Patent Publication Number: US-2011077548-A1

Title: Biosensors, communicators, and controllers monitoring eye movement and methods for using them

Description:
RELATED-APPLICATION INFORMATION 
     This application is a continuation-in-part of co-pending application Ser. No. 11/096,544, which claims benefit of provisional application Ser. No. 60/559,135, filed Apr. 1, 2004. The entire disclosures of these applications are expressly incorporated by reference herein. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     The U.S. Government may have a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of Grant No. 1 R43 CE 00151-01 awarded by the Department of Health and Human Services, Public Health Services, Centers for Disease Control (CDC), and Department of Defense (US Army) Contract No. W81XWH-05-C-0045. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to apparatus, systems, and methods for monitoring movement of a human eye, e.g., for monitoring fatigue, purposeful communication, and/or controlling devices based upon movement of an eye, eyelid, and/or other components of the eye or eyes of a person. 
     BACKGROUND 
     It has been suggested to use movement of the human eye to monitor involuntary conditions, such as a person&#39;s wakefulness or drowsiness. For example, U.S. Pat. No. 3,863,243 discloses a device that sounds an alarm to warn a person using the device that they are beginning to fall asleep. The device includes a frame similar to a set of eyeglasses onto which is mounted an optical fiber and a photocell that are directed towards the user&#39;s eye when the frame is worn. The photocell detects the intensity of light reflected off of the user&#39;s eye, i.e., either by the eyelid when the eye is closed or the eye surface when the eye is open. A timer distinguishes between regular blinks, and an extended time period during which the eye is closed, i.e., a time period that may indicate that the person is falling asleep. When a threshold time elapses, an alarm is sounded to notify and/or wake the user. 
     Another device is the Alertness Monitor by MTI Research Inc., which may be mounted on safety glasses, and emits a continuous infrared beam of light along the axis of the eyelid at a strategic position where the beam cannot be broken by the eyelashes except during an eyeblink, giving it the ability to measure eyeblink frequency. Other devices, such as those disclosed in U.S. Pat. Nos. 5,469,143 and 4,359,724, directly engage the eyelid or eyebrow of a user to detect movement of the eye and activate an alarm when a drowsiness condition is detected. Such devices may include mechanical devices, e.g., a mechanical arm, or a piezo-electric film against the eyelid. 
     It has been suggested to mount cameras or other devices to a dashboard, roof, or other location in a vehicle to monitor a driver&#39;s awareness. Such devices, however, require the user to maintain constant eye contact with the camera. In addition, they do not monitor eyelid movement if the user turns his head sideways or downwards, turns around, exits the vehicle, if the user moves around rapidly, or if the camera moves relative to the individual. Further, such cameras may violate privacy and/or have problems seeing through eyeglasses, sunglasses, or even contact lenses, and may not operate effectively in sunlight. 
     SUMMARY 
     The present invention is directed to apparatus, systems, and methods for monitoring movement of one or more eyes, eyelids, and/or pupils of a subject. Generally, humans blink at least about 5-30 times per minute, or about 7,000-43,000 times per day. Each involuntary-reflexive blink lasts about 200-300 milliseconds, generally averaging about 250 milliseconds, amounting to about 1,750-10,800 seconds per day of eye closure due to involuntary blinking. As tiredness or sleepiness occurs, the eye blink may get longer and slower and/or the blink rate may vary, and/or the eyelids may begin to droop with small amplitude eye lid blinks, e.g., until the eyes begin to close for short term “microsleeps,” i.e., sleep conditions that last for about 3-5 seconds or longer, or for prolonged sleep. Furthermore, the pupils may constrict more sluggishly, show unstable fluctuations in size, shrinking progressively in diameter, and/or demonstrate delayed responses to light flashes (i.e. delayed pupil response latency) as sleepiness and fatigue progresses. In addition, other ocular manifestations of drowsiness may occur, such as slow or delayed saccadic eye tracking responses, e.g., to a stimulus (i.e., delayed saccadic response latency), with either over- or under-shooting the target, and/or a loss of directed gaze with or without binocular vergence or divergence, eye drift, or esophoria. 
     In one embodiment, an apparatus for monitoring eyelid, pupil, and/or eye movement is provided that includes a device configured to be worn on a person&#39;s head, a light source for directing light towards the eyes of the person when the device is worn, and first and second fiberoptic bundles coupled to the device, the first bundle positioned for viewing a first eye of the person wearing the device, the second bundle positioned for viewing a second eye of the person wearing the device. The apparatus may also include a camera coupled to the first and second bundles for acquiring images of the first and second eyes. 
     Optionally, the apparatus may also include a third fiberoptic bundle oriented away from the user, e.g., for viewing a region towards which the user&#39;s head is turned. In addition or alternatively, the apparatus may carry one or more spatial sensors. The camera may be coupled to the first and second bundles for acquiring images of the first and second eyes, as well as to the third bundle for acquiring images of the area towards which the user&#39;s head and/or eyes are directed. The spatial sensors may allow simultaneous measuring or tracking of the user&#39;s head movement, e.g., relative to the user&#39;s eye movements. In addition, the arrays of emitters and/or sensors coupled to the camera may allow measurement of a variety of oculometric parameters of one or both eyes, such as eyelid velocity, acceleration and deceleration, eye blink frequency, “PERCLOS” (percentage of time the eyelid is open), the vertical height of the palpebral fissure (i.e. the region between the eye lids not covering the pupil), e.g., as a distance or percentage related to a completely open eye, and the like. 
     In another embodiment, a self-contained device is provided for detecting movement of a person&#39;s eyelid that includes a device adapted to be worn on the person&#39;s head, an emitter on the device for directing light towards an eye of the person when the device is worn, and a camera for detecting light from the emitter. The sensor produces an output signal indicating when the eye is open or closed, and a transmitter on the frame is coupled to the sensor for wireless transmission of the output signal to a remote location. The frame may also include a processor for comparing the output signal to a predetermined threshold to detect drowsiness-induced eyelid movement. Similar to the previous embodiments, the emitter and sensor may be a solid state biosensor device for emitting and detecting infrared light, or alternatively an array, e.g., one or two dimensional array, of emitters and/or sensors in a predetermined configuration on the frame, e.g., in a vertical, horizontal, diagonal, or other linear or other geometric array of more than one emitter and/or sensor oriented towards one or both eyes. In particular, an array of emitters and/or sensors may allow measurement of oculometric parameters, such as those identified elsewhere herein. 
     The emitter and/or sensors may be affixed to any number of points on the frame, e.g., around the lens and/or in the nose bridge, or alternatively anywhere along the frame, including near or on the nasal portion of the frame, the attachment of a temple piece of the frame, and/or surface mounted on the lens of an eyeglass. Alternatively, the emitter and/or sensor may be embedded in the lens of an eyeglass, or otherwise such that they operate through the lens. Thus, the emitter(s) and/or sensor(s) may be fixed on an eye-frame such that they move with the wearer&#39;s head movements, and continuously focus on the user&#39;s eyes in any body position, whether the user is in a vehicle, outdoors or in any other environment. 
     In still another embodiment, a system is provided for monitoring movement of a person&#39;s eye. The system includes a device configured to be worn on a person&#39;s head, one or more emitters on the device for directing light towards an eye of the person when the device is worn, and a camera, e.g., a CCD or CMOS device. The emitter(s) may be configured for projecting a reference frame towards the eye. The camera may be oriented towards the eye for monitoring movement of the eye relative to the reference frame. The camera may be provided on the device or may be provided remote from the device, but in relatively close proximity to the user. 
     Light from the emitter(s) may be emitted towards the eye of a user wearing the device to illuminate the eye(s) of the user, while projecting a reference frame onto the eye. The emitter(s) may project light “invisibly” to the user, i.e., outside the scotopic (night-vision) or photopic (day-vision) range of normal vision, e.g., in the infrared light range, such that the illumination and/or reference frame do not interfere substantially with the user&#39;s vision. The camera may image light produced by the emitters, e.g., in the infrared light range, thereby detecting the projected light as a spot of light, band of light or other “glint.” Movement of the eye relative to the reference frame may be monitored with the camera. A graphical output of the movement monitored by the camera, e.g., relative to a reference frame projected onto the eye, may be monitored. For example, infrared light from the emitters may be reflected off of the retina as a “red reflex” under white light, as a white or dark black pupil under infrared light, including the image of a dark pupil using methods of subtraction known in the art. 
     A processor, e.g., using one or more of these methods, may detect movement of the eye&#39;s pupil, e.g., measuring movement relative to the reference frame. This movement may be graphically displayed, showing the movement of the eye&#39;s pupil relative to the reference frame. Optionally, the output signal from the one or more sensors may be correlated with video signals produced by the camera monitoring movement of the eye relative to the reference frame, e.g., to determine the person&#39;s level of drowsiness, or psycho- or neuro-physiological cognitive, emotional, and/or alertness-related state of mind. 
     In yet another embodiment, a method is provided for controlling a computing device or other electronic or electro-mechanical device (e.g. radio, television, wheel-chair, telephone, alarm system, audible, visible or tactile alerting system, etc.) using a device worn on a user&#39;s head. The device may include one or more components, similar to other embodiments described herein, including a camera having at least one objective lens directed towards at least one eye of the user. The computer device may include a display including a pointer displayed on the display. The display may include a heads-up or heads-down display attached to the device worn on the user&#39;s head or otherwise attached or disposed on the user&#39;s head, a desk computer monitor that may be disposed in front of the user, a digitally projected image on a screen (e.g., as in a drive or flight simulator), and the like. Movement of the user&#39;s eye(s) may be monitored using the camera, and movement of the eye(s) may be correlated relative to the pointer on the display to cause the pointer to follow movement of the eye(s), e.g., similar to a computer mouse. Optionally, the camera may monitor the user&#39;s eye(s) for predetermined eye activities, e.g., blinks for predetermined lengths of time, that may correspond to instructions to execute one or more commands identified with the pointer on the display, e.g., similar to “double-clicking” on a computer mouse. 
     Other aspects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a patient in a hospital wearing an embodiment of an apparatus for monitoring the patient based upon movement of the patient&#39;s eye and/or eyelid. 
         FIG. 2  is an enlarged perspective view of the embodiment of  FIG. 1 , including a detection device and a processing box. 
         FIG. 3  is a schematic drawing of an exemplary embodiment of circuitry for transmitting an output signal corresponding to a sequence of eyelid movements. 
         FIG. 4  is a schematic drawing of an exemplary embodiment of circuitry for controlling equipment in response to an output signal corresponding to a sequence of eyelid movements. 
         FIG. 5  is a schematic drawing of an exemplary embodiment of circuitry for detecting eyelid movement. 
         FIGS. 6A-6C  are sectional and front views of alternate embodiments of a device for emitting light towards and detecting light reflected from a surface of an open eye. 
         FIGS. 7A-7C  are sectional and front views of the devices of  FIGS. 6A-6C , respectively, emitting light towards and detecting light reflected from a closed eyelid. 
         FIG. 8  is a perspective view and block diagram of another embodiment of a system for monitoring a user based upon movement of the user&#39;s eye and/or eyelid. 
         FIG. 9  is a block diagram of the components of yet another embodiment of a system for monitoring a user based upon movement of the user&#39;s eye and/or eyelid. 
         FIG. 10A  is a perspective view of still another embodiment of a system for monitoring a user based upon movement of the user&#39;s eye and/or eyelid. 
         FIG. 10B  is a schematic detail of a portion of the system of  FIG. 10A . 
         FIG. 10C  is a detail of an exemplary array of emitters and sensors that may be provided on a nose bridge of an eye frame, such as that of  FIG. 10A . 
         FIG. 10D  is a sectional view of the array of emitters and sensors of  FIG. 10C  emitting light and detecting light reflected from an eye. 
         FIG. 11A  is a schematic view of a system for selectively controlling a number of devices from a remote location based upon eyelid movement. 
         FIG. 11B  is a schematic view of additional devices that may be controlled by the system of  FIG. 11B . 
         FIG. 12A  is a table showing the relationship between the activation of an array of sensors, such as that shown in  FIGS. 10A-10D  and an eye being monitored by the array, as the eye progresses between open and closed conditions. 
         FIG. 12B  is a graph showing a stream of data provided by an array of sensors, such as that shown in  FIGS. 10A-10D , indicating the percentage of eye coverage as a function of time (“PERCLOS”). 
         FIG. 12C  is a graphical display of a number of physiological parameters, including PERCLOS, of a person being monitored by a system including a device such as that shown in  FIGS. 10A-10D . 
         FIG. 12D  is a table showing the relationship between the activation of two-dimensional arrays of sensors and an eye being monitored, as the eye progresses between open and closed conditions. 
         FIG. 13  is a perspective view of another system for monitoring a user based upon movement of the user&#39;s eye and/or eyelid. 
         FIG. 14  is a detail of a camera on the frame of  FIG. 13 . 
         FIGS. 15A-15I  are graphical displays of several parameters that may be monitored with the system of  FIG. 13 . 
         FIG. 16  is a detail of video output from a camera on the frame of  FIG. 13 . 
