Patent ID: 7225005

Claim:
A system for determining an in vivo blood property, the system comprising: an optical device configured to project a light beam onto a tissue of a subject; an imaging device configured to generate optical data; a device to display an image corresponding to the optical data, wherein the image indicates a spatial relationship between the light beam and a blood vessel within the tissue, and wherein a user can manipulate the optical device and, based on the image, bring the light beam and the blood vessel into a selected spatial relationship wherein the light beam is projected on the blood vessel at a first location on the blood vessel; a detector configured to generate a detector signal corresponding to light resulting from illumination of the blood vessel with the light beam having the selected spatial relationship, the detector signal indicating light intensities of light exiting the blood vessel at two or more locations on the blood vessel, the two or more locations being spaced apart from each other and from the first location; and a processor configured to determine an in vivo blood property based on the detector signal and the relative positions of the two or more locations on the blood vessel.