Simplification of Liquid Dielectric Property Evaluation Based on Comparison with Reference Materials and Electromagnetic Analysis Using the Cut-Off Waveguide Reflection Method

We proposed a new method to measure the complex permittivity of small biological tissue in millimeter-wave band using the TE
 01n
 mode of a cylindrical cavity resonator. We examined the validity of the proposed measurement technique using an agar sample. The agar sample was maded by mixing pure water 98 % and agar powder 2 %. We prepared agar samples of different thickness ranging from 0.3 to 0.8 mm, and measured the complex permittivity between the 32 GHz-35 GHz band for each sample. It was assumed that the agar samples have approximately the same complex permittivity as pure water. We compared the measured value of agar sample with the theoretical values of water. As a result, when the thickness of the agar sample of 0.57 mm or less, the measured values approximately agreed with the theoretical values of water.

Complex permittivity measurement method of high loss materials using cylindrical cavity resonator in millimeter-wave band

Before evaluating the quality of hemodialysis from the limited volume of human blood using a commercially available open-ended coaxial probe, we previously measured the complex relative permittivity of pure water from 200 MHz to 6 GHz with respect to its measured liquid volume, and found that 1.9 ml of water in a beaker with a diameter of 24 mm and a depth of 2 mm gives a variation within ± 0.5% for the real part and ± 7% for the imaginary part. Based on the above finding, we measured the dielectric properties of 2.5 ml whole blood at 25 °C for 10 normal healthy subjects and 9 hemodialysis patients. The measured results on healthy subjects show good agreement with the data reported by Gabriel for human blood at 37 °C, while they provide different dispersion characteristics of straight lines for their Cole–Cole plots. The measured results on the patients give further different dispersion characteristics versus the healthy subjects. In an investigation of the above differences statistically, Student's t-test revealed that the permittivity at infinite frequency for the Cole–Cole plots is significantly different with a level of 1% among its averaged values for normal healthy subjects and patients before dialysis. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 95(12): 56–61, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11421

Measurement and Hemodialysis Effect of Complex Relative Permittivity for Blood of Kidney Patients Using Open-Ended Coaxial Measurement Probe

SUMMARY A novel jig structure for S 11 calibration with short/open conditions and one reference material (referred to here as SOM) in dielectric measurement of liquids using a coaxial feed type stepped cut- off circular waveguide and a formula for exact calculation of S 11 for the analytical model of the structure using the method of moments (MoM) was proposed. The accuracy and validity of S 11 values calculated using the relevant formula was then verified for frequencies of 0.50, 1.5 and 3.0 GHz, and S 11 measurement accuracy with each termination condition was verified after calibration with SOM by combining the jig of the proposed structure with the study’s electromagnetic (EM) analysis method. The relative complex permittivity was then estimated from S 11 values measured with various liquids in the jig after calibration, and differences in results obtained with the proposed method and the conventional jig, the analytical model and the EM analysis method were examined. The validity of the proposed dielectric measurement method based on a combination of the above jig structure, numerical S 11 calculation and the calibration method was thus confirmed.

Calibration of a Coaxial-Loaded Stepped Cut-Off Circular Waveguide and Related Application of Dielectric Measurement for Liquids

Correlation Analysis between Complex Relative Permittivity and Biochemical Components for Blood of Dialysis Patients before and after Hemodialysis

Measurement of Complex Relative Permittivity of Pure Water and its Variation with Respect to Water Amount using Open-Ended Coaxial Probe

ヒト血液の複素比誘電率と温度との相関分析;ヒト血液の複素比誘電率と温度との相関分析;Correlation Analysis between Complex Relative Permittivity and Temperature for Human Blood

透析患者の透析前後における血液の生化学成分と複素比誘電率に基づくアドミタンスとの相関性;透析患者の透析前後における血液の生化学成分と複素比誘電率に基づくアドミタンスとの相関性;Correlation between Biochemical Components and Admittance based on Complex Relative Permittivity of Kidney Disease Patients^|^apos; Blood Before and After Hemodialysis

Akira Takeda

Papers

Measurement of Complex Relative Permittivity of Pure Water and its Variation with Respect to Water Amount using Open-Ended Coaxial Probe

Measurement and Hemodialysis Effect of Complex Relative Permittivity for Blood of Kidney Patients Using Open-Ended Coaxial Measurement Probe

Correlation Analysis between Complex Relative Permittivity and Biochemical Components for Blood of Dialysis Patients before and after Hemodialysis

ヒト血液の複素比誘電率と温度との相関分析;ヒト血液の複素比誘電率と温度との相関分析;Correlation Analysis between Complex Relative Permittivity and Temperature for Human Blood