Photoacoustic measurement of analyte concentration in the eye

Abstract

In one aspect, the invention features a method and device for measuring blood concentration of a substance such as glucose in the aqueous humor by illuminating the aqueous humor with a light source at a frequency that is absorbed by the substance to the measured, and then sensing photoacoustically generated sound waves originated within the aqueous humor as a consequence of illumination by the light source. The blood concentration can be estimated from the amplitude of the sound waves received. The method may be combined with other optical techniques for glucose measurement and/or with optical or ultrasonic techniques for topographic mapping of eye structures.

1 . A method of measuring the blood concentration of a substance comprising: 
 illuminating the aqueous humor with a light source at a frequency that is absorbed by the substance to the measured,    sensing photoacoustically generated sound waves originated within the aqueous humor as a consequence of illumination by the light source,    estimating blood concentration of said substance from an amplitude of said sound waves, and    displaying the estimated blood concentration.    
   
   
       2 . The method of  claim 1  wherein said substance is blood glucose.  
   
   
       3 . The method of  claim 1  wherein the light source is a laser light source.  
   
   
       4 . The method of  claim 1  wherein the light source is a superluminescent diode light source.  
   
   
       5 - 8 . (canceled)