Assessing the effect of vibrotactile feedback during continuous multidirectional platform motion: a frequency domain approach.
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.
Vichare
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Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA. vvichare@umich.edu
Wall
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Balkwill
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Sienko
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D000328:Adult; D000368:Aged; D001698:Biomedical Engineering; D025461:Feedback, Physiological; D006801:Humans; D008875:Middle Aged; D009038:Motion; D004856:Postural Balance / Q000502:physiology*; D014110:Touch / Q000502:physiology; D015837:Vestibular Diseases / Q000503:physiopathology*; D014732:Vibration