Abstract: A variety of optical probes and methods have utility in the examination of various materials, especially materials in the interior of cavities having restricted access through orifices or passageways. One type of such optical probe is elongated and includes a distal optical window, a divergent light source, a spatial mixer, and a light collector. Light from the light source is mixed in the spatial mixer to achieve uniform diffuse light in the vicinity of the optical window. The light collector receives light from the target through the spatial mixer. The optical probe may be made of two sections, a reusable section and a disposable. The disposable is elongated and contains a mounting section, an inside surface suitable for the spatial mixing of light, and an optical element which helps to seal the reusable probe section from the target.

Abstract: A method for using acetic acid as a signal enhancing contrast agent during fluorescence spectroscopy of normal and neoplastic tissue, particularly epithelium. In one aspect, the invention includes a method of detecting tissue abnormality in a diagnostic tissue sample in a patient, comprising the steps of obtaining a first fluorescence intensity spectrum from the diagnostic tissue sample; thereafter, applying acetic acid to the diagnostic tissue sample in sufficient concentration to alter the response of such diagnostic tissue sample to electromagnetic radiation for at least an effective period of time; during the effective period of time, obtaining a second fluorescence intensity spectrum from the diagnostic tissue sample; determining a parameter indicative of a change between the first and second fluorescence emission intensity spectra; and analyzing the determined parameter to determine a probability that the diagnostic tissue sample is normal or abnormal.