Patent attributes
An analyte sensor incorporates one or more techniques for discriminating between different optical signals. In one embodiment, the sensor includes a photodetector that detects a narrow band optical signal. In another embodiment, the sensor includes a multilayer filter including an absorption filter, a reflection filter, and a transparent layer between the absorption and reflection filters. In another embodiment, the sensor employs an indicator that emits light for a period of time after an excitation source is turned off. In another embodiment, the sensor employs a first indicator that is excited by an excitation light source and a second indicator that is excited by light emitted by the first indicator. The second indicator emits light for a period after the excitation source is turned off. In another embodiment, excitation light is polarized by a first polarizer, and a second polarizer at a photodetector passes only light polarized by the first polarizer.
