Self-aligning unobtrusive active eye interrogation

• US 9,039,180 B2
• Filed: 12/11/2012
• Issued: 05/26/2015
• Est. Priority Date: 12/11/2012
• Status: Active Grant

• Current Assignee: Elwha LLC (Intellectual Ventures LLC)
• Original Assignee: Elwah LLC
• Inventors: Brown, Allen L. Jr., Burger, Douglas C., Horvitz, Eric, Hyde, Roderick A., Jung, Edward K. Y., Leuthardt, Eric C., Kare, Jordin T., Karkanias, Chris Demetrios, Manferdelli, John L., Mundie, Craig J., Myhrvold, Nathan P., Pell, Barney, Tegreene, Clarence T., Wattenburg, Willard H., Whitmer, Charles, Wood, Lowell L. Jr., Zare, Richard N.
• Primary Examiner(s): Sugarman, Scott J
• Assistant Examiner(s): THOMAS, BRANDI N
• Application Number:
  US13/711,445
• Publication Number:
  US 20140160432A1
• Time in Patent Office: 896 Days
• Field of Search: 351/208, 351/200, 351/203, 351/205, 351/211, 351/210, 351/206, 351/221, 351/222, 351/237, 351/243, 351/244, 351/245
• US Class Current: 351/208
• CPC Class Codes: A61B 3/0025 characterised by electronic signal processing, e.g. eye models
• CPC Class Codes: A61B 3/113 for determining or recording eye movement
• CPC Class Codes: G06V 40/193 Preprocessing; Feature extraction

Abstract

Methods and system for determining a physiological parameter of a subject through interrogation of an eye of the subject with an optical signal are described. Interrogation is performed unobtrusively. The gaze direction of the eye of the subject is determined and an interrogation signal source and/or response signal sensor are moved into alignment with the eye using an actuator to facilitate detection of the signal from the eye of the subject.

Claims

1. A system for sensing information from an eye of a subject, comprising:

an interrogation signal source for delivering an interrogation signal to the eye of the subject;

a response signal sensor for sensing a response signal produced by the eye of the subject responsive to the interrogation signal;

a gaze signal sensor adapted for receiving a gaze signal containing information indicative of a gaze direction of the eye of the subject;

at least one actuator configured to adjust at least one of the interrogation signal source and the response signal sensor to bring at least one of the interrogation signal source and the response signal sensor into alignment with the eye of the subject; and

signal processing circuitry including;

a response signal processor configured to process a response signal sensed from the eye of the subject to determine a physiological parameter from the response signal;

a gaze signal processor configured to determine the gaze direction of the eye of the subject based upon the gaze signal;

an alignment detector configured to determine whether the eye of the subject is in alignment with respect to at least one of the interrogation signal source and the response signal sensor based at least in part upon the gaze direction; and

an actuator controller configured to;

determine a target position for at least one of the interrogation signal source and the response signal sensor based at least in part on the gaze direction; and

generate an actuator control signal to drive the at least one actuator to adjust at least one of the interrogation signal source and the response signal sensor to bring at least one of the interrogation signal source and the response signal sensor into alignment with the eye of the subject.

2. The system of claim 1, wherein the at least one actuator is configured to scan the at least one of the interrogation signal source and the response signal sensor through a region in which the eye of the subject is located such that the at least one of the interrogation signal source and the response signal sensor will be brought into alignment with the eye of the subject at at least one position within the scanned region.

3. The system of claim 1, including:

data capture circuitry configured to capture a response signal from the eye of the subject in connection with determination by the signal processing circuitry that the eye of the subject is in alignment with respect to at least one of the interrogation signal source and the response signal sensor.

14. The system of claim 1, wherein the at least one actuator is configured to adjust at least one of the interrogation signal source and the response signal sensor by at least one of adjusting the position of at least a portion of the interrogation signal source, adjusting at least one optical component of the interrogation signal source, adjusting the position of at least a portion of the response signal sensor and adjusting at least one optical component of the response signal sensor.

15. The system of claim 1, comprising a display, the display including at least one of a video monitor, a computer display, a video game display, a telephone display, a terminal of a data processing device, a display incorporated in a wearable item, a display incorporated in an article of furniture, a display incorporated in an article of medical or health-care related equipment, a display incorporated in an article of exercise equipment, and a display incorporated in a vehicle.

