While searching the web, I found this ZigBee based product, which is a 'life alert' type system for seniors:
The Lusora Intelligent Sensory Architecture (LISA) is a sleek, wireless personal security system that leverages advanced technologies to safeguard your home and family. Employing ZigBee-compliant smart sensors, LISA’s mesh network senses changes in the home environment that may indicate an emergency. Lusora’s first two products, a light-switch camera and a personal alert device, are designed for people caring for seniors. These and other sensor devices can be programmed individually through a Web interface to monitor the unique habits of the people in the home.
http://www.demo.com/demo2/demonstrators/lusora.html
The Lusora Intelligent Sensory Architecture (LISA) is a sleek, wireless personal security system that leverages advanced technologies to safeguard your home and family. Employing ZigBee-compliant smart sensors, LISA’s mesh network senses changes in the home environment that may indicate an emergency. Lusora’s first two products, a light-switch camera and a personal alert device, are designed for people caring for seniors. These and other sensor devices can be programmed individually through a Web interface to monitor the unique habits of the people in the home.
http://www.demo.com/demo2/demonstrators/lusora.html