scholarly journals Electrical characterization of bolus material as phantom for use in electrical impedance and computed tomography fusion imaging

2019 ◽  
Vol 5 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Parvind K Grewal ◽  
Majid Shokoufi ◽  
Jeff Liu ◽  
Krishnan Kalpagam ◽  
Kirpal S Kohli
Keyword(s):  
Electrical Impedance ◽  
Electrical Characterization ◽  
Fusion Imaging ◽  
Biological Tissues ◽  
Frequency Range ◽  
Imaging Studies ◽  
Impedance Tomography ◽  
Clinical Imaging

Abstract Phantoms are widely used in medical imaging to predict image quality prior to clinical imaging. This paper discusses the possible use of bolus material, as a conductivity phantom, for validation and interpretation of electrical impedance tomography (EIT) images. Bolus is commonly used in radiation therapy to mimic tissue. When irradiated, it has radiological characteristics similar to tissue. With increased research interest in CT/EIT fusion imaging there is a need to find a material which has both the absorption coefficient and electrical conductivity similar to biological tissues. In the present study the electrical properties, specifically resistivity, of various commercially available bolus materials were characterized by comparing their frequency response with that of in-vivo connective adipose tissue. It was determined that the resistivity of Gelatin Bolus is similar to in-vivo tissue in the frequency range 10 kHz to 1MHz and therefore has potential to be used in EIT/CT fusion imaging studies.

Electrical characterization of aluminous cement at the early age in the 10 Hz–1 GHz frequency range

2000 ◽  
Vol 30 (7) ◽  
pp. 1057-1062 ◽  
Author(s):  
Youssef El Hafiane ◽  
Agnès Smith ◽  
Jean Pierre Bonnet ◽  
Pierre Abelard ◽  
Philippe Blanchart
Keyword(s):  
Electrical Characterization ◽  
Early Age ◽  
Frequency Range ◽  
Aluminous Cement

Measurement of Acoustic Emission Wave Attenuation by Bones and Muscles

2007 ◽  
Author(s):  
Benjamin Pruden ◽  
Ozan Akkus
Keyword(s):  
Acoustic Emission ◽  
Wave Attenuation ◽  
Physiological Activity ◽  
Acoustic Emissions ◽  
Biological Tissues ◽  
The Body ◽  
Frequency Range ◽  
Mode Separation ◽  
Viscous Losses

Stress fractures occur in bones of athletes and soldiers due to the accumulation of microcracks [1]. Detection of precursor acoustic emissions (i.e. ultrasonic stress waves) resulting from microcrack activity may help predict failure onset before continuous physiological activity results in full-blown fracture. An acoustic emission wave generated from a microcrack in bone will be diminished by dispersion, mode separation, reflection, and viscous losses induced by the biological tissues (skin, muscle, fat) between the source and the transducer. While others have recorded waves emanating from unknown loci in human knee in vivo using acoustic emission method [2], there is no means to appreciate how far these waves can travel in the body. Several studies have characterized the ultrasound attenuation in bone [3] and muscle analog homogenates [4] in the frequency range above 300 kHz. On the other hand, acoustic emissions are prominent in the range of 20 kHz to 300 kHz. The current study focused on identifying the attenuation of acoustic emission waves in bone and muscle tissues in a frequency range which is more relevant to acoustic emissions. This information is critical for predicting whether an emission of certain magnitude at the source can reach surface mounted sensors without being totally attenuated.

scholarly journals Numerical Sensitivity Analysis for Dielectric Characterization of Biological Samples by Open-Ended Probe Technique

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3756
Author(s):  
Marta Cavagnaro ◽  
Giuseppe Ruvio
Keyword(s):  
Water Content ◽  
Ex Vivo ◽  
High Water ◽  
Biological Tissues ◽  
Fundamental Aspect ◽  
High Water Content ◽  
Insertion Depth ◽  
Dielectric Characterization

Dielectric characterization of biological tissues has become a fundamental aspect of the design of medical treatments based on electromagnetic energy delivery and their pre-treatment planning. Among several measuring techniques proposed in the literature, broadband and minimally-invasive open-ended probe measurements are best-suited for biological tissues. However, several challenges related to measurement accuracy arise when dealing with biological tissues in both ex vivo and in vivo scenarios such as very constrained set-ups in terms of limited sample size and probe positioning. By means of the Finite Integration Technique in the CST Studio Suite® software, the numerical accuracy of the reconstruction of the complex permittivity of a high water-content tissue such as liver and a low water-content tissue such as fat is evaluated for different sample dimensions, different location of the probe, and considering the influence of the background environment. It is found that for high water-content tissues, the insertion depth of the probe into the sample is the most critical parameter on the accuracy of the reconstruction. Whereas when low water-content tissues are measured, the probe could be simply placed in contact with the surface of the sample but a deeper and wider sample is required to mitigate biasing effects from the background environment. The numerical analysis proves to be a valid tool to assess the suitability of a measurement set-up for a target accuracy threshold.

Optimization of a probe for the spectroscopic electrical characterization of biological tissues

2007 ◽  
Vol 39 (2) ◽  
pp. 171-174
Author(s):  
L. Bernard ◽  
N. Burais ◽  
L. Nicolas ◽  
J. A. Vasconcelos
Keyword(s):  
Electrical Characterization ◽  
Biological Tissues
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