A measurement system to monitor postural behaviour: strategy assessment and classification rating

Postural instability is a symptom of disorders like ear diseases, high blood pressure, diabetes, psychiatric disorders, and neurodegenerative diseases like Parkinson and one of the main causes of falls. A continuous monitoring of the patient’s postural stability while performing the daily activities would be of strategic interest for the doctors to gain continuous information on the user pathology or its progression. This article focuses on the experimental assessment of a wearable inertial device aimed at the continuous monitoring of the user’s postural sway, which exploits a novel postural sway classification algorithm providing a classification index. Two performance keys have been proposed: 1) to assess the postural sway monitoring strategy and 2) to rate the reliability of the classification outcome. Experiments reported in this article have been performed involving “healthy” users miming typical instability dynamics under the supervision of the neurologists. In the case of study addressed through this article, a full classification success has been obtained with an overall reliability of about 70%.