Everyday Life Sounds and Speech Analysis for a Medical Telemonitoring System Eric CASTELLI , Dan ISTRATE Laboratory CLIPS-IMAG, Grenoble Cedex 9, France Eric.Castelli@imag.fr , Dan.Istrate@imag.fr Abstract In order to improve patients’ life conditions and to reduce the costs of the long hospitalization, the medicine is more and more interested in the telemonitoring techniques. These will allow the old people or the high risk patients to stay at home, and to benefit from a remotely and automated medical supervision. We develop in collaboration with TIMC-IMAG laboratory, a system of telemonitoring in a habitat equipped with physiological sensors, position encoders of the person, and microphones. The originality of our approach consists in replacing the video camera monitoring, hardly accepted by the patients by microphones recording the sounds (speech or noises) in the apartment. The microphones carry out a multichannel sound acquisition system which, thanks to the sound information coupled with physical information, will enable us to identify a situation of distress. We describe the practical solutions chosen for the acquisition system and the recorded corpus of situations. 1. Introduction Telemedecine consists in associating electronic techniques of monitoring with computers “intelligence" and with the speed of telecommunications (established either through network or radio connections). Telemedicine is announced as a significant reform of the medical care because it allows to improve the response time of the specialists which could be informed about a medical emergency and react as soon as the first symptoms appear without waste of time. The telemedecine also allows a significant reduction of the costs of public health by avoiding the hospitalization of the patients for long periods of time. The system we work on is designed for the surveillance of elderly persons who can benefit from telemedicine. Its main goal is to detect serious accidents as falls or faintness (which can be characterized by a long idle period of the signals) at any place in the apartment [5]. This technique allows a medical center in charge to analyze the information gathered by the telemonitoring system and to intervene if needed [2]. We noted that the elderly had difficulties in accepting a monitoring by video camera, because they consider that their constant recording is a violation of their privacy. Thus, the originality of our approach consists in replacing the video camera by a system of multichannel sound acquisition charged to analyze in real time the sound environment of the apartment in order to detect abnormal noises (falls of objects or of the patient), calls for help or moans which could characterize a situation of distress in the habitat. 2. Presentation of the Telemonitoring System The habitat we used for experiments is a 30 m 2 apartment situated in the TIMC laboratory buildings, at the Michalon hospital of Grenoble. The patient carries a set of sensors which give information about his activity : vertical position (standing) or horizontal (lying) and sudden move (falling). The localization sensors with infra-red radiation are installed in each part of the apartment in order to establish where the person is at any moment. These sensors communicate with the acquisition system by radio waves and by bus CAN. The control of the activities sensors is ensured by a PC using a monitoring software programmed in JAVA. Fig. 1. Position of the sensors inside the apartment The sound sensors are represented by 8 microphones, their position is given in Figure 1. An acoustic antenna composed of 4 microphones allows to monitor both the living room and the bedroom, aiming to localize the patient inside the two rooms and also to analyze the sounds. As the other rooms are much smaller, only one microphone per room is sufficient. The microphones used are omni-directional, condenser type, of small size and low cost. A signal conditioning card, consisting of an amplifier and an anti-aliasing filter is associated to each microphone. The acquisition system consists of a multi-channels acquisition card PCI 6034E of National Instruments, installed inside a second computer. The acquisition is made at a sampling Sejour Hall Salle de Bains Local Technique M1 M2 M3 M4 M5÷ ÷8 Acoustic antenna Telemonitoring System Living Room Technical room Hall Toilet Shower IS1 IS2 IS3 DC1 M1-8 - microphones IS1-3 – infrared sensors DC1 – Door contact Bedroom IS4