Professor Arai Kohei of Saga University's Faculty of Science and Engineering has developed a system whereby PC users can input text simply by looking at an on-screen keyboard. When the user gazes at a character for one second, the system, which uses a miniature camera, detects their line of sight and inputs the appropriate character. The system is called Mitsumeru Dake in Japanese, which means "Just Look." Professor Arai expects that the system will be useful to people with disabilities and for a range of medical and social-welfare applications. At present many people with disabilities are unable to use personal computers unless they have expensive special equipment.

An illustration of how the system works.

Reading the User's Line of Sight
In Professor Arai's system, a miniature camera attached to the computer notes the positions of three points for each eye: the inner corner of the eye, the inner extremity of the eyebrow, and the center of the pupil. On the basis of these six positions the system determines the direction in which the face is turned, and by following the line of sight it recognizes the exact location on the screen that the user is looking at. According to Professor Arai, even people wearing glasses can use the system.

In the early stages of the system's development the positions of the outer corners of the eyes and of the eyebrows were used. However, it was found that in cases such as people with cerebral palsy, where the face is constantly in motion, the camera was unable to determine the position of these points when the face was turned sideways. But when the inner corners of the eyes and eyebrows were taken as the coordinates, development of the system advanced by leaps and bounds. Professor Arai says that at a distance of about 30 cm from the on-screen keyboard characters, with the characters 2.5 cm apart, his system provides a very accurate method of inputting text.

Low Cost, High Performance
Professor Arai was prompted to develop his system by the arrival five years ago of a student at the university who had cerebral palsy. The university revamped the toilet facilities and installed ramps throughout the campus, but the student's mother had to operate the computer. "I thought then that I've got to do something about this," says Professor Arai.

Until that time similar input systems for disabled people involved attaching electrodes to the face in order to detect eyeball movement or wearing special goggles with infrared cameras in order to analyze the image on the retina. This meant the systems were expensive and cumbersome. Professor Arai makes the software available free of charge, so the only cost for his system is the ¥3,000 ($25 at ¥120 to the dollar) price of the camera. Bedridden people or those with impaired use of the hands can easily use the system to communicate their needs - to ask for a nurse, for example, or to indicate that they are thirsty.

This system is another example of how Japanese researchers and companies are putting technology to use in their quest to improve the lives of elderly and disabled people.