Patent ID: 7130672

Claim:
Apparatus for monitoring viability of a tissue element comprising: a) at least one light source that illuminates the tissue element from at least one illumination location with at least first illuminating radiation at a first wavelength and second illuminating radiation at a second wavelength; b) first and second radiation receivers located at first and second distances from the at least one illumination location respectively and at least one radiation detector operatively coupled with said first and second radiation receivers which generates first and second signals respectively responsive to illuminating the tissue element with the first and second illuminating radiations; and C) a processor that processes the signals to determine first and second tissue viability parameters for the tissue element; wherein the first and second distances are determined responsive substantially only to the first and second wavelengths and tissue characteristics so that sample depths for the first and second illuminating radiations are substantially equal; and further wherein the first tissue viability parameter is different than the second tissue viability parameter.