"Single elderly people" (single those over households of people 65 years old) have increased by approximately 75% compared to ten years ago, showing a trend of sharp increase. Therefore, the need to comfirm safety of "single elderly people" in daily life has been increasing. On the other hand, double-income households have been increasing in and after the middle of the 1990s. This indicates that close relatives with single elderly people must find time to keep watch over the lives of their single elderly relatives while managing their everyday life. Under these circumstances, the safety confirmation system is a system effective in supporting the lives of single elderly people and their close relatives. However, attention must be paid to the methods of safety confirmation and device installation. For example, if monitoring cameras and wall cables are installed in the house of a single elderly person, it might bring discomfort to him/her, so that it may cause a problem when the system is introduced.
This system judges safety based on the frequency of a door opening/closing. In addition, for the sensor for detecting door opening/closing, a wireless communications method was adopted. Furthermore, e-mail was adopted as the method for notifying close relatives of their relative's safety. This made it possible to build a safety confirmation system which does not hearily affect the daily lives of both the elderly people and close relatives.