         FIG. 17  is a schematic showing an exemplary embodiment of circuitry for processing signals from a five-element sensor array. 
         FIGS. 18A and 18B  show another embodiment of an apparatus for monitoring eye movement incorporated into an aviator helmet. 
         FIG. 19  is a schematic of a camera that may be included in the apparatus of  FIGS. 18A and 18B . 
         FIGS. 20A and 20B  are graphical images, showing simultaneous outputs from multiple cameras, showing the user&#39;s eyes open and closing, respectively. 
         FIGS. 21A-21C  are graphical displays, showing an elliptical graphic being created to identify a perimeter of a pupil to facilitate monitoring eye movement. 
         FIG. 22  is a flowchart, showing a method for vigilance testing a user wearing an apparatus for monitoring movement of the user&#39;s eyes. 
         FIG. 23  is a flowchart, showing a method for controlling a computing device based upon movement of an eye. 
         FIGS. 24A and 24B  are front and side views, respectively, of an apparatus for transcutaneously transmitting light to an eye and detecting emitted light exiting from the pupil of the eye. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Turning to the drawings,  FIG. 1  shows a patient  10  in a bed  12  wearing a detection device  30  for detecting eye and/or eyelid movement of the patient  10 . The detection device  30  may include any of the biosensor devices described herein, which may be used for monitoring voluntary movement of the eye, e.g., for purposeful communication, for monitoring involuntary eye movement, e.g., drowsiness or other conditions, and/or for controlling of one or more electronic devices (not shown). The detection device  30  may be coupled to a processing box  130  that converts the detected eye and/or eyelid movement into a stream of data, an understandable message, and/or into other information, which may be communicated, for example, using a video display  50 , to a medical care provider  40 . 
     Turning to  FIGS. 2 ,  6 A, and  7 A, an exemplary embodiment of an apparatus or system  14  is shown that includes an aimable and focusable detection device  30  that is attachable to a conventional pair of eyeglasses  20 . The eyeglasses  20  include a pair of lenses  21  attached to a frame  22 , which includes bridgework  24  extending between the lenses  21 , and side members or temple pieces  25  carrying ear pieces  26 , all of which are conventional. Alternatively, because the lenses  21  may not be necessary, the frame  22  may also be provided without the lenses  21 . 
     The detection device  30  includes a clamp or other mechanism  27  for attaching to one of the side members  25  and an adjustable arm  31  onto which is mounted one or more emitters  32  and sensors  33  (one shown). The emitter  32  and sensor  33  are mounted in a predetermined relationship such that the emitter  32  may emit a signal towards an eye  300  of a person wearing the eyeglasses  20  and the sensor  33  may detect the signal reflected from the surface of the eye  300  and eyelid  302 . In the exemplary embodiment shown in  FIGS. 6A and 7A , the emitter  32  and sensor  33  may be mounted adjacent one another. 
     Alternatively, as shown in  FIGS. 6B and 7B , the emitter  32 ′ and sensor  33 ′ may be mounted on the frame separately away from one another, e.g., such that the emitter  32 ′ and sensor  33 ′ are disposed substantially laterally with respect to each other. In a further alternative, shown in  FIGS. 6C and 7C , the emitter  32 ″ and sensor  33 ″ may be mounted across the eye  300  in axial alignment with another. As the eyelid  302  closes, it may break the beam  340  being detected by the sensor  33 ″. 
     In one embodiment, the emitter  32  and sensor  33  produce and detect continuous or pulsed light, respectively, e.g., within the infrared range to minimize distraction or interference with the wearer&#39;s normal vision. The emitter  32  may emit light in pulses at a predetermined frequency and the sensor  33  is configured to detect light pulses at the predetermined frequency. This pulsed operation may reduce energy consumption by the emitter  32  and/or may minimize interference with other light sources. Alternatively, other predetermined frequency ranges of light beyond or within the visible spectrum, such as ultraviolet light, or other forms of energy, such as radio waves, sonic waves, and the like, may be used. 
     The processing box  130  is coupled to the detection device  30  by a cable  34  including one or more wires therein (not shown). As shown in  FIG. 9 , the processing box  130  may include a central processing unit (CPU)  140  and/or other circuitry, such as the exemplary circuitry shown in  FIGS. 3-5 , for receiving and/or processing an output signal  142 , such as a light intensity signal, from the sensor  33 . The processing box  130  may also include control circuitry  141  for controlling the emitter  32  and/or the sensor  33 , or the CPU  140  may include internal control circuitry. 
     For example, in one embodiment, the control circuitry  141  may control the emitter  32  to produce a flickering infrared signal pulsed at a predetermined frequency, as high as thousands of pulses per second to as little as about 4-5 pulses per second, e.g., at least about 5-20 pulses per second, thereby facilitating detection of non-purposeful or purposeful eyeblinks as short as about 200 milliseconds per blink. The sensor  33  may be controlled to detect light pulses only at the predetermined frequency specific to the flicker frequency of the emitter  32 . Thus, by synchronizing the emitter  32  and the sensor  33  to the predetermined frequency, the system  10  may be used under a variety of ambient conditions without the output signal  142  being substantially affected by, for example, bright sun light, total darkness, ambient infrared light backgrounds, or other emitters operating at different flicker frequencies. The flicker frequency may be adjusted to maximize the efficient measurement of the number of eye blinks per unit time (e.g. about ten to about twenty eye blinks per minute), the duration of each eye blink (e.g. about 200 milliseconds to about 300 milliseconds), and/or PERCLOS (i.e., the percentage of time that the eyelid is completely or partially closed), or to maximize efficiency of the system, while keeping power consumption to a minimum. 
     The control circuitry  141  and/or processing box  130  may include manual and/or software controls (not shown) for adjusting the frequency, focus, or intensity of the light emitted by the emitter  32 , to turn the emitter  32  off and on, to adjust the threshold sensitivity of the sensor  33 , and/or to allow for self-focusing with maximal infrared reflection off of a closed eyelid, as will be appreciated by those skilled in the art. 
     In addition, the processing box  130  also may include a power source  160  for providing power to the emitter  32 , the sensor  33 , the CPU  144 , and/or other components in the processing box  130 . The processor box  130  may be powered by a conventional DC battery, e.g., a nine volt battery or a rechargeable lithium, cadmium, or hydrogen-generated battery, and/or by solar cells attached to or built within the system  14 . Alternatively, an adapter (not shown) may be connected to the processor box  130 , such as a conventional AC adapter or a twelve volt automobile lighter adapter. 
     The CPU  140  may include timer circuitry  146  for comparing the length of individual elements of the output signal  142  to a predetermined threshold to distinguish between normal blinks and other eyelid movement. The timer circuitry  146  may be separate discrete components or may be provided internally within the CPU  140 , as will be appreciated by those skilled in the art. The CPU  140  may convert the output signal  142  into a stream of data  144 , which may be used to communicate to other persons or equipment. For example, the stream of data  144  produced by the CPU  140  may be a binary signal, such as Morse code or ASCI code. Alternatively, the CPU  140  may be capable of producing other outputs, e.g., synthesized voice signals, control signals for equipment, or pictorial representations. 
     To facilitate communication, the processing box  130  may include a variety of output devices for using the stream of data  144 . For example, an internal speaker  150  may be provided, that may produce an alarm sound or a synthesized voice. An output port  148  may be provided to which a variety of equipment, such as the video display  50  shown in  FIG. 1 , may be directly coupled by hard-wire connections. 
     In addition or alternatively, the processing box  130  may include a transmitter  152  coupled to the CPU  144  for wireless communication of the stream of data  144  to a remote location. For example, as shown in  FIG. 9 , the system  14  may include a receiving and processing unit  154 , such as a computer or other control or display system. The transmitter  152  may be a radio frequency (“RF”) transmitter capable of producing a short range signal, for example, reaching as far as about one hundred feet or more, or alternatively about forty five feet to fifty feet, even through walls or obstacles. Alternatively, other transmitters, e.g., an infrared transmitter, may be provided. 
     The transmitter  152  may also be coupled to an amplifier (not shown) to allow the stream of data to be transmitted hundreds or thousands of feet or more, e.g., using Bluetooth or other RF protocols. For example, the amplifier and transmitter  152  may communicate via telephone communication lines, satellites and the like, to transmit the stream of data to a remote location miles away from the system, where the data can be monitored, analyzed in real time, or stored (e.g., as in a truck or aircraft “black box” recorder) for future or retrospective analysis. The system may include, or may be coupled to a global positioning system (GPS) for monitoring the location, movement, and/or state of cognitive alertness, wakefulness, sleepiness, or emotional/behavioral performance and/or safety of an individual wearing the detection device  30 . 
     The receiving and processing unit  154  may include a receiver  156 , e.g., a radio frequency receiver, for receiving signals  153 , including the stream of data, transmitted by the transmitter  152 . A processor  158  is coupled to the receiver  156  for translating, storing, and/or using the information in the stream of data, the processor  158  being coupled to memory circuitry  160 , a communication device  162 , and/or a control system  164 . For example, the receiving and processing unit  154  may include the memory circuitry  160  therein into which the processor  158  may simply store the stream of data for subsequent retrieval and analysis. 
     The processor  158  may interpret the stream of data, for example, by converting a binary code in the stream of data into an understandable message, i.e., a series of letters, words and/or commands, and/or may use augmentative communication devices or software (such as KE:NX or Words Plus) to facilitate communication. The resulting message may be displayed on the communication device  162 , which may include a video display for displaying text, pictures and/or symbols, a synthesized voice module for providing electronic speech, and the like. 
     Alternatively, the stream of data may be displayed graphically on a computer video screen or other electronic display device as a “real time” message signal or numerically (e.g., displaying blink rate, blink duration, PERCLOS, etc.), or displayed graphically similar to an EKG or EEG tracing. In addition, as shown in  FIG. 12C , the stream of data may be displayed along with other physiological data, such as skin conductance, body temperature, cardiovascular data (e.g. heart rate, blood pressure), respiratory data (e.g. respiration rate, blood oxygen and carbon dioxide levels), electromyographic (EMG) and/or actigraphic data (i.e. body movement, position), and/or other sleep polysomnographic (PSG) or electroencephalographic (EEG) variables. Alternatively, the stream of data may be integrated with controllers that monitor automobile or mechanical functions (e.g. vehicle speed, acceleration, braking functions, torque, sway or tilt, engine or motor speed, etc.) to make intelligent decisions regarding slowing down or speeding up the vehicle depending upon road and/or vehicle conditions, as well as functions relating to the state of consciousness, wakefulness, attentiveness, and/or real time performance vigilance responses of the driver or machine operator. 
     In addition, the message may be interpreted by the processor  158  for directing the control system  164  to control one or more pieces of machinery or equipment. For example, the stream of data may include a command to direct the control system  164  to control relay switches or other devices to turn off and on an electrical device, such as an appliance, electrical wheelchair, engine, light, alarm, telephone, television, computer, a tactile vibrating seat, and the like, or to operate an eye-activated computer mouse or other controller. 
     Alternatively, the processor  158  may use the stream of data to control PC, IBM, Macintosh, and other computers, and/or compatible computer software and/or hardware, e.g., to interact with a computer similar to a mouse, a “return” key, and/or a “joystick.” For example, the stream of data may include commands to activate a series of menus from which submenus or individual items may be selected, as are used in commercially available general use software and computer games, as well as special communications software, such as WORDS-PLUS or Ke:NX. The processor  158  may then control, scroll, or select items from computer software programs, operate a printer, or other peripheral device (e.g., selecting a font, paragraph, tab or other symbol operator, selecting commands, such as “edit,” “find,” “format,” “insert,” “help,” or controlling CD-ROM or disc drive operations, and/or other Windows and non-Windows functions). 
     Alternatively, the receiver  156  may be coupled directly to a variety of devices (not shown), such as radio or television controls, lamps, fans, heaters, motors, vibro-tactile seats, remote control vehicles, vehicle monitoring or controlling devices, computers, printers, telephones, lifeline units, electronic toys, or augmentative communication systems, to provide a direct interface between the user and the devices. 
     During use, the detection device  30  may be placed on a user&#39;s head, i.e., by putting the eyeglasses  20  on as shown in  FIG. 1 . The adjustable arm  31  and/or the clamp  27  may be adjusted to optimally orient the emitter  32  and sensor  33  towards the user&#39;s eye  300  (shown in  FIGS. 6A-6C  and  7 A- 7 C). The emitter  32  may be activated and a beam of light  340  directed from the emitter  32  towards the eye  300 . The intensity and/or frequency of the emitter  32  and/or the threshold sensitivity of the sensor  33  or other focus may then be adjusted (e.g. manually or automatically using self-adjusting features). 
     Because of the difference in the reflective characteristics of the surface of the eye  300  itself and the eyelid  302 , the intensity of the light reflected off of the eye  300  depends upon whether the eye  300  is open or closed. For example,  FIGS. 6A and 6B  illustrate an open eye condition, in which a ray of light  340  produced by the emitter  32  strikes the surface of the eye  300  itself and consequently is scattered, as shown by the rays  350 . Thus, the resulting light intensity detected by the sensor  33  is relatively low, i.e., the sensor  33  may not receive any substantial return signal. 
