scholarly journals Imaging biological tissues by utilizing ultrasound and electromagnetic fields

2021 ◽  
Author(s):  
Elena Renzhiglova
Keyword(s):  
Magnetic Moment ◽  
Relative Permittivity ◽  
Radiation Force ◽  
Biological Tissues ◽  
Ultrasound Wave ◽  
Electrical Tomography ◽  
Electrical Field ◽  
Impedance Modulation ◽  
Muscle Tissues ◽  
Electrical Permittivity

This thesis reports our research on developing a new method to image the electric conductivity and relative permittivity of biological tissues. The first method is Differential Frequency Magneto-Acousto-Electrical Tomography (DF-MAET) to image the electrical impedance of biological tissues with high spatial resolution. It is shown that DF-MAET signal is caused by the vibrations of the sample at a difference frequency (DF) because of the radiation force. In the second method, we investigated the possibility of using a novel mechanism for imaging the electrical permittivity of biological tissues. Theoretical study shows that a magnetic moment will be produced in biological tissues when both and ultrasound wave and an electrical field exist in the tissue. We report the results to detect this magnetic moment with both coils and electrodes attached to the tissue. We were able to detect the signal with electrodes, but its frequency dependence indicates that this signal is due to the impedance modulation by ultrasound, and that it is not related to the relative permittivity. Finally, we studied the ultrasonic vibration potentials generated in fat and muscle tissues.

Performance improvement of magneto-acousto-electrical tomography for biological tissues with sinusoid-Barker coded excitation

2018 ◽  
Vol 27 (9) ◽  
pp. 094302 ◽  
Author(s):  
Zheng-Feng Yu ◽  
Yan Zhou ◽  
Yu-Zhi Li ◽  
Qing-Yu Ma ◽  
Ge-Pu Guo ◽  
...  
Keyword(s):  
Performance Improvement ◽  
Biological Tissues ◽  
Electrical Tomography ◽  
Coded Excitation

An Analytical Quantum Model to Calculate Fluorescence Enhancement of a Molecule in Vicinity of a Sub-10 nm Metal Nanoparticle

2016 ◽  
Vol 71 (5) ◽  
pp. 963-969 ◽  
Author(s):  
Zahra Bagheri ◽  
Reza Massudi
Keyword(s):  
Enhancement Factor ◽  
Radiative Decay ◽  
Fluorescence Enhancement ◽  
Classical Model ◽  
Field Enhancement ◽  
Decay Rates ◽  
Metal Nanoparticle ◽  
Quantum Model ◽  
Electrical Field ◽  
Electrical Permittivity

An analytical quantum model is used to calculate electrical permittivity of a metal nanoparticle located in an adjacent molecule. Different parameters, such as radiative and non-radiative decay rates, quantum yield, electrical field enhancement factor, and fluorescence enhancement are calculated by such a model and they are compared with those obtained by using the classical Drude model. It is observed that using an analytical quantum model presents a higher enhancement factor, up to 30%, as compared to classical model for nanoparticles smaller than 10 nm. Furthermore, the results are in better agreement with those experimentally realized.

Three-Dimensional Microstructure of Muscle Tissues During Freezing and Thawing

1999 ◽  
Author(s):  
Hiroshi Ishiguro ◽  
Takashi Horimizu
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
Physiological Saline ◽  
Biological Tissues ◽  
Confocal Laser Scanning Microscope ◽  
Ice Crystals ◽  
Confocal Laser ◽  
Freezing And Thawing ◽  
Slow Cooling ◽  
Muscle Tissues

Abstract Three-dimensional behavior of ice crystals and cells during the freezing and thawing of biological tissues was investigated microscopically in real time by using a confocal laser scanning microscope (CLSM) and a fluorescent dye, acridine orange (AO). Fresh tender meat (2nd pectoral muscles) of chicken was stained with the AO in physiological saline, and then frozen and thawed in a uniform temperature under two different thermal protocols: a) slow-cooling and rapid-warming and b) rapid-cooling and rapid-warming. The CLSM noninvasively produced tomograms of the tissues to clarify the pattern of freezing, morphology of ice crystals in the tissues, and the interaction between ice crystals and cells.

