Photon flux gradients in layered turbid media: application to biological tissues

1986 ◽  
Vol 25 (5) ◽  
pp. 780 ◽  
Author(s):  
Nina Fukshansky-Kazarinova ◽  
Wolfram Lork ◽  
Eberhard Schafer ◽  
Leonid Fukshansky
Keyword(s):  
Biological Tissues ◽  
Turbid Media ◽  
Photon Flux

scholarly journals Fast 3D movement of a laser focusing spot behind scattering media by utilizing optical memory effect and optical conjugate planes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Vinh Tran ◽  
Sujit K. Sahoo ◽  
Cuong Dang
Keyword(s):  
Memory Effect ◽  
Light Propagation ◽  
Optical Memory ◽  
Biological Tissues ◽  
Frame Rate ◽  
Optimization Process ◽  
Turbid Media ◽  
Scattering Media ◽  
Focus Spot ◽  
Wavefront Shaping

AbstractControlling light propagation intentionally through turbid media such as ground glass or biological tissue has been demonstrated for many useful applications. Due to random scattering effect, one of the important goals is to draw a desired shape behind turbid media with a swift and precise method. Feedback wavefront shaping method which is known as a very effective approach to focus the light, is restricted by slow optimization process for obtaining multiple spots. Here we propose a technique to implement feedback wavefront shaping with optical memory effect and optical 4f system to speedy move focus spot and form shapes in 3D space behind scattering media. Starting with only one optimization process to achieve a focusing spot, the advantages of the optical configuration and full digital control allow us to move the focus spot with high quality at the speed of SLM frame rate. Multiple focusing spots can be achieved simultaneously by combining multiple phase patterns on a single SLM. By inheriting the phase patterns in the initial focusing process, we can enhance the intensity of the focusing spot at the edge of memory effect in with 50% reduction in optimization time. With a new focusing spot, we have two partially overlapped memory effect regions, expanding our 3D scanning range. With fast wavefront shaping devices, our proposed technique could potentially find appealing applications with biological tissues.

Rapid Diagnosis of Inhomogeneity in Turbid Media

2003 ◽  
Author(s):  
Siew Kan Wan ◽  
Zhixiong Guo ◽  
Sunil Kumar
Keyword(s):  
Biological Tissues ◽  
Turbid Media ◽  
Scattering Media ◽  
Time Resolved ◽  
Object A ◽  
Tissue Phantom ◽  
Novel Approach ◽  
Novel Method ◽  
High Absorption

In this work, a novel approach is proposed that would be able to rapidly diagnose the presence and location of inhomogeneity in turbid media. In this approach, ultrafast pulse laser is used as a detecting source and the time-resolved backscattered light signals are collected around the boundary of the target. The log slopes in the decaying log tail of the detected signals will be analyzed and used for the detection and image of embedded inhomogeneity. The relatively high absorption in the foreign object will result in a steeper log slope when the detector is located close to the object. A slim graphite of 1.6 mm in diameter embedded in a tissue phantom has been successfully detected in a preliminary experiment and the location of the graphite is determined from the v-groove profile of log slopes. A Monte Carlo program has been developed to further simulate and investigate the feasibility and quality of this method to diagnose the presence of a tumor-like material embedded inside a highly scattering media. A 2D reconstructed image confirms the potential of this novel method to detect and image accurately and rapidly the presence of tumors in biological tissues.

