Characterization and Analysis of Wideband Temperature-Dependent Dielectric Properties of Liver Tissue for Next-Generation Minimally Invasive Microwave Tumor Ablation Technology

Neira, Luz Maria; Sawicki, James F.; Veen, B.D. Van; Hagness, Susan C.

doi:10.1109/mwsym.2018.8439157

Cited by 10 publications

(3 citation statements)

References 14 publications

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“…Based on the data provided in study from Bonello et al, a sharp decline of dielectric values appears at around 47

^{\circ}

C for microwave applicator heating setup and around 64

^{\circ}

C for microwave oven heating setup, while our data generally follow linear trend of decay at these temperatures. Also, while Bonello et al reported the slope of linear fits for effective conductivity at 915 MHz to be −0.99 %/

^{\circ}

C for microwave oven and −1.18 %/

^{\circ}

C for microwave ablator heating setup, our data suggest a positive slope for conductivity for all frequencies lower than 2.45 GHz, which is in agreement with the data from Lazebnik et al Similar to reports of measurements on liver tissue, at frequencies below ∼2.45 GHz, effective conductivity of lung tissue increased with heating up to ∼79

^{\circ}

C, and was then followed by a rapid decrease. Above ∼110

^{\circ}

C, both permittivity and conductivity were approximately constant.…”

Section: Discussionsupporting

confidence: 92%

“…The broadband dielectric properties of ex vivo lung tissue were measured with the well‐known open‐ended coaxial probe technique . This method employs a vector network analyzer (VNA) connected to an open‐ended coaxial probe terminated with the tissue sample.…”

Section: Methodsmentioning

confidence: 99%

“…The broadband dielectric properties of ex vivo lung tissue were measured with the well-known open-ended coaxial probe technique. 17,19,[26][27][28] This method employs a vector network analyzer (VNA) connected to an open-ended coaxial probe terminated with the tissue sample. The dielectric properties of the sample at a specific temperature and frequency relative permittivity e r ðf ; TÞ and effective conductivity r ef ðf ; TÞare extracted from the measured complex reflection coefficients C c ðf ; TÞ at each frequency.…”

Section: B Dielectric Property Measurementmentioning

confidence: 99%

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Broadband lung dielectric properties over the ablative temperature range: Experimental measurements and parametric models

2019

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Purpose Computational models of microwave tissue ablation are widely used to guide the development of ablation devices, and are increasingly being used for the development of treatment planning and monitoring platforms. Knowledge of temperature‐dependent dielectric properties of lung tissue is essential for accurate modeling of microwave ablation (MWA) of the lung. Methods We employed the open‐ended coaxial probe method, coupled with a custom tissue heating apparatus, to measure dielectric properties of ex vivo porcine and bovine lung tissue at temperatures ranging between 31 and 150 ∘C, over the frequency range 500 MHz to 6 GHz. Furthermore, we employed numerical optimization techniques to provide parametric models for characterizing the broadband temperature‐dependent dielectric properties of tissue, and their variability across tissue samples, suitable for use in computational models of microwave tissue ablation. Results Rapid decreases in both relative permittivity and effective conductivity were observed in the temperature range from 94 to 108 ∘C. Over the measured frequency range, both relative permittivity and effective conductivity were suitably modeled by piecewise linear functions [root mean square error (RMSE) = 1.0952 for permittivity and 0.0650 S/m for conductivity]. Detailed characterization of the variability in lung tissue properties was provided to enable uncertainty quantification of models of MWA. Conclusions The reported dielectric properties of lung tissue, and parametric models which also capture their distribution, will aid the development of computational models of microwave lung ablation.

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“…Based on the data provided in study from Bonello et al, a sharp decline of dielectric values appears at around 47