Nonlinear effects of the finite amplitude ultrasound wave in biological tissues

2000 ◽  
Vol 45 (6) ◽  
pp. 508-512 ◽  
Author(s):  
Xiaozhou Liu ◽  
Xiufen Gong ◽  
Shigong Ye ◽  
Weiya Zhang
Keyword(s):  
Nonlinear Effects ◽  
Biological Tissues ◽  
Finite Amplitude ◽  
Ultrasound Wave

Stable isotopes in biota reflect the graduated influence of sewage effluent along a tropical macro-tidal creek

2017 ◽  
Vol 68 (10) ◽  
pp. 1855
Author(s):  
Kanchana Niwanthi Warnakulasooriya ◽  
Edward Charles Villers Butler ◽  
Karen Susanne Gibb ◽  
Niels Crosley Munksgaard
Keyword(s):  
Stable Isotopes ◽  
Stable Isotope ◽  
Tidal Creek ◽  
Biological Tissues ◽  
Quality Parameters ◽  
Food Sources ◽  
Sewage Effluent ◽  
Monitoring Tool ◽  
Muscle Tissues ◽  
Spatial Differences

In hydrodynamically complex environments, where conventional water-quality parameters may not adequately quantify sewage influence, stable isotopes in time-integrating biological tissues may provide an alternative monitoring tool. We measured nitrogen and carbon isotope ratios and concentrations in mangrove leaves and muscle tissues of two species of gastropod snails to determine the dispersion and biological assimilation of sewage-derived nutrients in a macro-tidal creek. The values of stable isotope of nitrogen (δ15N) in mangrove leaves and gastropods from the affected creek were significantly higher than those in samples from an unaffected creek, reflecting a graduated influence of sewage-derived N. The δ15N values in mangrove leaves showed high repeatability between sampling rounds and this, coupled with ease of sampling, makes them an effective monitoring tool to trace the influence of sewage effluent in receiving waters. The combined use of values of δ15N and stable isotope of carbon in gastropods showed some promise as a monitoring tool, but intra- and inter-specific variations in isotope values due to spatial differences in available food sources may affect their reliability in tracing sewage influence.

scholarly journals Quantitative ultrasound imaging of soft biological tissues: a primer for radiologists and medical physicists

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guy Cloutier ◽  
François Destrempes ◽  
François Yu ◽  
An Tang
Keyword(s):  
Quantitative Ultrasound ◽  
Tissue Characterization ◽  
Liver Steatosis ◽  
Ultrasound Image ◽  
Biological Tissues ◽  
Quantitative Information ◽  
Ultrasound Wave ◽  
Ultrasound Waves ◽  
Medical Physicists ◽  
General Topic

AbstractQuantitative ultrasound (QUS) aims at quantifying interactions between ultrasound and biological tissues. QUS techniques extract fundamental physical properties of tissues based on interactions between ultrasound waves and tissue microstructure. These techniques provide quantitative information on sub-resolution properties that are not visible on grayscale (B-mode) imaging. Quantitative data may be represented either as a global measurement or as parametric maps overlaid on B-mode images. Recently, major ultrasound manufacturers have released speed of sound, attenuation, and backscatter packages for tissue characterization and imaging. Established and emerging clinical applications are currently limited and include liver fibrosis staging, liver steatosis grading, and breast cancer characterization. On the other hand, most biological tissues have been studied using experimental QUS methods, and quantitative datasets are available in the literature. This educational review addresses the general topic of biological soft tissue characterization using QUS, with a focus on disseminating technical concepts for clinicians and specialized QUS materials for medical physicists. Advanced but simplified technical descriptions are also provided in separate subsections identified as such. To understand QUS methods, this article reviews types of ultrasound waves, basic concepts of ultrasound wave propagation, ultrasound image formation, point spread function, constructive and destructive wave interferences, radiofrequency data processing, and a summary of different imaging modes. For each major QUS technique, topics include: concept, illustrations, clinical examples, pitfalls, and future directions.

scholarly journals Acoustic Radiation Force Based Ultrasound Elasticity Imaging for Biomedical Applications

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2252 ◽  
Author(s):  
Lulu Wang
Keyword(s):  
Mechanical Properties ◽  
Clinical Diagnosis ◽  
Biological Tissue ◽  
Biomedical Applications ◽  
Acoustic Radiation ◽  
Radiation Force ◽  
Biological Tissues ◽  
Acoustic Radiation Force ◽  
Elasticity Imaging ◽  
Ultrasound Elasticity Imaging

Pathological changes in biological tissue are related to the changes in mechanical properties of biological tissue. Conventional medical screening tools such as ultrasound, magnetic resonance imaging or computed tomography have failed to produce the elastic properties of biological tissues directly. Ultrasound elasticity imaging (UEI) has been proposed as a promising imaging tool to map the elastic parameters of soft tissues for the clinical diagnosis of various diseases include prostate, liver, breast, and thyroid gland. Existing UEI-based approaches can be classified into three groups: internal physiologic excitation, external excitation, and acoustic radiation force (ARF) excitation methods. Among these methods, ARF has become one of the most popular techniques for the clinical diagnosis and treatment of disease. This paper provides comprehensive information on the recently developed ARF-based UEI techniques and instruments for biomedical applications. The mechanical properties of soft tissue, ARF and displacement estimation methods, working principle and implementation instruments for each ARF-based UEI method are discussed.

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