Design and Analysis of a Non-Vision-Based System for Detecting Unstable Gait

Abstract

An unstable gait provides early warning of more serious conditions. In this study, we propose the use of pressure sensors embedded into a shoe pad along with a 3D accelerometer fastened to the knee. We have implemented a portable gait-measuring device integrated with a ZigBee wireless sensor network. Moreover, the step length, step speed, and step distance are easily calculated in the user interface. These data can then be used to distinguish the seven decision points of a complete gait cycle. Analysis of the gait cycle is done using fuzzy logic. The detected gait phases can be compared with standard gait parameters from the literature. Thus, the analyzed gait parameters can provide early detection of the emergence of an unstable gait. Finally, because our system measures knee flexion angle, it can detect the swing phase of the gait cycle.