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Investigation of low temperature plasma capabilities to modify the structure and function of bio-polymers

Motrescu I., Hara T., Ogino A., Tanaka S., Fujiwara T., Kawagishi H., Kodani S., Popa G., Nagatsu M.

Journal of Automation Mobile Robotics and Intelligent Systems

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2009

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Vol. 3, No. 4

150-152

EN

The possibility to modify biopolymers using low temperature plasma is investigated. Two types of plasma are employed in this study: an atmospheric pressure plasma and a low pressure microwave plasma. In both cases changes of the structure and function of the exposed molecules are reported, the effects being stronger for the low-pressure plasma irradiation.

2

Current states of small and lightweight pulsatile motor driven LVAD

Okamoto E., Tanaka S., Makino T., Miura K., Okada S., Mitoh A., Mitamura Y.

Biocybernetics and Biomedical Engineering

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2007

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Vol. 27, no. 1-2

155-160

EN

A small size and lightweight motor-driven pulsatile LVAD using a ball screw has been developed. The motor-driven LVAD consists of a brushless DC motor and a ball-screw. The ball screw converts rotational motion of the motor into rectilinear motion of the pusher plate. The magnetic force between the tiny magnets on the pusher plate and the iron plate adhered on the pump diaphragm provides an active filling operation during the pump filling phase. The pump has a stroke volume of 55 ml, the whole volume of 285 ml and it weighs 360 g. The controller employs the fuzzy logic position and velocity control so that the LVAD experts’ experience could be used in the design of the controller. The LVAD was evaluated in the in-vitro experiments using the mock circulation. Maximum pump outflow of 5.1 l/min was obtained at the drive rate of 100 bpm against an afterload of 100 mmHg, and the active filling mechanism using the magnetic force provided a pump output of 3.6 l/min at a drive rate of 75 bpm under a preload of 0 mmHg. The operating efficiency of the LVAD was established to be measured between 8 and10%.

3

Use of an amphiphilic calix[4]arene with sulfonate functionality at the lower rim as a buffer additive in capillary electrophoresis

Mori M., Hirayama A., Tsue H., Tanaka S.

Acta Chromatographica

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2007

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No. 19

73-80

EN

An amphiphilic calix[4]arene with sulfonate groups on the lower rim has been investigated as a buffer additive for separation of positional isomers by capillary electrophoresis. Addition of the compound to the run-ning buffer led to successful separation of positional isomers of nitrophenols, dinitrobenzenes, and benzenediols. Association constants between the calixarene and the analytes indicated that size-selective host–guest inter-actions between them played a prominent role in determining the separation behavior.

4

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

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2006

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Vol. 26, no. 1

45-51

EN

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.