Combined optical and electrical neural stimulation

Abstract

A neural-stimulating device for stimulating nerve cells of a recipient is provided. The neural-stimulating device comprises an electromagnetic radiation source configured to generate one or more optical stimulation signals and an electrical stimulation generator configured to generate electrical stimulation signals. The neural-stimulating device also comprises an implantable stimulating assembly configured to be implanted in the recipient, and having disposed thereon an optical contact to deliver the one or more optical stimulation signals to the nerve cells, and an electrical contact to deliver the electric stimulation signals to the nerve cells.

What is claimed is: 
     
         1 . A method for stimulating nerve cells of a recipient comprising:
 generating one or more optical stimulation signals;   delivering said one or more optical stimulation signals to the nerve cells;   generating electrical stimulation signals; and   delivering said electrical stimulation signals to the nerve cells.   
     
     
         2 . The method of  claim 1 , wherein generating said one or more stimulation signals comprises:
 generating said one or more optical stimulation signals with a light source, and wherein said one or more optical stimulation signals generated by said light source are in the optical spectrum.   
     
     
         3 . The method of  claim 1 , wherein the nerve cells comprise spiral ganglion cells of the recipient, and wherein said method further comprises:
 delivering said one or more optical stimulation signals to the spiral ganglion cells.   
     
     
         4 . The method of  claim 1 ,
 wherein generating said one or more optical stimulation signals comprises generating a plurality of optical stimulation signals; and   independently delivering each of said plurality of optical stimulation signals to the nerve cells.   
     
     
         5 . The method of  claim 1 ,
 wherein generating said one or more optical stimulation signals comprises generating a plurality of sets of optical stimulation signals; and   independently delivering each of said plurality of sets of optical stimulation signals to the nerve cells.   
     
     
         6 . The method of  claim 1 , wherein said delivering said one or more optical stimulation signals to the nerve cells comprises:
 delivering said one or more optical stimulation signals via an optical contact configured to disperse said one or more optical stimulation signals.   
     
     
         7 . The method of  claim 1 , wherein said delivering said one or more optical stimulation signals to the nerve cells comprises:
 delivering said one or more optical stimulation signals via an optical contact configured to substantially focus said one or more optical stimulation signals.   
     
     
         8 . The method of  claim 1 , further comprising:
 delivering said one or more optical stimulation signals and said electrical stimulation signals to a same region of the nerve cells.   
     
     
         9 . The method of  claim 1 , further comprising:
 receiving an acoustic sound signal;   generating a set of encoded signals based on said acoustic sound signal;   generating said one or more optical stimulation signals based on said set of encoded signals; and   delivering said one or more optical stimulation signals to the nerve cells to cause perception by the recipient of one or more frequency components of said acoustic sound signal,   wherein deliver of said electrical stimulation signals cause sub-threshold stimulation of the nerve cells.   
     
     
         10 . The method of  claim 9 , further comprising:
 concurrently delivering said electrical stimulation signals and said one or more optical stimulation signals to the nerve cells.   
     
     
         11 . The method of  claim 9 , further comprising:
 generating said electrical stimulation signals which cause said sub-threshold electrical stimulation only when an acoustic signal has not been received at said microphone for a pre-determined period of time.   
     
     
         12 . The method of  claim 9 , further comprising:
 delivering said one or more electrical stimulation signals which cause said sub-threshold electrical stimulation at an intensity to attain substantial neural survival in the stimulated region of the nerve cells.   
     
     
         13 . The method of  claim 1 , further comprising:
 receiving an acoustic sound signal;   generating a set of encoded signals based on said acoustic sound signal,   generating said electrical stimulation signals based on said set of encoded signals; and   delivering said electrical stimulation signals to the nerve cells to cause perception by the recipient of one or more frequency components of said acoustic sound signal,   wherein said one or optical stimulation signals cause sub-threshold stimulation of the nerve cells.   
     
     
         14 . The method of  claim 13 , further comprising:
 concurrently delivering said electrical stimulation signals and said one or more optical stimulation signals to the nerve cells.   
     
     
         15 . The method of  claim 13 , further comprising:
 generating said one or more optical stimulation signals which cause said sub-threshold optical stimulation only when an acoustic signal has not been received at said microphone for a pre-determined period of time.   
     
     
         16 . The method of  claim 13 , further comprising:
 delivering said one or more optical stimulation signals which cause said sub-threshold optical stimulation at an intensity to attain substantial neural survival in the stimulated region of the nerve cells.   
     
     
         17 . The method of  claim 1 , further comprising:
 generating one or more optical stimulation signals configured to cause sub-threshold optical stimulation of the nerve cells;   generating electrical stimulation signals configured to cause sub-threshold electrical stimulation of the nerve cells based on a set of sound processor-encoded signals; and   concurrently delivering said electrical stimulation signals and said one or more optical stimulation signals to the nerve cells,   wherein said electrical stimulation signals and said one or more optical stimulation signals collectively cause perception by the recipient of one or more frequency components of said acoustic sound signal.   
     
     
         18 . The method of  claim 17 , wherein delivering said one or more optical stimulation signals which cause said sub-threshold optical stimulation comprises:
 delivering said one or more optical stimulation signals via an optical contact configured to cause dispersed optical stimulation.   
     
     
         19 . The method of  claim 17 , wherein delivering said one or more optical stimulation signals which cause said sub-threshold optical stimulation comprises:
 delivering said one or more optical stimulation signals via an optical contact configured to cause substantially focused optical stimulation.