BioInsights: Extracting personal data from "Still" wearable motion sensors

During recent years a large variety of wearable devices have become commercially available. As these devices are in close contact with the body, they have the potential to capture sensitive and unexpected personal data even when the wearer is not moving. This work demonstrates that wearable motion sensors such as accelerometers and gyroscopes embedded in head-mounted and wrist-worn wearable devices can be used to identify the wearer (among 12 participants) and his/her body posture (among 3 positions) from only 10 seconds of “still” motion data. Instead of focusing on large and apparent motions such as steps or gait, the proposed methods amplify and analyze very subtle body motions associated with the beating of the heart. Our findings have the potential to increase the value of pervasive wearable motion sensors but also raise important privacy concerns that need to be considered. Keywords— accelerometer; gyroscope; smartwatch; wrist; head; ballistocardiography; person identification; posture recognition; Support Vector Machines.