31-03-2010, 02:05 PM
Eye-gaze Communication Systems
Presented By
N.SRAVYA
COMPUTER SCIENCE & ENGINEERING
Under the esteemed guidance of
P.VENKAT NARYANA
Associate Professor
SHRI VISHNU ENGINEERING COLLEGE FOR WOMEN
BHIMAVARAM “ 534 202
Abstract
The field of human computer interaction has been undergoing a new renaissance lately. While many companies have, and continue to spend millions to develop highly visually appealing GUIs and state-of-art interaction systems for the common users since the inception of desktops, the development of interactive systems for the disabled has taken a kick start relatively recently. And the Eyegaze systems are one of the most pivotal inventions in this context. The Eyegaze System is a communication and control system for people with complex physical disabilities. You run the system with your eyes. By looking at control keys displayed on a screen, a person can synthesize speech, control his environment (lights, appliances, etc.), type, operate a telephone, run computer software, operate a computer mouse, and access the Internet and e-mail. Eyegaze Systems are being used to write books, attend school and enhance the quality of life of people with disabilities all over the world.
1. INTRODUCTION
Most of us blessed to operate the computer with ease using our hands. But there are some who canâ„¢t use their hands and for them the voice guided systems have been in use for quite some time now. But whIntat about paralytic patients with no mobility and speech Even when their brains are functional and they are visually and aurally blessed to know what is going around. So shouldnâ„¢t they be able to effectively use their intelligence and stay employed Now they can with the Eyegaze communication system.
The Eyegaze System is a direct-select vision-controlled communication and control system. It was developed in Fairfax, Virginia, by LC Technologies, Inc.,This system is mainly developed for those who lack the use of their hands or voice. Only requirements to operate the Eyegaze are control of at least one eye with good vision & ability to keep head fairly still. Eyegaze Systems are in use around the world. Its users are adults and children with cerebral palsy, spinal cord injuries, brain injuries, ALS, multiple sclerosis, brainstem strokes, muscular dystrophy, and Werdnig Hoffman syndrome. Eyegaze Systems are being used in homes, offices, schools, hospitals, and long term care facilities. By looking at control keys displayed on a screen, a person can synthesize speech, control his environment (lights, appliances, etc.), type, operate a telephone, run computer software, operate a computer mouse, and access the Internet
and e-mail. Eyegaze Systems are being used to write books, attend school and enhance the quality of life of people with disabilities all over the world.
Contents
Introduction
Skills needed by Eyegaze users
Working of the Eyegaze systems
How to run the Eyegaze systems
Uses
Menus of Eyegaze Systems
A web browsing system using eye-gaze input:
Environment Required FOR AN EYEGAZE SYSTEM
Developments in Eyegaze Technology
Conclusion
References
LIST OF FIGURES:
2.skills needed by users:
Good control of one eye :
The user must be able to look up, down, left and right. He must be able to fix his gaze on all areas of a 15-inch screen that is about 24 inches infront of his face. He must be able to focus on one spot for at least 1/2 second.
Adequate vision : The user should be able to view the screen correctly.
Ability to maintain a position in front of the Eyegaze monitor:
It is generally easiest to run the System from an upright, seated position, with the head centered in front of the Eyegaze monitor. However the Eyegaze System can be operated from a semi-reclined position if necessary.Continuous, uncontrolled head movement can make Eyegaze operation difficult, since the Eyegaze System must relocate the eye each time the user moves away from the cameraâ„¢s field of view and then returns. Even though the Systemâ„¢s eye search is completed in just a second or two, it will be more tiring for a user with constant head movement to operate the System.
Mental Abilities:
¢ Ability to read
¢ Memory
¢ Cognition
3. Working of Eyegaze Systems
As a user sits in front of the Eyegaze monitor, a specialized video camera mounted below the monitor observes one of the user's eyes. Sophisticated image processing software in the Eyegaze System's computer continually analyzes the video image of the eye and determines where the user is looking on the screen. Nothing is attached to the user's head or body.
In detail the procedure can be described as follows: The Eyegaze System uses the pupil-center/corneal-reflection method to determine where the user is looking on the screen. An infrared-sensitive video camera, mounted beneath the System's monitor, takes 60 pictures per second of the user's eye. A low power, infrared light emitting diode (LED), mounted in the center of the camera's lens illuminates the eye. The LED reflects a small bit of light off the surface of the eye's cornea. The light also shines through the pupil and reflects off of the retina, the back surface of the eye, and causes the pupil to appear white. The bright-pupil effect enhances the camera's image of the pupil and makes it easier for the image processing functions to locate the center of the pupil
.
The computer calculates the person's gazepoint, i.e., the coordinates of where he is looking on the screen, based on the relative positions of the pupil center and corneal reflection within the video image of the eye. Typically the Eyegaze System predicts the gazepoint with an average accuracy of a quarter inch or better.
