Inertial Measurement units based wireless sensor network for real time gait analysis

This paper discusses a methodology to analyze human gait using a wearable sensor mechanism based on Inertial Measurement Units (IMUs). Our approach uses three 6 DOF Inertial Measurement Units to analyze the motion of the lower limb. The kinematic constraints induced by a hinge joint are used to accurately estimate the joint axes of the knee and ankle joints. This method does not require the sensors to be placed on a predefined orientation. Kalman filtering based sensor fusion algorithm is implemented to fusion the gyroscope and accelerometer readings and calculate accurate joint angles. The accuracy of the algorithms is tested using pendulum motion and experimental results taken from people without any gait disorders. Finally the system is used to test two sets of people with and without gait disorders and a comparison of the results is also presented.