This study was conducted to identify the appropriate level of lightness of a computer screen effective for preventing eye fatigue and increasing the accessibility of digital color contents. We asked university students to perform tasks using a visual display terminal (VDT), and measured their work performance and input error rate, examined their physiological responses, and asked about their impressions of the screen. We prepared eight types of computer screen with varying differences in lightness between the characters and background. The difference in lightness affected their work efficiency and input error rate. However, there was little variation in the input error rate between the largest difference in lightness conforming to the international standard and the smallest difference in lightness not conforming to it. No significant differences in their blood pressure and heart rate were observed before and after performing the tasks. The level of fatigue was highest when the difference in lightness was smallest while complying with the international standard. Even when the computer screen met the international standard regarding the difference in lightness, it affected work efficiency and the sense of fatigue.

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This study was conducted to examine the size at which color samples give the same impression as a real or full space. In the experiment, 15 colors combined conditions of each of three chromas (low, middle, high) and each of five hues (5R, 5Y, 5G, 5B, 5P) in middle-level value were used and samples of 125mm_(Sample 1), 250mm_(Sample 2), 500mm_(Sample 3), 750mm_(Sample 4) squares and a real space in each color were used. The luminous environment in the laboratory was designated to be 1000lx in illuminance at a color temperature of 4100K. A semantic differential method using 20 adjective pairs was chosen to measure psychological responses. Six male and six female subjects aged 19 to 23 years old participated in experiment. The results were grouped according to the size of the sample that the subjects judged to have the same impression as a real space. Afterwards, an appropriate sample size for each color condition was determined considering the content of the subjective impression, In all hues, the fording that Sample 2 (250mm) was enough size in the middle chroma condition was obtained. The results indicated that in the low chroma color 5R and 5Y, Sample 3 (500mm) is sufficiently large. However in the other chromas, results were different. The results indicated that in color 5G and 5B, Sample 2 (250mm) is sufficiently large, and in color 5P, Sample 3 (500mm) is large enough.

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The aim of the present survey was to ascertain the status of mist sauna use, the actual physiological and psychological effects of regularly taking mist sauna baths, and the issues surrounding use among residents of homes installed with a mist sauna device. More than three-quarters of residents (77.0%) who chose themselves to have a mist sauna device installed took mist sauna baths. Among those who use the mist sauna, psychological and physiological effects include relaxation, relief of fatigue, sweating and relief of dryness. However there are also residents who choose not to use the mist saunas provided. Reasons for not using the mist sauna included associated energy costs and time expenditure, in addition to a lack of understanding of mist bathing methods. These findings suggest that in order for mist saunas to be applied to regular bathing, there is a further need for instruction regarding temperature settings, bathing time, and bathing methods using the mist sauna (concurrent use with tub bath or shower etc.) that enable the achievement of the desired effects. To this end, further investigation is required regarding individual differences in physiological and psychological effects of mist sauna use.

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In the present study, the bathing care load when the nursing care institution user is made to take a bath was clarified physiological and psychologically, and the necessity of the introduction of a new bathing equipment, mist sauna, to reduce the load was considered. Ten care staffs worked for the institution of Oyamada Memorial Spa Hospital have done the bathing care in the large bathroom, the bathing care used the oil pressure type bathtub, and other care respectively for 60 minutes. Blood elements, blood pressure, heart rate, and grip strength, Zikaku-sho shirabe and POMS were measured before and after the bathing care. Questionnaires about thermal sensation etc. were measured after the bathing care. As a result, it was clarified that the bathing care in the large bathroom accompanies the general fatigue and maintains negative feelings easily compared with the bathing care used the oil pressure type bathtub, because of the upper and lower movement and the thermal exposure. It was thought that it was effective to set up the mist sauna room as one of the countermeasures. The useful facilities for both the care staff and the bather should be developed and introduced to nursing care institution.

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The purpose of this study was to examine the effects of a dome sauna applied below the neck, on physiological and subjective responses in 10 young men (20.9±1.3 years). The experiments were carried out under two conditions: 70-90℃ (high-level) and 60-85℃ (middle-level). The subjects were covered with the dome sauna for 60min. and removed for 30min. Blood pressure, pulse, rectal temperature, and skin temperature were measured every 2min. During sauna use, at the middle-level, the average rectal temperature rose from 36.9±0.2℃ to 37.6±0.4℃ (p<0.05), and the average diastolic blood pressure fell from 57.2±4.7mmHg to 50.5±6.9mmHg (p<0.05). The results indicate similar to ordinary bathing. In the young subjects, this dome sauna was performed safely, and these results give us reason to pursue a forward strategy of experiments in elder people and patients with heart disease.

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