scholarly journals Ultra-Wideband Temperature Dependent Dielectric Spectroscopy of Porcine Tissue and Blood in the Microwave Frequency Range

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1707 ◽  
Author(s):  
Sebastian Ley ◽  
Susanne Schilling ◽  
Ondrej Fiser ◽  
Jan Vrba ◽  
Jürgen Sachs ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Microwave Frequency ◽  
Ultra Wideband ◽  
Frequency Range ◽  
Temperature Dependent ◽  
Hyperthermia Treatment ◽  
Non Invasive ◽  
Animal Liver ◽  
Cole Model ◽  
Diagnostic Technologies

The knowledge of frequency and temperature dependent dielectric properties of tissue is essential to develop ultra-wideband diagnostic technologies, such as a non-invasive temperature monitoring system during hyperthermia treatment. To this end, we characterized the dielectric properties of animal liver, muscle, fat and blood in the microwave frequency range from 0.5 GHz to 7 GHz and in the temperature range between 30 °C and 50 °C. The measured data were modeled to a two-pole Cole-Cole model and a second-order polynomial was introduced to fit the Cole-Cole parameters as a function of temperature. The parametric model provides access to the dielectric properties of tissue at any frequency and temperature in the specified range.

Ultrawideband temperature-dependent dielectric properties of animal liver tissue in the microwave frequency range

2006 ◽  
Vol 51 (7) ◽  
pp. 1941-1955 ◽  
Author(s):  
Mariya Lazebnik ◽  
Mark C Converse ◽  
John H Booske ◽  
Susan C Hagness
Keyword(s):  
Dielectric Properties ◽  
Liver Tissue ◽  
Microwave Frequency ◽  
Frequency Range ◽  
Temperature Dependent ◽  
Animal Liver

Temperature dependent dielectric spectroscopy of muscle tissue phantom

2020 ◽  
Vol 12 (9) ◽  
pp. 885-891
Author(s):  
Ondrej Fiser ◽  
Sebastian Ley ◽  
Marko Helbig ◽  
Jürgen Sachs ◽  
Michaela Kantova ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Muscle Tissue ◽  
Frequency Range ◽  
Temperature Dependent ◽  
Dielectric Parameters ◽  
Temperature Range ◽  
Non Invasive ◽  
Tissue Phantom ◽  
Cole Model ◽  
Polyethylene Powder

AbstractThe temperature dependence of the dielectric parameters of tissues and tissue-mimicking phantoms is very important for non-invasive temperature measurement in medical applications using microwaves. We performed measurements of this dependence in the temperature range of 25–50°C using distilled water as a reference liquid commonly used in dielectric property studies. The results were compared with the literature model in the frequency range of 150–3000 MHz. Using this method, the temperature dependence of dielectric parameters of a new muscle tissue-mimicking phantom based on agar, polyethylene powder, and polysaccharide material TX-151 was measured in the temperature range of 25–50°C. The temperature dependence of the dielectric properties of this new muscle phantom was fitted to that of the two-pole Cole–Cole model and the deviation of the results between measured and modeled data was quantified.

scholarly journals Dosimetry of Various Human Bodies Exposed to Microwave Broadband Electromagnetic Pulses

2021 ◽  
Vol 9 ◽  
Author(s):  
Jerdvisanop Chakarothai ◽  
Kanako Wake ◽  
Katsumi Fujii
Keyword(s):  
Microwave Frequency ◽  
Biological Tissues ◽  
Ultra Wideband ◽  
Inverse Laplace Transform ◽  
Frequency Range ◽  
Reflection And Transmission ◽  
Electromagnetic Pulses ◽  
Prony Method ◽  
The Time Domain ◽  
Cole Model

In this paper, human exposures to ultra-wideband (UWB) electromagnetic (EM) pulses in the microwave region are assessed using a frequency-dependent FDTD scheme previously proposed by the authors. Complex permittivity functions of all biological tissues used in the numerical analyses are accurately expressed by the four-term Cole–Cole model. In our method, we apply the fast inverse Laplace transform to determine the time-domain impulse response, utilize the Prony method to find the Z-domain representation, and extract residues and poles for use in the FDTD formulation. Update equations for the electric field are then derived via the Z-transformation. Firstly, we perform reflection and transmission analyses of a multilayer composed of six different biological tissues and then confirm the validity of the proposed method by comparison with analytical results. Finally, numerical dosimetry of various human bodies exposed to EM pulses from the front in the microwave frequency range is performed, and the specific energy absorption is evaluated and compared with that prescribed in international guidelines.

