应用脱成形同步挤压对放置在不同身体地点的单传感器加速度计的轨迹加速度进行估计 (Application of de-shape synchrosqueezing to estimate gait cadence from a single-sensor accelerometer placed in different body locations)

Objective: Commercial and research-grade wearable devices have become increasingly popular over the past decade. Information extracted from devices using accelerometers is frequently summarized as ``number of steps" (commercial devices) or ``activity counts" (research-grade devices). Raw accelerometry data that can be easily extracted from accelerometers used in research, for instance ActiGraph GT3X+, are frequently discarded. Approach: Our primary goal is proposing an innovative use of the {\em de-shape synchrosqueezing transform} to analyze the raw accelerometry data recorded from a single sensor installed in different body locations, particularly the wrist, to extract {\em gait cadence} when a subject is walking. The proposed methodology is tested on data collected in a semi-controlled experiment with 32 participants walking on a one-kilometer predefined course. Walking was executed on a flat surface as well as on the stairs (up and down). Main Results: The cadences of walking on a flat surface, ascending stairs, and descending stairs, determined from the wrist sensor, are 1.98$\pm$0.15 Hz, 1.99$\pm$0.26 Hz, and 2.03$\pm$0.26 Hz respectively. The cadences are 1.98$\pm$0.14 Hz, 1.97$\pm$0.25 Hz, and 2.02$\pm$0.23 Hz, respectively if determined from the hip sensor, 1.98$\pm$0.14 Hz, 1.93$\pm$0.22 Hz and 2.06$\pm$0.24 Hz, respectively if determined from the left ankle sensor, and 1.98$\pm$0.14 Hz, 1.97$\pm$0.22 Hz, and 2.04$\pm$0.24 Hz, respectively if determined from the right ankle sensor. The difference is statistically significant indicating that the cadence is fastest while descending stairs and slowest when ascending stairs. Also, the standard deviation when the sensor is on the wrist is larger. These findings are in line with our expectations. Conclusion: We show that our proposed algorithm can extract the cadence with high accuracy, even when the sensor is placed on the wrist.

翻译：目标: 商业和研究级磨损装置在过去十年中越来越受欢迎。从使用加速度计的装置中提取的信息经常被概括为“ 步骤数量” (商业设备) 或“活动计数 ” (研究级设备)。从用于研究的加速度计(例如 ActiGraph GT3X+) 中容易提取的辐射测量数据。方法 : 我们的首要目标是以创新方式使用 $ Ex- de shape 同步变来分析从不同身体地点安装的单一传感器中记录的原始加速度数据: 以手势为单位的“步骤数量” (商业设备) 或“活动计数 ” (研究级设备) 。从32名参与者的半控制实验中收集的数据, 如 Acligraph GT3X+, 经常被丢弃。我们的主要目标是使用平面和左上( 上下) $ $ 。主要结果: 从平面、上层楼梯和下方$ 1.24 美元, 向右下方为1美元, 从手表传感器分别显示 H- 0. 20 2.25 显示 Hz 的H. 和 h.26 。