Basic study on the ultrasound attenuation of fibrous biological tissue in the frequency range of 10-40 MHz

2002 ◽  
Author(s):  
N. Kudo ◽  
M. Yoshida ◽  
K. Yamamoto ◽  
T. Mikami ◽  
A. Kitabatake ◽  
...  
Keyword(s):  
Biological Tissue ◽  
Frequency Range ◽  
Basic Study ◽  
Ultrasound Attenuation

scholarly journals Basic study on active acoustic shielding (Improving noise-reducing performance in low-frequency range)

2014 ◽  
Vol 1 (6) ◽  
pp. EPS0065-EPS0065 ◽  
Author(s):  
Tatsuya MURAO ◽  
Masaharu NISHIMURA ◽  
Kazunori SAKURAMA ◽  
Shin-ichiro NISHIDA
Keyword(s):  
Low Frequency ◽  
Frequency Range ◽  
Basic Study

scholarly journals Comparación entre la función de cole-cole y la función de Debye para modelar el tejido biológico

2019 ◽  
pp. 1-5
Author(s):  
Celia María Calderón-Ramón ◽  
Héctor Daniel López-Calderón ◽  
Jesús Enríque Escalante-Martínez ◽  
María Inés Cruz-Orduña
Keyword(s):  
Biological Tissue ◽  
Breast Tissue ◽  
Relaxation Times ◽  
Biological Tissues ◽  
Electromagnetic Signal ◽  
Frequency Range ◽  
Electrical Parameters ◽  
Debye Function ◽  
Advantages And Disadvantages ◽  
The Time Domain

The study of the biological tissue varies its behavior, in function of the frequency to which it is subjected. The functions of Cole-Cole, Debye and Lorentz are considered the most used to study the parameters of conductivity and permittivity of biological tissue such as: liver, stomach, gray matter, pancreas, blood, breast tissue to name a few. Depending on the frequency, there may be three different relaxation times. These depend on the nature and physical characteristics of the tissue and its effect in the presence of an electromagnetic signal. The Cole-Cole function is most appropriate when considering a study in the frequency domain, and the Debye function is established to perform the study in the time domain. It is of particular interest to make a comparison between the methods of Cole-Cole and Debye, to define the advantages and disadvantages of each of them. The Lorentz function is used for frequencies of the Tera-Hertz order. Comparative graphs are obtained between both for the biological tissues mentioned above. For each of them the electrical parameters are calculated in a frequency range between 100 Hz and 10 GHz.

scholarly journals Evaluation of a Reflection Method on an Open-Ended Coaxial Line and its Use in Dielectric Measurements

10.14311/882 ◽  
2006 ◽  
Vol 46 (5) ◽  
Author(s):  
R. Zajíček ◽  
J. Vrba ◽  
K. Novotný
Keyword(s):  
Biological Tissue ◽  
Tissue Sample ◽  
Coaxial Line ◽  
Dielectric Measurement ◽  
Network Analyzer ◽  
Reflection Method ◽  
Frequency Range ◽  
Discrete Elements ◽  
Biological Substance ◽  
Coaxial Probe

This paper describes a method for determining the dielectric constant of a biological tissue. A suitable way to make a dielectric measurement that is nondestructive and noninvasive for the biological substance and broadband at the frequency range of the network analyzer is to use a reflection method on an open ended coaxial line. A coaxial probe in the frequency range of the network analyzer from 17 MHz to 2 GHz is under investigation and also a calibration technique and the behavior of discrete elements in an equivalent circuit of an open ended coaxial line. Information about the magnitude and phase of the reflection coefficient on the interface between a biological tissue sample and a measurement probe is modeled with the aid of an electromagnetic field simulator. The numerical modeling is compared with real measurements, and a comparison is presented. 

scholarly journals A Basic Study on RF Characteristics of Meander Line Employing Periodic Ground Structure on GaAs MMIC for Application to Miniaturization of RF Components

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Jang-Hyeon Jeong ◽  
Young Yun ◽  
Suk-Youb Kang
Keyword(s):  
Transmission Line ◽  
Gaas Substrate ◽  
Propagation Constant ◽  
Effective Permittivity ◽  
Frequency Range ◽  
Ground Structure ◽  
Basic Study ◽  
Passive Components ◽  
Rf Components ◽  
Meander Line

The meander line employing periodic ground structure (MLEPGS) was fabricated on GaAs substrate for application to miniaturization of RF components on MMIC, and its RF characteristics were thoroughly investigated. The MLEPGS with a length ofλ/8 showed loss less than 0.72 dB up to 20 GHz, which was low enough for application to RF passive components. The MLEPGS showed much higher propagation constantβand effective permittivityεeffthan conventional meander line. Concretely, the MLEPGS withTof 20 μm showedβof 1.08~20.85 rad/mm andεeffof 2703~2479 from 1 to 20 GHz, while the conventional meander line showedβof 0.18~3.36 rad/mm andεeffof 74.2~64.7 in the same frequency range. According to the result, the size of theλ/4 transmission line employing the MLEPGS was 0.151 mm2, which was 3.5% of the size of the transmission line employing conventional meander line.

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