岩永 光一

It is needed to consider many different situations for designing. We examined vertical work-space for standing posture to propose a comfortable kitchen. In the experiment, 90 points were prepared in 3 sagittal planes including a median sagittal plane. Electromyograms(EMG) and joint angles were recorded during keeping a right hand on each point. After that, subjective ratings of fatigue were obtained. We analyzed these data, and computed mathematical models to adapt different stature. And we proposed a new design of kitchen which had two main fertures; face-to-face and different height of worktop.

Toys that are equipped with the electronic devices and high functional mechanisms are fundamentally designed to run the program with the interruptions of user input or internal / external environmental data basing on the simple autonomic function in itself. Although internal function has got very high ability, present user-interfaces still employ the voice recognizer or simple switches. These present interfaces are categorized as very general and normal method, therefore missing originality. In this viewpoint, we proposed a new interface system for toys using bioelectric signals (especially electromyogram) that method is often used in the field of ergonomics and we made a prototype of bioelectric-controlled robot as a new type of toy.

Although there are many kind of toothbrush handle. the design based on the objective viewpoint is almost nonexistent. In this study, ergonomic methodology including electromyogram and subjective ratings was employed as the evaluation tool of the handle. As a result, optimal thickness of the handle is approximately φ 17.5 mm for the lower part and lO mm at least, 12.5 mm or more for the upper part. The form of crosssection on the upper part is recommended to be nearly circular form and suggested that flat-iike element should be adopted 40 it for more handling stability. The result of this research will become one of an important guideline for designers in future.

In this short communication, the recent trends of study in physiological anthropolgy are roughly reviewed as an introduction of the special issue. Physiological anthropology is originally one of the discipline-oriented sciences which treats of human beings living in modern societies. However, current topics of physiological anthropology are in accord with the needs of the times, since material prosperity was followed by a demand for an anthropocentric living enviroment. The author's coming interest about the study of human nature is presented here in brief.

An impotant consideration in cleaning tool design is the reduction of physical fatigue. A bathtub scrubbing hand tool (handle length=40cm, angle=20°, bestowed flexibility on cleaning part) was desinged to reduce physical fatigue. This scrubbing tool was then manufactured and evaluated by measuring electromyogaram and articular angle. This was compared with the one which is on the market, and another which doesn't have a handle. Under similar working conditions, results clearly showed that the designed hand tool reduced physical fatigue.

Purpose of the study was to find out better key shapes as input devices with tactile detection of hand. Eight male students volunteered as subjects. They were right handed. Shapes of circle, square, triangle, sexangle, plus, and minus were randomly presented one by one. Subjects answer the detected shape as possible using only left hand. Size and thickness of circle, square and triangle keys were changed. As the results, key of minus shape was the best for tactile detection. Triangle key was better than square one. Regarding key size and thickness, minimum circumference of key was 18 mm, minimum thickness of key was 0.4 mm for circle, square and triangle keys.

The relationship between increase in rectal temperature and body build during submaximalwork was studied in 8 Japanese males.After resting at 28°C with 50% relative humidity for30min, subjects worked on a bicycle ergometer at load of 450kgm/min with pedaling frequency50rpm for 61min at 28°C or 45°C with 50% relative humidity.Rectal temperature, oxygenuptake and heart rate were measured at rest and during work.Relative work loads wereobtained from prediction of maximal oxygen uptake.Body weight, stature, skinfold thicknessand body density were measured.Body surface area, body fat % and mean skinfold thicknesswere caiuculated by prediction equations.The correlation coefficients between increase in rectal temperature and body build at 45°Cwere larger than those at 28°C.In the conditicn of 45°C, body surface area-to-mass ratio wascorrelated significantly with increase in rectal temperature, whereas the relationship was notsignificant at 28°C.In the condition of 28°C, sigmificant relationship between relative work loadand increase in rectal temperature was found.Body suriace area-to-mass ratio, which meansrelative heat exchange between human body and environment, affects the change in rectaltemperature at high ambient temperature.