ABSTRACT
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.
ABSTRACT
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.
Subject(s)
Clothing , Monitoring, Ambulatory/instrumentation , Motion , Telemedicine , Activities of Daily Living/classification , Humans , Magnetics , Monitoring, Ambulatory/methodsABSTRACT
Functional MRI (f-MRI) is a non-invasive technique developed to permit functional mapping of the brain with a better temporal and spatial resolution than that offered by PET techniques. In our study, f-MRI was performed using blood oxygenation level dependent (BOLD) contrast imaging based on the magnetic properties of hemoglobin. This method relies on changes in the blood supply to the brain that accompany sensory stimulation or changes in cognitive state. All the images were obtained at 1.5 T on a Signa GEMS without ultrafast imaging. The vestibular stimulation was cold irrigation of the external auditory meatus (caloric stimulation). A population of normal healthy volunteers without a history of vestibular dysfunction was studied. The hippocampal formation as well as the retrosplenial cortex and the subiculum were activated by vestibular stimulation, suggesting that this activation may be related to spatial disorientation and a sensation of self-rotation experienced by the subjects during vestibular stimulation. The other results are similar to those obtained using PET.
Subject(s)
Hippocampus/physiology , Magnetic Resonance Imaging , Vestibular Nuclei/physiology , Brain Mapping , Female , Humans , MaleABSTRACT
Recent works show the possibility of MRI to study brain functionalities. Today, treatment relies essentially on addition and subtraction of images accumulated during rest and activity periods. But this technic is not discriminating and we have developed a software to see and treat images with filtering algorithm and statistical analysis of signal. The first results are given. Perfections are possible and are being realized.