Proposal and Evaluation of the Toilet Timing Suggestion Method for the Elderly Airi Tsuji Graduate School of Engineering and Science, Kyoto Institute of Technology Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan Email: diff.dim0505@gmail.com Tomoko Yonezawa Kansai University 2-1-1 Ryozenji, Takatsuki Osaka 569-1095, Japan Email: yone@kansai-u.ac.jp HirotakeYamazoe Osaka University 8-1 Mihogaoka, Ibaraki Osaka 567-0047, Japan Email: yamazoe@am.sanken.osaka-u.ac.jp Shinji Abe NTT Cyber Solutions Laboratories Human Interaction Project 1-1 Hikarinooka Yokosuka-Shi Kanagawa 239-0847, Japan Email:abe.sinji@lab.ntt.co.jp Noriaki Kuwahara Graduate School of Engineering and Science, Kyoto Institute of Technology Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan Email: nkuwahar@kit.ac.jp Kazunari Morimoto Graduate School of Engineering and Science, Kyoto Institute of Technology Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan Email: morix@kit.ac.jp Abstract—We are researching and developing the toilet timing suggestion method for the elderly in order to support their comfortable outing because the elderly are likely to experience frequent urination and often encounter the difficult situation of searching for a restroom with holding their water. Our proposed system calculates the toilet timing in consideration with both their outing schedule and the amount of body water of them, and recommends going to a restroom sufficiently before they feel the need of urinating. In order to implement the system, we’ve come up with the physiological formula for non-invasive estimation of the amount of body water, and based on the estimation, the toilet timing is calculated. Also, we’ve devised the suggestion method of the toilet timing to the elderly in order both not to interfere their things to do while their outing and not to be ignored by them. In this paper, we describe our proposed system, and show the experimental result for evaluating both the toilet timing calculation and the suggestion method. I. INTRODUCTION For healthy elderly people, going out is one of the most important activity to keep their cognitive and physical abilities and gives them good stimulation and pleasure in daily-life [1]. Promoting barrier-free environments in public spaces in Japan encourages the elderly to go out independently. However, going out is likely to become their pain for some elderly people with aging especially due to a matter of restroom. Because elderly people have a weak bladder, they are likely to experience frequent urination and often encounter the difficult situation of searching for a restroom with holding their water. If the caregiver accompanies the elderly, the caregiver can suggest going to the restroom sufficiently before the elderly wants to go to restroom, or can look for the nearest restroom for the elderly. However, the number of the elderly living alone rapidly increases in Japan, and they cannot receive such support. Consequently, they often tend not to drink water enough while their outing due to the anxiety to go to a restroom. It is likely to be the cause of getting dehydrated especially in summer [2]. Aiming for elderly’s comfortable and independent outing, we are researching and developing the toilet timing suggestion system according to their outing schedule, their surrounding environment, and their activities like eating and drinking [3]. In order to implement the system, we’ve come up with the simplistic physiological formula for non-invasive estimation of the amount of body water, and based on the estimation, the toilet timing is calculated. This formula considers the surrounding environment of the elderly like air temperature and their activities like eating and drinking, and rearranges the toilet timing according to changes in the environment and activities. Also, we’ve devised the suggestion method of the toilet timing to the elderly in order both not to interfere their things to do while their outing and not to be ignored by them. In this paper, we describe our proposed system, and show the experimental result for evaluating both the toilet timing calculation and the suggestion method. II. SYSTEM ARCHITECTURE A. System Overview Fig.1 shows our proposed system overview. The detailed implementations are described as follows. 1) The initial schedule generating unit calculates the initial toilet timing according to outing plan and current air temperature. 2) Suggestion unit recommends restroom based on the generated schedule.