Corneal measurment apparatus and a method of using the same

Abstract

A corneal measurement apparatus for measuring a subject's cornea, comprising (A.) an illumination projection subsystem comprising a light source (B.) a mask subsystem disposed in a path of light from the light source, comprising (i) a first slit mask defining a plurality of apertures, (ii) a second slit mask defining a selection aperture, (iii) a translation apparatus adapted to translate the second mask, the translation apparatus and the second slit mask being configured and arranged such that by translating the selection slit, portions of the light can be selectively transmitted through each of the plurality of apertures toward the cornea, (C.) an imaging element configured and arranged to image the plurality of apertures onto the cornea, and (D.) an image capture subsystem arranged to capture images of the portions of light after the light impinges on the cornea.

1 . an apparatus for measuring a subject's cornea, comprising:
 (A.) an illumination projection subsystem comprising a light source;   (B.) a mask subsystem disposed in a path of light from the light source, comprising
 (i) a first slit mask defining a plurality of apertures, 
 (ii) a second slit mask defining a selection aperture, 
 (iii) a translation apparatus adapted to translate the second slit mask, the translation apparatus and the second slit mask being configured and arranged such that by translating the selection aperture, portions of the light can be selectively transmitted through ones of the plurality of apertures toward the cornea, sequentially; 
   (C.) an imaging element configured and arranged to image the plurality of apertures onto the cornea; and   (D.) an image capture subsystem arranged to capture images of the portions of light after the light impinges on the cornea.   
     
     
         2 . The apparatus in  claim 1 , further comprising
 (E.) a second illumination projection subsystem comprising a second light source;   (F.) a second mask subsystem disposed in a path of second light from the second light source, comprising
 (i) a third slit mask defining a second plurality of apertures, 
 (ii) a fourth slit mask defining a second selection aperture, 
 (iii) a second translation apparatus adapted to translate the fourth slit mask, the second translation apparatus and the fourth slit mask being configured and arranged such that by translating the second selection aperture, portions of the second light can be selectively transmitted through each of the second plurality of apertures toward the cornea; and 
   (G.) a second imaging element configured and arranged to image the second plurality of apertures onto the cornea,   the image capture subsystem arranged to capture images of the portions of second light after the light impinges on the cornea.   
     
     
         3 . The apparatus in  claim 1 , wherein the second slit mask is disposed upstream of the first slit mask. 
     
     
         4 . The apparatus in  claim 1 , wherein the illumination projection subsystem is configured and arranged to project light from the light source through each of the plurality of apertures defined in first slit mask without moving the illumination projection subsystem. 
     
     
         5 . The apparatus in  claim 1 , wherein the light source comprises at least one LED arranged to project light in the path of light. 
     
     
         6 . The apparatus in  claim 1 , further comprising a condenser lens configured and arranged to gather light from the light source and project the light in the path of light. 
     
     
         7 . The apparatus in  claim 6 , wherein the imaging element and condenser lens are configured and arranged to operate as a condenser-projector system. 
     
     
         8 . The apparatus in  claim 1 , wherein the imaging element and the first slit mask are disposed in a Scheimflug arrangement to obtain a plane of slit images the cornea. 
     
     
         9 . The apparatus in  claim 1 , wherein the plurality of apertures are disposed in a single plane. 
     
     
         10 . The apparatus in  claim 1 , wherein the plurality of apertures are formed on a single substrate. 
     
     
         11 . The apparatus in  claim 10 , wherein the plurality of apertures is defined by openings in an opaque layer deposited on the substrate. 
     
     
         12 . The apparatus in  claim 1 , further comprising an image processing subsystem coupled to the image capture subsystem, the image processing subsystem being adapted to convert the images into a single representation of the cornea. 
     
     
         13 . The apparatus in  claim 1 , further comprising a subject positioning apparatus adapted to maintain the subject's cornea in a location. 
     
     
         14 . The apparatus in  claim 5 , wherein the light source comprises at least one high power LED. 
     
     
         15 . The apparatus in  claim 5 , wherein the light source consists of a single LED. 
     
     
         16 . A method of facilitating measurement of a subject's cornea, comprising:
 (A.) providing a plurality of apertures;   (B.) projecting light toward the plurality of apertures;   (C.) translating a selection aperture while maintaining the plurality of apertures in fixed locations to selectively transmit a portion of the light toward the cornea, the portion of the light passing through the selection aperture and a selected one of the plurality of apertures; and   (D.) imaging the portions of light after the light impinges on the cornea.   
     
     
         17 . The method of  claim 16 , wherein the light passes through the selection aperture prior to passing through any of the plurality of apertures. 
     
     
         18 . The method of  claim 16 , wherein the step of projecting light comprises projecting light from at least one LED. 
     
     
         19 . The method of  claim 16 , wherein the step of imaging produces images, and the method further comprises processing the images to convert the images into a single representation of the cornea.