Patent ID: 8144960
Filing Date: 2012-03-27
Classification: A61B

Abstract:
1. A method of determining the concentration of a chemical substance that produces refractive and/or polarization changes when light is passed through the aqueous fluids in the eye, the method comprising: measuring a spatial position change within an image of an eye comprising a corneal surface illumination gradient reference portion and an internal eye illumination gradient image portion while maintaining a predetermined degree of precision due to the mathematically consistent spatial ratio between the reference and the measured illumination intensity gradients across the surface of both images in the presence of focus and imager alignment errors; utilizing a surface of the cornea as an illumination gradient reference image; and determining the change within the internal eye illumination gradient image using the reference image, wherein a difference between a spatially shifted illumination gradient across the internal eye image portion and an un-shifted illumination gradient across the returned corneal surface image portion is a mechanically stable ratio that enables the precise measurement of all spatial positional shifts of the internal eye illumination gradient image.