Non-invasive measurement of blood component using retinal imaging

A method for the detection of the concentration of a blood component in an individual comprising:

• (a) projecting light having selected wavelengths into an eye of the individual to illuminate the fundus;
• (b) detecting the light reflected from the fundus and forming an image of a portion of the fundus containing blood vessels;
• (c) analyzing selected wavelength components in the detected light from the blood vessels in the image to determine the concentration of a selected blood component;
• (d) sensing the blood flow of the individual being tested to detect systole and wherein this information is used to time the step of detecting the light reflected from the fundus and forming an image.

A method for the detection of the concentration of a blood component in an individual comprising:

• (a) projecting light having selected wavelengths into an eye of the individual to illuminate the fundus;
• (b) detecting the light reflected from the fundus and forming an image of a portion of the fundus containing blood vessels;
• (c) analyzing selected wavelength components in the detected light from the blood vessels in the image to determine the concentration of a selected blood component;
• (d) transmitting data corresponding to the image over a communications link to a remote location, and performing the step of analyzing selected wavelength components at the remote location.

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 to determine the intensity of the reflected light at these wavelengths;
• (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 intensity of such light reflected from the fundus;
• 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.