27. The system of claim 1, including:

a rangefinder adapted for determining at least one of the distance between the eye of the subject and the interrogation signal source and the distance between the eye of the subject and the response signal sensor; and

an autofocus system for focusing the at least one of the interrogation signal source and the response signal sensor responsive to the determined distance.

28. The system of claim 15, including electrical circuitry configured to cause a visual stimulus to be displayed on the display to attract the gaze of the subject.

4. A system for controlling the sensing of information from an eye of a subject, comprising:

signal processing circuitry including;

a gaze signal input adapted to receive a gaze signal containing information indicative of a gaze direction of the eye of the subject sensed from at least the eye of the subject;

a response signal input adapted to receive a response signal sensed from the eye of the subject by a response signal sensor responsive to delivery of an interrogation signal to the eye of the subject;

a response signal processor configured to process a response signal sensed from the eye of the subject to determine a physiological parameter from the response signal;

a gaze signal processor configured to determine the gaze direction of the eye of the subject based upon the gaze signal;

an alignment detector configured to determine whether the eye of the subject is in alignment with respect to at least one of the interrogation signal source and the response signal sensor based at least in part upon the gaze direction; and

an actuator controller configured to;

determine a target position for at least one of the interrogation signal source and the response signal sensor based at least in part on the gaze direction; and

generate an actuator control signal to cause the at least one actuator to adjust at least one of the interrogation signal source and the response signal sensor to bring at least one of the interrogation signal source and the response signal sensor into alignment with the eye of the subject.

5. The system of claim 4, including:

interrogation signal control circuitry configured to drive production of the interrogation signal by an interrogation signal source.

6. The system of claim 4, wherein the response signal processor is configured to process the response signal by determining a first response signal at a first polarization, determining a second response signal at a second polarization, and comparing the response signal determined at the first polarization to the response signal determined at the second polarization, wherein the first polarization and the second polarization are different.

7. The system of claim 5, wherein the interrogation signal control circuitry is configured to drive production of a pulsed interrogation signal by the interrogation signal source.

16. The system of claim 4, including:

gaze tracking stimulus control circuitry configured to drive production of a gaze tracking stimulus by at least one gaze tracking stimulus source.

17. The system of claim 7, wherein the signal processing circuitry is configured to combine multiple response signals produced by the eye of the subject in response to multiple pulses of the pulsed interrogation signal by at least one of summing the multiple response signals, averaging the multiple response signals, determining a moving average of the multiple response signals, and determining a weighted sum of the multiple response signals.

18. The system of claim 4, including interrogation signal control circuitry configured to drive production of a first interrogation signal having a first optical wavelength and production of a second interrogation signal having a second optical wavelength, wherein the signal processing circuitry is configured to process a first response signal sensed from the eye of the subject in response to the first interrogation signal and a second response signal sensed from the eye of the subject in response to the second interrogation signal by comparing the first and second response signals in order to determine the physiological parameter.

29. The system of claim 4, wherein the gaze signal input and the response signal input are the same input.

30. The system of claim 4, wherein the gaze signal input and the response signal input are separate inputs.

32. The system of claim 18, wherein the signal processing circuitry is configured to drive production of the first interrogation signal simultaneously with respect to the second interrogation signal.

33. The system of claim 18, wherein the signal processing circuitry is configured to drive production of the first interrogation signal sequentially with respect to the second interrogation signal.

34. The system of claim 4, including an output structure adapted to output a signal relating to the determined physiological parameter, wherein the output structure includes at least one of a data transmission structure, a data storage structure, a display, an audio output, and a visual output.

8. A system comprising:

a housing;

an interrogation signal source housed in the housing and adapted for delivering an interrogation signal to an eye of a subject, the interrogation signal source including at least one light source and at least one optical system;

a response signal sensor housed within the housing and adapted for sensing a response signal produced by the eye of the subject responsive to the interrogation signal, the response signal containing information regarding a physiological parameter of the subject;

an input structure adapted for receiving an input signal;

at least one actuator configured to adjust at least one of the interrogation signal source and the response signal sensor based at least in part upon the input signal to bring at least one of the interrogation signal source and the response signal sensor into alignment with the eye of the subject;

an output structure adapted for transmitting an output signal; and

mounting means adapted for mounting the housing with respect to a display in such a manner that the interrogation signal source and response signal sensor are alignable with the eye of the subject during normal use of the display by the subject.

