Vision prosthesis with artificial muscle actuator

Abstract

A visual prosthesis includes an artificial muscle configured to deform in response to a focusing signal. The artificial muscle is coupled to at least a portion of an optical system for changing a focal point thereof.

1 . An apparatus for adaptively accommodating a patient's vision, the apparatus comprising
 a plurality of individually-addressable artificial muscles, each of which is configured
 to contract in response to a first focusing signal indicative of the patient's attempt to regard a first object, and 
 to relax in response to a second focusing signal indicative of a second focusing signal indicative of the patient's attempt to regard a second object; and 
   a lens having a plurality of lenslets, each lenslet being coupled to at least one of the artificial muscle elements.   
     
     
         2 . The apparatus of  claim 1 , further comprising a rangefinder for providing the first focusing signal. 
     
     
         3 . The apparatus of  claim 1 , wherein the artificial muscle elements comprise an electro-active polymer that deforms in response to electrical stimulation. 
     
     
         4 . The apparatus of  claim 1 , wherein the lens comprises an intraocular lens. 
     
     
         5 . The apparatus of  claim 1 , wherein the lens comprises a contact lens. 
     
     
         6 . The apparatus of  claim 1 , wherein the lens comprises an eyeglass lens. 
     
     
         7 . An apparatus for accommodating a patient's vision, the apparatus comprising:
 a vision-correcting lens having a lens surface; and   an artificial muscle integral with the lens surface, the artificial muscle being configured to respond to a first focusing signal indicative of a range to an object of regard;   whereby contraction of the artificial muscle deforms the lens surface and thereby causes a change in an optical property of the vision-correcting lens.   
     
     
         8 . The apparatus of  claim 7 , further comprising a rangefinder for providing the first focusing signal. 
     
     
         9 . The apparatus of  claim 7 , wherein the artificial muscle comprises an electro-active polymer that deforms in response to electrical stimulation. 
     
     
         10 . The apparatus of  claim 7 , wherein the lens comprises an intraocular lens. 
     
     
         11 . The apparatus of  claim 7 , wherein the lens comprises a contact lens. 
     
     
         12 . The apparatus of  claim 7 , wherein the lens comprises an eyeglass lens. 
     
     
         13 . The apparatus of  claim 7 , further comprising a biasing element for urging the lens surface to deform in a preferred direction in response to contraction of the artificial muscle. 
     
     
         14 . The apparatus of  claim 7  further comprising a plate in mechanical communication with the vision-correcting lens. 
     
     
         15 . The apparatus of  claim 14 , wherein the plate comprises a flat plate and the artificial muscle is configured to press the plate against the vision-correcting lens in response to a first focusing signal indicative of a distance to an object of regard, thereby changing an optical property of the vision-correcting lens. 
     
     
         16 . The apparatus of  claim 14 , wherein the plate comprises a peripheral portion that contacts a first portion of the lens and a central portion that defines an expansion cavity between the plate and a second portion of the lens. 
     
     
         17 . An apparatus for adaptively accommodating a patient's vision, the apparatus comprising:
 a reservoir for storing a fluid;   a lens in fluid communication with the reservoir; and   an artificial muscle configured
 to contract in response to a first focusing signal indicative of a range to an object of regard, and 
 to relax in response to a second focusing signal indicative of a range to an object of regard, 
   whereby   in response to contraction of the artificial muscle, the fluid moves between the reservoir and the lens in a first direction, and   in response to relaxation of the artificial muscle, the fluid moves between the reservoir and the lens in a second direction opposite the first direction.   
     
     
         18 . The apparatus of  claim 17 , wherein the artificial muscle is disposed to squeeze the reservoir, thereby pumping the fluid from the reservoir to the lens. 
     
     
         19 . The apparatus of  claim 17 , wherein the artificial muscle is integral with the reservoir, whereby when the artificial muscle contracts, the reservoir squeezes the fluid into the lens. 
     
     
         20 . The apparatus of  claim 17 , wherein the artificial muscle is disposed to exert pressure against the lens, thereby pumping fluid from the lens to the reservoir.