An attempt of monitoring daily activities at home

In order to make elderly people safe and healthy, a monitoring system installed at home was built and evaluated in ordinary house. As a preliminary study, the authors attempted to monitor daily behavior of subjects in the kitchen and dining room because nutrition will be essential to keep health. Many sensors were installed such as infrared sensors to detect human movement, magnetic switches to detect opening and closing doors, a carbon dioxide sensor to detect presence of the subject, temperature sensors at the kitchen sink to detect cooking. Three subjects (22 years female, 30 years male, and 76 years male) who live alone were monitored for a month each. Output of sensors were sampled and stored in a computer. Monitoring was performed automatically so that no manual operation to the instruments was applied during whole period of monitoring. As a result, habits of daily activities could be clearly identified. For example, difference between behavioral pattern in a weekday and that in a holiday was obvious. It was also found that presence and absence of the subject in a room can be identified by a carbon dioxide sensor. By using many sensors, reliable information about daily activities can be obtained even malfunctioning of some sensor occurs occasionally