Highly Accurate Wearable Attitude and Heading Reference System for kinematics assessment and AAL applications

In this paper we propose a wireless wearable device useful for a series of real-time monitoring functions depending on the desired application and the placement of the unit on the body of the subject. It contains a 3-axis accelerometer, a 3-axis gyroscope and a 3-axis magnetometer, realizing an Attitude Heading Reference System (AHRS), plus a barometric unit. The AHRS provides the correct 3D orientation referred to the terrestrial axis through an implemented data fusion algorithm. On the sensor board can also be real time execute the automatic fall detection algorithm, handling the orientation data from AHRS and the acceleration data from the triaxial accelerometer, in addition to the orientation filtering that corrects the raw data coming from the barometer to furnish the right altitude of the subject. Based on the excellent results achieved the proposed AHRS, we have developed a series of custom devices for the automatic evaluation of kinematic parameters useful to the diagnosis of certain pathologies. In particular, the developed AHRS has been used as an aid to clinical diagnosis of patients with Parkinson’s disease, chronic back pain and Multiple Sclerosis.