School of Information and Communications Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
College of Physics and Electronic Engineering, Shanxi University, Taiyuan 030006, China.
Sensors (Basel). 2024 Jun 27;24(13):4184. doi: 10.3390/s24134184.
A 77 GHz frequency-modulated continuous wave (FMCW) radar was utilized to extract biomechanical parameters for gait analysis in indoor scenarios. By preprocessing the collected raw radar data and eliminating environmental noise, a range-velocity-time (RVT) data cube encompassing the subjects' information was derived. The strongest signals from the torso in the velocity and range dimensions and the enveloped signal from the toe in the velocity dimension were individually separated for the gait parameters extraction. Then, six gait parameters, including step time, stride time, step length, stride length, torso velocity, and toe velocity, were measured. In addition, the Qualisys system was concurrently utilized to measure the gait parameters of the subjects as the ground truth. The reliability of the parameters extracted by the radar was validated through the application of the Wilcoxon test, the intraclass correlation coefficient (ICC) value, and Bland-Altman plots. The average errors of the gait parameters in the time, range, and velocity dimensions were less than 0.004 s, 0.002 m, and 0.045 m/s, respectively. This non-contact radar modality promises to be employable for gait monitoring and analysis of the elderly at home.
利用 77GHz 调频连续波（FMCW）雷达从室内场景中提取生物力学参数进行步态分析。通过预处理采集到的原始雷达数据并消除环境噪声，得出一个包含受试者信息的距离-速度-时间（RVT）数据立方体。在速度和距离维度上分别分离来自躯干的最强信号和来自脚趾的包络信号，以提取步态参数。然后，测量了六个步态参数，包括步时、步长、跨步长、躯干速度和脚趾速度。此外，还同时使用 Qualisys 系统测量受试者的步态参数作为地面实况。通过应用 Wilcoxon 检验、组内相关系数（ICC）值和 Bland-Altman 图验证了雷达提取参数的可靠性。时间、距离和速度维度的步态参数的平均误差分别小于 0.004s、0.002m 和 0.045m/s。这种非接触雷达模式有望用于在家中监测和分析老年人的步态。
