This paper shows the steady behaviors of attendant's propelling a wheelchair from back side, with our new proposed experimental system. The propelling behaviors are important to develop and design the wheelchairs having motorized auxiliary wheels which reduce the load of attendants. But it's difficult to obtain the behaviors because the propelling task is autonomous: we unconsciously determine own pushing force and walking speed against wheelchair's conditions. So, we propose and produce the new system to examine autonomous propelling behavior against wheelchair conditions at first. Next we investigate the propelling task in terms of propelling force, walking speed, postures on the system. As the results, we found that attendant regulate own propelling force at 10-30% of max performance and the exerted force decreases with increasing walking speed. Besides, almost of attendants exert only less than 40W propelling power.

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In this study, the authors developed the Lift-free soft keyboard (LFSK), a system with an input scheme for the soft keyboard, such that no tapping motions are required for the text entry. Basic mechanism for identifying keystrokes on LFSK is that the system recognizes a keystroke is generated if the speed of the tip of the stylus stays on a key within a certain threshold of speed. By using this system, the users are free from frequent tapping motions, hence less workload on their wrists and forearms are expected. The objective of this study was to evaluate the performance and muscular load for using this input scheme. In the experiment, eight participants performed word-processing task with the LFSK as well as the conventional tap-based soft keyboard. Dependent variables include surface EMGs to monitor neck, shoulder, forearm and finger muscle activities, subjective discomfort, typing speed, and number of errors. LFSK condition resulted in significantly less muscular loads at the upper extremity (p<0.01). Subjective preference supported LFSK in terms of fatigues on the wrist and elbow (p<0.01). The performance, however, was decreased during typing with LFSK (p<0.01).Analysis on type of errors made provided valuable design ideas to improve the usability for LFSK. These findings indicated that LFSK may have a potential ability to control with less muscular load by improving the design.

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Semi-sitting position on a bed is commonly used as load training and daily living posture during recuperative period, but often causes shear stress between body and mattress, and body pressure concentration on the buttocks. In this study, an experimental bed was developed for searching comfort-posture condition to reduce shear stress due to difference in stature and posture changes, and to disperse of the body-pressure compared to the conventional semi-sitting position. Support plate of this bed is divided into 7, of which 4 are adjustable lengths. Lengths and angles of the plates are adjusted by using 10 linear actuators. The bed in flat position is 400mm in height, 770mm in width, 1, 780-2, 230mm in length. For convenience of transportation, the bed divides into two units. RR intervals, parasympathetic activity, cutaneous blood flow, pressure distribution were compared under two conditions; adjusted semi-sitting position by the developed experimental bed, and the conventional semi-sitting position. These results show that uncomfortable state can be improved by supporting natural-body-flexion posture with this experimental bed.

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In this study a relationship between the learning and the workload was examined after performing four experiments based on the working structure classification referring to the single works (the card classification test, the memory and operation test, and the both hands collaboration test) and the combination works (combination of those 3 tests). The results obtained were summarized as follows:
(1) When the learning of the single work was evaluated by the work achievement Q, it was 67.5% in the card classification test, 63.7% in the memory and operation test, and 79.5% in the both hands collaboration test, respectively. That of the combination work showed 70.0%, which was close to the mean value of the single work in comparison.
(2) When the workload of the single work was evaluated by the total workload W, it was 0.9 in the card classification test, 1.0 in the memory and operation test, and 1.4 in the both hands collaboration test, respectively. The combination work test showed 0.9, which indicated the lower workload than that of the single work.
(3) Referring to the work achievement Q related to the total workload W, a regressive equation was obtained to indicate the total workload index.
(4) The total workload index is considered useful as basic data in the production activity of every cell manufacturing firm.

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Eye pupil size response and its size recovery time under the state of dark adaptation were studied experimentally when they were irradiated by High Intensity Discharge (HID) headlight. Seven male students with normal but corrected visual acuity were volunteered. An eye-mark recorder camera system was applied to measure the pupil size and its size recovery time. Mean and standard deviation of diameter of pupil size under the state of light adaptation were 2.9±0.6mm, and 5.3±0.5mm under the dark adaptation. Horizontal irradiation angles to eyes by the HID headlight were 10°, 15° and 20° respectively. Mean diameters of eye pupil just after irradiated by the HID headlight were 2.3±0.3mm at 10°, 2.6±0.4mm at 15°, and 2.7±0.3mm at 20° respectively. These results showed statistical significance by ANOVA analysis. Recovery times of pupil size after having irradiated by the HID headlight were 13.82±2.67s at 10°, 11.66±2.15s at 15°, and 11.03±2.35s at 20° respectively. ANOVA showed statistical significance among the horizontal irradiation angles. Results of the experiment proved that the pupil diameters irradiated by the HID headlight were smaller than those under light adaptation. This implies irradiation by the HID headlight has bigger glare-effects on irradiated car drivers and pedestrians.

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