     In  FIGS. 7A and 7B , the eye  300  is shown with the eyelid  302  closed as may occur during normal blinks, moments of drowsiness, intentional blinks, or other eyelid movement. Because the light  340  strikes the eyelid  302 , it is substantially reflected back to the sensor  33 , as shown by the ray  360 , resulting in a relatively high light intensity being detected by the sensor  33 . Alternatively, as shown in  7 C, the beam of light  340  may be broken or cut by the eyelid  302  when the eye  300  is closed. 
     The sensor  33  consequently produces a light intensity signal that indicates when the eye  300  is open or closed, i.e., corresponding to the time during which reflected light is not detected or detected, respectively, by the sensor  33 . Generally, the intensity of the infrared light reflected from the surface of the eyelid is not substantially affected by skin pigmentation. If it is desired to adjust the intensity of light reflected from the eyelid, foil, glitter, reflective moisturizer creams and the like may be applied to increase reflectivity, or black eye liner, absorptive or deflective creams and the like may be applied to reduce reflectivity. 
     Returning to  FIG. 9 , the light intensity detected by the sensor  33  results in an output signal  142  including a series of time-dependent light intensity signals (as shown, for example, in  FIG. 12B ). The output signal  142  is received by the CPU  140  coupled to the sensor  33 , which compares the length of time of each light intensity signal  142 , for example, corresponding to a closed eye condition, with a predetermined threshold. The timer circuitry  146  may provide a threshold time to the CPU  140  for distinguishing normal blinks from intentional and/or other unintentional eyelid movement, which the CPU  140  may then filter out of the output signal  142 . The CPU  140  then produces a stream of data  144  that may be used for voluntary and/or involuntary communication. 
     In one useful application, the detection device  30  may be used to detect impending drowsiness or “micro-sleeps” (i.e., sleep intrusions into wakefulness lasting a few seconds) of a user, with the processing box  130  triggering a warning to alert the user, others in his or her presence, or monitoring equipment of the onset of drowsiness. The threshold of the timer circuitry  146  may be adjusted such that the CPU  140  detects relatively long periods of eye closure, as may occur when a person is falling asleep. 
     For example, because normal blinks are relatively short, the threshold may be set at a time ranging from close to zero seconds up to several seconds, e.g., between about two and three hundred milliseconds (200-300 ms), or, in another embodiment, about two hundred fifty milliseconds (250 ms), e.g., to distinguish normal blinks from drowsiness-induced eyelid movement. When the CPU  140  detects a drowsiness condition, i.e., detects a high light intensity signal exceeding the predetermined threshold time, it may activate a warning device. The warning device may be included within the processing box  130 , such as the speaker  150 , or alternatively on the frame, for example, by mounting a warning light (not shown) or an alarm speaker (not shown in  FIG. 9 , see  FIG. 10C ) on the frame. In another alternative, the warning device may be a tactile device, e.g., a vibrating seat, and the like, as described elsewhere herein. 
     Alternatively, the detection device  30  may be used to unobtrusively record or monitor drowsiness-induced eyelid movement, with the CPU  140  producing a stream of data  144  that the transmitter  152  may transmit to the receiving and processing unit  154  ( FIG. 9 ). For example, the device  30  may be used in conjunction with a vehicle safety system to monitor a driver&#39;s level of awareness or attentiveness. The stream of data  144  may be transmitted to a receiving and processing unit  154  mounted in a vehicle, which may store data on the driver&#39;s drowsiness and/or may use the data to make decisions by predetermined algorithmic responses to control the vehicle, e.g., adjust the vehicle&#39;s speed or even turn the vehicle&#39;s engine off. Thus, the detection device  30  may be used to monitor truck drivers, taxi drivers, ship or airline pilots, train conductors or engineers, radar or airport control tower operators, operators of heavy equipment or factory machinery, scuba divers, students, astronauts, entertainment participants or observers, and the like. 
     The detection device  30  and system  14  may also be used in a medical diagnostic, therapeutic, research, or professional setting to monitor the wakefulness, sleep patterns, and/or sympathetic and parasympathetic effects of stressful conditions or alerting drugs (e.g. caffeine, nicotine, dextro-amphetamine, methylphenidate, modafanil), sedating drugs (e.g. benzodiazapines, Ambien), or circadian rhythm altering effects of light and darkness or melatonin, which may affect blink rate, blink velocity, blink duration, or PERCLOS of a patient or vehicle operator. The signals may be stored and analyzed in real time for trend changes measured over time to predict drowsiness effects of individuals using device. 
     Similar to the method just described, the CPU  140  may produce a stream of data  144 , which the transmitter may send to a remote receiving and processing unit  154 . The receiving and processing unit  154  may store the stream of data  144  in the memory circuitry  160  for later retrieval and analysis by researchers, medical professionals, or safety personnel (e.g., similar to the way in which flight recorder data may be stored in an aircraft&#39;s “black box” recorder). The receiving and processing unit  154  may also display the stream of data  144 , for example at a nurse&#39;s station, as an additional parameter to continually monitor a patient&#39;s physical, mental, or emotional condition. The unit  154  may store and/or produce a signal, e.g., by a series of algorithms, that must be responded to within a predetermined time (e.g., performance vigilance monitoring) to prevent false positives and negatives. 
     A number of medical conditions may be monitored by the detection device  30  and system  14 , such as petit mal epilepsy, in which the eyes flutter at a rate of about three cycles per second, grand mal or psychometer seizures, where the eyes may stare or close repetitively in a jerky manner, myoclonic seizures, in which the lids may open and close in a jerky manner, or tics, or other eye movements, such as encountered by people with Tourette&#39;s syndrome. The system may be used to monitor g-LOC (loss of consciousness) of pilots caused by positive or negative g-force effects, hypoxemia of passengers or crew in aircraft due to losses in cabin pressure, nitrogen narcosis or “the bends” in divers, or the effects of gases, chemicals, drugs, and/or biological agents on military personnel or other individuals. 
     The system may also be used to monitor psychological situations, for example, to detect stress or when a person lies (e.g., by closing or otherwise moving their eyes when lying), during hypnosis, to monitor attentiveness, to measure one or more of: the “negative” side effects and/or “positive” therapeutic effects of drugs or pharmaceuticals on conditions where ocular functions are compromised (e.g. L-dopa in improving blink rates in Parkinson&#39;s disease; drugs used to treat ocular tics or neuromuscular disorders such as ALS or myasthenia gravis); drug or alcohol levels based on correlative ocular measures (e.g. nystagmus or delayed pupil responses to light flashes); the therapeutic and side effects of anti-convulsants, drugs, alcohol, toxins, or the effects of hypoxia or ventilation, and the like. Neurological conditions in patients of all ages may also be monitored where the innervation or mechanical function of the eye or eyelid may be affected, such as in Parkinson&#39;s disease, muscle diseases, e.g., myotonia, myotonic muscular dystrophy, blepharospasm, photophobia or light sensitivity, encephalopathy, seizures, Bell&#39;s palsy, or where the condition may produce loss of vision (e.g. macular degeneration), eyelid drooping or ptosis, such as third cranial nerve palsy or paresis, brainstem lesions or stroke, tumors, infection, metabolic diseases, trauma, degenerative conditions, e.g., multiple sclerosis, amyotrophic lateral sclerosis, polyneuropathy, myesthenia gravis, botulism, tetanus, tetany, tardive dyskinesia, brainstem encephalitis, and other primary eyelid conditions, such as exophthalmos, thyrotoxicosis or other thyroid conditions. In a similar manner, the detection device  30  may be used in an ambulatory fashion to study the progression and/or regression of any of the above neuro-ophthalmological and opthalmological disturbances. 
     Similarly, the detector device  30  may be used in biofeedback applications, for example, in biofeedback, hypnosis or psychological therapies of certain conditions (e.g. tic disorders). The detector device  30  may produce a stimulus, e.g. activating a light or speaker, and monitor the user&#39;s eyelid movement in anticipation of receiving a response, e.g., a specific sequence of blinks, acknowledging the stimulus within a predetermined time. If the user fails to respond, the processor may store the response, e.g. including response time, and/or may automatically transmit a signal, such as an alarm signal. 
     In addition, the detection device  30  may be used to monitor individuals in non-medical settings, such as during normal activity in a user&#39;s home or elsewhere. For example, individuals with involuntary medical conditions, such as epilepsy or narcolepsy, may be monitored, or other individuals, such as, infants and children, prison inmates, demented patients (e.g., with Alzheimer&#39;s disease), law enforcement personnel, military personnel, bank tellers, cashiers, casino workers, students, swing or graveyard shift workers, and the like, may be monitored. Similar applications may be applied in a sleep laboratory during polysomnographic procedures (e.g. PSG, MSLT or MWT) for monitoring sleep patients to measure parameters, such as onset of sleep, sleep latency, time of eyelid closing or opening, time of awakening during the night, etc., or to animal research where eye blinking, pupil changes, and/or slow or rapid eye movement may be a factor to be studied, or to the ocular neuro-developmental functions of infants. 
     The detection device  30  may be used to study or monitor the drowsiness, awakening, or alerting effects of prescribed pharmaceuticals (e.g. stimulants), alcohol or other illicit drugs, toxins, poisons, as well as other relaxing, sedating or alerting techniques or devices. Similarly, the performance and vigilance abilities of the user may be tested and analyzed as a direct function of, or in relationship to, PERCLOS. 
     When the CPU  140  detects the presence of particular eyelid movement, such as an extensive period of eye closure, which may occur, for example, during an epileptic seizure, a syncopal episode, a narcoleptic episode, or when dozing off while driving or working, the CPU  140  may produce an output signal which activates an alarm. Alternatively, the transmitter  152  may send an output signal to shut off equipment being used, to notify medical personnel, such as by automatically activating a telephone to dial emergency services, to signal remote sites, such as police stations, ambulances, vehicle control centers, guardians, and the like. 
     The system  14  may also find useful application for voluntary communication. A user wearing the detection device  30  may intentionally blink in a predetermined pattern, for example, in Morse code or other blinked code, to communicate an understandable message to people or equipment (e.g., to announce an emergency). The CPU  140  may convert a light intensity signal  142  received from the sensor  33  and corresponding to the blinked code into a stream of data  144 , or possibly directly into an understandable message including letters, words and/or commands. 
     The stream of data  144  may then be displayed on a video display  50  (see  FIG. 1 ) coupled to the output port  148 , or emitted as synthesized speech on the internal speaker  150 . The stream of data  144  may be transmitted by the transmitter  152  via the signal  153  to the receiving and processing unit  154  for displaying messages, or for controlling equipment, such as household devices, connected to the control system  164 . In addition to residential settings, the system  14  may be used by individuals in hospitalized or nursing care, for example by intubated, ventilated, restrained, paralyzed or weakened patients, to communicate to attending medical staff and/or to consciously signal a nurse&#39;s station. These include all patients who have no physical ability to communicate verbally, but who retain ability to communicate using eye blinking of one or both eyes (e.g., patients with amyotrophic lateral sclerosis, transverse myelitis, locked-in syndrome, cerebravascular strokes, terminal muscular dystrophy and those intubated on ventilation). 
     The device may be used in any environment or domain, e.g., through water or other substantially transparent fluids. Further, the device  30  may also be used as an emergency notification and/or discrete security tool. A person who may be capable of normal speech may wear the device  30  in the event of circumstances under which normal communication, i.e., speech, is not a viable option. For example, a bank or retail employee who is being robbed or is otherwise present during the commission of a crime may be able to discretely blink out a preprogrammed warning to notify security or to call law enforcement. Alternatively, a person with certain medical conditions may wear the device in the event that they are physically incapacitated, i.e., are unable to move to call for emergency medical care, but are still able to voluntarily move their eyes. In such cases, a pre-recorded message or identifying data (e.g. name of the user, their location, the nature of the emergency, etc.) may be transmitted to a remote location by a specific set of eyeblink codes or preprogrammed message. In this manner, the detection device  30  may be used to monitor patients in an ICU setting, patients on ventilators, prisoners, elderly or disabled persons, heavy equipment operators, truck drivers, motorists, ship and aircraft pilots, train engineers, radar or airport control tower operators, or as a nonverbal or subliminal tool for communication by military guards, police bank tellers, cashiers, taxi-drivers, and the like. The detection device  30  may also be used as a recreational device, for example, as a children&#39;s toy similar to a walkie-talkie or to operate a remote control toy vehicle. 
     In addition, it may be desirable to have the CPU  140  perform an additional threshold comparison to ensure continued use of the detection device  30 . For example, additional timer circuitry may be coupled to the CPU  140  such that the CPU  140  may compare the light intensity signals received from the sensor  33  to a second predetermined threshold provided by the timer circuitry. The second predetermined threshold may correspond to a time period during which a person would normally blink. If the CPU  140  fails to detect a normal blink within this time period or if the user fails to respond to a predetermined stimulus (e.g. a blinking light or sound), the CPU  140  may produce a signal, activating the speaker  150  or transmitting a warning using the transmitter  152 . 
