Yasumi Ito

Evaluation of the mechanical characteristics of human thighs for developing complex dummy tissues

Wearable robots pose high risks to humans because they are directly mounted on human bodies, and methods for assessing their safety have not yet been established. For developing such safety tests, we have fabricated dummy legs that emulate the structure of the human body. Furthermore, all mechanical characteristics of human tissues that relate to their interactions with a wearable robot - elasticity, viscosity, normal stress, deformation, and friction coefficient - must be considered in parallel. Moreover, complex dummy tissues were developed and their characteristics were compared with those of human tissues. Mechanical characteristics of tissues for both humans and dummy were evaluated using a rheometer and an ultrasonic probe to clarify the similarities or differences. Consequently, we identified a mechanism of biological soft tissues as well as a way of imitating these characteristics in complex dummy tissues.

Investigation on Shock Response of Magnesium Alloy Honeycomb Sandwich Panels under Low Velocity Impact Loading

This paper describes the results of an experimental investigation on the drop off impact test on a range of sandwich panels. The magnesium alloy sandwich panels were fabricated with rolled sheets at different thickness by pressing and bonding method. Out-plane compression test was employed to obtain its basic deformation-force behavior. The impact experiments were carried out in which a steel cylinder was dropped off at various height levels, ranging from 0.5m to 1.5 cm to impact the panel. A high speed camera was employed to take pictures at 20 thousand frames per second and the low-velocity impact response on the sandwich panels is recorded with a dynamic force senor under the panel simultaneously. The shock response with time and the impact absorption energy were analyzed and compared. The results of this study proved that the magnesium alloy honeycomb sandwich panels have good impact energy absorption performance.

Effect of HIV on Japanese Population

The Japan population decrease since 2005. In particular, the working population has begun to decrease in 1995. In our former study, the death toll of the three major causes of deaths in Japan was estimated until in 2060. These three major causes of deaths are malignant neoplasms, heart diseases and cerebro-vascular diseases. These have more influences on a senior population. However, an effect of HIV is greater on the working population than senior population. In present Japan, influence from HIV carrier / AIDS to give total population is small. However, the reported number increases every year, and it is considered that the influence will grow in the future. We estimate an effect of HIV on Japanese population. In these calculations of the simulated population, the total fertility rate is used 1.29, therefore the Japanese population decreases simply.

MECHANICAL PROPERTIES OF THE HUMAN CAROTID ARTERY USING ULTRASONOGRAPHY AND PRESUMPTION OF ARTERIOSCLEROSIS

Every year, a quite large number of people die from cardiac and cerebrovascular diseases that are related to arteriosclerosis. Arteriosclerosis shows symptoms only in the advance stage, and hence it is vital to diagnosis it at an early stage to prevent diseases like cerebral infraction, myocardial infraction, etc. In this study, a new technique has been proposed for measuring the in vivo elastic modulus of human common carotid artery using ultrasound. This method is based on the in vivo elastic modulus calculated from the dynamic changes in the diameter of the common carotid artery and the systolic and diastolic blood pressures. It is found that the in vivo elastic modulus of common carotid artery is a useful marker of the development of the arteriosclerosis.

Study on Man-Machine Interface Control System Using Skin Surface Electromyogram (SEMG)

Until recently, keyboard has been used as the primary input method for machinery operation system. But in recent years, numerous methods related to direct input interface have been developed. One of them is to measure the surface electric potential that generates on the skin surface during muscle contraction. Based on this fact, hand finger operation can also be recognized with the help of the surface muscle electric potential. This report mainly explains the method of recognizing the crookedness states of the hand fingers from surface electromyogram (SEMG) signals.Moreover, the research on the biosignal control system with eye movement is also reported. We have designed a new biosignal control system that offers the disable the opportunity to control some electrical appliances. The biosignal control system is based on the signals derived from the forehead during eye movement, using five electrodes fixed on the forehead. The four directions of eye movement (up, down, left, and right) allow as four primary control signals. With selection of 2 signals from the four primary signals, we can get 16 different signals.

Strain distribution measurement of the decubitus pocket using strain gauge

The pressure sore is a trouble by the mechanical loading. As for this, the stress concentration occurs to the skin surface, and, next, sphacelism is meant by the skin. It is the present conditions that there is not correct evaluation method so that it is anisotropy composite material as for the biotissue such as the skin, and behaving becomes complicated transformation by the external force.Therefore, by this report, we use a strain gauge for the skin of the decubitus (bedsore) pocket penumbra and report it about the result that tried the distortion distribution measurement.