基于步高数据的双足步态对称性检测系统研究OACHSSCD

Aims:To address the high cost of optical gait analysis systems and the cumulative drift of inertial measurement units in displacement estimation,this study proposes a low-cost bilateral gait symmetry detection system based on ultrasonic ranging.Methods:Heel and toe ultrasonic sensors were mounted on both shoes to measure foot-to-ground distances.A two-dimensional foot model was used to estimate foot posture,step height,step length,and cadence.Gait symmetry was evaluated using the step-height symmetry index(SI),normalized cross-correlation(NCC),time-delay estimation(TDE),energy ratio(ER),and root mean square error(RMSE).Ten healthy participants were recruited to simulate normal,shuffling,and dragging gaits for experimental verification.Results:For step-length estimation,the mean absolute error(MAE),root mean square error(RMSE),bias and coefficient of determination(R2)were 2.76 cm,3.54 cm,0.37 cm and 0.945,respectively.The corresponding metrics for cadence estimation were 4.47 steps/min,5.71 steps/min,0.10 steps/min and 0.959.Symmetry analysis revealed that the equilibrium ratio(ER)of normal and shuffling gaits was close to 1;and the normalized cross-correlation(NCC)was overall higher than 0.9.The temporal deviation error(TDE)of shuffling gait decreased to 436 ms(toe)and 424 ms(heel).For dragging gait,the symmetry index(SI)rose to 1.223,while the heel-related ER,RMSE and TDE increased to 18.410,30.01 mm and 968 ms correspondingly.Conclusions:The proposed system can accurately extract stride length,cadence and gait symmetry features,which provides a reference for low-cost gait monitoring and rehabilitation assessment.