Electrode multiplexing method for retinal prosthesis

Abstract

A method is disclosed for efficient multiplexing of a plurality of electrodes in a nerve stimulator using improved, predetermined, regular, repeatable geometric patterns arranged in a predetermined mosaic to form a desired array. Multiple electrodes within said array are addressed by the nerve stimulator as being a stimulating electrode by an instruction specifying a single identifier, indicating a position within each regular geometric pattern. As such, each electrode within the array, maintaining the specified position within its respective repeatable geometric pattern, becomes a stimulating electrode and is connected to the appropriate electronic circuit for subsequent, potential use in nerve stimulation.

1 . A multiplexing method for neural prosthesis, comprising: 
 regular, repeatable geometric patterns arranged in a predetermined mosaic to form a desired electrode array;    a single integer number to specify the stimulating electrode within each of said regular, repeatable geometric patterns thereby specifying all stimulating electrodes throughout said desired electrode array;    a single integer number to specify the electrical return path electrode within each of said regular, repeatable geometric patterns thereby specifying all electrical return path electrodes throughout said desired electrode array;    a single boolean number to specify whether or not said electrical return path electrode within each of said regular, repeatable geometric patterns is paired with an adjacent electrode;    individual or uniform control over stimulation amplitude of electrical stimulation from each of said regular, repeatable geometric patterns.    
     
     
         2 . The switching methodology of  claim 1 , wherein said stimulating electrodes are connected to current or voltage sources by way of a pre-determined rule set.  
     
     
         3 . The pre-determined rule set of  claim 2 , wherein said stimulating electrodes may deliver electrical stimulus simultaneously.  
     
     
         4 . A method of defining the stimulating electrode as any one or several electrodes corresponding to a particular position within said regular, repeatable geometric pattern of  claim 1  that collectively form an electrode array.  
     
     
         5 . A method of surrounding each stimulating electrode defined by the method of  claim 4  with a guard ring such that charge transfer to or from adjacent and distant electrodes within other regular, repeatable geometric patterns within an array is reduced.  
     
     
         6 . A method of forming a partial guard ring at the periphery of an electrode array such that charge transfer to or from adjacent and distant electrodes within other regular, repeatable geometric patterns within an array is reduced.  
     
     
         7 . A method of using an entire repeatable geometric pattern of  claim 1  as a single entity such that said repeatable geometric patterns may be used as subunits to form larger repeatable geometric patterns.