Real-Time Gait Phase Recognition Based on Time Domain Features of Multi-MEMS Inertial Sensors

Gait phase analysis is widely used in disease diagnosis, rehabilitation training and other fields by studying the characteristics of human gait. It systematically evaluates human body’s skeletal muscles and nerves with combined disciplines. MEMS (Micro Electromechanical System) inertial sensors are extensively used in attitude detection because of its high-precision, portability and good real-time performance in time-domain analysis. In this paper, we presented a multi-degree-of-freedom MEMS gait detection method, which resolved the problems of single sensor and limited gait phase. We designed a sensor-based gait signal acquisition system, in which gait data acquisition program and feature analysis algorithm were compiled to verify the feasibility of the proposed method. We performed coordinate transformation and corrected position information to eliminate the gait phase detection error caused by random noise interference. Acceleration and angular velocity information were collected from 20 experimenters. We applied an adaptive threshold gait phase detection algorithm to classify the gait information collected by single sensor. In order to improve the results of gait phase classification, we used multi-sensor redundant measurement to analyze characteristics of five gait phases. The acceleration and angular velocity information collected by the three sensors placed at instep, ankle and thigh were input into SVM. The classification results of the five gait phases are approximately 90%. Lastly, we built a human body structure model to simulate human motion in real time, realizing the real-time gait phase detection, which proves effectiveness of the proposed algorithm.