scholarly journals Accessing to arteriovenous blood flow dynamics response using combined laser speckle contrast imaging and skin optical clearing

2015 ◽  
Vol 6 (6) ◽  
pp. 1977 ◽  
Author(s):  
Rui Shi ◽  
Min Chen ◽  
Valery V. Tuchin ◽  
Dan Zhu
Keyword(s):  
Blood Flow ◽  
Flow Dynamics ◽  
Laser Speckle ◽  
Contrast Imaging ◽  
Laser Speckle Contrast Imaging ◽  
Optical Clearing ◽  
Speckle Contrast ◽  
Blood Flow Dynamics ◽  
Dynamics Response

scholarly journals Nephron blood flow dynamics measured by laser speckle contrast imaging

2011 ◽  
Vol 300 (2) ◽  
pp. F319-F329 ◽  
Author(s):  
Niels-Henrik Holstein-Rathlou ◽  
Olga V. Sosnovtseva ◽  
Alexey N. Pavlov ◽  
William A. Cupples ◽  
Charlotte Mehlin Sorensen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Signal Transmission ◽  
Experimental Studies ◽  
Flow Dynamics ◽  
Laser Speckle ◽  
Tubuloglomerular Feedback ◽  
Contrast Imaging ◽  
Laser Speckle Contrast Imaging ◽  
Speckle Contrast ◽  
Blood Flow Dynamics

Tubuloglomerular feedback (TGF) has an important role in autoregulation of renal blood flow and glomerular filtration rate (GFR). Because of the characteristics of signal transmission in the feedback loop, the TGF undergoes self-sustained oscillations in single-nephron blood flow, GFR, and tubular pressure and flow. Nephrons interact by exchanging electrical signals conducted electrotonically through cells of the vascular wall, leading to synchronization of the TGF-mediated oscillations. Experimental studies of these interactions have been limited to observations on two or at most three nephrons simultaneously. The interacting nephron fields are likely to be more extensive. We have turned to laser speckle contrast imaging to measure the blood flow dynamics of 50–100 nephrons simultaneously on the renal surface of anesthetized rats. We report the application of this method and describe analytic techniques for extracting the desired data and for examining them for evidence of nephron synchronization. Synchronized TGF oscillations were detected in pairs or triplets of nephrons. The amplitude and the frequency of the oscillations changed with time, as did the patterns of synchronization. Synchronization may take place among nephrons not immediately adjacent on the surface of the kidney.

ASSESSMENT OF OPTICAL CLEARING INDUCED IMPROVEMENT OF LASER SPECKLE CONTRAST IMAGING

2010 ◽  
Vol 03 (03) ◽  
pp. 159-167 ◽  
Author(s):  
JING WANG ◽  
DAN ZHU ◽  
MIN CHEN ◽  
XIAOJING LIU
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Laser Speckle ◽  
Contrast Imaging ◽  
Laser Speckle Contrast Imaging ◽  
Optical Clearing ◽  
Speckle Contrast ◽  
Tissue Phantom ◽  
Contrast Analysis ◽  
Clearing Method

Laser Speckle Contrast Imaging (LSCI) plays an important role in studying blood flow, but suffers from limited penetration depth of light in turbid tissue. The strong scattering of tissue obviously reduces the image contrast which decreases the sensitivity to flow velocity. Some image processing or optical clearing methods have been proposed to lessen the deficiency, but quantitative assessment of improvement is seldom given. In this study, LSCI was applied to monitor the blood flow through a capillary embedded within various tissue phantoms at depths of 0.25, 0.45, 0.65, 0.85 and 1.05 mm, and the flow velocity in capillary was controllable from 0 to 4 mm/s. Here, glycerol, a common optical clearing agent, was mixed with Intralipid at different volume ratio to make the reduced scattering coefficient of tissue phantom decrease from 13.00 to 0.50 cm-1. The quantitative analysis demonstrates that the optical clearing method can obviously enhance the image contrast, imaging depth, and sensitivity to blood flow velocity. Comparing the Laser Speckle Contrast Analysis methods and the optical clearing method, we find that for typical turbid tissue, the sensitivity to velocity estimated by the Laser Speckle Temporal Contrast Analysis (LSTCA) is twice of that by the Laser Speckle Spatial Contrast Analysis (LSSCA); while the sensitivity to velocity estimated by using the two analysis methods has a 10-fold increase, respectively, if addition of glycerol makes the reduced scattering coefficient of tissue phantom decrease by 30%. Combining the LSTCA and the optical clearing method, the sensitivity to flow velocity will be further enhanced.

scholarly journals Characterization of cerebral blood flow dynamics with multiscale entropy

2017 ◽  
Vol 10 (05) ◽  
pp. 1743005 ◽  
Author(s):  
Alexey N. Pavlov ◽  
Arkady S. Abdurashitov ◽  
Olga N. Pavlova ◽  
Maria V. Ulanova ◽  
Anastasia A. Bodrova ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Dynamics ◽  
Laser Speckle ◽  
Multiscale Entropy ◽  
Cerebral Veins ◽  
Contrast Imaging ◽  
Speckle Contrast ◽  
Sound Exposure ◽  
Blood Flow Dynamics

Based on the laser speckle contrast imaging (LSCI) and the multiscale entropy (MSE), we study in this work the blood flow dynamics at the levels of cerebral veins and the surrounding network of microcerebral vessels. We discuss how the phenylephrine-related acute peripheral hypertension is reflected in the cerebral circulation and show that the observed changes are scale-dependent, and they are significantly more pronounced in microcerebral vessels, while the macrocerebral dynamics does not demonstrate authentic inter-group distinctions. We also consider the permeability of blood–brain barrier (BBB) and study its opening caused by sound exposure. We show that alterations associated with the BBB opening can be revealed by the analysis of blood flow at the level of macrocerebral vessels.

Laser speckle contrast imaging of cerebral blood flow of newborn mice at optical clearing

2017 ◽  
Author(s):  
Polina A. Timoshina ◽  
Ekaterina M. Zinchenko ◽  
Daria K. Tuchina ◽  
Madina M. Sagatova ◽  
Oxana V. Semyachkina-Glushkovskaya ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Laser Speckle ◽  
Contrast Imaging ◽  
Newborn Mice ◽  
Laser Speckle Contrast Imaging ◽  
Optical Clearing ◽  
Speckle Contrast

Enhancing vascular visualization in laser speckle contrast imaging of blood flow using multi-focus image fusion

2018 ◽  
Vol 12 (1) ◽  
pp. e201800100 ◽  
Author(s):  
Wenzhi Lv ◽  
Yang Wang ◽  
Xiao Chen ◽  
Xiaoxi Fu ◽  
Jinling Lu ◽  
...  
Keyword(s):  
Blood Flow ◽  
Image Fusion ◽  
Laser Speckle ◽  
Contrast Imaging ◽  
Laser Speckle Contrast Imaging ◽  
Speckle Contrast ◽  
Focus Image
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