IEEE SMC Hiroshima Chapter Acta Medica Okayama 1883-3977 2009 1 2009 Development of Thumb-Operated Dial-Type Integrated Switch for Automobile and its Effectiveness 330 335 EN Atsuo Murata Makoto Moriwaka A thumb-operated dial-type integrated switch for automobile use was developed, and the task completion time for this type of integrated switch was compared with that for a traditional integrated switch. The rotation torque of an encoder and the rotation diameter were selected as experimental parameters. An attempt was made to identify the optimal and recommended condition of rotation torque and diameter. It was demonstrated that the thumb-operated dial-type integrated switch lead to faster task completion time as compared with the traditional integrated switch. As for the thumb-operated dial-type integrated switch, the following combination of the rotation torque and the rotation diameter were not proper: diameter of 20mm for the rotation torque of 12.9mN・m and 9.2mN・m, and diameters of 20mm and 40mm for the rotation torque of 8.6 mN・m. It was also suggested that the optimal condition cannot be identified using the condition of the rotation force only, and that the optimal condition must be determined taking into account the combination of the rotation torque and the rotation diameter. No potential conflict of interest relevant to this article was reported.

IEEE SMC Hiroshima Chapter Acta Medica Okayama 2008 1 2008 Effect of vehicle display information and switch type on usability -Comparison between young and older adults- 71 76 EN Atsuo Murata Recently, in-vehicle highly intelligent information devices are rapidly widespread. Under such circumstances, the accurate evaluation of the effect of display information and switch type on driving performance is important in order to develop in-vehicle information devices that do not menace the safety. In this article, we present a basic idea to estimate properly the effect of the vehicles display information and the switch system on driving performance. We compared the index such as mean task completion time, subjective rating on usability, tracking error, and NASA-TLX workload between young and older adults. The results suggest that young will be better than older adults at both abilities on processing displayed information and operating the switch. We were found that there was a significant interaction between the switch types and installation location. On the other hand, the displayed information did not affect the performance. No potential conflict of interest relevant to this article was reported.