Non-invasive measurement of blood components using retinal imaging

Apparatus for detecting the concentration of a photoreactive analyte in the blood of an individual comprising:

• (a) means for projecting light into the eye of an individual to illuminate the fundus that contains wavelengths not including light at wavelengths that will break down the photoreactive analyte and for detecting the light reflected from the fundus to determine the intensity of the reflected light at these wavelengths;
• (b) means for projecting light into the eye to illuminate the fundus containing wavelengths that break down the photoreactive analyte and for projecting light into the eye to illuminate the fundus containing the wavelengths that do not break down the photoreactive analyte, and for detecting the intensity of such light reflected from the fundus;
• and
• (c) means for determining the difference between the intensity of light detected with no wavelengths that break down the photoreactive analyte projected on the fundus and the intensity of light detected when light which breaks down the photoreactive analyte has been projected onto the fundus, from which the analyte concentration may be determined.

A method of detecting the concentration of a photoreactive analyte in the blood of an individual comprising:

• (a) projecting light into the eye of the individual to illuminate the fundus that contains wavelengths not including light at wavelengths that will break down the photoreactive analyte and detecting the light reflected from the fundus and for forming an image of a portion of the fundus containing blood vessels and determining the intensity of the reflected light at these wavelengths in the image;
• (b) projecting light into the eye to illuminate the fundus containing wavelengths that break down the photoreactive analyte, and projecting light into the eye to illuminate the fundus containing the wavelengths that do not break down the photoreactive analyte and detecting the light reflected from the fundus and forming an image of a portion of the fundus containing blood vessels and determining the intensity of the reflected light in the image at the wavelengths that do not break down the photoreactive analyte;
• and
• (c) determining the difference between the intensity of light detected with no wavelengths that break down the photoreactive analyte projected on the fundus and the intensity of light detected when light which breaks down the photoreactive analyte has been projected onto the fundus, from which the analyte concentration may be determined.

Apparatus for detecting the concentration of a photoreactive analyte in the blood of an individual comprising:

• (a) means for projecting light into the eye of an individual to illuminate the fundus that contains wavelengths not including light at wavelengths that will break down the photoreactive analyte and means for detecting the light reflected from the fundus and for forming an image of a portion of the fundus containing blood vessels and determining the intensity of the reflected light at these wavelengths in the image at the wavelengths that do not break down the photoreactive analyte;
• (b) means for projecting light into the eye to illuminate the fundus containing wavelengths that break down the photoreactive analyte and for projecting light into the eye to illuminate the fundus containing the wavelengths that do not break down the photoreactive analyte, and means for detecting the light reflected from the fundus and for forming an image of a portion of the fundus containing blood vessels and for determining the intensity of the light reflected from the fundus;
• and
• (c) means for determining the difference between the intensity of light detected with no wavelengths that break down the photoreactive analyte projected on the fundus and the intensity of light detected when light which breaks down the photoreactive analyte has been projected onto the fundus, from which the analyte concentration may be determined.