     This may be useful, if, for example, the detection device  30  is removed by a perpetrator during commission of a crime, falls off because of the onset of a medical episode, as well as to prevent “false alarms,” or to measure the “state of attentiveness” of the user. Alternatively, performance vigilance tasks may be required of the user to determine whether the signal transmitted is a purposeful or “false alarm” signal, and also for measuring attention or drowsiness levels for purposes of biofeedback, and also to measure compliance of the user wearing the device. 
     Alternatively, the polarity of the output signal  142  may be reversed such that a stream of data is produced only when the eye is opened, for example, when monitoring patients in a sleep lab to measure onset of sleep, sleep latency, time of eyelid closure, etc., or to monitor sleeping prison inmates. For such uses, the CPU  140  may activate an alarm only when an open eye condition is detected, as will be appreciated by those skilled in the art. 
     Turning to  FIG. 8 , another embodiment of the detection device  30  is shown. In this embodiment, the emitter and sensor are a single solid state light emission and detecting biosensor device  132 , which are mounted directly onto the eyeglasses  20 . The biosensor device  132 , which may produce and detect infrared light, may be as small as two millimeters by four millimeters (2 mm×4 mm) and weigh only a few grams, thereby enhancing the convenience, comfort and/or discretion of the detection device  30 . Because of the small size, the biosensor device  133  may be mounted directly in the lens  21 , as shown in  FIG. 8 , on an outside or inside surface of the lens  21 , in the bridgework  24  or at another location on the frame  22  that may facilitate detection of eye movement. The biosensor device  132  may measure less than about five millimeters by five millimeters surface area, and may weigh as little as about one ounce, thereby providing a emitter/sensor combination that may be unobtrusive to vision, portable, and may be conveniently incorporated into a light weight eye frame. Because the entire system may be self-contained on the frame, it moves with the user no matter which direction he or she looks and may operate in a variety of environments or domains, day or night, underwater, etc. 
     Hamamatsu manufactures a variety of infrared emitter and detector devices that may be used for the biosensor device  132 , such as Model Nos. L1909, L1915-01, L2791-02, L2792-02, L2959, and 5482-11, or alternatively, a Radio Shack infrared emitter, Model No. 274-142, may be used. Multiple element arrays, e.g., linear optical scanning sensor arrays, appropriate for use may be available from Texas Advanced Optoelectronic Solutions, Inc. (TAOS) of Plano, Tex., such as Model Nos. TSL 201 (64 pixels×1 pixel), TSL 202 (128×1), TSL 208 (512×1), TSL 2301 (102×1). These sensors may be used in combination with lens arrays to facilitate focusing of the detected light, such as the Selfoc lens array for line scanning applications made by NSG America, Inc. of Irvine, Calif. 
     In addition, multiple biosensor devices  132  may be provided on the eyeglasses  20 , for example, a pair of biosensor devices  132  may be provided, as shown in  FIG. 8 , for detecting eyelid movement of each eye of the user (not shown). A cable  134  may extend from each biosensor device  132  to a processing box  130 , similar to the processing box  130  described above. The CPU  140  of the processing box  130  (not shown in  FIG. 8 ) may receive and compare the output signal from each biosensor device  132  to further augment distinguishing normal blinks from other eyelid movement. 
     The pair of biosensor devices  132  may allow use of more sophisticated codes by the user, e.g., blinking each eye individually or together, for communicating more effectively or conveniently, as will be appreciated by those skilled in the art. In one form, a blink of one eye could correspond to a “dot,” and the other eye to a “dash” to facilitate use of Morse code. The output signals from each eye could then be interpreted by the CPU  140  and converted into an understandable message. 
     In another form, a right eye blink (or series of blinks) may cause an electric wheelchair to move to the right, a left eye blink (or series of blinks) may move to the left, two simultaneous right and left eye blinks may cause the wheelchair to move forward, and/or four simultaneous right and left eye blinks may cause the wheelchair to move backward. Similar combinations or sequences of eye blinks may be used to control the on/off function, or volume or channel control of a television, AM/FM radio, VCR, tape recorder or other electronic or electromechanical device, any augmentative communications or controlling device, or any device operable by simple “on/off” switches (e.g., wireless television remote controls single switch television control units, universal remote controllers, single switch multi-appliance units with AC plug/wall outlet or wall switch modules, computer input adapters, lighted signaling buzzer or vibrating signal boxes, switch modules of all types, video game entertainment controller switch modules and switch-controlled electronic toys). 
     In additional alternatives, one or more lenses or filters may be provided for controlling the light emitted and/or detected by the biosensor device, an individual emitter, and/or detector. For example, the angle of the light emitted may be changed with a prism or other lens, or the light may be columnated or focused through a slit to create a predetermined shaped beam of light directed at the eye or to receive the reflected light by the sensor. An array of lenses may be provided that are adjustable to control the shape, e.g. the width, etc., of the beam of light emitted or to adjust the sensitivity of the sensor. The lenses may be encased along with the emitter in plastic and the like, or provided as a separate attachment, as will be appreciated by those skilled in the art. 
     Turning to  FIG. 10A , another embodiment of a system  414  is shown that includes a frame  422  including a biosensor device  432  with associated processor and transmitter circuitry  430  provided directly on the frame  422 , for example, to enhance the convenience and discretion of the system  414 . The frame  422  may include a bridge piece  424  onto which the biosensor device  432  may be fixedly, slidably, and/or adjustably mounted, and a pair of ear supports  423 ,  425 . 
     One of the supports  423  may have a larger size compared to the other support  425 , for example, to receive the processor and transmitter circuitry  430  embedded or otherwise mounted thereon. A processor  440 , similar to the CPU  140  in the processing box  130  previously described, may be provided on the frame  422 , and a power source, such as a lithium battery  460 , may be inserted or affixed to the support  423 . A radio frequency or other transmitter  452  (e.g., using Bluetooth or other protocols) is provided on the support  423 , including an antenna  453 , which may be embedded or otherwise fastened along the ear support  423 , in the temple piece or elsewhere in the frame  422 . 
     The system  414  may also include manual controls (not shown) on the ear support  423  or elsewhere on the frame  422 , for example to turn the power off and on, or to adjust the intensity and/or threshold of the biosensor device  432 . Thus, the system  414  may be substantially self-contained on the frame  422 , which may or may not include lenses (not shown) similar to eyeglasses. External cables or wires may be eliminated, thereby providing a more convenient and comfortable system for communication and/or monitoring a user. 
     In another alternative, shown in  FIGS. 10B ,  10 C, and  10 D, a linear array  530  of emitters  532  and sensors  533  may be provided, e.g., in a vertical arrangement mounted on a nose bridge  524  of an eye frame  522 . A CPU  540 , battery  460 , transmitter antenna  543 , and warning indicator  550  may also be provided on the frame  522 , e.g., in the temple piece  525 , similar to the previously described embodiments. An LED  542  or similar stimulus device may also be provided at a predetermined location on the eye frame  522  to allow routine biofeedback responses from the user. In addition, a receiver  544  may be provided for receiving the stream of data created by the CPU  540  and transmitted by the transmitter  543 . 
     As shown particularly in  FIG. 10C , each of the sensors  533  and the emitter  532  may be coupled to the CPU  540  or other control circuitry for controlling the emitter  532  and/or for processing the light intensity signals produced by the sensors  532 . Thus, the CPU  540  may cycle through the sensors  533  in the array  530  and sequentially process the signal from each of the sensors  533 , similar to the processors described elsewhere herein. As shown in  FIG. 10D , the emitter  532  includes a lens  534  to focus a beam of light (indicated by individual rays  360   a ,  360   b ) onto the eye  300 , e.g., towards the pupil  301 . The sensors  533  are embedded within the nose bridge  524  and a slit  535  is provided for each, the slits  535  having a predetermined size to control the reflected light detected by each sensor  533 . Thus, each sensor  535  may detect movement of the eyelid  302  past a particular portion of the eye  300 , e.g., to measure PERCLOS, as shown in  FIG. 12A . The sensors or emitters may have lenses or columnating devices to focus emitted or reflected light. 
     The linear array  530  may facilitate measurement of additional parameters related to eyelid movement in addition to mere eye closure, for example, to measure the velocity of the eyelid opening or closing, i.e., the rate of eye closure, the CPU  540  may compare the time delay between the activation of successive sensors  533 . In addition, the output signals from the sensors  553  may be processed to measure the percentage of pupil coverage of the eyelid  302 , for example, due to partial eye closure, as a function of time, e.g., to monitor when the eye is partially, but not completely, closed, and/or to monitor the percentage of time that the eye is closed (PERCLOS), as shown in  FIGS. 12A-12C , e.g., compared to the user&#39;s baseline of maximal eye opening. 
     Turning to  FIG. 12D , in another embodiment, a two-dimensional array of sensors may be provided. Although a 5×5 array  633  and a 9×11 array  733  are shown as exemplary embodiments, other arrays including any number of elements in the array may be provided. For example, as described further below, the sensors may be in the form of a CMOS or CCD device, including hundreds or thousands of pixels in a grid or other pattern. The sensors  633 ,  733  may then be used to measure surface area reflectivity of light from the emitter  632 , i.e., the processor (not shown) may process the signals from each sensor in the array  633 ,  733  to create a stream of data indicating the percentage of surface area of the eye  300  covered by the eyelid  302  and/or relative position of the pupil. 
     The sensors in the array  633 ,  733  may be sufficiently sensitive or have sufficient resolution such that they may detect “red reflex” or the equivalent infrared “bright pupil” reflection due to the reflection of light off of the retina through the pupil  301 . Thus, the sensors may produce a light intensity signal that includes a substantially zero value, indicating no red reflex or bright pupil, a low output, indicating red reflex or white pupil reflex, and a high output, indicating reflection off of a closed eyelid  302 . The red reflex may appear as a bright white light pupil (resulting from infrared light from the emitter(s) reflecting off of the retina when the eyelid is open, or as a dark or “black pupil” if the processor uses subtraction algorithms). The processor may process the light intensity signals to detect when the pupil  301  is covered by the eyelid  302 , i.e., at which point the user cannot see, even though their eye  300  may not be entirely covered by the eyelid  302 , generally at a PERCLOS value of about 50-75 percent in primary gaze. Alternatively, as the eyelid, eye, and pupil descend, the sensor(s) may detect a red reflex or bright pupil even though the PERCLOS measurement may be as great as 75-80 percent or more, e.g., where the eye may still see through a narrow slit-like palpebral fissure opening in downward gaze. 
     In another alternative, the processor and/or transmitter circuitry (such as the CPU  140  in the processor box  130  of  FIG. 2 , or the CPU&#39;s  440 ,  540  of  FIGS. 10A and 10B ) may include identification circuitry (not shown), either as a discrete memory chip or other circuit element, or within the CPU itself. The identification circuitry may be preprogrammed with a fixed identification code, or may be programmable, for example, to include selected identification information, such as the identity of the user, the user&#39;s location, biometric measures specific to the user (e.g. unique iris or retinal patterns, finger prints, voice identification), an identification code for the individual detection device, and the like. 
     The CPU may selectively add the identification information to the transmitted stream of data  553 , or the identification information may be automatically or periodically, continuously or discontinuously, included in the stream of data  553 , thereby allowing the stream of data  553  to be associated with a particular detection device, individual user, and/or a specific location. The identification information may be used by the processor, for example, at a remote location, to distinguish between streams of data received from a number of detection devices, which may then be stored, displayed, etc. as previously described. Thus, the detection device may not require users to consciously communicate certain identification or other standard information when the system is used. 
     As shown in  FIG. 11A , the receiver  544  may allow the user to control one or more devices coupled to the receiver  544  through a single switch multi-appliance control unit  550 . The control unit  550  includes its own transmitter adapted to transmit on/off or other control signals that may be received by individual control modules  552   a - 552   f . The user  10  may blink to create a transmitted stream of data  553  that includes commands to turn off and on, or otherwise control, selected appliances using the control unit  550  and control modules  552   a - 552   f , such as, a radio  554 , a television  556 , a light  558   a , a light  562  controlled by a wall switch  560 , a fan  566  plugged into a wall socket  564 , and the like. 
     Alternatively, as shown in  FIG. 11B , the receiver  554  may be coupled to other systems, such as a computer  570  and printer  572 , a vehicle integration system  574 , a lifeline unit  576 , a GPS or other satellite transmitter  578 , and the like. The transmitted stream of data  553  may be processed alone or along with additional data, such as other vehicle sensor information  573 , and/or human factors (e.g. EKG, EEG, EOG, pulse, blood pressure, respiratory rate, oximetry, actigraphy, head position, voice analysis, body temperature, skin conductance, self-assessment measures and performance vigilance responses, observation by others through a fixed non-wearable dash-board or visor-mounted camera system, etc.), to further enhance monitoring a user, such as a long-distance truck driver. 
     Turning to  FIG. 13 , yet another embodiment of a system  810  for monitoring eye movement is shown. Generally, the system  810  includes a frame  812  that may include a bridge piece  814  and a pair of ear supports  816 , one or more emitters  820 , one or more sensors  822 , and/or one or more cameras  830 ,  840 . The frame  812  may include a pair of lenses (not shown), such as prescription, shaded, or protective lenses, although they may be omitted. Alternatively, the system may be provided on other devices that may be worn on a user&#39;s head, such as a pilot&#39;s oxygen mask, protective eye gear, a patient&#39;s ventilator, a scuba or swimming mask, a helmet, a hat, a head band, a head visor, protective head gear, or within enclosed suits protecting the head and/or face, and the like (not shown). The components of the system may be provided at a variety of locations on the device that generally minimize interference with the user&#39;s vision and/or normal use of the device. 
