US Patent 7235045 Fluorescence imaging endoscope

An endoscope having an optical guide that is optically coupled to a first broadband light source and a second laser light source that emits light at a wavelength in a range of 350 nm to 420 nm. The endoscope has an image sensor at a distal end and collects a reflectance image including red, green and blue components with the image sensor in response to illumination by said broadband light source. The image sensor also collects an autofluorescence image having a blue component, a green component and a red component. A processor processes the fluorescence image by determining a ratio of the fluorescence image and the reflectance image to provide a processed fluorescence image.