Nursing homes are overcrowded and medical staff is overworked. Then, the management of this type of institution become so difficult. Monitoring system may be used to facilitate task of nurses and medical staff. Various solutions and supervision systems require extracting information regarding people present in the monitored environment. Innovative sensors are required to have more robustness. The need of new sensors is identified by the drawbacks of supervision software. In this manner, we have initiated our work to develop a bed sensor, as the implemented monitoring system cannot detect the presence of the immobile and silent subject in his room. Generally in nursing homes, a resident get on his bed when he get in his room, so the subject spent more time in his bed when he is present in the room. Thus, bed sensor provide an important information for medical staff. Information will be presented in simple manner to nurses, so the manner to present this information represent a significant task in e-Monitor'Age project