川嶋 大介

<p>For cell discrimination of cancerous cell, diffusibility α is proposed based on the Nernst-Planck equation by Electrochemical Impedance Spectroscopy. Diffusibility α is calculated by the Nernst-Planck equation, and it means ion transfer rate though the cell membrane. The effect of osmotic concentration on α is studied by changing the sucrose concentration with measuring the suspension of Medical Research Council cell strain 5. It shows that the smaller the osmotic concentration, the larger the α, and the distribution of α is clear at the same osmotic concentration.</p>

<p>Recently, in the field of regenerative tissue engineering, huge amount of cells are needed for developping new organs and tissues. However, during cell cultivation, cells sometimes show degeneration or change their original characters so that it is needed to separate those cells from original cells. Although fluorescent labeling and magnetic labeling of cells have been used for cell separation, invasive label-free methods are required from the point of view of cell damage. Therefore, our aim is to develop a high-efficiency label-free cell separation system based on the difference in electrical characteristics of cells. In this study, for its first step, an attempt was made to distinguish different type of cells by measuring their electrical properties.</p>

<p>For the discrimination of living and dead yeast cell, visualization and quantification of dead cell ratio Φ_d in the microchannel are performed based on electrical impedance tomography (EIT). Based on the dead cell indicator, Ψ_d defined as the ratio of imaginary part of impedance between different Φ_d distribution in microchannel is reconstructed by the algorithm of electrical impedance tomography. The reconstructed images shows the good performance regarding quantification of Φ_d within 28.4 % in error rate.</p>

Poster session: W065c

Session7-04

Symposium S31-2

<p>In recent years, regenerative medicine technology attracts attention. It is a technology to extract cells from human organs and tissues and to create new organs and tissues by culturing in large quantities. However, unintended unusual cells are appeared during culturing of cells, which need to be removed. Therefore, in order to separate cells with high efficiency and label free, we aim to sense normal cells and unusual cells by intrinsic electrical properties. In this study, a cell mass spheroid was used as a measurement target. An attempt was made to find the difference in relative permittivity and conductivity of cell spheroids. As a result, differences were obtained at specific frequencies for relative permittivity.</p>

<p>For the design and evaluation of microfluidic applications, it is important to measure concentration distributions of target substances in liquid and to quantify their generation or reduction during chemical reactions. We have thus developed a concentration imaging method for aqueous solutions, based on the near-infrared (NIR) absorption characteristic of water. This method needs to add no substance to the aqueous solutions and can be applied to various aqueous solutions. Moreover, a useful advantage of this method is that it can measure concentrations of multiple substances simultaneously. In this study, when the aqueous solutions of HCl and NaOH were flowed in parallel through a microfluidic channel, the concentration distributions of HCl, NaOH, and NaCl were measured using the NIR-based imaging method, where three wavelengths of 1412 nm, 1442 nm, and 1520 nm in the ν₁ + ν₃ absorption band of water were used. The concentration images indicated the generation of NaCl by the neutralization reaction and the interdiffusion processes of HCl and NaOH.</p>

<p>Development of highly efficient cell sensing method is needed in the field of regenerative medical. Electrochemical impedance spectroscopy (EIS) method are progressing as a noninvasive cell measurement method. When the EIS method is applied to a cell suspension at a concentration in a culture environment, the electrical characteristics of the cells cannot be clearly measured. On the other hand, when compared with the sucrose solution used for the dispersion medium, impedance of the cell suspension is decrease. In this study, we measure decrease of impedance of the cell suspension in microchannel. As a result, it was found that there is a difference in the decrease rate of impedance of different cell type suspension and it is useful for cell identification.</p>

© 2017 IEEE. Electrical impedance spectroscopy (EIS) has been proven to be a useful technique for analyzing biological cell suspensions and tissues because of its capacity of noninvasive measurement. In this paper, the electrical characteristics of medical research council cell strain 5 (MRC-5) are detected by EIS in a multi-layered microchannel. In this research, the equivalent circuit of MRC-5 solution is created by the principle of cell electrical properties. In the experiments, MRC-5 and yeast cells are detected by EIS in multi-layered microchannel, the results reveal that EIS in the micro sensor distinguishes the different cells by their different electrical impedance.

