System and method for attenuating the effect of ambient light on an optical sensor

• US 7,755,022 B2
• Filed: 07/28/2008
• Issued: 07/13/2010
• Est. Priority Date: 04/15/2003
• Status: Active Grant

• Current Assignee: Senseonics, Incorporated (Senseonics Holdings, Inc.)
• Original Assignee: Sensors For Medicine and Science Incorporated
• Inventors: Lynn, Robert W., Colvin, Arthur E. Jr., Lesho, Jeffrey C., Walters, Steven J., Lorenz, Carrie R., O'Connor, Casey J., Zerwekh, Paul Samuel
• Primary Examiner(s): Lee; John R
• Application Number:
  US12/180,745
• Publication Number:
  US 20090039286A1
• Time in Patent Office: 715 Days
• Field of Search: 250/214.AL, 250/214.B, 250/214.C, 250/214.R, 250/458.1
• US Class Current: 250/214.0AL
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14556 by fluorescence A61B5/14555 takes precedence
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/645 Specially adapted constructive features of fluorimeters
• CPC Class Codes: G01N 2201/1244 Ambient light detector, e.g. for invalidating
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 1/165 incorporating printed inductors
• CPC Class Codes: H05K 2201/086 for inductive purposes, e.g. printed inductor with ferrite core
• CPC Class Codes: H05K 2201/09972 Partitioned, e.g. portions of a PCB dedicated to different functions; Boundary lines therefore; Portions of a PCB being processed separately or differently
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: H05K 3/403 Edge contacts; Windows or holes in the substrate having plural connections on the walls thereof H05K3/4092 takes precedence

Abstract

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.

Claims

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.