Vichare V V, Wall C, Balkwill M D, Sienko M D
Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:6910-3. doi: 10.1109/IEMBS.2009.5333618.
This study uses frequency domain techniques to demonstrate the effect of vibrotactile feedback during continuous multidirectional perturbations of a support platform. Eight subjects with bilateral or unilateral vestibular loss were subjected to two-axis pseudo random surface platform motion while donning a multi-axis feedback balance aid that mapped body tilt estimates onto their trunks via a 3-row by 16-column array of tactile vibrators (tactors). Four tactor display configurations with spatial resolutions ranging between 22.5 degrees and 90 degrees , in addition to the tactors off configuration, were evaluated. Power spectral density (PSD) functions of body sway in the anterior-posterior (A/P) and medial-lateral (M/L) directions were computed at frequencies ranging from 0.0178 Hz to 3.56 Hz. Transfer functions between the platform motion and body sway were also computed. Vibrotactile feedback produced significant decreases in A/P and M/L spectral power, decreased transfer function gains up to a frequency of 1.8 Hz and 0.6 Hz in the A/P and M/L directions, respectively, and increased phase leads above 0.3 Hz. The lack of a consistent difference among tactor configurations argue in favor of the simplest 4-column configuration during multidirectional continuous surface perturbations.
本研究采用频域技术来证明在支撑平台连续多向扰动期间振动触觉反馈的效果。八名双侧或单侧前庭丧失的受试者在佩戴多轴反馈平衡辅助装置时，接受两轴伪随机表面平台运动，该装置通过一个3行16列的触觉振动器（触觉器）阵列将身体倾斜估计值映射到他们的躯干上。除了触觉器关闭配置外，还评估了四种空间分辨率在22.5度至90度之间的触觉器显示配置。在0.0178赫兹至3.56赫兹的频率范围内，计算了身体在前后（A/P）和内外（M/L）方向上摆动的功率谱密度（PSD）函数。还计算了平台运动与身体摆动之间的传递函数。振动触觉反馈使A/P和M/L频谱功率显著降低，在A/P和M/L方向上分别在高达1.8赫兹和0.6赫兹的频率下降低了传递函数增益，并在高于0.3赫兹时增加了相位超前。触觉器配置之间缺乏一致差异表明，在多向连续表面扰动期间，最简单的4列配置是有利的。