     As shown, an array of emitters  820  are provided on the frame  812 , e.g., in a vertical array  820   a  and a horizontal array  820   b . In addition or alternatively, the emitters  820  may be provided in other configurations, such as a circular array (not shown), and may or may not include light filters and/or diffusers (also not shown). In an exemplary embodiment, the emitters  820  are infrared emitters configured to emit pulses at a predetermined frequency, similar to other embodiments described elsewhere herein. The emitters  820  may be arranged on the frame such that they project a reference frame  850  onto a region of the user&#39;s face including one of the user&#39;s eyes. As shown, the reference frame includes a pair of crossed bands  850   a ,  850   b  dividing the region into four quadrants. In an exemplary embodiment, the intersection of the crossed bands may be disposed at a location corresponding substantially to the eye&#39;s pupil during primary gaze, i.e., when the user is looking generally straight forward. Alternatively, other reference frames may be provided, e.g., including vertical and horizontal components, angular and radial components, or other orthogonal components. Optionally, even one or two reference points that remain substantially stationary may provide sufficient reference frame for determining relative movement of the eye, as explained further below. 
     An array of sensors  822  may also be provided on the frame  812  for detecting light from the emitters  820  that is reflected off of the user&#39;s eyelid. The sensors  822  may generate output signals having an intensity identifying whether the eyelid is closed or open, similar to other embodiments described elsewhere herein. The sensors  822  may be disposed adjacent to respective emitters  820  for detecting light reflected off of respective portions of the eyelid. 
     Alternatively, sensors  822  may only be provided in a vertical array, e.g., along the bridge piece  814 , for monitoring the amount of eyelid closure, similar to embodiments described elsewhere herein. In a further alternative, the emitters  820  and sensors  822  may be solid state biosensors (not shown) that provide both the emitting and sensing functions in a single device. Optionally, the emitters  820  and/or sensors  822  may be eliminated, e.g., if the cameras  830 ,  840  provide sufficient information, as explained further below. 
     Circuitry and/or software may be provided for measuring PERCLOS or other parameters using the signals generated by the array of sensors. For example,  FIG. 17  shows an exemplary schematic that may be used for processing signals from a five element array, e.g., to obtain PERCLOS measurements or other alertness parameters. 
     Returning to  FIG. 13 , the system  810  also includes one or more cameras  830  oriented generally towards one or both of the user&#39;s eyes. Each camera  830  may include a fiber optic bundle  832  including a first end mounted to or adjacent the bridge piece  814  (or elsewhere on the frame  812 , e.g., at a location that minimizes interferences with the user&#39;s vision), and a second end  837  that is coupled to a detector  838 , e.g., a CCD or CMOS sensor, which may convert images into digital video signals. An objective lens  834  may be provided on the first end of the fiber optic bundle  832 , as shown in  FIG. 14 , e.g., to focus images onto the fiber optic bundle  832 . Optionally, the fiber optic bundle  832  may include one or more illumination fibers that may terminate adjacent the lens  834  to provide emitters  836 , also as shown in  FIG. 14 . The illumination fiber(s) may be coupled to a light source (not shown), e.g., similar to the embodiment shown in  FIG. 22  and described further below. Although only one camera  830  is shown in  FIG. 13  (e.g., for monitoring the user&#39;s left eye), it will be appreciated that another camera (not shown) may be provided in a symmetrical configuration for monitoring the other of the user&#39;s eyes (e.g., the right eye), including similar components, e.g., a fiber optic bundle, lens, emitter(s) and/or detector (although, optionally, the cameras may share a common detector, as explained further below). Optionally, it may be desirable to have multiple cameras (not shown) directed towards each eye, e.g., from different angles facing the eye(s). Optionally, these camera(s) may include fiberoptic extensions, prismatic lenses, and/or reflecting mirrors (e.g., reflecting infrared light), impenetrable or blocking mirrored surfaces on the side of the lenses facing the eyes, and the like. Such accessories may be provided for bending, turning, reflecting, or inverting the images of the eyes transmitted to the camera(s) in a desired manner. 
     The camera(s)  830  may be configured for detecting the frequency of light emitted by the emitters  820  and/or  836 , e.g., infrared light or other light beyond the visible range. Optionally, if the fiber optic bundle(s)  832  include one or more illumination fibers for emitters  836 , the emitters  820  on the frame  812  may be eliminated. In this embodiment, it may also be possible to eliminate the sensors  822 , and use the camera(s)  830  to monitor movement of the user&#39;s eye(s), e.g., as explained further below. Optionally, the system  810  may include a second camera  840  oriented away from the user&#39;s head, e.g., to monitor the user&#39;s surroundings, such an area directly in front of the user&#39;s face. The camera  840  may include similar components to the camera  830 , e.g., a fiberoptic bundle  841 , lens (not shown), and/or emitter(s) (also not shown). Optionally, the camera  830  may sufficiently sensitive to generate images under ambient lighting conditions, and the emitters may be omitted. The camera  840  may be coupled to a separate detector  839 , as shown in  FIG. 13 , or may share the detector  838  with the camera(s)  830 , as explained further below. 
     Each of the fiberoptic bundles  832 ,  841  may include, for example, between about five thousand and one hundred thousand (5,000-100,000) pixelated light-carrying optical fibers, or between about ten thousand and fifty thousand (10,000-50,000) fibers. The number of fibers may depend on the particular needs of a given application, e.g., to provide a desired optical resolution in the images obtained of the user&#39;s eye(s) (i.e., for the “endocamera(s)” fibers), as well as of the surrounding environment (i.e., for the “exocamera” fibers). Optionally, the fibers for the bundles may include one or more illumination fibers. In exemplary embodiments, bundles may be used having five thousand (5,000) fibers (providing 75×75 pixel resolution), ten thousand (10,000) fibers (providing 100×100 pixel resolution), fifty thousand (50,000) fibers (providing 224×224 pixel resolution), and one hundred thousand (100,000) fibers (providing 316×316 pixel resolution). The resulting fiber optic bundle(s)  832 ,  841  may have a diameter, for example, between about three to five millimeters (3-5 mm), with or without cladding. The fiber optic bundle(s)  832 ,  841  may be secured along the frame  812  or may be provided within the frame  812 . For example, the frame  812  may be formed with one or more passages, e.g., extending from the bridge piece  814  to the ear supports  816 , for receiving the fiber optic bundle(s)  832 ,  841  therethrough. Alternatively, the fiber optic bundle(s)  832 ,  841  may be molded, fused, or otherwise embedded into the frame  812 , e.g., when the frame  812  is made. Optionally, the fiber optic bundle(s)  832 ,  841  may extend from the frame  812  to a detector and/or processor (not shown) separate from the frame  812 , similar to the embodiments described below with reference to  FIGS. 18A and 18B . 
     One or both of the ear supports  816  may include a panel  818  for mounting one or more components, e.g., a controller or processor, such as exemplary processor  842 , a transmitter  844 , an antenna  845 , detector(s)  838 ,  839 , and/or a battery  846 . The processor  840  may be coupled to the emitters  820 , the sensors  822 , and/or the cameras  830 ,  840  (e.g., to the detector(s)  838 ,  839 ) for controlling their operation. The transmitter  844  may be coupled to the processor  842  and/or detector(s)  838 ,  839  for receiving the output signals from the sensors  822  and/or cameras  830 ,  840 , e.g., to transmit the signals to a remote location, as described below. Alternatively, the transmitter  844  may be coupled directly to output leads from the sensors  822  and/or the cameras  830 ,  840 . The frame  812  may also include manual controls (not shown), e.g., on the ear support  816 , for example, to turn the power off and on, or to adjust the intensity and/or threshold of the emitters  820 , the sensors  822 , and/or the cameras  830 ,  840 . 
     If desired, the system  810  may also include one or more additional sensors on the frame  812 , e.g., physiological sensors, for example, for the purposes of integration and cross-correlation of additional bio- or neuro-physiological data relating to the cognitive, emotional, and/or behavioral state of the user. The sensors may be coupled to the processor  842  and/or to the transmitter  844  so that the signals from the sensors may be monitored, recorded, and/or transmitted to a remote location. For example, one or more position sensors  852   a ,  852   b  may be provided, e.g., for determining the spatial orientation of the frame  812 , and consequently the user&#39;s head. For example, actigraphic sensors may be provided to measure tilt or movement of the head, e.g., to monitor whether the user&#39;s head is drooping forward or tilting to the side. Acoustic sensors, e.g., a microphone  854  may be provided for detecting environmental noise or sounds produced by the user. 
     In addition or alternatively, the frame  812  may include one or more sensors for measuring one or more physical characteristics of the user, e.g., for the purpose of physiological systems integration and/or cross correlation. For example, EEG electrodes  856  may be provided on the ear support  816 , above or below the nasion, on the mastoid, over the occipital area, and/or other region that may contact the user&#39;s skin (e.g., moist surface contact electrodes), or may not contact the user&#39;s skin (e.g., dry wireless electrodes) to measure and transmit brain activity (e.g., waking, drowsy, or other sleep-related brain activity), e.g., of different frequencies ranging from about one to five hundred Hertz (1-500 Hz) for visual or short or long term spatial and/or temporal trend analysis (e.g. Fast Fourier or spectral analysis). An EKG electrode (not shown) may be provided that is capable of measuring cardiac activity through a skin contact site. A pulse sensor (not shown) may be used to measure cardiovascular pulsations, or an oximetry sensor  858  may be used to measure oxygen saturation levels. A thermistor or other sensor may measure respiratory air flow, e.g., through the user&#39;s nose. A thermistor, thermocouple, or other temperature sensor (not shown) may be provided for measuring the user&#39;s skin temperature. A sweat detector (not shown) may be provided for measuring moisture on the user&#39;s skin, and/or a microphone or other acoustic sensor (also not shown) may be attached to the frame  812  to detect vocal or breathing sounds of the user. One or more electrooculographic (EOG) electrodes may be provided that contact the user&#39;s skin at desired areas that measure fluctuations in electrical potentials during movement of the eyes. 
     In addition, the system  810  may include one or more feedback devices on the frame  812 . These devices may provide feedback to the user, e.g., to alert and/or wake the user, when a predetermined condition is detected, e.g., a state of drowsiness or lack of consciousness. The feedback devices may be coupled to the processor  842 , which may control their activation. For example, a mechanical vibrator device  860  may be provided at a location that may contact the user, e.g., on the ear support  816 , that may provide tactile vibrating stimuli through skin contact. An electrode (not shown) may be provided that may produce relatively low power electrical stimuli. A visible white or colored light emitter, such as one or more LED&#39;s may be provided at desired locations, e.g., above the bridge piece  814 . Alternatively, audio devices  862 , such as a buzzer or other alarm, may be provided, similar to other embodiments described elsewhere herein. In a further alternative, aroma-emitters may be provided on the frame  810 , e.g., on or adjacent to the bridge piece  814 . 
     In addition or alternatively, one or more feedback devices may be provided separate from the frame  812 , but located in a manner capable of providing a feedback response to the user. For example, audio, visual, tactile (e.g., vibrating seat), or olfactory emitters may be provided in the proximity of the user, such as any of the devices described elsewhere herein. In a further alternative, heat or cold generating devices may be provided that are capable of producing thermal stimuli to the user, e.g., a remotely controlled fan or air conditioning unit. 
     The system  810  may also include components that are remote from the frame  812 , similar to other embodiments described elsewhere herein. For example, the system  810  may include a receiver, a processor, and/or a display (not shown) at a remote location from the frame  812 , e.g., in the same room, at a nearby monitoring station, or at a more distant location. The receiver may receive signals transmitted by the transmitter  842 , including output signals from the sensors  822 , cameras  830 ,  840 , or any of the other sensors provided on the frame  812 . 
     A processor may be coupled to the receiver for analyzing signals from the components on the frame  812 , e.g., to prepare the signals for graphical display. For example, the processor may prepare the signals from the sensors  822  and/or cameras  830 ,  840  for display on a monitor, thereby allowing the user to be monitored by others. Simultaneously, other parameters may be displayed, either on a single or separate display(s). For example,  FIGS. 15A-15I  show signals indicating the output of various sensors that may be on the frame  812 , which may be displayed along a common time axis or otherwise correlated, e.g., to movement of the user&#39;s eye and/or level of drowsiness. The processor may superimpose or otherwise simultaneously display the video signals in conjunction with the other sensed parameters to allow a physician or other individual to monitor and personally correlate these parameters to the user&#39;s behavior. 
     In a further alternative, the processor may automatically process the signals to monitor and/or study the user&#39;s behavior. For example, the processor may use the output signals to monitor various ocular parameters related to eye movement, such as eye blink duration (EBD), eye blink frequency, eye blink velocity, eye blink acceleration, interblink duration (IBD), PERCLOS, PEROP (percentage eyelid is open), pupil size fluctuations, eye gaze and eye ball movements, and the like, such as those described in U.S. Pat. No. 6,542,081, incorporated by reference herein. 
