Sensory Interactions for Human Balance Control Revealed by Galvanic Vestibular Stimulation

Galvanic vestibular stimulation (GVS) is a simple, safe, and specific way to elicit vestibular reflexes. Yet, despite a long history, it has only recently found popularity as a research tool and is rarely used clinically. The obstacle to advancing and exploiting GVS is that we cannot interpret the evoked responses with certainty because we do not understand how the stimulus acts as an input to the system. This paper examines the electrophysiology and anatomy of the vestibular organs and the effects of GVS on human balance control and develops a model that explains the observed balance responses. These responses are large and highly organized over all body segments and adapt to postural and balance requirements. To achieve this, neurons in the vestibular nuclei receive convergent signals from all vestibular receptors and somatosensory and cortical inputs. GVS sway responses are affected by other sources of information about balance but can appear as the sum of otolithic and semicircular canal responses. Electrophysiological studies showing similar activation of primary afferents from the otolith organs and canals and their convergence in the vestibular nuclei support this. On the basis of the morphology of the cristae and the alignment of the semicircular canals in the skull, rotational vectors calculated for every mode of GVS agree with the observed sway. However, vector summation of signals from all utricular afferents does not explain the observed sway. Thus we propose the hypothesis that the otolithic component of the balance response originates from only the pars medialis of the utricular macula.

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Toward Stochastic Explanation of Neutrally Stable Delayed Feedback Model of Human Balance Control

Proceedings of the ISCIE International Symposium on Stochastic Systems Theory and its Applications ◽

10.5687/sss.2011.244 ◽

2011 ◽

Vol 2011 (0) ◽

pp. 244-249 ◽

Cited By ~ 1

Author(s):

Katsutoshi Yoshida

Keyword(s):

Balance Control ◽

Delayed Feedback ◽

Feedback Model ◽

Human Balance ◽

Human Balance Control

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Hardware-In-the-Loop Equipment for the Development of an Automatic Perturbator for Clinical Evaluation of Human Balance Control

Applied Sciences ◽

10.3390/app10248886 ◽

2020 ◽

Vol 10 (24) ◽

pp. 8886

Author(s):

Carlo Ferraresi ◽

Daniela Maffiodo ◽

Walter Franco ◽

Giovanni Gerardo Muscolo ◽

Carlo De Benedictis ◽

...

Keyword(s):

Balance Control ◽

The Body ◽

Clinical Settings ◽

Control Analysis ◽

Hardware In The Loop ◽

Control Laws ◽

Component Selection ◽

Risk Of Falls ◽

Human Balance ◽

Human Balance Control

Nowadays, increasing attention is being paid to techniques aimed at assessing a subject’s ability to maintain or regain control of balance, thus reducing the risk of falls. To this end, posturographic analyses are performed in different clinical settings, both in unperturbed and perturbed conditions. This article presents a new Hardware-In-the-Loop (HIL) equipment designed for the development of an automatic perturbator for postural control analysis, capable of providing controlled mechanical stimulation by means of an impulsive force exerted on a given point of the body. The experimental equipment presented here includes the perturbator and emulates its interaction with both the subject’s body and the operator performing the test. The development of the perturbator and of the entire HIL equipment is described, including component selection, modeling of the entire system, and experimentally verified simulations used to study and define the most appropriate control laws.

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