Patent ID: 6304766
Filing Date: 2001-10-16
Classification: A61B,G01N,Y10S

Abstract:
An optical-based sensor for determining the presence or concentration of an analyte in a medium, said sensor comprising:an optically transmissive sensor body which functions as an optic wave guide, said sensor body having a surface;a radiation source which emits radiation, said radiation source being embedded within said sensor body such that radiation emitted by said source travels within said sensor body;fluorescent indicator molecules disposed on the surface of said sensor body, said indicator molecules emitting fluorescent light in response to radiation emitted by the radiation source, the level of fluorescence varying with the concentration of the analyte to which said indicator molecules are exposed; anda photosensitive element which is responsive to fluorescent light emitted by said indicator molecules, said photosensitive element being embedded within said sensor body;wherein radiation emitted by said source passes out of said sensor body, at least some of the radiation passing out of said sensor body being reflected internally within said sensor body before passing out of said sensor body;wherein said indicator molecules fluoresce in response to radiation emitted by said source which passes out of said sensor body; andwherein at least some of the fluorescent light emitted by said indicator molecules passes into said sensor body and is detected by said photosensitive element, at least some of the fluorescent light detected by said photosensitive element being reflected internally within said sensor body before striking said photosensitive element.