System and method for attenuating the effect of ambient light on an optical sensor
View Patent ↗The present invention provides systems and methods for attenuating the effect of ambient light on optical sensors and for measuring and compensating quantitatively for the ambient light.
1. A sensor system, comprising:
an optical sensor that includes indicator molecules, a first photodetector, a light source for illuminating the indicator molecules, said photodetector configured to capture a first signal corresponding to the amount of light reaching the first photodetector at a point in time when the indicator molecules are illuminated by the light source, and said photodetector configured to also generate a second signal corresponding to the amount of light reaching the first photodetector at a point in time when the indicator molecules are not being illuminated by the light source, and a transmitter configured to transmit a wireless signal;
a sensor reader comprising a receiver for receiving said wireless signal transmitted from said sensor, a user interface for displaying information to a user of the sensor reader, and a second photodetector for detecting the intensity of ambient light; and
a processor in communication with said sensor reader, said processor being configured to receive data from said second photodetector and programmed to issue an alert to a user if the data from said second photodetector indicates that the intensity of said ambient light is greater than a pre-determined threshold.
2. The sensor system according to claim 1 , wherein said optical sensor is configured to generate a third signal, which is a function of said first and second signals.
3. The sensor system according to claim 2 , wherein said third signal is generated by subtracting said second signal from said first signal.
4. The sensor system according to claim 2 , wherein said wireless signal includes said third signal.
5. The sensor system according to claim 1 , wherein the sensor reader further comprises a housing which is configured to house the receiver, user interface, and photodetector.
6. The sensor system according to claim 1 , further comprising an opaque wrist band, wherein the housing is attached to the opaque wrist band.
7. The sensor system according to claim 3 , wherein said photodetector data includes said ambient light signal.
8. The sensor system according to claim 1 , wherein the light source is configured to be driven with about 2 milliamps of current.
9. The sensor system according to claim 1 , wherein the processor is further programmed to (a) receive data transmitted from the optical sensor, (b) compute a value that is based on the data transmitted from the sensor, and (c) display the value on the user interface.