A mini wearable wireless sensor for rehabilitation applications

In the last ten years, a lot of focus has been on capturing body movements by inertial and magnetometer sensors. Accuracy of the sensors have been increasing and they cover more body motions. This paper presents design and fabrication of a real-time angle measurement system with applications in rehabilitation. The system consists of a wireless angle measurement and a central node to send and receive data. Each wireless angle measurement includes a 3-D accelerometer, gyroscope and magnetometer sensor, a microcontroller and a transceiver operating at Industrial, Scientific and Medical (ISM) band frequency 2.4 GHz. To estimate angle a complementary filter is presented. The system is implemented and successfully evaluated in different angles and Root Mean Square (RMS) static and dynamic errors for three-angles are reduced to less than 2.1 and 2.6 degree respectively.