Full-field tracking and measuring of particle motion in capillary vessels by using time-varying laser speckle

2016 ◽  
Author(s):  
Luying Zhang ◽  
Bo Wang ◽  
Yi Wang
Keyword(s):  
Particle Motion ◽  
Laser Speckle ◽  
Time Varying ◽  
Full Field

scholarly journals Separation of cortical arteries and veins in optical neurovascular imaging

2014 ◽  
Vol 07 (03) ◽  
pp. 1350069 ◽  
Author(s):  
Linna Zhao ◽  
Yao Li ◽  
Hongyang Lu ◽  
Lu Yuan ◽  
Shanbao Tong
Keyword(s):  
Cerebral Cortex ◽  
Optical Imaging ◽  
Signal To Noise Ratio ◽  
Vascular Diseases ◽  
Region Growing ◽  
Field Method ◽  
Laser Speckle ◽  
Cerebral Vessel ◽  
Full Field ◽  
Arteries And Veins

Separation of arteries and veins in the cerebral cortex is of significant importance in the studies of cortical hemodynamics, such as the changes of cerebral blood flow, perfusion or oxygen concentration in arteries and veins under different pathological and physiological conditions. Yet the cerebral vessel segmentation and vessel-type separation are challenging due to the complexity of cortical vessel characteristics and low spatial signal-to-noise ratio. In this work, we presented an effective full-field method to differentiate arteries and veins in cerebral cortex using dual-modal optical imaging technology including laser speckle imaging (LSI) and optical intrinsic signals (OIS) imaging. The raw contrast images were acquired by LSI and processed with enhanced laser speckle contrast analysis (eLASCA) algorithm. The vascular pattern was extracted and segmented using region growing algorithm from the eLASCA-based LSI. Meanwhile, OIS images were acquired alternatively with 630 and 870 nm to obtain an oxyhemoglobin concentration map over cerebral cortex. Then the separation of arteries and veins was accomplished by Otsu threshold segmentation algorithm based on the OIS information and segmentation of LSI. Finally, the segmentation and separation performances were assessed using area overlap measure (AOM). The segmentation and separation of cerebral vessels in cortical optical imaging have great potential applications in full-field cerebral hemodynamics monitoring and pathological study of cerebral vascular diseases, as well as in clinical intraoperative monitoring.

scholarly journals Electroretinography in dogs: a review 

2014 ◽  
Vol 59 (No. 11) ◽  
pp. 515-526 ◽  
Author(s):  
M. Drazek ◽  
M. Lew ◽  
S. Lew ◽  
A. Pomianowski
Keyword(s):  
Small Animal ◽  
Cell Types ◽  
Time Varying ◽  
Outer Retina ◽  
Light Stimulation ◽  
Full Field ◽  
Retinal Disorders ◽  
Spatially Distributed ◽  
Different Cell Types ◽  
Stimulation Of

Electroretinography (ERG) in the form of full-field, flash ERG is the most commonly used technique in veterinary ophthalmology for diagnosing the functioning of the outer retina. Under light stimulation spatially distributed different cell types within the retina produce time-varying electric responses. These are recorded in the form of ERG traces consisting of a series of positive and negative wavelets. The possibility of selective stimulation of individual types of retinal cells and the analysis of constituent components of ERGs are the basis for determining the source of abnormalities and diagnosis of various types of dysfunction. In many cases, the ERG allows diagnosis of hereditary retinal disorders in dogs before the appearance of behavioural and ophthalmoscopic symptoms. This review is an introduction to the electrophysiology of vision, intended for small animal practitioners, and aimed at presenting the benefits of ERG for early ophthalmic diagnostics in dogs.

scholarly journals A review of the clinical applications and performance of laser speckle contrast imaging

2020 ◽  
Vol 6 (2) ◽  
pp. 77
Author(s):  
Muhsin Billah Bin Khashru ◽  
Zeng Tao Wang ◽  
Bilkis Akthar ◽  
Md Faisal Talukder
Keyword(s):  
Blood Flow ◽  
Speckle Pattern ◽  
Clinical Applications ◽  
Laser Speckle ◽  
Coherent Light ◽  
Contrast Imaging ◽  
Laser Speckle Contrast Imaging ◽  
Full Field ◽  
Speckle Contrast ◽  
And Performance

<p class="abstract">Laser speckle contrast imaging (LSCI) is a useful tool for visualizing full-field blood flow images. Speckle pattern is formed when a coherent light illuminates a rough object, and the backscattered radiation is transformed into images and be shown on a screen. Movement within the object results in the fluctuation of patterns over time. The same data can be obtained by employing the Doppler effect, yet producing a two-dimensional Doppler map needs scanning; speckle imaging renders the same information without the requirement to scan. Nowadays, LSCI has gained expanded consideration, in part because of its accelerated adoption for blood flow studies in the different surgical departments. Here we represent and review the application of laser speckle contrast methods to the field of perfusion visualization as clinical studies from various medical fields and discuss the limitations hindering clinical acceptance.</p>

Blood flow observed by time-varying laser speckle

1985 ◽  
Vol 10 (3) ◽  
pp. 104 ◽  
Author(s):  
Hitoshi Fujii ◽  
Kunihiko Nohira ◽  
Yoshihisa Shintomi ◽  
Toshimitsu Asakura ◽  
Takehiko Ohura
Keyword(s):  
Blood Flow ◽  
Laser Speckle ◽  
Time Varying

scholarly journals Active dynamics of colloidal particles in time-varying laser speckle patterns

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Silvio Bianchi ◽  
Riccardo Pruner ◽  
Gaszton Vizsnyiczai ◽  
Claudio Maggi ◽  
Roberto Di Leonardo
Keyword(s):  
Colloidal Particles ◽  
Laser Speckle ◽  
Time Varying ◽  
Speckle Patterns
Sign in / Sign up

Export Citation Format

Share Document