Marco Dozza - PhD in Bioengineering, 2003-2007

Biofeedback Systems for Postural Control

XVIIth ISPGR Conference, 29 May · 2 June 2005 - Marseille, France

• F.B. Horak, M. Dozza , and L. Chiari, “Audio biofeedback: sensory substitution for vestibular loss”, Gait & Posture, vol.21(Suppl.1),pp.S131-2, June 2005.



Abstract - Introduction: This study tests the hypothesis that audio-biofeedback (ABF) signaling accelerations related to body center of mass movements can provide an effective and specific sensory substitution for loss of vestibular information. Methods: We quantified the effects of ABF on standing postural sway (center of foot pressure area) of 9 subjects with profound, bilateral loss of vestibular function (BVL) and 9 age-matched, healthy control subjects under 3 conditions: eyes closed on solid surface and eyes open or closed on a foam support surface. When using ABE subjects received a unique, nonlinear frequency- and volume modulation of stereo sound that represented the anterior-posterior- (AP) and medial-lateral- displacement and velocity of trunk sway [1]. Results: ABF significantly reduced postural sway more in BVL subjects (39%, SE ±7.51) than control subjects (28%, SE ±4.23) when standing on foam with eyes closed. The benefit from ABF was proportional to the amount of BVL deficit. The relative benefit from ABF across sensory conditions also depended on how much each subject was dependent on visual or somatosensory information. Limiting ABF information to the AP direction specifically improved primarily AP postural sway. Discussion and Conclusion: This ABF sound wave modulation provides effective sensory substitution when other information is compromised by pathology or by environmental conditions. BVL and control subjects use different strategies for reducing postural sway with ABF may provide an effective balance aid because patients with profound BVL who could not stand on the foam with eyes closed effectively substituted with ABF.

[1] L. Chiari, M. Dozza, A. Cappello, F. B. Horak, V. Macellari, and D. Giansanti, "Audio-biofeedback for balance improvement: an accelerometry-based system," IEEE Trans. Biomed. Eng, vol. 52, no. 12, pp. 2108-2111, Dec.2005.

This research was supported by NIH grants DC004082 and DC006201.

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