Ubiquitous but non invasive evaluation of the activity of a person from a unique index built on the electrical activities on the residential power line

In the context of ubiquitous computing, there is a particular interest in objectivizing the level of activity of elderly persons living independently in their own home. Whereas many existing monitoring systems are very intrusive and/or require a large number of sensors, an indirect approach based on the monitoring of the electrical appliances activities in home seems very attractive. We evaluated this approach and built a unique activity indicator which integrates all the activity of the person. This was experimented during 6 months within 12 flats occupied by single elderly persons.