Telesurveillance of the Dependent Seniors Using Passive Infra-red Sensors in a Geriatric Hospital

To study the validity of a 'smart' system of telesurveillance in elderly patients, GARDIEN, a passive infra-red sensor network, was connected to a computer placed at a remote site from the patient. It switched on automatically every day and remained active throughout the night. Data corresponding to movements within the room were collected twice per second. During the experimental period, the data file were analyzed manually and automatically; the results of the automatic processing were displayed in the form of a list with all movements noted together with the time and each movement’s duration was stored in a patient file. GARDIEN showed the patient data either in the form of curves or as three-dimensional histograms. We studied the nocturnal activity of 23 Alzheimer patients, with or without cognitive impairment. Their activity profiles were different. Moreover, the nocturnal motor activity patterns permitted to identify pathological states.