We present a study and whole experimental tele-monitoring and medical tele-surveillance system for maintaining patients at home. The project features networked sensors, in a fully equipped apartment, operated by an advanced information and communication system based on Internet, Java, and object oriented modeling. The sensors are connected, mainly wirelessly, with a in-home software module devoted to signals analysis and detection of critical situation such as falls, sickness, sudden palsy, stroke, hypothermia, etc. This module communicates, either via modem or ethernet network, with a remote medical control station in charge of appropriate response to received information and alarms. The system is designed to be a powerful information and communication tools for medical and social workers. It offers a series of functions such as medical file management, user profiles and rights management, drafting and management of ordinances and visit notes, confidentiality of medical information, and management of scenarios of detectable events. The access to the system is allowed to authorized users only (physicians, emergentists, social workers, etc.), and is available on as much authorized computers as needed, by means of a Java applet invoked from any traditional web browsers.