Abstract
Analysis of spatiotemporal gait parameters is useful as movement function evaluations for the elderly and patients with gait disorders. A laser range sensor (LRS) has been employed as the leg tracking technique for spatiotemporal gait analysis in the clinical sites. However, previous systems had difficulty tracking legs during walking along a circular trajectory, which was often included in clinical tests, because of frequent overlaps and occlusions of legs. Therefore, this paper presents a spatiotemporal gait analysis system that fuses LRS and kinetic insoles. The system tracks leg motions using LRS, considering gait phase detection and change of the noise covariance for Kalman filter, by using the insoles via force sensing. In addition, the system detects foot contact positions using the center of pressure position measured by the insole. In the experiment participants walked along a circular trajectory, the proposed sensor fusion tracked leg motions in longer distance compared with the previous method. In addition, when compared with a motion capture system, the accuracy of the tracked leg trajectories ranged from 30 to 95 mm and the foot contact position was improved by using the insoles. From the results, the proposed sensor fusion was valid as the spatiotemporal gait analysis system.
