Miniature Wireless Inertial Sensor for Measuring Human Motions

A sensor system for measuring human motions is presented. The system consists of a number of miniature wireless inertial sensors that are attached to limbs of a person, and a PC with a wireless receiver that interprets and presents the measurement data. Each of the sensors measures 3D- acceleration, 3D-magnetization (earth magnetic field) and 3D- angular speed (gyroscopes). The data is transmitted via a proprietary protocol on an 802.15.4 radio. The angular accuracy of the calibrated system was found to be better than 3 degrees. The system is currently being applied in a pilot trial for motor rehabilitation of stroke patients.