ACTIDOM--a microsystem based on MEMS for activity monitoring of the frail elderly in their daily life.

A "ambulatory activity recorder" was developed, with 3 accelerometers and 3 magnetometers, to detect and qualify the elementary activities of a person, such as walking and transfers. The signal processing is explained, along with the preliminary results obtained on young and older healthy subjects. This work open the way to continuous and automatic monitoring of the level of mobility.

Evaluation of postural stability by means of a single inertial sensor.

Human posture control during standing is a combination of many complicated control processes. Physical therapists perform different clinical balance tests to either assess postural control or identify balance disorders that can ultimately cause a patient to fall. In this article, several standardized clinical exercises for balance assessment are executed together with an orientation tracker strapped onto the volunteer's sternum. The tracker estimates the 3-D orientation of the trunk in real-time using an efficient attitude determination algorithm. The device is fully portable and sensitive to anteroposterior and mediolateral sways. Analysis of the resulting angles provides several parameters that are useful in assessing and quantifying balance function. This approach could be a valuable tool for a therapist for patient's follow-up and could be combined with existing procedures such as force platforms or optical motion analysis systems. Also, statistical analysis on these parameters could help to characterize normal and pathological performances in a population.

Body motion capture for activity monitoring.

CEA-LETI has developed a 3D orientation tracker based on accelerometers and magnetometers. Owing to an efficient data fusion algorithm, the tracker provides accurate 3D orientation angles. The tracker is small enough to be used as a wearable device and therefore is an interesting tool for body motion capture. Investigations are being performed to analyse how activity of a person can be monitored from body motion measured with the tracker. In the domain of healthcare monitoring, many applications are envisaged such as rehabilitation with 3D body motion capture, elderly dependency evaluation, context acquisition for physiological monitoring.