     The video signals from the camera  830  may be processed to monitor various eye parameters, such as pupillary size, location, e.g., within the four quadrant defined by the crossed bands  850 , eye tracking movement, eye gaze distance, and the like. For example, because the camera(s)  830  may be capable of detecting the light emitted by the emitters  822 , the camera(s)  830  may detect a reference frame projected onto the region of the user&#39;s eye by the emitters.  FIG. 16  shows an exemplary video output from a camera included in a system having twenty emitters disposed in a vertical arrangement. The camera may detect twenty discrete regions of light arranged as a vertical band. The camera may also detect a “glint” point, G, and/or a moving bright pupil, P. Thus, the movement of the pupil may be monitored in relation to the glint point, G, and/or in relation to the vertical band  1 - 20 . 
     Because the emitters  822  are fixed to the frame  812 , the reference frame  850  may remain substantially stationary relative to the user. Thus, the processor may determine the location of the pupil in terms of orthogonal coordinates (e.g., x-y or angle-radius) relative to the reference frame  850 . Alternatively, if the reference frame is eliminated, the location of the pupil may be determined relative to any stationary “glint” point on the user&#39;s eye or other predetermined reference point. For example, the camera  830  itself may project a point of light onto the eye that may be reflected and detected by the camera. This “glint” point may remain substantially stationary since the camera  830  is fixed to the frame  812 , thereby providing the desired reference point from which subsequent relative movement of the eye may be determined. 
     In addition, video signals from a remote camera separate from the frame  812  may image the user&#39;s face from a distance (e.g., on the dashboard of a car, a drive, flight, or other simulator, or in a sonar, radar, or other monitoring station), e.g., to monitor various facial measures, such as facial expression, yawning frequency, and the like, in addition, or alternative to, the projected light reference frame from the emitters. In addition or alternatively, the parameters from other sensors may be processed and correlated, such as head orientation, tilt, body movement, physiological parameters, and the like. In one embodiment, the processor may correlate two or more of these various parameters to generate a composite fatigue index (“COFI”). For example, when eye blinks or pupil coverage by the eyelid exceed a threshold duration, the processor may monitor the position sensors to detect head tilt and/or the physiological sensors for brain activity likely to indicate that the user is falling asleep or otherwise becoming incapable of driving or operating equipment. The processor may assign numerical values to these parameters using an empirical algorithm stored in memory and add or otherwise correlate the parameters to assign a numerical COFI to the user&#39;s current condition. 
     When a predetermined COFI threshold is exceeded, the system  810  may activate an alarm or otherwise notify the user and/or another party at a remote location. Thus, the system  810  may provide a more effective way to monitor the user&#39;s fatigue, drowsiness, alertness, mental state, and the like. In a further alternative, the system  810  may be used to generate predetermined outputs, e.g., to activate or deactivate equipment, such as a vehicle being operated by the user when a predetermined condition, e.g., COFI value, is determined by the system  810 . 
     Alternatively, the processor may be provided on the frame  812 , e.g. as part of processor  842 , for monitoring the parameters for a predetermined event to occur, such as exceeding a predetermined COFI threshold. In a further alternative, the eye tracking parameters described above may be monitored by a remote camera, e.g., in a fixed position in front of the user, such as the dashboard of a vehicle and the like. The remote camera may be coupled to the processor, either directly or via its own transmitter, which may also be integrated into the COFI determination and/or monitored by third parties along with algorithmically defined response measures. Additional information on the various apparatus, systems, and methods for using them are described in U.S. Pat. No. 6,163,281, issued Dec. 19, 2000, U.S. Pat. No. 6,246,344, issued Jun. 12, 2001, and U.S. Pat. No. 6,542,081, issued Apr. 1, 2003, the entire disclosures of which are expressly incorporated by reference herein. 
     Returning to  FIG. 13 , in an alternative embodiment, the cameras  832 ,  840  may be coupled to a single detector (not shown), similar to the configuration shown in  FIG. 22 . The fiber optic bundles  832 ,  841  may be coupled to one or more lenses for delivering and/or focusing images from the cameras  830 ,  840  onto respective regions of the detector. The detector may be a CCD or CMOS chip having an active imaging area, e.g., between about five and ten millimeters (5-10 mm) in cross-section. In exemplary embodiments, the active imaging area of the detector may be square, rectangular, round, or elliptical, as long as there is sufficient area for receiving simultaneous images from both cameras  830  and camera  840 . Exemplary outputs displaying simultaneous video images from the cameras  830 ,  840  is shown in  FIGS. 20A and 20B , and described further below. In this alternative, with sufficient resolution and processing, it may be possible to eliminate the emitters  820  and/or sensors  822  from the system  810 . 
     Turning to  FIGS. 18A and 18B , another embodiment of an apparatus  910  is shown for monitoring eyelid movement of an individual wearing the apparatus  910 . As described elsewhere herein, the apparatus  910  may be used as a biosensor, a communicator, and/or a controller, and/or may be included in a system, e.g., for monitoring voluntary-purposeful and/or involuntary-nonpurposeful movement of one or both of the user&#39;s eyes. 
     As shown, the apparatus  910  includes a helmet  912  that may be worn on a user&#39;s head, and a biosensor assembly  920 . The helmet  912  may be a standard aviator&#39;s helmet, such as those used by helicopter or jet aircraft pilots, e.g., including a pair of night vision tubes or other goggles  914  mounted thereon. Optionally, the helmet  912  may include one or more heads-up displays, e.g., small flat-panel LCDs mounted in front of or adjacent one or both eyes. Alternatively, the helmet  912  may be replaced with a frame (not shown, see, e.g.,  FIG. 13 ) including a bridge piece, a rim extending above or around each eye, and/or a pair of ear supports, similar to other embodiments described herein. The frame may include a pair of lenses (also not shown), such as prescription, shaded, and/or protective lenses, although they are not necessary for operation of the apparatus. Alternatively, one or both lenses may be replaced with displays, e.g., relatively small flat panel LCDs, which may be used as a simulator and/or recreational device, as explained further below. In further alternatives, the apparatus  910  may include other devices that may be worn on a user&#39;s head, such as a hat, cap, head band, head visor, protective eye and head gear, face mask, oxygen mask, ventilator mask, scuba or swimming mask, and the like (not shown). 
     The components of the apparatus  910  may be provided at a variety of locations on the helmet  912  (or other head-worn device), e.g., to generally minimize interference with the user&#39;s vision and/or normal activity while wearing the apparatus  910 . As shown, the biosensor assembly  920  includes a camera  922  mounted on top of the helmet  912 , e.g., using Velcro, straps, and/or other temporary or removable connectors (not shown). This may allow the camera  922  to be removed when not in use. Alternatively, the camera  922  may be substantially permanently connected to the helmet  912 , incorporated directly into the helmet  912  (or other frame), connected to a head-mounted television, LCD monitor or other digital display, and the like, similar to other embodiments described herein. 
     The biosensor assembly  920  also includes one or more fiber optic bundles  924  that extend from the camera  922  to the front of the helmet  912  to provide one or more “endo cameras” for imaging the user&#39;s eye(s). As shown, a pair of fiber optic bundles  924  are shown that extend from the camera  922  to respective tubes of the goggles  914 . In the exemplary embodiment, the fiber optic bundles  924  may be sufficiently long to extend from the camera  922  to the goggles  914 , e.g., between about twelve and eighteen inches long, although alternatively, the fiber optic bundles  924  may be longer, e.g., between about two and four feet long, or shorter, depending upon the location of the camera  922  on the helmet  910  (or if the camera  922  is provided separately from the helmet  910 ). 
     Ends  926  of the fiber optic bundles  924  may be permanently or removably attached to the goggles  914 , e.g., to brackets  916  connected to or otherwise extending from the goggles  914 . Alternatively, the fiber optic bundles  924  may be held temporarily or substantially permanently onto the goggles  914  using clips, fasteners, adhesives, and the like (not shown). As shown, the ends  926  of the fiber optic bundles  924  are mounted below the goggles  914  and angled upwardly towards the eyes of the user. The angle of the ends  926  may be adjustable, e.g., about fifteen degrees up or down from a base angle of about forty five degrees. Alternatively, the ends  926  of the fiber optic bundles  924  may be provided at other locations on the helmet  912  and/or goggles  914 , yet be directed towards the eyes of the user. 
     With additional reference to  FIG. 19 , each fiber optic bundle  924  may include a fiber optic image guide  928 , i.e., a bundle of optical imaging fibers, and an illumination fiber bundle  930 , e.g., encased in shrink tubing (not shown), extending between the camera  922  and the ends  926  of the fiber optic bundle  924 . Each illumination fiber bundle  930  may include one or more optical fibers coupled to a light source, e.g., within the camera  922 . For example, the camera  922  may include a light emitting diode (LED) housing  932  including one or more LEDs  934  (one shown for simplicity), and the illumination fiber bundle(s)  930  may be coupled to the LED housing  932  to deliver light to the end(s)  926 . 
     The light emitted by the light source  934  may be outside the range of normal human vision, for example, in the infrared range, e.g., with a nominal output wavelength between about eight hundred forty and eight hundred eighty nanometers (840-880 nm), such that the light emitted does not interfere substantially with the user&#39;s normal vision. The light source may generate light substantially continuously or light pulses at a desired frequency, similar to the embodiments described elsewhere herein. Alternatively, other sources of light for illuminating the face and/or one or both eyes of the user may be provided instead of the illumination fiber bundle  930 . For example, similar to the embodiments described elsewhere herein, one or more emitters (not shown) may be provided, e.g., an array of emitters disposed along one or more regions of the helmet  912  and/or goggles  914 . 
     The end  926  of each fiber optic bundle  924  may include one or more lenses, e.g., an objective lens  936  (shown in  FIG. 18A ) that may focus the image guide  928  in a desired manner, e.g., towards an eye of the user. Each image guide  928  may have forward line of sight (zero degrees (0°) field of view) and the objective lens  936  may provide a wider field of view, e.g., about forty five degrees (45°). Optionally, the line of sight may be adjustable, e.g., between about thirty and sixty degrees (30-60°) by adjusting the objective lens  936 . Further, the objective lens  936  may optimize the viewing distance, e.g., to about two inches (2 in.), thereby improving focus on the user&#39;s eye(s). Thus, the image guide(s)  928  may carry images of the user&#39;s eye(s) through the fiber optic bundle(s)  924  to the camera  922 . 
     As shown in  FIG. 19 , the camera  922  may include one or more lenses, e.g., a magnification section  938 , for delivering and/or focusing images from the image guide(s)  928  (and/or camera  944 ) onto the active area  942  of the imaging device  940 . The imaging device  940  may be a variety of known devices that provide a two-dimensional active area for receiving images, e.g., a CMOS or CCD detector. In an exemplary embodiment, the imaging device  940  may be a CMOS device, such as that made by Sensovation, Model cmos SamBa HR-130, or Fast Camera 13 made by Micron Imaging, Model MI-MV13. The magnification section  938  may be mechanically mated to the camera  922  via a C-mount or other connection (not shown). 
     In an exemplary embodiment, each image guide  928  may be capable of providing as many as ten to fifty thousand (10,000 to 50,000) pixels of image data, e.g., similar to the fiberoptic bundles described elsewhere herein, which may be projected onto the active area  942  of the imaging device  940 . For the apparatus  910  shown in  FIGS. 18A and 18B , the images from both fiber optic bundles  924  are projected onto a single imaging device  940 , as shown in  FIG. 19 , i.e., such that the images from each of the user&#39;s eyes occupy less than half of the active area  942 . 
     Optionally, the apparatus  910  may include an “exocamera”  944  oriented away from the user&#39;s head, e.g., to monitor the user&#39;s surroundings, similar to the embodiments described elsewhere herein. For example, as shown in  FIG. 18A , another fiber optic bundle  945  may be provided that extends from the camera  922 . As shown, the fiber optic bundle  945  is oriented “forward,” i.e., generally in the same direction as when the user looks straight ahead, and terminates in a microlens  946 . This fiber optic bundle  945  may be relatively short and/or substantially rigid such that its field of the view is substantially fixed relative to the helmet  912 . Alternatively, the exocamera  944  may be provided at other locations on the helmet  912  and/or goggles  914 , e.g., including a flexible fiberoptic bundle, similar to the exocamera  840  described above. Thus, the exocamera  944  may provide images away from the user, e.g., straight ahead of the user&#39;s face. 
     The exocamera  944  may or may not include one or more illumination fibers, but may include an image guide that may be coupled to the imaging device  940 , e.g., via the magnification section  938  or separately. Thus, the images from the exocamera  944  may be delivered onto the same active area  942  as the images of each of the user&#39;s eyes received from the image guides  928 , similar to other embodiments described herein. This configuration may allow or facilitate temporal and/or spatial synchronization, allowing for overlaying or superimposing endocamera image(s) over exocamera images, or through “triangulation measurements” or other algorithms for eye tracking purposes to identify “where,” “what,” and/or “how long” (duration of gaze) the user&#39;s eyes are looking at relative to the user&#39;s head directional position. 
