scholarly journals A New Method of Measuring Retinal Vessel Diameters from Fundus Photographs Based on Retinal Structure and Light Reflection

2021 ◽  
Author(s):  
Satoshi Wakebe ◽  
Kotaro Yamasue ◽  
Hidetoshi Itoh
Keyword(s):  
Blood Vessel ◽  
Diffuse Reflection ◽  
Repeated Measurement ◽  
New Method ◽  
Dimensional Structure ◽  
Cylindrical Shape ◽  
Reflection Model ◽  
Luminance Profile ◽  
Fundus Photographs ◽  
Minimum Points

<p>We propose a new method and software for measuring blood vessel diameters from fundus photographs. In this method the edge of the blood vessel is the two minimum points in the luminance profile and diameter is distance between minimum points. We noticed the relation between W-shape of luminance profile at blood vessel transversal line and cylindrical shape, and analyzed the validity of this method using the diffuse reflection model of a cylinder shape based on the optics. The simulation image by the diffuse reflection model of the cylinder was similar to that of the blood vessel images. A newly developed software using the minimum points can measure repeated measurement in a series of photographs at the same point of the same person. The data of the repeated measurement of each person showed stability, and the coefficient of variation showed no affection of different diameter and arteriovenous distinction. Hence, we believe that the minimum points are valid as blood vessel edges. The software that measures these blood vessel edges has an extremely simple measurement procedure, possesses few errors, and is easy to automate. This method is relevant because the central reflex, which has not been utilized previously, optically represents the cylindrical three-dimensional structure of blood vessels.</p><div><div> </div> </div>

scholarly journals A New Method of Measuring Retinal Vessel Diameters from Fundus Photographs Based on Retinal Structure and Light Reflection

2021 ◽  
Author(s):  
Satoshi Wakebe ◽  
Kotaro Yamasue ◽  
Hidetoshi Itoh
Keyword(s):  
Blood Vessel ◽  
Diffuse Reflection ◽  
Repeated Measurement ◽  
New Method ◽  
Dimensional Structure ◽  
Cylindrical Shape ◽  
Reflection Model ◽  
Luminance Profile ◽  
Fundus Photographs ◽  
Minimum Points

<p>We propose a new method and software for measuring blood vessel diameters from fundus photographs. In this method the edge of the blood vessel is the two minimum points in the luminance profile and diameter is distance between minimum points. We noticed the relation between W-shape of luminance profile at blood vessel transversal line and cylindrical shape, and analyzed the validity of this method using the diffuse reflection model of a cylinder shape based on the optics. The simulation image by the diffuse reflection model of the cylinder was similar to that of the blood vessel images. A newly developed software using the minimum points can measure repeated measurement in a series of photographs at the same point of the same person. The data of the repeated measurement of each person showed stability, and the coefficient of variation showed no affection of different diameter and arteriovenous distinction. Hence, we believe that the minimum points are valid as blood vessel edges. The software that measures these blood vessel edges has an extremely simple measurement procedure, possesses few errors, and is easy to automate. This method is relevant because the central reflex, which has not been utilized previously, optically represents the cylindrical three-dimensional structure of blood vessels.</p><div><div> </div> </div>

Improvement of Method and Mechanism for Conical and Paraboloid Springs Hardening

2021 ◽  
Vol 1037 ◽  
pp. 227-232
Author(s):  
Nikita A. Zemlyanushnov ◽  
Nadezhda Y. Zemlyanushnova
Keyword(s):  
New Method ◽  
Cylindrical Shape ◽  
Plastic Deformations ◽  
Conical Shape ◽  
Inner Surface ◽  
Hardening Mechanisms ◽  
The Difference ◽  
Compression Springs

The disadvantage of the known methods of hardening springs is the impossibility of their use when hardening springs of a conical shape or of a shape of a paraboloid of rotation, since they are intended only for cylindrical shape springs and are not suitable for conical shape springs or those of a shape of a paraboloid of rotation specifically because of the difference in the shape of the springs. One of the disadvantages of the known springs hardening mechanisms is the impossibility of hardening the inner surface of the conical compression springs. A new method of hardening springs is proposed, the unmatched advantage of which is the ability to create plastic deformations on the inner and outer surfaces of the spring coils compressed to contact and on the surfaces along the line of contact between the coils. A new advantageous mechanism for hardening springs is proposed, which makes it possible to harden the inner surface of compression springs having a conical shape or a paraboloid shape of rotation, in a compressed state.

Atomic scale saw by dislocation slipping: A new method to generate one‐dimensional structure

1992 ◽  
Vol 60 (20) ◽  
pp. 2481-2483 ◽  
Author(s):  
J. P. Peyrade ◽  
F. Voillot ◽  
M. Goiran ◽  
H. Atmani ◽  
A. Rocher ◽  
...  
Keyword(s):  
Atomic Scale ◽  
New Method ◽  
Dimensional Structure ◽  
One Dimensional

New method of echo detection for diffuse reflection laser ranging

2015 ◽  
Author(s):  
Kun-peng Wang ◽  
Yan Zhang ◽  
Xing-qi Wang ◽  
Lin Quan ◽  
Peng Zhao
Keyword(s):  
Diffuse Reflection ◽  
New Method ◽  
Laser Ranging ◽  
Echo Detection

scholarly journals Segmentation of Retinal Blood Vessels Based on Cake Filter

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Xi-Rong Bao ◽  
Xin Ge ◽  
Li-Huang She ◽  
Shi Zhang
Keyword(s):  
Blood Vessel ◽  
Blood Vessels ◽  
False Positive Rate ◽  
New Method ◽  
Real Component ◽  
Low Contrast ◽  
Small Vessels ◽  
Retinal Blood Vessels ◽  
Average Accuracy ◽  
Positive Rate

Segmentation of retinal blood vessels is significant to diagnosis and evaluation of ocular diseases like glaucoma and systemic diseases such as diabetes and hypertension. The retinal blood vessel segmentation for small and low contrast vessels is still a challenging problem. To solve this problem, a new method based on cake filter is proposed. Firstly, a quadrature filter band called cake filter band is made up in Fourier field. Then the real component fusion is used to separate the blood vessel from the background. Finally, the blood vessel network is got by a self-adaption threshold. The experiments implemented on the STARE database indicate that the new method has a better performance than the traditional ones on the small vessels extraction, average accuracy rate, and true and false positive rate.

Development of a System to Measure the Optical Properties of Facial Skin using a 3D Camera and Projector

2021 ◽  
Author(s):  
Kumiko Kikuchi ◽  
Shoji Tominaga ◽  
Jon Y. Hardeberg
Keyword(s):  
Optical Properties ◽  
Diffuse Reflection ◽  
Specular Reflection ◽  
Three Dimensional ◽  
Depth Image ◽  
Facial Skin ◽  
Subsurface Scattering ◽  
Surface Reflection ◽  
Reflection Model ◽  
Reflection Component

We have developed a system to measure both the optical properties of facial skin and the three-dimensional shape of the face. To measure the three-dimensional facial shape, our system uses a light-field camera to provide a focused image and a depth image simultaneously. The light source uses a projector that produces a high-frequency binary illumination pattern to separate the subsurface scattering and surface reflections from the facial skin. Using a dichromatic reflection model, the surface reflection image of the skin can be separated further into a specular reflection component and a diffuse reflection component. Verification using physically controlled objects showed that the separation of the optical properties by the system correlated with the subsurface scattering, specular reflection, or diffuse reflection characteristics of each object. The method presented here opens new possibilities in cosmetology and skin pharmacology for measurement of the skin’s gloss and absorption kinetics and the pharmacodynamics of various external agents.

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