Nobuyuki Kabei

Development of an Electrostatic Generator for a Cardiac Pacemaker that Harnesses the Ventricular Wall Motion.

Abstract A variable-capacitance-type electrostatic (VCES) generator that harnesses ventricular motion was developed with the aim of driving a cardiac pacemaker permanently without a battery. The developed model of the VCES generator was handmade, but it was too large to implant into the thoracic cavity of a laboratory animal. For this reason, to demonstrate its feasibility, a somewhat complicated method that measured the left ventricular wall motion by means of the accelerometer module put on the free wall and reproduced the motion in real time with a vibration mode simulator was used. The VCES generator was vibrated on the simulator, and its generated power was supplied to the cardiac pacemaker, which then stimulated the heart. A mean power of approximately 36 μW was generated, which was enough to drive the cardiac pacemaker. Continuous electric generation and cardiac pacing were performed successfully for more than 2 h in the animal experiment.

A Microactuator Using Phase Transition of Paraffln. Development of an Actuator with Scissors for Surgical Operation.

Our aim is to develop a microactuator to be used for endoscopic surgery. The purpose of this study was to construct cylinder-piston-type microactuators that are actuated by phase transition of material. We use a paraffin as the working material because paraffin has a large coefficient of expansion due to the phase transition in the temperature range of 35 to 45 degrees of centigrade. Firstly, we made a microactuator whose outer diameter was 1.5 mm and the length was 65 mm. The actuator generates the stroke of 2 mm against the load of 1 kg. Secondly, a micro-scissors was attached to the piston of the actuator. It was confirmed that the micro-scissors can cut the paper, string and rubber tube without any trouble. The operation time for one cycle of cutting was approximately 13 secondns.

Characteristics of magneto-fluidic control devices which use magnetic fluid as working fluid

Abstract We developed a magneto-fluidic control device which used a magnetic fluid as working fluid. It was found that an output fluid power of the device could be controlled directly by an electrical signal.