     Thus, the camera  922  may simultaneously capture images from one or more “endocameras,” i.e., from fiber optic bundles  924  and from the exocamera  944 . This may ensure that the images captured by each device are synchronized with one another, i.e., linked together in time such that an image of one eye taken at a specific time correspond to an image of the other taken at substantially the same time. Further, these images may be substantially synchronized with data from other sensors, e.g., one or more physiological sensors, which may enhance the ability to monitor and/or diagnose the user, and/or predict the user&#39;s behavior. Because of this synchronization, image data may be captured at relatively high rates, e.g., between about five hundred and seven hundred fifty frames per second or Hertz (500-750 Hz). Alternatively, separate detectors may be provided, which capture image data that may be synchronized, e.g., by a processor receiving the data. In this alternative, slower capture rates may be used, e.g., between about thirty and sixty Hertz (30-60 Hz), to facilitate synchronization by a processor or other device subsequent to capture. Optionally, the camera  922  and/or associated processor may be capable of capturing relative slow oculometrics, e.g., at rates of between about fifteen and sixty (15-60) frames per second. 
       FIGS. 20A and 20B  illustrate exemplary outputs from a camera receiving simultaneous image signals from two endocameras  2010  and an exocamera  2020  (or from a device compiling images from separate cameras and/or detectors). As shown, an endocamera is directed towards each of the user&#39;s eyes, and the exocamera is directed outwardly at the user&#39;s surroundings (i.e., generally straight in front of the user&#39;s face). In  FIG. 20A , both of the user&#39;s eyes  2010 L,  2010 R are open and the exocamera image  2020  shows a horizontal view of the room ahead of the user. In contrast, in  FIG. 20B , one of the user&#39;s eyes  2010 L is completely closed, and the other eye  2010 R is partially closed such that the eyelid covers most of the pupil. The exocamera image  2020  shows that the user&#39;s head has begun to tilt to the left and droop forward. Optionally, additional information may be displayed and/or stored along with these images, such as real time data from other sensors on the apparatus  910 , similar to that shown in  FIGS. 12A-12C  or  FIGS. 15A-15I . 
     Returning to  FIGS. 18A ,  18 B, and  19 , the images from the camera  922  (and/or camera  944 ) may be transferred from the apparatus  910  via cable  948  (best seen in  FIG. 18A ). For example, the imaging device  940  may convert the optical images from the active area  942  into electrical signals that may be carried via the cable  948  to one or more processors and/or controllers (not shown), similar to other embodiments described elsewhere herein. Alternatively, images from the fiberoptic bundles  924  and/or exocamera  944  may be carried from the apparatus  910  to one or more remote devices, e.g., camera, detector, and/or processor (not shown), similar to other embodiments described herein. In this alternative, the bundles  924  may be between about two and six feet long, e.g., providing sufficient length to allow the user to move normally yet remain coupled to the remote device(s). 
     Alternatively or in addition, the apparatus  910  may include a wireless transmitter (not shown), such as a short or long range radio frequency (RF) transmitter, e.g., using Bluetooth or other protocols, that may be coupled to the camera  922 . The transmitter may be located in the camera  922  or elsewhere on the helmet  912 . The transmitter may transmit images signals representing the image data to a receiver at a remote location, similar to other embodiments described elsewhere herein. In yet another alternative, the apparatus  910  may include memory (also not shown) for storing the image data, either instead of or in addition to the transmitter and/or cable  948 . For example, the data may be stored in a recorder device, e.g., similar to a “black box” recorder used in aircraft, such that the recorder may be retrieved at a later time, e.g., for analysis after a vehicular accident, medical incident, and the like. 
     Optionally, the apparatus  910  may include one or more controllers (not shown), e.g., within the camera  922 , and/or on or in the helmet  912  for controlling various components of the apparatus  910 . For example, a controller may be coupled to the one or more LEDs  934  such that the LEDs  934  emit pulses at a predetermined frequency, e.g., to reduce energy consumption of the apparatus  910 . In addition, the apparatus  910  may include one or more power sources, e.g., batteries and/or cables, for providing electrical power to one or more components of the apparatus  910 . For example, one or more batteries (not shown) may be provided in the camera  922  for providing power to the imaging device  940  and/or the LED(s)  934 . 
     If desired, the apparatus  910  may also include one or more additional sensors (not shown), e.g., on the helmet  910 . The sensors may be coupled to the biosensor assembly  920 , cable  948 , and/or wireless transmitter (not shown) if included so that the signals from the sensors may be monitored, recorded, and/or transmitted to a remote location. For example, one or more position sensors may be provided, e.g., for determining the spatial orientation of the helmet  912 , and consequently the user&#39;s head, as described elsewhere herein. In addition or alternatively, the apparatus  910  may include one or more physiological sensors (not shown), e.g., for measuring one or more physical characteristics of the user, such as one or more EEG electrodes, EKG electrodes, EOG electrodes, pulse sensors, oximetry sensors, thermistors, thermocouples, or other temperature sensors, e.g., for measuring the user&#39;s skin temperature, sweat detectors for measuring moisture on the user&#39;s skin, and/or sensors for measuring respiratory air flow, e.g., through the user&#39;s nose. 
     In addition, the apparatus  910  may include one or more feedback devices (also not shown), e.g., to alert and/or wake the user, such as a mechanical vibrator device that may provide tactile vibrating stimuli through skin contact, one or more electrodes that may produce relatively low power electrical stimuli, one or more light emitters, such as LEDs, audio devices, aroma-emitters, and the like. Alternatively, feedback devices may be provided separate from the apparatus  910 , but located in a manner capable of providing a feedback response to the user. For example, audio, visual, tactile (e.g., a vibrating seat), or aroma-emitters may be provided in the proximity of the user, such as any of the devices described above. In a further alternative, heat or cold generating devices may be provided that are capable of producing thermal stimuli to the user, e.g., a remotely controlled fan or air conditioning unit. 
     A system including the apparatus  910  may include components that are remote from the apparatus  910 , similar to other embodiments described elsewhere herein. For example, the system may include one or more receivers, processors, and/or displays (not shown) at a remote location from the apparatus  910 , e.g., in the same room, at a nearby monitoring station, or at a more distant location. The receiver may receive signals transmitted by a transmitter on the apparatus  910 , including image signals from the camera  922  and/or signals from other sensors on the apparatus  910 . 
     A processor may be coupled to the receiver for analyzing signals from the apparatus  910 , e.g., to prepare the signals for graphical display. For example, the processor may prepare the video signals from the camera  922  for display on a monitor, similar to the images shown in  FIGS. 20A and 20B , thereby allowing the user to be monitored by third parties, e.g., medical professionals, supervisors or other co-workers, and the like. Simultaneously, other parameters may be displayed, either on a single monitor or on separate displays, similar to other embodiments described elsewhere herein. The processor may superimpose or otherwise simultaneously display video signals of the user&#39;s eyes and/or exocamera images, alone or in conjunction with the other sensed parameters, to allow a physician or other individual to monitor and personally correlate these parameters to the user&#39;s behavior. 
     In a further alternative, the processor may automatically process the signals to monitor or study the user&#39;s behavior. For example, the processor may use the output signals to monitor various parameters related to eye movement, such as eye blink duration (EBD), eye blink frequency, eye blink velocity, eye blink acceleration, interblink duration (IBD), PERCLOS, PEROP (percentage eyelid is open), and the like. The video signals from the camera  922  may be processed to continuously or discontinuously and/or sequentially monitor single or multiple eye parameters, in any combination or pattern of acquisition, such as pupillary size, relative location, eye tracking movement, eye gaze distance, and the like, as described elsewhere herein. Thus, the apparatus  910  and/or system may monitor one or more oculometrics or other parameters, such as those disclosed in U.S. Pat. No. 6,542,081, incorporated by reference herein. 
     To facilitate monitoring pupillary size (e.g., dilation, constriction, and/or eccentricity) and/or eye movement, the system may include a processor communicating with the camera  922  for processing the video signals and identifying a pupil of the eye from the video signals. For example, with higher resolution cameras, such as CMOS and CCD detectors, the processor may be able to identify the edges, and consequently the circumference, diameter, and/or cross-sectional area of the pupil. A display may be coupled to the processor for displaying video images of the eye from the video signals processed by the processor. 
     In addition, turning to  FIGS. 21A-21C , a processor may superimpose a graphic on the display, e.g., onto the video images to facilitate identifying and/or monitoring the pupil  301  of an eye  300 . As shown, because of the contrast between the edge of the pupil  301  and the surrounding iris  304 , the processor may approximate this border, and create a graphic halo, ellipse, or other graphic  306  that may be superimposed on the image data of one or both eyes (only one eye  300  shown in  FIGS. 21A-21C  for simplicity). An observer may use this graphic  306  to facilitate monitoring the user of the apparatus  910 . Alternatively, the processor may determine the size and/or shape of the halo virtually to facilitate monitoring the user without actually displaying the halo on a display. For example, the processor may use the size and shape of the halo to determine a center of the halo, to thereby determine coordinates of the center of the halo, e.g., in an x-y coordinate system. 
     In addition or alternatively, the processor may automatically analyze the information regarding the size and/or shape of the pupil  301  (or the graphic  306 ), thereby correlating the video signals to determine the person&#39;s level of drowsiness or other physical and/or mental condition. This analysis may include monitoring the relative location of the pupil, a size of the pupil, and/or an eccentricity of the pupil, e.g., over time. For example, the processor may monitor the diameter of the pupil  300  over time, which may be displayed in chart form, e.g., as shown in  FIG. 15E , stored in memory as a function of time, and/or superimposed on images of the eye, e.g., in real time. 
     For example,  FIG. 21A  may show the pupil  301  in a relaxed state under ambient conditions, e.g., corresponding to graphic  306  having a diameter “d 1 .” As shown in  FIG. 21B , if the user blinks or closes the eye  300 , the pupil  301  may dilate, such that the pupil  301  is initially dilated when the eye  300  is reopened, as represented by graphic  306  having a diameter “d 2 .” The processor may compare changes in diameter of the graphic  306  or the pupil  301  itself to determine the delay for the pupil  301  to return to the diameter “d 1 ” after a blink or other eye closure. This delay or loss of reactivity to visible or invisible light flashes may at least partially indicate a level of drowsiness, a level of impairment, e.g., intoxication, and/or the onset of a medical event, including lethal or terminal events such as brain damage or brain death due to hypoxemia, hypoglycemia, stroke, myocardial infarction, toxins, poisons, and the like. 
     In addition or alternatively, the processor may determine the approximate eccentricity of the pupil, e.g., as it is partially covered by the eyelid  302 . For example, as shown in  FIG. 21C , when the eyelid  302  is partially closed, the halo  306  superimposed on the images (or otherwise determined virtually by the processor without actually being displayed) may adopt an elliptical shape corresponding to a width “w” and height “h” of the exposed portion of the pupil  301 . The height “h” may be related to the diameter “d 1 ,” i.e., the ratio of the height “h” to diameter “d 1 ” may be equal to or less than one (h/d 1 ≧1), as an indicator of the degree that the eyelid  302  covers the pupil  301 . For example, this ratio may reduce from one to zero once the pupil  301  is completely covered by the eyelid  302 . 
     Similarly, the width “w” may also be related to the diameter “d 1 ” (w//d 1 ≧1), as an indicator of the degree that the eyelid  302  covers the pupil  301 , e.g., as the eyelid  302  begins to cover more than half of the pupil  301 . In addition or alternatively, a ratio of the height and width (h/w≧1) may relate information on eccentricity of the pupil  301 , e.g., based upon coverage by the eyelid  302 . Such parameters may be analyzed individually, collectively, and/or along with other oculometric and/or physiological parameters to monitor, analyze and/or predict future behavior of the user. The data may be compared with empirical or other data retained or accessed by the processor to provide information regarding the user&#39;s condition, e.g., a COFI value, as described elsewhere herein. 
     If, for example, the analysis of the user&#39;s pupil results in a determination that the user&#39;s alertness level has fallen below a predetermined level, a warning may be provided to the user and/or to one or more third persons, similar to other embodiments described herein. Such methods may also be useful to determine whether the user is being affected by drugs, alcohol, and/or medical conditions, as explained elsewhere herein. 
     In addition, as a threshold and/or to test the user&#39;s vigilance, an apparatus or system, such as any of those described herein, may test the user&#39;s pupillary response. Such a test may confirm that a patient is active, i.e., not asleep, or even deceased, while wearing the apparatus. For example, if a light source is flashed for a predetermined duration and/or pulse frequency at the user&#39;s eye, the user&#39;s pupil may dilate briefly from its relaxed state (based upon ambient lighting), and then constrict back to the relaxed state within a predictable period of time. 
     Turning to  FIG. 22A , an exemplary method is shown for testing the vigilance of a user of any of the apparatus and systems described herein. For example, a user may wear the apparatus  810  shown in  FIG. 18  monitoring one or both of the user&#39;s eyes, as described further above. At step  2210 , base or parameters of the user&#39;s eye(s) may be determined under a related state. For example, the relaxed diameter of the pupil may be measured or otherwise monitored under ambient conditions. 
