Detecting relative speed changes of moving objects through scattering medium by using wavefront shaping and laser speckle contrast analysis

Li, Yangyang; Liu, Rui; Wang, Yang; Wen, Dong; Meng, Liangwei; Lu, Jinling; Li, Pengcheng

doi:10.1364/oe.24.008382

Cited by 13 publications

(3 citation statements)

References 28 publications

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“…[ 76 ] It was further accepted that

1/K^2

is an approximate estimation of

T/\tau

. [ 97–102 ] The hypothetical relation between the speckle correlation time and velocity of scattering particles is defined as [ 42,80,103 ]

\begin{equation} v\propto \frac{1}{\tau } \end{equation}

where v is the velocity of scattering particles. Respectively,

1/K^2

is showing quantitatively the velocity of flowing scattering particles.…”

Section: Basics Of the Dynamic Light Scatteringmentioning

confidence: 99%

Advances in Dynamic Light Scattering Imaging of Blood Flow

Sdobnov,

Piavchenko,

Bykov

et al. 2023

Laser & Photonics Reviews

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Dynamic light scattering (DLS) is a well known experimental approach uniquely suited for the characterization of small particles undergoing Brownian motion in randomly inhomogeneous turbid scattering medium, including water suspension, polymers in solutions, cells cultures, and so on. DLS is based on the illuminating of turbid medium with a coherent laser light and further analyzes the intensity fluctuations caused by the motion of the scattering particles. The DLS‐based spin‐off derivative techniques, such laser Doppler flowmetry (LDF), diffusing wave spectroscopy (DWS), laser speckle contrast imaging (LSCI), and Doppler optical coherence tomography (DOCT), are exploited widely for non‐invasive imaging of blood flow in brain, skin, muscles, and other biological tissues. The recent advancements in the DLS‐based imaging technologies in frame of their application for brain blood flow monitoring, skin perfusion measurements, and non‐invasive blood micro‐circulation characterization are overviewed. The fundamentals, breakthrough potential, and practical findings revealed by DLS‐based blood flow imaging studies, including the limitations and challenges of the approach such as movement artifacts, non‐ergodicity, and overcoming high scattering properties of studied medium, are also discussed. It is concluded that continued research and further technological advancements in DLS‐based imaging will pave the way for new exciting developments and insights into blood flow diagnostic imaging.

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“…[ 76 ] It was further accepted that

1/K^2

is an approximate estimation of

T/\tau

. [ 97–102 ] The hypothetical relation between the speckle correlation time and velocity of scattering particles is defined as [ 42,80,103 ]

\begin{equation} v\propto \frac{1}{\tau } \end{equation}

where v is the velocity of scattering particles. Respectively,

1/K^2

is showing quantitatively the velocity of flowing scattering particles.…”

Section: Basics Of the Dynamic Light Scatteringmentioning

confidence: 99%

Advances in Dynamic Light Scattering Imaging of Blood Flow

Sdobnov,

Piavchenko,

Bykov

et al. 2023

Laser & Photonics Reviews

View full text Add to dashboard Cite

show abstract

“…The relationship between the flow V and speckle contrast K s (V~(K s ) −2 ) is met when: (1) assuming Lorentzian velocity distribution, (2) camera exposure time /shutter speed (T) > > correlation time of the intensity fluctuations (τ c ), typically T > 100-400 × τ c , and (3) speckle size (which controlled by the camera lens) ≥ 2 × camera pixel size [18,22,23,27,45]. For the reader's information, V is often coined speckle flow index (SFI) and previous works show a linear response range between SFI and flow speed [28,[46][47][48].…”

Section: Lsi Image Analysismentioning

confidence: 99%

Multiparameter wide‐field integrated optical imaging system‐based spatially modulated illumination and laser speckles in model of tissue injuries

Bloygrund

Franjy-Tal

Rosenzweig

et al. 2019

Journal of Biophotonics

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In this report, an integrated optical platform based on spatial illumination together with laser speckle contrast technique was utilized to measure multiple parameters in live tissue including absorption, scattering, saturation, composition, metabolism, and blood flow. Measurements in three models of tissue injury including drug toxicity, artery occlusion, and acute hyperglycemia were used to test the efficacy of this system. With this hybrid apparatus, a series of structured light patterns at low and high spatial frequencies are projected onto the tissue surface and diffuse reflected light is captured by a CCD camera. A six position filter wheel, equipped with four bandpass filters centered at wavelengths of 650, 690, 800 and 880 nm is placed in front of the camera. Then, light patterns are blocked and a laser source at 650 nm illuminates the tissue while the diffusely reflected light is captured by the camera through the two remaining open holes in the wheel. In this manner, near‐infrared (NIR) and laser speckle images are captured and stored together in the computer for off‐line processing to reconstruct the tissue's properties. Spatial patterns are used to differentiate the effects of tissue scattering from those of absorption, allowing accurate quantification of tissue hemodynamics and morphology, while a coherent light source is used to study blood flow changes, a feature which cannot be measured with the NIR structured light. This combined configuration utilizes the strengths of each system in a complementary way, thus collecting a larger range of sample properties. In addition, once the flow and hemodynamics are measured, tissue oxygen metabolism can be calculated, a property which cannot be measured independently. Therefore, this merged platform can be considered a multiparameter wide‐field imaging and spectroscopy modality. Overall, experiments demonstrate the capability of this spatially coregistered imaging setup to provide complementary, useful information of various tissue metrics in a simple and noncontact manner, making it attractive for use in a variety of biomedical applications.

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“…Another common approach is based on contrast analysis of the speckle pattern images created by scattered light. These methods are known as Laser Speckle Contrast Analysis (LASCA), and Laser Speckle Contrast Imaging (LSCI) [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Analyzing the requirements of high-speed camera parameters for enhanced laser speckle sensing of flow dynamics

Golberg

Califa²,

Garcı́a³

et al. 2020

Eng. Res. Express

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A novel method for optimizing fast camera parameters to sense flow dynamics is presented. A wide-field statistic of the temporal auto-correlation intensity function from sample back-scattered laser light can be obtained from the high-end fast cameras that have come on to the market in recent years. Although these statistics can reveal flow dynamics within different sample regions, these cameras can be very costly. Here we investigated the impact of several key camera features such as camera frame rate, sensor exposure time, etc, on the output data (auto-correlation decay time and function fit models). The post-processing algorithm steps are described in detail, followed by the findings from in-vitro and in-vivo experiments investigating ways to re-leaf the camera parameters. The experimental results define fast-camera minimum specification requirements for the correct monitoring of normal blood flow conditions. These findings thus contribute to a better understanding of the impact of each parameter on speckle statistics and can contribute to customizing cheaper hardware to specific needs without compromising on accuracy.

show abstract

Detecting relative speed changes of moving objects through scattering medium by using wavefront shaping and laser speckle contrast analysis

Cited by 13 publications

References 28 publications

Advances in Dynamic Light Scattering Imaging of Blood Flow

Advances in Dynamic Light Scattering Imaging of Blood Flow

Multiparameter wide‐field integrated optical imaging system‐based spatially modulated illumination and laser speckles in model of tissue injuries

Analyzing the requirements of high-speed camera parameters for enhanced laser speckle sensing of flow dynamics

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