M-Sense Research Group, University of Vermont, Burlington, VT 05405, USA.
Medidata Solutions, A Dassault Systèmes Company, New York, NY 10014, USA.
Sensors (Basel). 2022 Sep 15;22(18):6982. doi: 10.3390/s22186982.
Wearable sensors facilitate the evaluation of gait and balance impairment in the free-living environment, often with observation periods spanning weeks, months, and even years. Data supporting the minimal duration of sensor wear, which is necessary to capture representative variability in impairment measures, are needed to balance patient burden, data quality, and study cost. Prior investigations have examined the duration required for resolving a variety of movement variables (e.g., gait speed, sit-to-stand tests), but these studies use differing methodologies and have only examined a small subset of potential measures of gait and balance impairment. Notably, postural sway measures have not yet been considered in these analyses. Here, we propose a three-level framework for examining this problem. Difference testing and intra-class correlations (ICC) are used to examine the agreement in features computed from potential wear durations (levels one and two). The association between features and established patient reported outcomes at each wear duration is also considered (level three) for determining the necessary wear duration. Utilizing wearable accelerometer data continuously collected from 22 persons with multiple sclerosis (PwMS) for 6 weeks, this framework suggests that 2 to 3 days of monitoring may be sufficient to capture most of the variability in gait and sway; however, longer periods (e.g., 3 to 6 days) may be needed to establish strong correlations to patient-reported clinical measures. Regression analysis indicates that the required wear duration depends on both the observation frequency and variability of the measure being considered. This approach provides a framework for evaluating wear duration as one aspect of the comprehensive assessment, which is necessary to ensure that wearable sensor-based methods for capturing gait and balance impairment in the free-living environment are fit for purpose.
可穿戴传感器有助于在自由生活环境中评估步态和平衡障碍，通常观察期为数周、数月甚至数年。需要支持传感器佩戴的最小持续时间的数据，以捕捉损伤测量的代表性变异性，以平衡患者负担、数据质量和研究成本。先前的研究已经检查了各种运动变量（例如，步态速度、坐立测试）所需的持续时间，但这些研究使用不同的方法，并且仅检查了步态和平衡障碍潜在测量指标的一小部分。值得注意的是，在这些分析中尚未考虑姿势摆动测量。在这里，我们提出了一个三级框架来检查这个问题。差异检验和组内相关系数 (ICC) 用于检验从潜在佩戴持续时间（一级和二级）计算得出的特征的一致性。还考虑了每个佩戴持续时间特征与既定患者报告结果之间的关联（三级），以确定必要的佩戴持续时间。利用连续 22 名多发性硬化症患者 (PwMS) 佩戴可穿戴加速度计 6 周收集的加速度计数据，该框架表明，监测 2 至 3 天可能足以捕捉步态和摆动的大部分变异性；然而，可能需要更长的时间（例如，3 至 6 天）来建立与患者报告的临床测量的强相关性。回归分析表明，所需的佩戴持续时间取决于正在考虑的测量的观察频率和可变性。这种方法提供了一个评估佩戴持续时间的框架，作为全面评估的一个方面，这对于确保基于可穿戴传感器的自由生活环境中步态和平衡障碍的捕获方法符合目的是必要的。
