Previous studies have shown that social participation improved the quality of life of people with dementia (PwD), pointing to the importance of enhancing subjective experiences in preventing dementia and avoiding its progression. However, technologies that take subjective aspects into account and promote daily experiences suitable for each PwD are still underdeveloped. Therefore, in this study, a database of micro happiness was first created by interviewing 77 PwD regarding their experiences in daily life. Micro happiness data here refers to as a database of daily subjective experiences that PwD find enjoyable. Furthermore, the authors proposed a micro happiness recommendation algorithm that takes into account the life functions of PwD, such as age, symptoms, and nursing care levels, and makes it possible to make recommendations in accordance with the algorithm. Using this micro happiness recommendation system incorporating this algorithm, the authors conducted a questionnaire survey to 94 care managers, and confirmed the effectiveness of happiness propagation, such as that they became aware of happiness that they had previously overlooked, and that they wanted to know more about what other happinesses were available. Depth interviews with care managers and dementia patients also demonstrated the usefulness of this database in diagnosing dementia and making initial lifestyle suggestions. It is necessary to further investigate changes in indicators such as quality of life through a longitudinal intervention study to see if there is a micro happiness recommendation effect on dementia patients as well as on the caregivers' side. Keywords: micro happiness; subjective experience; recommender system

Ryo Shinozawa is a second-year engineering student at the Institute of Science Tokyo (the previous name was the Tokyo Institute of Technology), Japan. He won the JSME Young Fellow Award for his presentation research presentation: Ryo Shinozawa, Mikiko Ohno, Satoko Hotta, Yoshifumi Nishida, "Accumulation and Utilization of Subjective Experiences of Elderly People with Dementia," Proceedings of the JSME Conference on Robotics and Mechatronics, pp. 2A1-H09, 2023