What the electrical impedance can tell about the intrinsic properties of an electrodynamic shaker.
What the electrical impedance can tell about the intrinsic properties of an electrodynamic shaker.
复制标题
DOI：
10.1371/journal.pone.0174184
复制
发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Lütkenhöner B
中科院分区：
文献类型：
--
作者：
Lütkenhöner B
小型电动振动器在人类前庭系统的诊断研究中越来越受欢迎。更具体地说，它们用作机械刺激器，用于引发前庭诱发肌源电位（VEMP）。然而，在典型的测量条件下，振动台的性能在很大程度上尚不清楚，这与振动台的正常使用有很大不同。这里展示了如何在不需要加速度计或测力计等特殊传感器的情况下确定振动台的基本属性。本质上，振动台的机械部件在电阻抗中留下了特征，并且使用简单模型对该特征的解释可以得出关于振动台特性的结论。所开发的理论（非常通用，因此也可用于其他情况）适用于为 VEMP 测量中常用的微型摇床获得的实验数据。结果表明，实验条件对振动筛的性能有很大影响。相关因素特别是摇床的空间方向（直立、水平或倒置）以及作用在摇床桌子上的静力（在实际测量中对应于摇床压在测试人员头部的力）。这些结果强调了 VEMP 测量适当标准化的必要性。位移和加速度的直接测量证明了电阻抗得出的结论的一致性。
Small electrodynamic shakers are becoming increasingly popular for diagnostic investigations of the human vestibular system. More specifically, they are used as mechanical stimulators for eliciting a vestibular evoked myogenic potential (VEMP). However, it is largely unknown how shakers perform under typical measurement conditions, which considerably differ from the normal use of a shaker. Here, it is shown how the basic properties of a shaker can be determined without requiring special sensors such as accelerometers or force gauges. In essence, the mechanical parts of the shaker leave a signature in the electrical impedance, and an interpretation of this signature using a simple model allows for drawing conclusions about the properties of the shaker. The theory developed (which is quite general so that it is usable also in other contexts) is applied to experimental data obtained for the minishaker commonly used in VEMP measurements. It is shown that the experimental conditions substantially influence the properties of the shaker. Relevant factors are, in particular, the spatial orientation of the shaker (upright, horizontal or upside-down) and the static force acting on the table of the shaker (which in a real measurement corresponds to the force by which the shaker is pressed against the test person’s head). These results underline the desirability of a proper standardization of VEMP measurements. Direct measurements of displacement and acceleration prove the consistency of the conclusions derived from the electrical impedance.