     At step  2220 , one or more pulses of light may be emitted towards the eye(s), which may cause the eye(s) to dilate and/or constrict from the relaxed state, e.g., at substantially the same frequency as the frequency of pulsed light flashes. For example, one or more emitters on the apparatus  810  may be activated in a predetermined sequence to cause the eye(s) to dilate. Thereafter, in step  2230 , the eye(s) of the user may be monitored, e.g., subconsciously or unconsciously with the camera  830  or sensors  822 , to determine the reaction time of the eye to return to the relaxed state. The reaction time may be compared to an empirical database or other data to confirm that the user is conscious, awake, and/or alive. If desired, steps  2220  and  2230  may be repeated one or more times to confirm the reaction time and/or provide an average reaction time, if desired, e.g., to avoid false negative determinations. 
     If the light source is outside the visible light range, e.g., within the infrared range, the pupil may still react to flashes of light in this manner. One advantage of using infrared light is that it may not distract or bother the user, since the user will not consciously observe the light. Yet, the pupil may still react to such flashes sufficiently that a system monitoring the eye may identify when the pupil dilates and constricts in response to such flashes. 
     It may be sufficient, e.g., during a threshold test, to generate a single flash of light and monitor the pupil&#39;s response. Alternatively, a series of flashes may be used to monitor pupillary response over time, e.g., to study trends or eliminate false data that may arise from a single flash. For a series of flashes, the pulse rate should be longer than the time the pupil takes to naturally return to its relaxed state after dilating in response to a flash of light, e.g., at least between about fifty and one hundred milliseconds (50-100 ms). Alternatively, pulses of light, e.g., near-infrared light (having wavelengths between about 640-700 nanometers) may be directed at the user&#39;s eye(s). The system may detect rhythmic fluctuations in pupillary response. Such responses may result from a primitive oculometric response, possibly relating to night vision, e.g., “seeing” in the dark or sensing infrared light sources in the dark. 
     Such pupillary response testing may also be used to identify false positives, e.g., when a user has died, yet the system fails to detect any eye closure and/or movement. Similarly, pupillary response testing may also be able to determine whether a user is asleep or unconscious. In addition, pupillary response testing may be used to determine whether a user is under the influence of alcohol, drugs, and the like, which may affect the rate at which the pupil constricts back to its relaxed state after dilating in response to flashes of light. In addition or alternatively, pupillary response testing may also be used to determine the blood concentration or amount of drug or alcohol in the user&#39;s body depending on correlation between oculometric measures and corresponding scientifically-determined blood levels. 
     Turning to  FIG. 22B , another method for testing threshold vigilance is shown. This method generally involves providing stimuli instructing the user to deliberately move their eye(s) in a desired manner, at step  2240 , and monitoring the eye at step  2250 , e.g., for deliberate movement confirming that the user has followed the instructions and moved their eye(s) in the desired manner. Any of the apparatus described herein may include one or more stimulus devices, e.g., speakers, lights, vibratory or other tactile devices. Alternatively, such devices may be provided remotely from the user, e.g., on a dashboard of a vehicle, a video display, and the like. 
     For example, a user may be instructed to close their eye(s) for a predetermined time if a visible light on the apparatus is activated. Once the light is activated, the system may monitor the eye(s) to confirm that the user responds within a predetermined time frame and/or in a predetermined manner (e.g., one or more blinks in a predetermined sequence). Alternatively, other stimuli may be provided instead of light flashes, such as visible instructions on a display (on or separate from the apparatus), audible signals (e.g., verbal commands from a speaker on or near the device), tactile signals, and the like. In these embodiments, the user may be instructed to perform a series of actions, e.g., looking up or down, left or right, blinking in a desired sequence, closing their eye until instructed, following a pointer on a display, and the like. Such testing may be useful to confirm, for example, whether a test subject is awake, aware, and/or alert during a series of tests or while performing various activities. 
     In another embodiment, apparatus and systems, such as those described elsewhere herein, may be used to control a computer system, e.g., similar to a computer mouse, joystick, and the like. For example, with reference to the apparatus  810  shown and described with reference to  FIG. 13 , the camera(s)  830  may be used to monitor the location of the user&#39;s pupil(s) to direct and/or activate a mouse pointer on a computer screen or other display. A processor receiving the image data from the camera  922  may analyze the image data to determine the relative location of the pupil(s) within the active area  942  of the detector  940 . Optionally, one or more displays may be fixed relative to the frame  812  disposed in front of or within the field of view of one or both of the user&#39;s eyes. For example, a flat panel LCD or other display (not shown) may be mounted to the frame  812  in place of lenses. Such an apparatus may be used for simulations, e.g., within a medical or other research facility, for recreational use, e.g., as a video game console, and the like. 
     Turning to  FIG. 23 , an exemplary method is shown for controlling a computing device based upon detected eye movement using any of the apparatus or systems described herein. For example, the apparatus  910  shown in  FIG. 18A  may be used that includes a fiberoptic bundle  924  for imaging one or both eyes of the user. Optionally, as explained further below, the apparatus may also carry one or more exocameras, e.g., disposed adjacent one or both eyes of the user that may be oriented outwardly along the user&#39;s forward view. First, at step  2310 , it may be desirable to initialize a system including such an apparatus, i.e., establish a reference frame, such as a base or reference location, a reference frame with orthogonal components, and the like. For example, the user may be instructed to look at a pointer or other predetermined location on the display, thereby maintaining the user&#39;s eye(s), and consequently the user&#39;s pupil(s) substantially stationary. The processor may analyze the image data from the camera  830  while the user&#39;s eye(s) are substantially stationary, e.g., to determine the location of the pupil on the images that corresponds to the reference point or “base location.” For example, the pointer or base location may be located substantially straight ahead of the user&#39;s pupil. Optionally, the user may be instructed to look sequentially at two or more identified locations on the display, thereby providing a scale for relative movement of the user&#39;s eye. In this alternative, it may be desirable to have the user look at opposite corners of the display, e.g., to identify the limits of appropriate eye movement relative to the display. 
     Once initialization is complete, the user may be free to move their eye(s), e.g., left and right, up and down, e.g., relative to the pointer and/or the rest of the display. At step  2320 , the system may monitor such movement of the eye, i.e., the processor may analyze the image data to determine the relative location of the user&#39;s pupil(s) from the base location(s). For example, if the user moves his/her eye(s) up and right from the base location, i.e., up and right relative to the pointer on the computer screen, the processor may determine this movement. In response, at step  2330 , the processor may move the pointer up and right, i.e., thereby tracking the user&#39;s gaze. When the user stops moving his/her eye(s), the processor may stop the pointer once it arrives at the location where the user is currently looking on the display. 
     Optionally, at step  2340 , the user may be able to execute a command once the pointer has moved to a desired location on the display, e.g., similar to activating a button on a mouse. For example, the processor may monitor the image data for a signal from the user, e.g., one or more purposeful blinks in a predetermined sequence. This may be as simple as a single blink of a predetermined duration, e.g., several seconds long, to a more complicated series of blinks, e.g., including one or both of the user&#39;s eyes. Alternatively, the signal may be a predetermined period with no blinks, e.g., three, five, or more seconds long. When the processor identifies the signal, the processor may activate the command. For example, the user may stop moving their eye(s) when it reaches an icon, word command, and the like on the display, and the processor may move the point until it overlies or otherwise is located at the icon or command. The user may then blink or act, as explained above, similar to a “double-click” of a button on a computer mouse, thereby instructing the processor to complete the selected command or communicate the selected command to a desired destination. For example, the selected command may result in a computer program being executed, or a piece of equipment or other device being activated, deactivated, or otherwise controlled in a desired manner. Thus, the system may be used to complete a variety of tasks, from controlling a computer device coupled to the processor and/or display, to turning on or off a light switch or vehicle. Such apparatus and/or systems may thereby provide methods for using a computer hands-free, i.e., using only movement of the user&#39;s eye(s). 
     For example, in one application, the system may be used to operate a vehicle, such as a helicopter, jet, or other aircraft, e.g., to activate or otherwise control weapons, navigational, or other onboard systems. In another application, the system may be used in a video game or other simulation, e.g., to enhance virtual reality immersion. For example, the system may allow a user to quickly navigate through multiple menus, scenes, or other activities, while leaving the user&#39;s hands free to perform other functions, e.g., perform other activities in addition or simultaneously with eye-controlled functions, which may allow more and/or more complicated tasks at the same time. 
     In addition, one or more exocameras may be used to enhance and/or otherwise facilitate tracking eye movement relative to the pointer on the display. For example, an exocamera may be provided adjacent at least one eye, e.g., at a predetermined distance or other relationship from the eye, that is oriented towards the display. Thus, the exocamera may provide images of the display, e.g., showing movement of the pointer in real time that may synchronized with movement of the eye monitored with the endocamera. The processor may relate this data using triangulation or other algorithms to enhance accuracy of tracking the pointer with eye movement. This may ensure the accuracy that, when the user intends to execute a command by blinking with the pointer on a command, the intended command is actually selected, e.g., when the display shows multiple available commands. 
     In addition, such systems and methods may be used in medical or other diagnostic procedures, such as vigilance testing. For example, the processor may analyze data from the endocameras and exocameras to correlate movement of the eye(s) relative to images on the display to study a variety of oculometric parameters, such as slow rolling eye movement, poor eye fixation and/or tracking, wandering gaze, increased eye blinking, hypnotic staring, prolonged eyelid droops or blinking, slow velocity eyelid opening and closing, startled eyelid opening velocities, long-term pupillary constrictive changes, unstable pupil diameters, obscured visual-evoked pupil reactions, and/or other parameters discussed elsewhere herein. These procedures may be used to study an individual&#39;s responsive faced with various environmental, alcohol or drug-induced, and/or other conditions. 
     Turning to  FIG. 24 , in another embodiment, an apparatus  2410  may be provided for transcutaneously lighting an eye  300  of a user wearing the apparatus  2410 . The apparatus  2410  may be generally similar to any of the embodiments described herein, such as the frame  812  shown in  FIG. 13 . As shown, the apparatus  2410  may include one or more emitters or other light source(s)  2422  that contact the user&#39;s head  308 , e.g., the user&#39;s temple(s) adjacent one or both eyes  300  (one shown for simplicity). In addition, the apparatus  2410  may include one or more sensors, such as fiberoptic bundle  2430 , e.g., terminating in a lens  2434  for acquiring images of the user&#39;s eye  300 . 
     In one exemplary embodiment, an infrared emitter  2422  may be fixedly or adjustably mounted on one or both ear pieces  2422  of a frame  2412  such that the emitter  2422  contacts and transmits light towards the user&#39;s skin. For example, the emitter  2422  may include a plurality of LEDs, which may be emit collimated, non-coherent (non-laser) infrared light. The emitter  2422  may be oriented generally towards the eye  300  such that light from the emitter  2422  may travel through or along the user&#39;s head  308  into the eye  300 , as represented by dashed arrows  2450 . For example, it has been found that skin and other tissue may be at least translucent to certain frequencies of light, such as infrared light. Thus, at least some of the light from the emitter(s)  2422  may transmit transcutaneously along or through the user&#39;s skin and/or other tissue until at least some of the light enters the eye  300 . 
     The light may reflect off of the retina (not shown) within the eye  300 , such that at least some of the light escapes out of the pupil  301 , as represented by arrows  2452 . The lens  2434  and fiberoptic bundle  2430  may relay images of the eye to a detector (not shown), similar to other embodiments described herein, which may identify the pupil  301  as a bright spot on the images due to the light  2452 . A processor or other device coupled to the detector may monitor the pupil  301 , such as its relative location on the images, size, and/or shape, similar to other embodiments described herein, e.g., using the “white pupil” or “dark pupil” techniques described elsewhere herein. In addition or alternatively, the transcutaneous light may illuminate the entire eye  300 , especially the retina, which may be observed from in front of the user&#39;s face, e.g., as a dimmer sphere or other shape with the pupil  301  showing as a bright spot surrounded by the dimmer shape. 
     This embodiment may have the advantage that one or more emitters do not have be positioned in front of the user&#39;s eye, which may partially obstruct or distract the user&#39;s field of view. Furthermore, because this system uses infrared sensing cameras and/or detectors that operated independently of the angle of incident infrared light, this embodiment may eliminate technical difficulties arising out of a loss of proper orientation of emitters to detectors. In addition, without emitter(s) in front of the eye, glint or other reflections off of the eye may be eliminated, which may facilitate analyzing the image data. 
     It will be appreciated that the various components and features described with the particular embodiments may be added, deleted, and/or substituted with the other embodiments, depending upon the intended use of the embodiments. For example, Appendices A and B of provisional application Ser. No. 60/559,135, incorporated by reference herein, provide additional information on possible structural features, and/or methods for using the apparatus and systems described herein. The entire disclosures of Appendices A and B are expressly incorporated herein by reference. 
     While the invention is susceptible to various modifications, and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood that the invention is not to be limited to the particular forms or methods disclosed, but to the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the scope of the appended claims.