System and method for monitoring eye movement

• US 6,542,081 B2
• Filed: 12/18/2000
• Issued: 04/01/2003
• Est. Priority Date: 08/19/1996
• Status: Expired

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: William C. Torch
• Inventors: Torch, William C.
• Primary Examiner(s): TONG, NINA C
• Application Number:
  US09/740,738
• Publication Number:
  US 20010028309A1
• Time in Patent Office: 834 Days
• Field of Search: 340/575, 340/576, 340/539, 340/573.1, 382/118, 382/117, 600/558
• US Class Current: 340/575
• CPC Class Codes: A61B 2503/22 Motor vehicles operators, e.g. drivers, pilots, captains
• CPC Class Codes: A61B 2562/043 in a linear array
• CPC Class Codes: A61B 3/0066 with identification means for the apparatus
• CPC Class Codes: A61B 3/10 Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
• CPC Class Codes: A61B 3/113 for determining or recording eye movement
• CPC Class Codes: A61B 5/1103 Detecting eye twinkling
• CPC Class Codes: A61B 5/16 Devices for psychotechnics using teaching or educational appliances G09B1/00 - G09B7/00; Testing reaction times ; Devices for evaluating the psychological state
• CPC Class Codes: A61B 5/163 by tracking eye movement, gaze, or pupil change
• CPC Class Codes: A61B 5/4094 Diagnosing or monitoring seizure diseases, e.g. epilepsy
• CPC Class Codes: A61B 5/486 Bio-feedback A61B5/375 takes precedence
• CPC Class Codes: A61B 5/6803 Head-worn items, e.g. helmets, masks, headphones or goggles
• CPC Class Codes: A61B 5/6821 Eye
• CPC Class Codes: A61M 2021/0044 by the sight sense
• CPC Class Codes: A61M 2021/0083 especially for waking up
• CPC Class Codes: A61M 21/02 for inducing sleep or relaxation, e.g. by direct nerve stimulation, hypnosis, analgesia for massage A61H; electrotherapy A61N, e.g. applying alternating or intermittent electric currents for producing anaesthesia A61N1/36021
• CPC Class Codes: A61M 2205/3569 sublocal, e.g. between console and disposable
• CPC Class Codes: A61M 2205/3592 using telemetric means, e.g. radio or optical transmission
• CPC Class Codes: A61M 2230/06 Heartbeat rate only
• CPC Class Codes: A61M 2230/10 Electroencephalographic signals
• CPC Class Codes: A61M 2230/42 Rate
• CPC Class Codes: G01S 17/00 : Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
• CPC Class Codes: G01S 17/88 : Lidar systems specially adapted for specific applications
• CPC Class Codes: G01S 7/481 : Constructional features, e.g. arrangements of optical elements
• CPC Class Codes: G08B 21/06 : indicating a condition of sleep, e.g. anti-dozing alarms
• CPC Class Codes: G08B 25/016 : Personal emergency signalling and security systems emergency non-personal manually actuated alarm activators G08B25/12
• CPC Class Codes: Y02A 90/10 : Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

Apparatus for monitoring movement of a person'"'"'s eye, e.g., to monitor drowsiness. The system includes a frame that is worn on a person'"'"'s head, an array of emitters on the frame for directing light towards the person'"'"'s eye, and an array of sensors on the frame for detecting light from the array of emitters. The sensors detect light that is reflected off of respective portions of the eye or its eyelid, thereby producing output signals indicating when the respective portions of the eye is covered by the eyelid. The emitters project a reference frame towards the eye, and a camera on the frame monitors movement of the eye relative to the reference frame. This movement may be correlated with the signals from the array of sensors and/or with signals from other sensors on the frame to monitor the person'"'"'s level of drowsiness.

Claims

1. A system for monitoring movement of a person'"'"'s eye, comprising:

a device configured to be worn on a person'"'"'s head;

an array of emitters on the device for directing light towards an eye of the person when the device is worn, the array of emitters configured for projecting a reference frame towards the eye; and

a camera oriented towards the eye for monitoring movement of the eye relative to the reference frame; and

one or more sensors on the device for detecting light from the array of emitters that is reflected off of the eye or its eyelid, the one or more sensors producing an output signal indicating when the eye is open or closed.

2. The system of claim 1, wherein the one or more sensors comprise an array of sensors in a predetermined relationship with the array of emitters for detecting light from the array of emitters that is reflected off of respective portions of the eye or its eyelid, each sensor producing an output signal indicating when the respective portion of the eye is covered or not covered by the eyelid.