Copyright © (2018) by Chemical and Biological Microsystems Society. All rights reserved. A novel electrical impedance tomography (μEIT) method for cell visualization with recognition of living yeast cell (L-yeast) and dead yeast cell (D-yeast) is proposed. The proposed method combines μEIT with electrical impedance spectroscopy in order to visualize the L-yeast and D-yeast cell condition which cannot be considered in conventional μEIT. Also, in experiment two wire measurement method is applied instead of conventional 4 wire measurement method in order to eliminate the noise. As an experimental result, the spatial distribution of L-yeast and D-yeast in microchannel was successfully visualized with low noise.

A wireless tomography system has been developed to measure the real-time behavior of solid-liquid two phase flow in the centrifuge for controlling a rotational velocity and particle supply rate. The purpose of this study is development of real-time behavior of solid-liquid two phase flow measurement technique and image conductivity distribution in a rotating body because Acentrifugation technology for industry process should be improved to obtain more effective separation, shorten processtime and save energy but a technique for measuring the behavior ofsolid-liquid two phase flow in the centrifuges has not existed yet. The real-time behavior of solid-liquid two phase flow measurement and the rotational velocity control become innovative technologies. As technics to measure typical behavior of solid-liquid two phase, the process tomography is used because the processtomography is suitable for real-time measurement in a rotating body. Processtomography has high temporal resolution. This detector was used with the wireless because electrical cables are not available for centrifuges under high speed rotational condition. This wireless tomography system is used for a lab scale rotating machinery measurement experiment in thisresearch. The wireless tomography system was attached around the lab scale rotating machinery for the behavior of solid-liquid two phase flow measurement experiment. Consequently, we could wirelessly measure the behavior of solid-liquid two phase flow in the lab scale rotating machinery in real time and get data to image the behavior ofsolid-liquid two phase flow in the quantitative. So the wireless tomography system has developed and can measure the behavior of solid-liquid two phase flow in the lab scale rotating machinery in real time.

Copyright © 2018 ASME The purpose of this study is the calibration in normalization technique for the real-time measurement of void-fraction inside fluid by using VC system at each temperature condition. There is an existing method of measuring electrical response called a VC system. A VC system is a voltage applied current measured system. The VC method measures electrically between electrodes attached around the measurement subject and detects internal distribution from impedance difference of the component to be measured. We deal with water and air in this research. In this method, we measure the difference between the electrical characteristics of air and water. And the measurement technique is requirement of pre-measurement. In homogeneous case, we need to measure current for normalization with real-time measured current. This method has problem that the impedance of water depends on the temperature. So the impedance of water at pre-measurement is different as compared real-time impedance. That's why, the technique for measuring void-fraction is not high accuracy at present. The measurement technology should be improved to obtain more accurate area of air inside fluid. This requirement is achieved by real-time measurement and real-time separation based on the different electrical properties of air and water while calibrating with temperature. In order to improve accuracy of the proposed method, we conducted a system comparison experiment before calibration with temperature and after calibration. In conclusion, we could measure the void fraction in real time more accurately.

© 2018 International Heat Transfer Conference. All rights reserved. In recent years, chemical analyses/syntheses using microfluidic chips, or microreactors, have been vigorously studied because it is possible to precisely control chemical reactions between very small amounts of samples. For the design and evaluation of microreactors, it is important to measure concentration distributions of target substances in liquid and to quantify their generation or reduction during chemical reactions. We have thus developed a concentration imaging method for aqueous solutions, based on the near-infrared (NIR) absorption characteristic of water. This method needs to add no substance to the aqueous solutions and can be applied to various aqueous solutions. Moreover, a great advantage of this method is to measure the concentrations of multiple substances simultaneously. In this study, when the aqueous solutions of HCl and NaOH were flowed in parallel through a microfluidic channel, the concentration distribution of HCl, NaOH, and NaCl were measured by the NIR-based imaging method, where three wavelengths of 1412 nm, 1442 nm, and 1520 nm in the ν1 + ν3 absorption band of water were used. The concentration images indicated the generation of NaCl by neutralization reaction and the interdiffusion processes of HCl and NaOH.

Paper No: FD8

Paper number: 5623

Paper number: 21.5