Galvanic vestibular stimulation system and method

Abstract

A system and method of altering the output of a vestibular system including providing a source of time-varying galvanic current, transcutaneously delivering time-varying galvanic current to vestibular afferents associated with the vestibular system in order to modulate firing level of the vestibular afferents, and inducing a coherent time-varying sway response that counteracts postural sway. In an alternative embodiment there is provided a galvanic vestibular stimulation system including a source which transcutaneously delivers time-varying galvanic current to vestibular afferents in order to modulate the firing level of the vestibular afferents, a monitor which monitors postural sway thereby providing indication of necessary galvanic current to be delivered. The system induces a coherent time-varying sway response that counteracts the monitored postural sway.

What is claimed is:  
     
         1 . A method of altering the output of a vestibular system comprising: 
 providing a source of time-varying galvanic current;    transcutaneously delivering time-varying galvanic current to vestibular afferents associated with said vestibular system in order to modulate firing level of said vestibular afferents; and    inducing a coherent time-varying sway response that counteracts postural sway.    
     
     
         2 . The method of  claim 1 , wherein said firing level is increased in response to delivering cathodal galvanic currents.  
     
     
         3 . The method of  claim 1 , wherein said firing level is decreased in response to delivering anodal galvanic currents.  
     
     
         4 . The method of  claim 1 , wherein said postural sway is self-generated.  
     
     
         5 . The method of  claim 1 , wherein said postural sway is externally-generated.  
     
     
         6 . The method of  claim 1  further comprising monitoring postural sway in order to determine the characteristics of the galvanic current to be delivered.  
     
     
         7 . The method of  claim 1 , wherein said coherent time-varying sway reduces said postural sway.  
     
     
         8 . The method of  claim 1 , wherein said coherent time-varying sway eliminates said postural sway.  
     
     
         9 . A galvanic vestibular stimulation system comprising: 
 a source of time-varying galvanic current; and    a delivery module which transcutaneously delivers time-varying galvanic current to vestibular afferents associated with said vestibular system in order to modulate firing level of said vestibular afferents; and    means for inducing a coherent time-varying sway response that counteracts postural sway.    
     
     
         10 . The system of  claim 9 , wherein said firing level is increased in response to delivering cathodal galvanic currents.  
     
     
         11 . The system of  claim 9 , wherein said firing level is decreased in response to delivering anodal galvanic currents.  
     
     
         12 . The system of  claim 9 , wherein said postural sway is self-generated.  
     
     
         13 . The system of  claim 9 , wherein said postural sway is externally-generated.  
     
     
         14 . The system of  claim 9  further comprising a monitor that monitors postural sway in order to determine the characteristics of the galvanic current to be delivered.  
     
     
         15 . The system of  claim 9 , wherein said coherent time-varying sway reduces said postural sway.  
     
     
         16 . The system of  claim 9 , wherein said coherent time-varying sway eliminates said postural sway.  
     
     
         17 . A galvanic vestibular stimulation system comprising: 
 a time-varying galvanic current source which transcutaneously delivers time-varying galvanic current to vestibular afferents in order to modulate the firing level of said vestibular afferents: 
 a monitor which monitors postural sway thereby providing indication of necessary galvanic current to be delivered; and  
 means for inducing a coherent time-varying sway response that counteracts the monitored postural sway.  
   
     
     
         18 . A method of altering the output of a vestibular system comprising: 
 providing a source of time-varying anodal binaural galvanic current; and    transcutaneously delivering time-varying anodal binaural galvanic current to vestibular afferents associated with said vestibular system in order to reduce firing level of said vestibular afferents, thus reducing or eliminating the functionality of said vestibular afferents.    
     
     
         19 . A method of altering the output of a vestibular system comprising: 
 providing a source of time-varying cathodal binaural galvanic current; and    transcutaneously delivering time-varying cathodal binaural galvanic current to vestibular afferents associated with said vestibular system in order to increase firing level of said vestibular afferents, thus enhancing the functionality of said vestibular afferents.