9. The system of claim 8, including a gaze signal sensor adapted for receiving a gaze signal containing information indicative of a gaze direction of the eye of the subject.

10. The system of claim 9, including at least one gaze tracking stimulus source adapted to deliver a gaze tracking stimulus to at least the eye of the subject, wherein the gaze signal is produced in response to the gaze tracking stimulus.

11. The system of claim 8, wherein the interrogation signal source is adapted to deliver a pulsed interrogation signal.

12. The system of claim 8, wherein the at least one actuator is configured to scan the at least one of the interrogation signal source and the response signal sensor through a region in which the eye of the subject is located such that the at least one of the interrogation signal source and the response signal sensor will be brought into alignment with the eye of the subject at at least one position within the scanned region.

13. The system of claim 8, including:

data capture circuitry configured to capture a response signal from the eye of the subject in connection with determination by the signal processing circuitry that the eye of the subject is in alignment with respect to at least one of the interrogation signal source and the response signal sensor.

19. The system of claim 8, wherein the mounting means is adapted for mounting the housing with respect to the display such that during normal use of the display by the subject, the interrogation signal source and response signal sensor are positioned within the visual field of at least one eye of the subject and are oriented in substantially the same direction as the display surface of the display.

20. The system of claim 8, wherein the interrogation signal source includes at least one of an optical signal source, an acoustic signal source, a broad spectrum light source, a near-infrared light source, a mid-infrared light source, and a tunable laser source.

21. The system of claim 8, wherein the response signal sensor includes at least one of an acoustic sensor, an optical sensor, a spectrometer based on a CCD array, a near-infrared camera, a Raman spectrometer based on a CCD camera, a mid-infrared detector, and a broad spectrum pyroelectric detector.

22. The system of claim 8, further comprising signal processing circuitry adapted to process the response signal, wherein the interrogation signal source is adapted to deliver a pulsed interrogation signal, and wherein the signal processing circuitry is configured to combine multiple response signals produced by the eye of the subject in response to multiple pulses of the pulsed interrogation signal by at least one of summing the multiple response signals, averaging the multiple response signals, determining a moving average of the multiple response signals, and determining a weighted sum of the multiple response signals.

23. The system of claim 8, wherein the interrogation signal source is adapted to deliver an interrogation signal containing multiple wavelengths of light, and including at least a first response signal sensor configured to sense a first response signal produced by the eye of the subject responsive to a first wavelength component of the interrogation signal, and a second response signal sensor configured to sense a second response signal produced by the eye of the subject responsive to a second wavelength component of the interrogation signal.

24. The system of claim 8, including at least a first interrogation signal source configured to deliver a first interrogation signal having a first optical wavelength and at least a second interrogation signal source configured to deliver a second interrogation signal having a second optical wavelength, and wherein the signal processing circuitry is configured to process a first response signal sensed from the eye of the subject in response to the first interrogation signal and a second response signal sensed from the eye of the subject in response to the second interrogation signal by comparing the first and second response signals to determine the physiological parameter.

25. The system of claim 8, wherein the output structure includes at least one of a data transmission structure, a serial port, a parallel port, an electromagnetic transmission means, an optical transmission means, an output structure adapted to transmit an output signal to the display, an output structure adapted to transmit an output signal to a data processing device, an audio output, and a visual output.

26. The system of claim 8, wherein the at least one actuator is configured to adjust at least one of the interrogation signal source and the response signal sensor by at least one of adjusting the position of at least a portion of the interrogation signal source, adjusting at least one optical component of the interrogation signal source, adjusting the position of at least a portion of the response signal sensor, and adjusting at least one optical component of the response signal sensor.

31. The system of claim 8, wherein the signal processing circuitry is configured to gate detection of the response signal relative to the pulsed interrogation signal.

35. The system of claim 9, including circuitry adapted for determining a target position of the at least one of the interrogation signal source and the response signal sensor and for providing an input signal indicative of the target position to the input structure.

36. The system of claim 9, wherein the gaze signal sensor includes at least one of a camera, an infrared camera, a CCD camera, an optical sensor, an optical sensor array.