Prior to operating the eyetracking applications, the Eyegaze System must learn several physiological properties of a user's eye in order to be able to project his gazepoint accurately. The system learns these properties by performing a calibration procedure. The user calibrates the system by fixing his gaze on a small yellow circle displayed on the screen, and following it as it moves around the screen. The calibration procedure usually takes about 15 seconds, and the user does not need to recalibrate if he moves away from the Eyegaze System and returns later.
4. How to run the Eyegaze System
A user operates the Eyegaze System by looking at rectangular keys that are displayed on the control screen. To "press" an Eyegaze key, the user looks at the key for a specified period of time. The gaze duration required to visually activate a key, typically a fraction of a second, is adjustable. An array of menu keys and exit keys allow the user to navigate around the Eyegaze programs independently
5. Uses of Eyegaze
Every year more than 100 000 people are diagnosed with motor neurone diseases.Typically, even when all other ways of communicating are either severely damaged or completely lost, the eyes still function. Communication by Gaze Interaction (COGAIN) is a Network of Excellence designed specifically to help people with these disabilities to communicate more effectively with eye gaze. At the COGAIN stand you can see how this technology is used by a person who relies on it.
Current eye tracking equipment allows users to generate text on a computer by using eye gaze. Users are able to select letters and numbers by looking at a keyboard on a screen with their eyes, and can construct words and sentences that can be spoken aloud by the system. Using these systems both empowers and enables people with disabilities as they can now communicate without the need for an assistant or helper, giving the users greater freedom in their lives.
Eye tracking systems that allow text entry by eye gaze have been in existence for about two decades, but the technology is still only available to a small portion of the potential user population. Obstacles for more wide-spread use currently include: the high cost of eye tracking equipment, the limitation that gaze communication applications may only work with a particular dedicated eye tracking device, and finally that eye tracking
devices are often hard to use and require experts to operate them.
5.1. The Basic Eyegaze Can:
¢ Adjust to a new user in about 15 seconds. (Calibration)
¢ Type with one of four keyboards, then print or speak. (Typewriter)
¢ Turn pages on the computer screen by looking at "up" or "down". (Read Text)
¢ Play games, two "Paddle" games, plus Solitaire and Slot Machine. (Games)
¢ Teach new users with simplified screens. (Teach Screens)
5.2. With Options The Eyegaze Can:
¢ Be at two sites!! Portable computer has a handle to hand-carry between two sites. Two sets of other components and cables for access to Eyegaze System at school, work or home. Dimensions 9"x5'txl7'1, weight approximately 16 lbs. (Transportable Computer)
¢ Be a keyboard to a second computer to run any keyboard-controlled software, by means of the T-TAM connector. (Second Computer Mode)
¢ Speak 100 "canned phrases" through a speech synthesizer, with a single glance of the eye. Phrases can be changed by caregiver or user. (Phrases)
¢ Control appliances anywhere in the home or office from one Eyegaze screen. No special wiring. (Lights and Appliances)
¢ Dial and answer a speaker phone from one screen. "Phone Book" stores 16 frequently used numbers. (Telephone)
6.Menu of Eye-gaze Systems
The main menu : The Main Menu appears on the screen as soon as the user completes a 15-second calibration procedure. The Main Menu presents a list of available Eyegaze programs. The user calls up a desired program by looking at the Eyegaze key next to his program choice.
Main menu screen
Main Menu options :
6.1 The Phrase Program :The Phrases program, along with the speech synthesizer, provides quick communications for non-verbal users. Looking at a key causes a preprogrammed message to be spoken. The Phrases program stores up to 126 messages, which can be composed and easily changed to suit the user.
Phrases screen
6.2 Typewriter Program :
Simple word processing can be done using the Typewriter Program. The user types by looking at keys on visual keyboards. Four keyboard configurations, simple to complex, are available. Typed text appears on the screen above the keyboard display. The user may "speak" or print what he has typed. He may also store typed text in a file to be retrieved at a later time. The retrieved text may be verbalized, edited or printed.
Alpha Keyboard
6.3 The telephone program :
The telephone program allows the user to place and receive calls. Frequently used numbers are stored in a telephone "book". Non-verbal users may access the speech synthesizer to talk on the phone
Telephone control system
6.4 Run Second PC :
The Run Second PC program permits the Eyegaze Communication System to act as a peripheral keyboard and Mouse interface to a Windows computer. The user can run any off-the-shelf software he chooses on the second computer. He can access the Internet, and send e-mail by looking at keyboard and mouse control screens on the Eyegaze monitor. The programs being run are displayed on the second computer's monitor. Typed text appears simultaneously on the Eyegaze and second pc's screens
For children, Two new Eyegaze programs have been added to the Eyegaze System. Both run with the Second PC option. Eye Switch is a big, basic on-screen switch to run "cause & effect" software programs on a Second PC. Simple Mouse is an easy mouse control program to provide simplified access to educational software on a Second PC.
Fig. Mouse control screen
6.5 The Lights & appliances Program :
The Lights & appliances Program which includes computer-controlled switching equipment, provides Eyegaze control of lights and appliances anywhere in the home or office. No special house wiring is necessary. The user turns appliances on and off by looking at a bank of switches displayed on the screen
6.6 Paddle games & Score Four:
These are the Visually controlled Games.
