Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada; Division of Physical Medicine and Rehabilitation, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, Canada.
Gait Posture. 2021 Oct;90:137-140. doi: 10.1016/j.gaitpost.2021.08.020. Epub 2021 Aug 27.
Quantitative assessments of activities of daily living (ADL) play an essential role in evaluating the impact of disease and interventions on people's quality of life. Motion capture systems traditionally used for quantitative assessments of postural transitions and movement associated with ADL are limited to the laboratory setting. Wearable accelerometers can remove these limitations and enable easier-to-use, longer-term, and remote functional evaluations.
To investigate the validity of a single tri-axial accelerometer mounted on the head for monitoring postural transition and the timed-up-and-go test.
Two accelerometers with a sampling frequency of 100 Hz were attached to twelve able-bodied study participants' sternum and right mastoid process. We developed algorithms for the functional calibration of accelerometers and the detection of the postural transitions by measuring the head inclination angle and variations of the gravitational components of the accelerometer readout. Participants performed a battery of ADL tests involving a wide variety of postural transitions. The head-mounted accelerometers results were compared with a sternum-mounted accelerometer and validated against a video motion capture system as a gold standard reference.
The results indicate that, utilizing our proposed algorithm, a single tri-axial accelerometer mounted on the head can deliver high accuracy (>95 %), sensitivity (>90 %), and specificity (100 %) for detecting both postural transitions and walking events. Together with the small size and unobtrusive placement of the head-mounted accelerometer, these results demonstrate an attractive solution for the reliable assessment of ADLs and clinical evaluations based on functional tests such as the timed-up-and-go test.
日常生活活动（ADL）的定量评估在评估疾病和干预措施对人们生活质量的影响方面起着至关重要的作用。传统上用于评估与 ADL 相关的姿势转换和运动的运动捕捉系统仅限于实验室环境。可穿戴加速度计可以消除这些限制，并实现更易于使用、更长时间和远程的功能评估。
研究安装在头部的单个三轴加速度计监测姿势转换和计时起立行走测试的有效性。
将两个采样频率为 100Hz 的加速度计分别安装在 12 名健康研究参与者的胸骨和右乳突上。我们开发了用于加速度计功能校准和通过测量头部倾斜角度和加速度计读数的重力分量变化来检测姿势转换的算法。参与者进行了一系列涉及各种姿势转换的 ADL 测试。将头戴式加速度计的结果与胸骨式加速度计进行比较，并与视频运动捕捉系统作为金标准参考进行验证。
结果表明，利用我们提出的算法，安装在头部的单个三轴加速度计可以实现高准确性（>95%）、高灵敏度（>90%）和特异性（100%），用于检测姿势转换和行走事件。头戴式加速度计的小巧尺寸和不显眼的放置位置，这些结果表明，基于计时起立行走测试等功能测试，可靠评估 ADL 和临床评估具有吸引力的解决方案。
