Neuromotor Recovery Laboratory, Department of Physical Therapy and Athletic Training, College of Health and Rehabilitation Sciences: Sargent College, Boston University, Boston, MA 02215, USA.
Department of Mechanical Engineering, Boston University, Boston, MA 02215, USA.
Sensors (Basel). 2021 Oct 21;21(21):6976. doi: 10.3390/s21216976.
We present the use of a single inertial measurement unit (IMU) worn on the thigh to produce stride-by-stride estimates of walking speed and its spatiotemporal determinants (i.e., stride time and stride length). Ten healthy and eight post-stroke individuals completed a 6-min walk test with an 18-camera motion capture system used for ground truth measurements. Subject-specific estimation models were trained to estimate walking speed using the polar radius extracted from phase portraits produced from the IMU-measured thigh angular position and velocity. Consecutive flexion peaks in the thigh angular position data were used to define each stride and compute stride times. Stride-by-stride estimates of walking speed and stride time were then used to compute stride length. In both the healthy and post-stroke cohorts, low error and high consistency were observed for the IMU estimates of walking speed (MAE < 0.035 m/s; ICC > 0.98), stride time (MAE < 30 ms; ICC > 0.97), and stride length (MAE < 0.037 m; ICC > 0.96). This study advances the use of a single wearable sensor to accurately estimate walking speed and its spatiotemporal determinants during both healthy and hemiparetic walking.
我们展示了一种使用单个惯性测量单元 (IMU) 佩戴在大腿上的方法，以逐步估计行走速度及其时空决定因素（即步长和步长）。 10 名健康人和 8 名脑卒中患者使用 18 个摄像头运动捕捉系统完成了 6 分钟步行测试，该系统用于进行地面真实测量。使用从 IMU 测量的大腿角度位置和速度产生的相图中提取的极半径，为每个个体训练了特定于个体的估计模型，以估计行走速度。连续的大腿角度位置数据中的弯曲峰值用于定义每个步长并计算步长时间。然后，使用逐步估计的行走速度和步长时间来计算步长长度。在健康组和脑卒中组中，IMU 对行走速度（MAE <0.035 m/s；ICC> 0.98）、步长时间（MAE <30 ms；ICC> 0.97）和步长长度（MAE <0.037 m；ICC> 0.96）的估计均表现出低误差和高一致性。本研究推进了使用单个可穿戴传感器在健康和偏瘫行走期间准确估计行走速度及其时空决定因素的方法。
