Patent ID: 8781560

Claim:
An apparatus for determining tissue characteristics which indicate the presence of cancerous or pre-cancerous tissue on a body, comprising: a base unit comprising an illumination unit, a separate tissue interface unit comprising an excitation unit for delivering illumination from the illumination unit to the tissue and a detection unit capable of detecting responses in the tissue resulting from the illumination, said excitation and detection units being confocal and facing the tissue from the same side so that they converge at the tissue, a fixation member of predetermined length interposed between said units and the tissue to maintain alignment and focus with the tissue, said detection unit being aligned to maintain the detection unit and tissue in a substantially fixed position relative to each other as successive responses are detected despite natural movement of the body with respect to the detection unit and wherein the illumination unit comprises an illumination source and an illumination filter set said filter set having a plurality of filters selected to reduce artifacts due to reflected excitation, at least one filter being selected to enhance detection of reflectance and at least one filter being selected to enhance detection of fluorescence and wherein the illumination unit further comprises a mask that provides for selective illumination of the target tissue, said mask including a generally horizontally oriented slit allowing light transmission therethrough while blocking all other transmission, so that a column of a plurality of points in a single horizontal line of illumination can be applied simultaneously to the target tissue and thereby more easily distinguish between normal and abnormal tissue.