3. The system of claim 1, wherein the array of emitters and the one or more sensors are disposed separately and substantially laterally from one another.

4. The system of claim 1, wherein the array of emitters and the one or more sensors comprise solid state devices capable of operating both as an emitter and as a sensor.

5. The system of claim 1, wherein the camera is configured for producing a video signal, and wherein the system further comprises a processor for correlating the output signal from the one or more sensors with the video signal from the camera for determining the person'"'"'s level of drowsiness.

6. The system of claim 5, further comprising a warning indicator on the device, the warning indicator being activated when the processor determines a predetermined level of drowsiness has occurred.

7. The system of claim 1, wherein the array of emitters comprises a plurality of emitters disposed in a substantially vertical arrangement on the device.

8. The system of claim 7, wherein the array of emitters further comprises a plurality of emitters disposed in a substantially horizontal arrangement on the device.

9. The system of claim 1, wherein the array of emitters is configured for projecting a set of crossed bands towards the eye for dividing a region including the eye into four quadrants.

10. The system of claim 1, further comprising a transmitter on the device for wireless transmission of video output signals from the camera to a remote location.

11. The system of claim 1, wherein the array of emitters comprise infrared emitters configured to emit pulses of infrared light.

12. The system of claim 11, wherein the camera comprises an infrared camera.

13. The system of claim 1, wherein the camera is mounted on the device.

14. The system of claim 13, wherein the camera comprises a fiberoptic assembly.

15. The system of claim 13, wherein the camera comprises at least one of a CCD and CMOS detector.

16. The system of claim 1, further comprising a sensor on the device for detecting one or more physiological characteristics of the person.

17. The system of claim 16, wherein the sensor comprises at least one of an EEG electrode, an EKG electrode, an oximetry sensor, a pulse sensor, an airflow sensor, and a temperature sensor.

18. The system of claim 1, further comprising at least one of an orientation sensor for detecting the spatial orientation of the device and an actigraphic sensor.

19. The system of claim 1, wherein the device comprises at least one of an eyeglass frame, a hat, a helmet, a visor, and a mask.

20. A system for monitoring movement of a person'"'"'s eye, comprising:

a frame configured to be worn on a person'"'"'s head;

an array of emitters on the frame for directing light towards an eye of the person when the frame is worn, the array emitters configured to project a reference frame towards the eye;

an array of sensors on the frame in a predetermined relationship with the array of emitters for detecting light from the array of emitters that is reflected off of respective portions of the eye or its eyelid, each sensor producing an output signal indicating when the respective portion of the eye is covered or not covered by the eyelid;

a camera on the frame for monitoring movement of the eye relative to the reference frame, the camera configured for producing a video signal of a region of the eye and the reference frame; and

a transmitter coupled to the sensor for wireless transmission of the output signal and the video signal to a remote location.

21. The system of claim 20, further comprising a processor for correlating the output signal and the video signal to determine the person'"'"'s level of drowsiness.

22. The system of claim 21, further comprising a display for providing a graphical output of the output signal simultaneous with the video signal.

23. A method for monitoring movement of a person'"'"'s eye using a detection device including an array of emitters that are directed towards an eye of the person when the detection device is worn, and a camera oriented towards the eye, the method comprising:

emitting light from the array of emitters towards the eye to project a reference frame onto the eye;

monitoring movement of the eye relative to the reference frame with the camera; and

generating a graphical output of the movement monitored by the camera relative to the reference frame;

wherein the detection device further comprises one or more sensors, and wherein the method further comprises detecting light from the array of emitters reflected off of the eye with the one or more sensors, the one or more sensors producing a light intensity signal indicating when the eye is open or closed.

24. The method of claim 23, wherein the array of sensors is disposed in a predetermined relationship with the array of emitters for detecting light from the array of emitters that is reflected off of respective portions of the eye or its eyelid, each sensor producing an output signal indicating when the respective portion of the eye is covered or not covered by the eyelid.

25. The method of claim 24, further comprising correlating the output signal from the one or more sensors with video signals produced by the camera monitoring movement of the eye relative to the reference frame, thereby determining the person'"'"'s level of alertness.

26. The method of claim 23, wherein the monitoring step comprises measuring movement of the eye'"'"'s pupil relative to the reference frame.

27. The method of claim 26, further comprising graphically displaying the movement of the eye'"'"'s pupil relative to the reference frame.

28. The method of claim 25, further comprising providing a warning to the person when the determined level of alertness falls below a predetermined level.