A wireless sensor network for the biomechanical analysis of the gait

In this paper a data acquisition system based on wireless sensor networks to support the biomechanical gait analysis will be presented. The system is composed by sensor nodes that can be fasten to the limbs of a person. Each node contains the ESP8266 platform connected to a MPU6050 module that includes a gyroscope and an accelerometer. The system starts working in a self-adjusting (auto calibration) phase. Data-acquisition follows next when the signal from the accelerometer is converted in degrees and the one from the gyroscope in degrees per second. In the host computer data from the gyro are modeled employing a rotational matrix applying the Euler angle method and the quaternions. The outputs of both sensors are combined by means of a complementary filter and the information so obtained confirms that the body is in motion. A special mechanical device was designed to validate sensor measurements. New improvements will be soon incorporated, even though the results obtained so far testify that it already can be used as an inexpensive substitute for the costly opto-tracking cameras.