Dielectric Spectrogram for Evaluating Ischemic Microstructural Changes of the Liver in Simple Cold Preservation

Yamada, Takuya; Mori, Yoshio; Onitsuka, Atsuyoshi; Hayashi, Masatomo; Senga, Shoshi; Futamura, Naoki; Sakamoto, Kenichi; Sago, Tetsu; Takagi, Hisato; Yasumura, Mikio; Iwata, Hiroji

doi:10.1007/s005950200213

Cited by 7 publications

(6 citation statements)

References 13 publications

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“…The discrepancy in turning points between Haemmerich's study and the present study may be attributed to the different measurement temperatures used. Lower storage temperature prolongs survival period (Yamada et al 2002); hence, high measurement temperatures might lead to rapid cell death. This finding may explain why the turning point in the present study appeared 60-75 min earlier than that in Haemmerich's study.…”

Section: Discussionmentioning

confidence: 99%

“…However, no quantitative relation has been established between the dielectric properties and biological activities of hepatic tissue. Yamada et al (2002) studied the correlation between dielectric parameters of rat liver and the area of extracellular/cellular components at single frequency under simple cold preservation. The results indicated that the tissue microstructure could be used as an index of biological activity to study the correlation between dielectric properties and biological activities.…”

Section: Introductionmentioning

confidence: 99%

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Correlation between the dielectric properties and biological activities of humanex vivohepatic tissue

Wang

et al. 2015

Phys. Med. Biol.

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Dielectric properties are vital biophysical features of biological tissues, and biological activity is an index to ascertain the active state of tissues. This study investigated the potential correlation between the dielectric properties and biological activities of human hepatic tissue with prolonged ex vivo time through correlation and regression analyses. The dielectric properties of 26 cases of normal human hepatic tissue at 10 Hz to 100 MHz were measured from 15 min after isolation to 24 h at 37 °C with 90% humidity. Cell morphologies, including nucleus area (NA) and alteration rate of intercellular area (ICAR), were analyzed as indicators of biological activities. Conductivity, complex resistivity, and NA exhibited opposing changes 1 h after isolation. Relative permittivity and ex vivo time were not closely correlated (p> 0.05). The dielectric properties measured at low frequencies (i.e. <1 MHz) were more sensitive than those measured at high frequencies in reflecting the biological activity of ex vivo tissue. Highly significant correlations were found between conductivity, resistivity and the ex vivo time (p < 0.05) as well as conductivity and the cell morphology (p < 0.05). The findings indicated that establishing the correlation between the dielectric properties and biological activities of human hepatic tissue is of great significance for promoting the role of dielectric properties in biological science, particularly in human biology.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Correlation between the dielectric properties and biological activities of humanex vivohepatic tissue

Wang

et al. 2015

Phys. Med. Biol.

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“…Although dielectric properties have been widely studied, few mathematical results have been reported regarding the underlying mechanism of the correlation between the dielectric properties and the ex vivo time. Yamada et al [24] examined the relationship between dielectric properties and microstructural changes in liver tissues during cold preservation (4 • C). However, the relationship was analyzed only at 1 kHz and 1 MHz.…”

Section: Introductionmentioning

confidence: 99%

Bivariate polynomial for time-dependent dielectric properties of ex-vivo porcine and human liver tissue at frequencies below 100 MHz

Wang

et al. 2023

Meas. Sci. Technol.

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Time-dependent dielectric properties of ex vivo tissue are important for biological viability assessment, successful organ transplantation and finding the optimal substitute for the in vivo tissue. However, there are relatively few studies on the time dependence of dielectric properties and especially the mathematical models related to it. This study mathematically describes the time-dependent dielectric properties of excised liver tissues at frequencies below 100MHz. A bivariate higher-order polynomial was used to reflect the mathematical correlation of dielectric properties (relative permittivity ε and conductivity σ ) with frequency and ex vivo time under controlled temperature and humidity. Statistical analysis, cross validation and error analysis were used to assess the fitting performance and prediction ability of the bivariate higher-order polynomial fitting model. The results showed that the dielectric properties of excised porcine liver tissues and human liver tissues could be well fitted and predicted by the bivariate higher-order polynomial fitting model at frequencies below 100MHz. Encouragingly, the dielectric properties can be calculated at a given frequency and ex vivo time at controlled temperature and humidity. This presents a new way of obtaining accurate dielectric properties of ex vivo biological tissues in a specific outer environment. It is also possible to extrapolate back the ex vivo time after excision from the body using the dielectric properties.

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“…Another example is to use bioimpedance parameters for monitoring organs to be transplanted to determine their suitability for transplantation. The idea is to quantify the damage caused by ischemia before, during and after the transplantation (Harms et al, 2001;Sola et al, 2003;Yamada et al, 2002).…”

Section: Bioimpedance Methods For Tissue Monitoringmentioning

confidence: 99%

Image reconstruction in EIT using advanced regularization frameworks

Taguchi¹

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NOTICE: The author has granted a nonexclusive license allowing Library and Archives Canada to reproduce, publish, archive, preserve, conserve, communicate to the public by telecommunication or on the Internet, loan, distribute and sell theses worldwide, for commercial or noncommercial purposes, in microform, paper, electronic and/or any other formats. AVIS: L'auteur a accorde une licence non exclusive permettant a la Bibliotheque et Archives Canada de reproduire, publier, archiver, sauvegarder, conserver, transmettre au public par telecommunication ou par Plntemet, prefer, distribuer et vendre des theses partout dans le monde, a des fins commerciales ou autres, sur support microforme, papier, electronique et/ou autres formats. Canada Bien que ces formulaires aient inclus dans la pagination, il n'y aura aucun contenu manquant.

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Dielectric Spectrogram for Evaluating Ischemic Microstructural Changes of the Liver in Simple Cold Preservation

Abstract: Our results suggest that the serial changes in tissue conductivity and the relative permittivity reflect changes in liver tissue microstructures during cold preservation.

Cited by 7 publications

References 13 publications

Correlation between the dielectric properties and biological activities of humanex vivohepatic tissue

Correlation between the dielectric properties and biological activities of humanex vivohepatic tissue

Bivariate polynomial for time-dependent dielectric properties of ex-vivo porcine and human liver tissue at frequencies below 100 MHz

Image reconstruction in EIT using advanced regularization frameworks

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