System and method for monitoring eye movement

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.

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  mounted on the device; 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 of 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    1 , wherein the camera comprises a fiberoptic assembly. 
     
     
       15. The system of claim  13    1 , 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 senior, 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 of 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 coveted 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 one or more sensors comprise an 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. 
     
     
       29. The system of  claim 1 , wherein the camera is oriented towards the eye for monitoring movement of the eye. 
     
     
       30. The system of  claim 1 , wherein the camera is oriented away from the person to monitor the person's surroundings. 
     
     
       31. A system for monitoring movement of a person's eye, comprising:
   a device configured to be worn on a person's head;        one or more emitters on the device for directing light towards an eye of the person when the device is worn;        a sensor on the device comprising a bundle of fiberoptic cables terminating in a lens directed towards the eye of the person when the device is worn, the sensor configured for converting images of the eye into output signals; and        a processor coupled to the sensor for monitoring one or more eye movement parameters of the eye based upon the output signals.     
     
     
       32. The system of  claim 31 , further comprising a display coupled to the processor for displaying the images of the eye together with the one or more eye movement parameters of the eye. 
     
     
       33. The system of  claim 32 , further comprising one or more sensors on the device for monitoring one or more physiological parameters, wherein the processor is coupled to the one or more sensors for displaying the one or more physiological parameters on the display. 
     
     
       34. A system for monitoring movement of a person's eye, comprising:
   a device configured to be worn on a person's head;        one or more emitters on the device for directing light towards an eye of the person when the device is worn;        a bundle of fiberoptic cables comprising a first end mounted to the device for detecting light that is reflected off of the eye or its eyelid; and        a sensor coupled to a second end of the bundle for converting images of the eye from the first end of the bundle of fiberoptic cables into output signals.     
     
     
       35. The system of  claim 34 , wherein the one or more emitters are carried by the fiberoptic bundle. 
     
     
       36. The system of  claim 34 , further comprising a camera on the device that is oriented away from the person to monitor the person's surroundings. 
     
     
       37. The system of  claim 34 , further comprising a processor coupled to the sensor, the processor configured for monitoring one or more eye movement parameters of the person's eye based upon the one or more output signals. 
     
     
       38. The system of  claim 37 , further comprising one or more sensors on the device for detecting one or more physiological characteristics of the person, the processor further configured for correlating the one or more physiological characteristics with the output signals to generate a composite fatigue index of the person wearing the device.