Department of Mechanical Engineering, Wilkes University, Wilkes-Barre, PA 18766, USA.
Sensors (Basel). 2017 Mar 18;17(3):619. doi: 10.3390/s17030619.
Measurement of the displacement of the center-of-pressure (COP) is an important tool used in biomechanics to assess postural stability and human balance. The goal of this research was to design and validate a low-cost portable device that can offer a quick indication of the state of postural stability and human balance related conditions. Approximate entropy (ApEn) values reflecting the amount of irregularity hiding in COP oscillations were used to calculate the index. The prototype adopted a portable design using the measurements of the load cells located at the four corners of a low-cost force platform. The test subject was asked to stand on the device in a quiet, normal, upright stance for 30 s with eyes open and subsequently for 30 s with eyes closed. Based on the COP displacement signals, the ApEn values were calculated. The results indicated that the prototype device was capable of capturing the increase in regularity of postural control in the visual-deprivation conditions. It was also able to decipher the subtle postural control differences along anterior-posterior and medial-lateral directions. The data analysis demonstrated that the prototype would enable the quantification of postural stability and thus provide a low-cost portable device to assess many conditions related to postural stability and human balance such as aging and pathologies.
测量中心压力（COP）的位移是生物力学中评估姿势稳定性和人体平衡的重要工具。本研究的目的是设计和验证一种低成本的便携式设备，能够快速指示姿势稳定性和与人体平衡相关的状态。采用近似熵（ApEn）值来计算反映 COP 振荡中隐藏不规则程度的指标。该原型采用了一种便携式设计，使用位于低成本力平台四个角的称重传感器来进行测量。测试对象被要求在设备上安静、正常、直立站立 30 秒，睁眼，然后闭眼 30 秒。根据 COP 位移信号，计算 ApEn 值。结果表明，原型设备能够捕捉到在视觉剥夺条件下姿势控制规则性的增加。它还能够辨别前后和内外方向上微妙的姿势控制差异。数据分析表明，该原型设备将能够量化姿势稳定性，从而提供一种低成本的便携式设备来评估与姿势稳定性和人体平衡相关的许多条件，如衰老和病理学。