scholarly journals Quantitative Interpretation of UWB Radar Images for Non-Invasive Tissue Temperature Estimation during Hyperthermia

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 818
Author(s):  
Alexandra Prokhorova ◽  
Sebastian Ley ◽  
Marko Helbig
Keyword(s):  
Three Dimensional ◽  
Microwave Frequency ◽  
Ultra Wideband ◽  
Tissue Temperature ◽  
Hyperthermia Treatment ◽  
Temperature Estimation ◽  
Radar Images ◽  
Non Invasive ◽  
Uwb Radar ◽  
Thermal Therapies

The knowledge of temperature distribution inside the tissue to be treated is essential for patient safety, workflow and clinical outcomes of thermal therapies. Microwave imaging represents a promising approach for non-invasive tissue temperature monitoring during hyperthermia treatment. In the present paper, a methodology for quantitative non-invasive tissue temperature estimation based on ultra-wideband (UWB) radar imaging in the microwave frequency range is described. The capabilities of the proposed method are demonstrated by experiments with liquid phantoms and three-dimensional (3D) Delay-and-Sum beamforming algorithms. The results of our investigation show that the methodology can be applied for detection and estimation of the temperature induced dielectric properties change.

Mechanisms Responsible for Dielectric Properties of Various Faujasites and Linde Type A Zeolites in the Microwave Frequency Range

2011 ◽  
Vol 115 (7) ◽  
pp. 3090-3098 ◽  
Author(s):  
Benoit Legras ◽  
Isabelle Polaert ◽  
Lionel Estel ◽  
Michel Thomas
Keyword(s):  
Dielectric Properties ◽  
Microwave Frequency ◽  
Type A ◽  
Frequency Range

Dielectric Properties of Potato Puree in Microwave Frequency Range as Influenced by Concentration and Temperature

2009 ◽  
Vol 12 (4) ◽  
pp. 896-909 ◽  
Author(s):  
Jasim Ahmed ◽  
Nadide Seyhun ◽  
Hosahalli S. Ramaswamy ◽  
Giorgio Luciano
Keyword(s):  
Dielectric Properties ◽  
Microwave Frequency ◽  
Frequency Range

scholarly journals Bimodal microwave and ultrasound phantoms for non-invasive clinical imaging

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Enrique Villa ◽  
Natalia Arteaga-Marrero ◽  
Javier González-Fernández ◽  
Juan Ruiz-Alzola
Keyword(s):  
Dielectric Properties ◽  
Soft Tissues ◽  
Sucrose Concentration ◽  
Acoustic Properties ◽  
Gelling Agent ◽  
Non Invasive ◽  
Significant Performance ◽  
Cole Model ◽  
Ultrasound Applications

AbstractA precise and thorough methodology is presented for the design and fabrication of bimodal phantoms to be used in medical microwave and ultrasound applications. Dielectric and acoustic properties of human soft tissues were simultaneously mimicked. The phantoms were fabricated using polyvinyl alcohol cryogel (PVA-C) as gelling agent at a 10% concentration. Sucrose was employed to control the dielectric properties in the microwave spectrum, whereas cellulose was used as acoustic scatterer for ultrasound. For the dielectric properties at microwaves, a mathematical model was extracted to calculate the complex permittivity of the desired mimicked tissues in the frequency range from 500 MHz to 20 GHz. This model, dependent on frequency and sucrose concentration, was in good agreement with the reference Cole–Cole model. Regarding the acoustic properties, the speed of sound and attenuation coefficient were employed for validation. In both cases, the experimental data were consistent with the corresponding theoretical values for soft tissues. The characterization of these PVA-C phantoms demonstrated a significant performance for simultaneous microwave and ultrasound operation. In conclusion, PVA-C has been validated as gelling agent for the fabrication of complex multimodal phantoms that mimic soft tissues providing a unique tool to be used in a range of clinical applications.

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