1. Department of Ubiquitous Health Informatics, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
2. Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
3. Department of Information and Communication Engineering, University of Tokyo, Tokyo, Japan
4. Business Development of Healthcare Business Smart-life Solutions Department, NTT DOCOMO, Inc., Tokyo, Japan
5. foo.log, Inc., Tokyo, Japan
6. Department of Medical Informatics and Economics, Graduate School of Medicine, University of Tokyo, Tokyo, Japan