Dielectric properties of rat liver in vivo: a noninvasive approach using an open-ended coaxial probe at audio/radio frequencies

Raicu, Valerică; Saibara, Toshiji; Irimajiri, Akihiko

doi:10.1016/s0302-4598(98)00171-8

Cited by 55 publications

(57 citation statements)

References 10 publications

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“…As the difference in time constant between the EPI and sample decreases below 2-3 decades the accuracy of our method also decreases. This is in accordance with Raicu et al [7] and Stoneman et al [10] who commented that separation methods will not yield if the measured sample has dispersion in the same frequency range as the EPI. Geometrical considerations should also be done.…”

Section: Discussionsupporting

confidence: 91%

“…Brodi et al [6] argue for the CPE as a more realistic model of the EPI than C p (w) -R p (w). Raicu et al [7] and Stoneman et al[10] use a CPE alone as model to reduce the number of elements that describe the EPI. As discussed above these models can, if properly fitted to measurement data, be given similar properties at most frequencies, but at DC they fail as realistic models.…”

Section: Introductionmentioning

confidence: 99%

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Impedance-based tissue discrimination for needle guidance

Kalvøy¹,

Frich²,

Grimnes³

et al. 2009

Physiol. Meas.

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Measurement of electrical impedance can discriminate between tissues of different electrical properties. A measurement system with adequate spatial resolution focused on a volume around the tip of a needle or other invasive clinical equipment can be used to determine in which type of tissue the tip is positioned. We have measured the sensitivity zone of a needle electrode with an active electrode area of 0.3 mm 2 , and measured impedance spectra in porcine tissue in vivo. Small electrode impedance data will be influenced by electrode polarization impedance (EPI) at low frequencies. To refine existing methods for needle guidance with higher spatial resolution, we have used multivariate analysis and new interpretations of EPI, and tissue data gathered with selected needle electrodes. The focus of this study is on discrimination between muscle and fat/subdermis for drug administration, but our results also indicate that these refinements will facilitate new clinical applications for impedance-based needle guidance in general.

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Section: Discussionsupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Impedance-based tissue discrimination for needle guidance

Kalvøy¹,

Frich²,

Grimnes³

et al. 2009

Physiol. Meas.

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“…In order to minimize this effect, we use double-distilled and deionized water of electrical conductivity of 1 μS cm -1 as dissolving media. Electrode polarization effects at low frequency are corrected using the method proposed by Raicu et al [13]. The dielectric permittivity spectrum e′(w) was determined by the relation e′(w)= K·C s (w), where w=2pf is the angular frequency, K is the cell constant, and C s the capacitance of the sample.…”

Section: Introduction 2 Materials and Methodsmentioning

confidence: 99%

Electro-Optical Properties Characterization of Fish Type III Antifreeze Protein

2007

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Antifreeze proteins (AFPs) are ice-binding proteins that depress the freezing point of water in a non-colligative manner without a significant modification of the melting point. Found in the blood and tissues of some organisms (such as fish, insects, plants, and soil bacteria), AFPs play an important role in subzero temperature survival. Fish Type III AFP is present in members of the subclass Zoarcoidei. AFPIII are small 7-kDa-or 14-kDa tandem-globular proteins. In the present work, we study the behavior of several physical properties, such as the low-frequency dielectric permittivity spectrum, circular dichroism, and electrical conductivity of Fish Type III AFP solutions measured at different concentrations. The combination of the information obtained from these measurements could be explained through the formation of AFP molecular aggregates or, alternatively, by the existence of some other type of interparticle interactions. Thermal stability and electrooptical behavior, when proteins are dissolved in deuterated water, were also investigated.

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“…However, such tissue electrical models are only applicable for electrical property detection due to frequency differing voltages and hence does not account for any changes in cell structure or coagulation process. Raicu et al [8] proposed a parallel combination of capacitor and resistor to represent liver tissue sample. Kunii et al [9] proposed resistor and capacitor in series as a branch of difference tissue and put them all in parallel for the full liver equivalent circuit.…”

Section: Literature Studiesmentioning

confidence: 99%