Sun Ruopeng, Moon Yaejin, McGinnis Ryan S, Seagers Kirsten, Motl Robert W, Sheth Nirav, Wright John A, Ghaffari Roozbeh, Patel Shyamal, Sosnoff Jacob J
Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
Department of Electrical and Biomedical Engineering, University of Vermont, Burlington, Vermont, USA.
Digit Biomark. 2018 Jan 23;2(1):1-10. doi: 10.1159/000485958. eCollection 2018 Jan-Apr.
Balance impairment is common in individuals with multiple sclerosis (MS). However, objective assessment of balance usually requires clinical expertise and/or the use of expensive and obtrusive measuring equipment. These barriers to the objective assessment of balance may be overcome with the development of a lightweight inertial sensor system. In this study, we examined the concurrent validity of a novel wireless, skin-mounted inertial sensor system (BioStamp®, MC10 Inc.) to measure postural sway in individuals with MS by comparing measurement agreement between this novel sensor and gold standard measurement tools (force plate and externally validated inertial sensor). A total of 39 individuals with MS and 15 healthy controls participated in the study. Participants with MS were divided into groups based on the amount of impairment (MS: EDSS 2-4, = 19; MS: EDSS ≥6, = 20). The balance assessment consisted of two 30-s quiet standing trials in each of three conditions: eyes open/firm surface, eyes closed/firm surface, and eyes open/foam surface. For each trial, postural sway was recorded with a force plate (Bertec) and simultaneously using two accelerometers (BioStamp and Xsens) mounted on the participant's posterior trunk at L5. Sway metrics (sway area, sway path length, root mean square amplitude, mean velocity, JERK, and total power) were derived to compare the measurement agreement among the measurement devices. Excellent agreement (intraclass correlation coefficients >0.9) between sway metrics derived from the BioStamp and the MTx sensors were observed across all conditions and groups. Good to excellent correlations ( >0.7) between devices were observed in all sway metrics and conditions. Additionally, the acceleration sway metrics were nearly as effective as the force plate sway metrics in differentiating individuals with poor balance from healthy controls. Overall, the BioStamp sensor is a valid and objective measurement tool for postural sway assessment. This novel, lightweight and portable sensor may offer unique advantages in tracking patient's postural performance.
平衡功能障碍在多发性硬化症（MS）患者中很常见。然而，平衡功能的客观评估通常需要临床专业知识和/或使用昂贵且侵入性的测量设备。随着一种轻便的惯性传感器系统的开发，这些平衡功能客观评估的障碍可能会被克服。在本研究中，我们通过比较这种新型传感器与金标准测量工具（测力平台和外部验证的惯性传感器）之间的测量一致性，检验了一种新型无线、可贴于皮肤的惯性传感器系统（BioStamp®，MC10公司）测量MS患者姿势摆动的同时效度。共有39例MS患者和15名健康对照者参与了本研究。MS患者根据损伤程度分为两组（MS：扩展残疾状态量表[EDSS] 2 - 4，n = 19；MS：EDSS≥6，n = 20）。平衡评估包括在三种条件下分别进行两次30秒的安静站立试验：睁眼/坚实表面、闭眼/坚实表面、睁眼/泡沫表面。对于每次试验，使用测力平台（Bertec）记录姿势摆动，并同时使用安装在参与者L5水平后躯干上的两个加速度计（BioStamp和Xsens）进行记录。得出摆动指标（摆动面积、摆动路径长度、均方根幅度、平均速度、急动度和总功率）以比较测量设备之间的测量一致性。在所有条件和组中，观察到BioStamp和MTx传感器得出的摆动指标之间具有极好的一致性（组内相关系数>0.9）。在所有摆动指标和条件下，观察到各设备之间具有良好到极好的相关性（r>0.7）。此外，加速度摆动指标在区分平衡功能差的个体与健康对照者方面几乎与测力平台摆动指标一样有效。总体而言，BioStamp传感器是一种用于姿势摆动评估的有效且客观的测量工具。这种新型轻便且便携的传感器在跟踪患者姿势表现方面可能具有独特优势。