MODELING OF THE INTERACTION OF POLARIZED LIGHT WITH BIOLOGICAL TISSUES

2020 ◽  
Vol 2 ◽  
pp. 136-147
Author(s):  
V.V. DREMIN ◽  
E.V. ZHARKIKH
Keyword(s):  
Monte Carlo ◽  
Scattered Light ◽  
Polarization State ◽  
Polarized Light ◽  
Biological Tissues ◽  
Turbid Media ◽  
Advantages And Disadvantages

This paper provides a brief overview of approaches for modeling the interaction of polarized light with turbid media. This paper presents several implementations of Monte Carlo programs that track the polarization state of scattered light. Several classes of models based on the Stokes–Muller formalism and the Jones formalism are considered. Their advantages and disadvantages are analyzed.

scholarly journals Going beyond histology. Synchrotron micro-computed tomography as a methodology for biological tissue characterization: from tissue morphology to individual cells

2009 ◽  
Vol 7 (42) ◽  
pp. 49-59 ◽  
Author(s):  
Rolf Zehbe ◽  
Astrid Haibel ◽  
Heinrich Riesemeier ◽  
Ulrich Gross ◽  
C. James Kirkpatrick ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Single Cells ◽  
Three Dimensional ◽  
Biological Tissues ◽  
Optical Methods ◽  
Surrounding Tissue ◽  
Photon Flux ◽  
X Rays ◽  
Histological Techniques ◽  
X Ray

Current light microscopic methods such as serial sectioning, confocal microscopy or multiphoton microscopy are severely limited in their ability to analyse rather opaque biological structures in three dimensions, while electron optical methods offer either a good three-dimensional topographic visualization (scanning electron microscopy) or high-resolution imaging of very thin samples (transmission electron microscopy). However, sample preparation commonly results in a significant alteration and the destruction of the three-dimensional integrity of the specimen. Depending on the selected photon energy, the interaction between X-rays and biological matter provides semi-transparency of the specimen, allowing penetration of even large specimens. Based on the projection-slice theorem, angular projections can be used for tomographic imaging. This method is well developed in medical and materials science for structure sizes down to several micrometres and is considered as being non-destructive. Achieving a spatial and structural resolution that is sufficient for the imaging of cells inside biological tissues is difficult due to several experimental conditions. A major problem that cannot be resolved with conventional X-ray sources are the low differences in density and absorption contrast of cells and the surrounding tissue. Therefore, X-ray monochromatization coupled with a sufficiently high photon flux and coherent beam properties are key requirements and currently only possible with synchrotron-produced X-rays. In this study, we report on the three-dimensional morphological characterization of articular cartilage using synchrotron-generated X-rays demonstrating the spatial distribution of single cells inside the tissue and their quantification, while comparing our findings to conventional histological techniques.

Light transmittance in turbid media slabs used to model biological tissues; scaling laws

Optik ◽  
2010 ◽  
Vol 121 (5) ◽  
pp. 435-441 ◽  
Author(s):  
Héctor O. Di Rocco ◽  
Daniela I. Iriarte ◽  
Juan A. Pomarico ◽  
Héctor F. Ranea-Sandoval
Keyword(s):  
Scaling Laws ◽  
Biological Tissues ◽  
Turbid Media ◽  
Light Transmittance

Three-Dimensional Visualization of the T-System of Frog Muscle Using High Voltage Electron Microscopy and a Lanthanum Stain

1977 ◽  
Vol 35 ◽  
pp. 570-571 ◽  
Author(s):  
Lee D. Peachey ◽  
Clara Franzini-Armstrong
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Three Dimensional ◽  
Biological Tissues ◽  
High Voltage Electron Microscopy ◽  
Transverse Tubular System ◽  
Peroxidase Reaction ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
T System

The effective study of biological tissues in thick slices of embedded material by high voltage electron microscopy (HVEM) requires highly selective staining of those structures to be visualized so that they are not hidden or obscured by other structures in the image. A tilt pair of micrographs with subsequent stereoscopic viewing can be an important aid in three-dimensional visualization of these images, once an appropriate stain has been found. The peroxidase reaction has been used for this purpose in visualizing the T-system (transverse tubular system) of frog skeletal muscle by HVEM (1). We have found infiltration with lanthanum hydroxide to be particularly useful for three-dimensional visualization of certain aspects of the structure of the T- system in skeletal muscles of the frog. Specifically, lanthanum more completely fills the lumen of the tubules and is denser than the peroxidase reaction product.

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