The Eyes Have it

Dan Powell, lead nanotechnologist at Goddard, uses the NaviGaze system, which gives users control by tracking tracking head movements and blinks.

Rick Steele

NASA program develops a system that tracks eye movements for cursor control

NASA is exploring new frontiers in accessibility with a program that could give disabled users line-of-sight control over their computer screens.

The space agency has provided funding to create a system that tracks head and eye movements to register cursor movements and clicks. Developers plan to provide the system free to the public.

Officials at Goddard Space Flight Center in Greenbelt, Md., have developed the system under a Small Business Innovation Research contract with Cybernet Systems Corp. of Ann Arbor, Mich.

NaviGaze allows people who lack arm or hand mobility to control cursor movements with simple head movements. It can be customized to support a wide range of head mobility, the system's developers said.

'We think this is very important, because it is a high priority of ours to include physically impaired people who are blind or otherwise handicapped in the U.S. space program,' said David Rosage, program manager for the NASA Academy at the space center.

'If you come to Goddard you will know it because you will see people who are disabled in different ways doing research and involved in NASA's work. This is another tool to enable them.'

NaviGaze uses a commercial USB camera that tracks eye movement to determine what actions to take.

Cybernet already has completed the first of three potential phases of its NaviGaze SBIR project.

During a demonstration in Washington, Cybernet research engineer Ryan J. O'Grady showed how the system keys on a 'template correlation' of the user's eye to control cursor movement.

The gesture recognition algorithms in NaviGaze, written in C++, 'recognize' the image of an individual user's eye during a two-minute setup period, O'Grady said. Then, in future sessions, the software searches for the user's eye image via the USB-connected camera.

'It starts with a small region [of the camera's field of view] and gives a percentage correlation of the eye image,' O'Grady said. 'When it finds the best match, it marks it.'

Once the system has locked on to the eye image, the user can control the cursor on the screen with head movements and achieve further control by blinking.

An indicator at the top of the screen shows the status of the blink control: green for a single mouse click, yellow for a double click, and red for click and drag. The user achieves the click and drag function by blinking for four seconds.

O'Grady also showed how a user could type using NaviGaze and a virtual keyboard, available on the Internet for free download.

NaviGaze also can function by tracking and monitoring other movements, such as opening and closing the mouth, for people with limited control of eye blinks.

The system also lets a different user control the cursor via a mouse connected to the Microsoft Windows system.

Once developers refine NaviGaze further, Cybernet executives plan to make it available in October for free download via the company's Web site at cybernet.com. They expect NASA to distribute NaviGaze as well.

'Stay tuned,' Rosage said. 'You are going to see a lot more coming out of this. [This technology] will be able to serve people in other ways. There is work on a similar system for the blind.'

Cybernet has applied for a second-stage SBIR contract, but NASA officials have not yet evaluated its proposal.

'We would like to make further improvements to make it a holistic program that would allow users to control lights and doors in a house,' said Joseph S. Tesar, Cybernet's director of research and development.

'Our goal is to create a system that anyone could install and use,' Tesar said.

Setting up a NaviGaze system would require the software and a USB camera. Such cameras now cost about $100.

System developers seek to promote NaviGaze for use as a low-cost method for computer use by handicapped people. Existing commercial systems that control cursors via head movement typically use hardware that costs thousands of dollars, Tesar said.

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