6.7 Read Text Program :
The Read Text Program allows the user to select text for display and to "turn pages" with his eyes. Any ASCII format text can be loaded for the user to access. Books on floppy disk are available from Services for the Blind.
6.8 Television :
Television programs can be displayed directly on the desktop Eyegaze System screen. On-screen volume and channel controls provide independent operation. (Not available on the Portable Eyegaze System.)
A web browsing system using eye-gaze input:
Recently, the eye-gaze input system was reported as a novel human-machine interface. The operation of this system only requires user eye movement. Using this system,many communication aid systemshave been developed for people with severe physical handicaps,such as ALS patients. We have reported a new eyegaze input system already. It utilizes a personnel computer and a home video camera to detect eye-gaze under natural light.In this paper, we propose a new web browsing system for our conventional eye-gaze input system.
Eye-Gaze input system has to detect gaze direction of users. Our Eye-Gaze input system
Runs an image analysis software for Eye-Gaze detection. The overview of our Eye-Gaze detection methods is shown in Fig below
On horizontal Eye-Gaze detection, the detecting method uses the difference in reflectance between the Iris and the sclera; this is estimated by the difference in reflectance between the Iris and the sclera; this is estimated by the difference of integral value of the brightness on area A and B, shown in fig. On vertical Eye-Gaze detection, We draw attention to the vertical movement of Iris.The light intensity distribution from eye image changes with Iris movement. The light intensity distribution from eye image changes with Iris movement. The vertical Eye-Gaze can be detected using this change ,shown in fig.1(b)
In this , we propose the web browsing system using above methods. Hardware configuration and screen shot are shown in fig.2 and fig.3 respectively.The indicators for web browsing are displayed on monitor of personnel computer.
By switching 3 function groups, this system offers many
Function groups,this system offers many functions such as mouse cursor control, scrolling of screen , decision of selected object , refreshing web page and text input by using screen keyboard.User can switch function groups by gazing menu indicator,shown in fig.4.
This system analyzes the location of selectable object on web page, such as hyperlink, radio button, edit box, ETC.
This system stores the locations of these objects, in other words, the mouse cursor skips to the object of candidate input. Therefore it enables web browsing at a faster pace.
The evaluation experiments for the proposed system were conducted with five objects. Subjects were browsing through two web sites, the results show that the subjects can operate this system as they planned, and correct easily errors in operation.
7. Environment required for an Eyegaze system
Because eyetracking is done using infrared light.Eyegaze system must take care of light sources in the room in order to ensure the best accuracy. The Eyegaze System must be operated in an environment where there is limited of ambient infrared light. Common sources of infrared light are sunlight and incandescent light bulbs. The System makes its predictions based on the assumption that the only source of infrared light shining on the user's eye is coming from the center of the camera. Therefore, stray sources of infrared may degrade the accuracy or prevent Eyegaze operation altogether. The System works best away from windows, and in a room lit with fluorescent or mercury-vapor lights, which are low in infrared.
8. Developments in Eyegaze Technology
LC technologies have recently developed a Portable Eyegaze System. The Portable Eyegaze System can be mounted on a wheelchair and run from a 12-volt battery or wall outlet. It weighs only 6 lbs (2.7 kg) and its dimensions are 2.5"x8"x9" (6.5cm x20cm x23cm). The Portable Eyegaze System comes with a flat screen monitor and a table mount for its monitor. The monitor can be lifted off the table mount and slipped into a wheelchair mount.
The Scientist Stephan Hawking uses this system with wheelchair to communicate.
9. Conclusion
Today, the human eye-gaze can be recorded by relatively unremarkable techniques. This thesis argues that it is possible to use the eye-gaze of a computer user in the interface to aid the control of the application. Care must be taken, though, that eye-gaze tracking data is used in a sensible way, since the nature of human eye-movements is a combination of several voluntary and involuntary cognitive processes.
The main reason for eye-gaze based user interfaces being attractive is that the direction of the eye-gaze can express the interests of the user-it is a potential porthole into the current cognitive processes-and communication through the direction of the eyes is faster than any other mode of human communication. It is argued that eye-gaze tracking data is best used in multimodal interfaces where the user interacts with the data instead of the interface, in so-called non-command user interfaces
References
[1] IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING,VOL.10,NO.1,MARCH 2002The Camera Mouse: Visual Tracking of Body features to Provide Computer Access for People With Severe Disabilities.
Margrit Betke,James Gips,Peter Fleming
[2] Perceptual Gaze Extent & Level of Detail in VR:Looking outside the Box
Hunter Murphy*,Andrew T. Duchowski*
Department of Computer Science,Clemson University
{hmurphy/Andrew}[at]vr.clemson.edu
[3] Disability studies Quarterly
Spring 2002,Volume 22,N0.2
Pages 159-174cds.hawaii.edu
