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Analysis of effect of radiation exposure on cultured cells using electrical cell-substrate impedance Sensing (ECIS) method

Goda N., Yamamoto Y., Nakamura M., Maruyama T., Kusuhara T., Mohri S., Kataoka N., Kajiya F.

Biocybernetics and Biomedical Engineering

2007

Vol. 27, no. 1-2

227-236

A mathematical model for the micro-dynamics of cultured cells measured with the ECIS (Electrical Cell-substrate Impedance Sensing) system that can separately evaluate the cell-to-cell distance and the cell-to-substrate distance is proposed. For wide applications of this method, mathematical models considering various types of cells and confluent conditions were constructed. Using ECIS TM, frequency the characteristics of 25 Hz to 60 kHz of impedance of HUVEC (human umbilical vein endothelial cells), BAEC (bovine aortic endothelial cells), in the pre-confluent condition and the full confluent condition of each cell were measured. A mathematical model of the micro-dynamics of the cultured cells measured with ECIS from 1 kHz to 10 kHz, which was the most interesting frequency range for the micro-dynamic analysis in the ECIS methods is proposed. The evaluation method of the cell-to-cell distance (A) and the cell-to-substrate distance (h) could be improved. In the application, we investigated the effect of the X-ray radiation exposure from 1 Gy to 100 Gy on the cultured cells BAEC using the ECIS system. Impedance changes could be confirmed by exposure to 100 Gy. The X-ray stimulation of 100 Gy resulted in a significant increase of the value of the cell-to-cell distance (A).

Development of implantable assist pump and its peripheral devices

Okamoto E., Makino T., Yamamoto Y., Asao H., Watanabe N., Nakamura M., Tanaka S., Inoue Y., Yasuda T., Mitamura Y.

Biocybernetics and Biomedical Engineering

2006

Vol. 26, no. 1

45-51

Two national project for development of an artificial heart system are being undertaken in Japan, and Hokkaido Tokai University has taken part in both national projects in order to develop peripheral devices of an implantable VAD (ventricular assist device) system. Each of the peripheral devices incIudes a transcutaneous energy transmission system, an internal battery system, and a transcutaneous information transmission system. Maximum energy transmission efficiency of the transcutaneous energy transmission system is over 85% (DC to DC) at an energy transmission ratio of 25 W. The internal battery system mainly consists of three lithium ion batteries, a charge circuit, and a power interface (case size of 11Ox80x30 mm). The internal battery system can drive a VAD for over 2 hours with maximum battery case surface temperature of 43°C. The information transmission system (diameter of 52 mm and thickness of 12 mm) mainly consists of an ASK modulator and an ASK demodulator employing carrier frequencies of 4 MHz and 10 MHz. It can transmit data electromagnetically between inside and outside of the body bi-directionally at a data transmission ratio of 56 kbps. Long-term animal experiments showed that each peripheral device has adequate performance to support the operation of implantable VAD.

Event matching prediction of insulator pollution by use of appropriate database selected by conditional probability.

Nakamura M., Goto S., Katafuchi T., Taniguchi T.

Systems Science

1999

Vol. 25, nr 2

101-110

A new prediction method called an event matching prediction (EMP) for the purpose of prediction deposits of insulators located in coastal substations has been proposed by the authors in a previous study. Performance of the EMP is strongly related to selections of a database of events and a closeness function. This paper aims at improving the performance of the EMP. A method for making an appropriate database of events has been discussed based on conditional probability. The function for measuring the closeness of the events has been defined as an exponential product of the distances of the corresponding data. By use of the the prediction of the insulator pollution based on EMP, a reliable decision making for the washing timing of the polluted insulator has been developed and evaluated based on actual data in Karatsu substation, Japan.