Patent ID: 6510338
Filing Date: 2003-01-21
Classification: A61B

Abstract:
A method for fluorescence diagnosis of tissue, including the steps of:providing an illuminating light source emitting light over a wide bandwidth; guiding light emitted from the illuminating light source along an illuminating beam path to illuminate the tissue; providing a stimulation filter system selected to transmit light from the illuminating light source in a stimulation wavelength range in which the light stimulates an emission of fluorescence light in at least two separate fluorescence wavelength ranges from fluorescent substances present in the tissue; inserting the stimulation filter system into the illuminating beam path; exposing the tissue to the light transmitted by the stimulation filter system to stimulate emission of the fluorescence light in the at least two separate wavelength ranges; guiding fluorescence light emitted from the tissue along an observation beam path; inserting into the observation beam path a first observation filter system selected to transmit fluorescence light having a first of the at least two separate fluorescence wavelength ranges which is emitted from the tissue and to substantially separate the transmitted fluorescence light from light in the stimulation wavelength range which is reflected from the tissue; inserting into the observation beam path instead of the first observation filter system a second observation filter system selected to transmit fluorescence light having a second of the at least two separate fluorescence wavelength ranges which is emitted from the tissue and to substantially separate the transmitted fluorescence light from light in the stimulation wavelength range which is reflected from the tissue; and forming a first image of the tissue with the fluorescence light from the first observation filter system; forming a second image of the tissue with the fluorescence light from the second observation filter system; and selectively observing the first and the second images.