apply this approach to monitor the blood flow index in the human forearm in vivo during the cuff occlusion challenge. We detect depth-dependent reactive hyperemia. Finally, we applied a controllable pressure to the human forehead in vivo to demonstrate that our approach can separate superficial from the deep blood flow. Our results can be beneficial for neuroimaging sensing applications that require short interoptode separation.

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“…In other words, TD-DCS can provide higher sensitivity detection for deep dynamics. In recent years, TD-DCS technology has developed rapidly, including the proposal of various theoretical models, the verification of simulation and phantom experiments, as well as in vivo measurement of the human arm and head [11][12][13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Time Domain Diffuse Correlation Spectroscopy for Detecting Human Brain Function: Optimize System on Real Experimental Conditions by Simulation Method

et al. 2021

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In order to achieve high-sensitivity time-domain diffuse correlation spectroscopy (TD-DCS) measurement of functional changes in cerebral blood flow, this study applied simulation methods to optimize the TD-DCS system under real experimental conditions (including the consideration of the effects of finite coherence length and non-ideal instrument response function IRF). Under a real experimental condition where the incident power is 75 mW, the source-detector distance is 1.0 cm, and the full width at half maxima of the IRF is 160 ps, we used simulation experiments to investigate the relationship between the contrast of the intensity autocorrelation function ( 2 ) in two brain functional states (i.e., baseline and activation) and TD-DCS system parameters (including , IRF, source-detector distance, gate opening time and gate width).Our simulation results show that both longer and longer integration time are beneficial to a more sensitive detection. With a fixed and integration time, the optimal parameters of gate opening time is 800 ps (relative to the peak time of IRF), and gate width is equal to or larger than 800 ps. This study may be useful for guiding the sensitive measurement of human brain functions (e.g., changes in cerebral blood flow) using the TD-DCS technology.

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Analytical models for time-domain diffuse correlation spectroscopy for multi-layer and heterogeneous turbid media

Cited by 18 publications

References 23 publications

Using a simulation approach to optimize time-domain diffuse correlation spectroscopy measurement on human head

Using a simulation approach to optimize time-domain diffuse correlation spectroscopy measurement on human head

Time-domain diffuse correlation spectroscopy (TD-DCS) for noninvasive, depth-dependent blood flow quantification in human tissue in vivo

Time Domain Diffuse Correlation Spectroscopy for Detecting Human Brain Function: Optimize System on Real Experimental Conditions by Simulation Method

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