Patent ID: 7289204

Claim:
An apparatus for measuring fluorescence lifetimes of fluorescence sensors for one or more analytes, the apparatus comprising (a) one or more excitation light sources, said light sources being adapted to produce one or more excitation signals; (b) one or more fluorescence sensor systems, said sensor systems each comprising one or more fluorescence sensors for sensing the one or more analytes and being adapted to receive said one or more excitation signals to produce one or more optical sensor signals in response thereto, and to produce one or more electrical output signals in response to said optical sensor signals, said one or more electrical output signals being delayed with respect to said one or more excitation signals and being characteristics of the fluorescence lifetimes of the one or more fluorescence sensors; (c) one or more reference systems, said reference systems each comprising one or more reference light sources and being adapted to receive said one or more excitation signals to produce reference optical signals in response thereto, and to produce one or more electrical reference output signals in response to said one or more optical reference signals; and (d) one or more phase detectors, said phase detectors being adapted to detect one or more delays of said one or more electrical output signals of said one or more fluorescence sensor systems and said one or more reference systems, and to produce one or more phase output signals; wherein said one or more fluorescence sensors and said one or more reference light sources are incorporated in an exchangeable sensor cap.