Methods and devices suitable for imaging blood-containing tissue

Abstract

Disclosed are methods and devices useful for imaging blood-containing tissue, for example for angiography, especially retinal angiography, whereby an image is generated by dividing pixels of an image acquired at some wavelength range by corresponding pixels of an image acquired at a different wavelength range. In some embodiments, a first wavelength range includes predominantly light having wavelengths between about 400 nm and about 620 nm and a second wavelength range includes predominantly light having wavelengths between about 620 nm and about 800 nm.

What is claimed is: 
     
         1 . A method of generating an image of the surface of biological tissue, comprising:
 a) illuminating an area of interest of the surface with light comprising wavelengths within a first wavelength range, said first wavelength range including predominantly light having wavelengths of between about 400 nm and about 620 nm;   b) acquiring a first pixelated image of light reflected from said area of interest of the surface at said first wavelength range of light;   c) illuminating said area of interest of the surface with light comprising wavelengths within a second wavelength range, said second wavelength range including predominantly light having wavelengths of between about 620 nm and about 800 nm;   d) acquiring a second pixelated image of light reflected from said area of interest of the surface at said second wavelength range of light; and   e) generating a monochromatic third pixelated image from said first image and said second image by:
 for each desired location i of said area of interest, identifying a corresponding pixel P1(i) in said first image and a corresponding pixel P2(i) in said second image; and 
 calculating a pixel P3(i) in said third image corresponding to said location i, by dividing one of a mathematical formula of P1(i) and a mathematical formula of P2(i) by the other. 
   
     
     
         2 . (canceled) 
     
     
         3 . The method of  claim 1 , wherein:
 said mathematical formula of P1(i) comprises a mathematical formula of the form (xP1(i)+m) A ;   said mathematical formula of P1(i) comprises a mathematical formula of the form (yP2(i)+n) B ; and   a mathematical formula describing said calculating is substantially a mathematical formula selected from the group consisting of:
     P 3( i )=[( xP 1( i )+ m ) A /( yP 2( i )+ n ) B ] and  P 3( i )=[( yP 2( i )+ n ) B /( xP 1( i )+ m ) A ], 
   wherein A and B are, independently, any suitable positive number except 0 and including 1;   wherein x and y are, independently, any suitable number including 1; and   wherein m and n are, independently, any suitable number including 0.   
     
     
         4 . The method of  claim 1 , wherein a mathematical formula describing said calculating is substantially a mathematical formula selected from the group consisting of P3(i)=[P1(i)/P2(i)] and P3(i)=[P2(i)/P1(i)]. 
     
     
         5 . (canceled) 
     
     
         6 . The method of  claim 1 , wherein said illuminating with light comprising wavelengths within said first wavelength range is simultaneous with said illuminating with light comprising wavelengths within said second wavelength range. 
     
     
         7 . The method of  claim 6 , wherein said illuminating is with white light. 
     
     
         8 . The method of  claim 6 , wherein said illuminating is with light having at least two discrete wavelengths of light: at least one discrete wavelength within said first wavelength range and at least one discrete wavelength within said second wavelength range. 
     
     
         9 . The method of  claim 1 , wherein:
 said acquiring of said first pixelated image is not simultaneous with said acquiring of said second pixelated image;   said illuminating said area of interest with light comprising wavelengths within said first wavelength range is only during said acquiring of said first pixelated image; and   said illuminating said area of interest with light comprising wavelengths within said second wavelength range is only during said acquiring of said second pixelated image.   
     
     
         10 . (canceled) 
     
     
         11 . The method of  claim 1 , wherein said first pixelated image and said second pixelated image are acquired substantially simultaneously. 
     
     
         12 . The method of  claim 11 , comprising:
 directing light collected for acquiring said first image from said area of interest to a first image-acquirer to acquire said first image; and   directing light collected for acquiring said second image from said area of interest to a second image-acquirer different from said first image-acquirer to acquire said second image.   
     
     
         13 . The method of  claim 11 , comprising:
 directing light collected for acquiring said first image and said second image from said area of interest to a single image-acquirer;   separating data acquired by said single image-acquirer constituting said first image from data acquired by said single image-acquirer constituting said second image.   
     
     
         14 . The method of  claim 1 , wherein said first image and said second image are acquired sequentially. 
     
     
         15 - 17 . (canceled) 
     
     
         18 . A device useful for generating an image of the surface of biological tissue, comprising:
 a) an illuminator configured to illuminate an area of interest with light comprising wavelengths within a first wavelength range, said first wavelength range including predominantly light having wavelengths of between about 400 nm and about 620 nm, and to illuminate said area of interest with light comprising wavelengths within a second wavelength range, said second wavelength range including predominantly light having wavelengths of between about 620 nm and about 800 nm;   b) an image-acquirer suitable for acquiring a first pixelated image of light reflected from said area of interest of the surface of biological tissue with a said first wavelength range of light;   c) an image-acquirer suitable for acquiring a second pixelated image of light reflected from said area of interest with a said second wavelength range of light; and   d) a processor configured to generate a monochromatic third pixelated image from said first image and said second image by:
 for each desired location i of a said area of interest, identifying a corresponding pixel P1(i) in said first image and a corresponding pixel P2(i) in said second image; and 
 calculating a pixel P3(i) in said third image corresponding to said location i, by dividing one of a mathematical formula of P1(i) and a mathematical formula of P2(i) by the other. 
   
     
     
         19 . The device of  claim 18 , wherein said device is configured to acquire said first image and said second image substantially simultaneously. 
     
     
         20 . The device of  claim 18 , wherein said device is configured to acquire said first image and said second image sequentially. 
     
     
         21 . The device of  claim 18 , wherein said image-acquirer suitable for acquiring said first pixelated image and said image-acquirer suitable for acquiring said second pixelated image are the same image-acquirer. 
     
     
         22 . The device of  claim 18 , wherein said image-acquirer suitable for acquiring said first pixelated image and said image-acquirer suitable for acquiring said second pixelated image are different image-acquirers. 
     
     
         23 . The device of  claim 18 , further comprising a display component configured to visually display a said generated third image. 
     
     
         24 - 25 . (canceled) 
     
     
         26 . The device of  claim 18 , wherein said illuminator is configured to simultaneously illuminate said area of interest with light comprising wavelengths within said first wavelength range and wavelengths within said second wavelength range. 
     
     
         27 . (canceled) 
     
     
         28 . The device of  claim 26 , wherein said illuminator includes at least two discrete light sources of at least two discrete wavelengths of light, at least one discrete wavelength of light within said first wavelength range and at least one discrete wavelength of light within said second wavelength range. 
     
     
         29 . The device of  claim 18 , wherein said illuminator includes a source of at least two discrete wavelengths of light, at least one discrete wavelength of light within said first wavelength range and at least one discrete wavelength of light within said second wavelength range,
 the device configured:
 to illuminate said area of interest with said discrete wavelength of light within said first wavelength range only during acquisition of a said first pixelated image; and 
 to illuminate said area of interest with said discrete wavelength of light within said second wavelength range only during acquisition of a said second pixelated image. 
   
     
     
         30 . (canceled)