By John Williams When degenerative illness or a traumatic injury reduces a person's ability to control his or her body, the muscles that move the hands, fingers, eyes, and head often retain at least some of their capabilities. That's why scientists have long tried to build interactive systems that would allow a computer user to control an interface through the motions of these parts alone.
They have had some success. The U.S. military uses eye- and head-motion tracking to guide weapons systems. And several companies have built devices they claim can accurately track glances or subtle head and hand motions and convert them into cursor movements. But these expensive systems have yet to filter down to the general market for assistive technology.
Software company Eye Control Technologies, aims to change that. For $99, virtually anyone can afford ECT's trackIR, a kit that includes special NaturalPoint software, shiny dots, rings, a wand that users wear or hold, and a receptor device that tracks the reflections off these devices.
The system is definitely a promising product, and it does have the potential to permit easier control of Windows software. But it still has some flaws. For example, sunlight sometimes interferes with the trackIR's operation, and a wealth of options can easily overwhelm or confuse a user. Reluctantly, I must say I can't recommend it yet.
CHASING LIGHT. Here's how it works: Users first install software from two floppy disks onto their computer. They then connect a highly sensitive black-and-white camera mounted on a tripod to their PC via its USB port. The camera sits atop a regular cathode-ray tube (CRT) monitor or next to a laptop or flat-panel display and points toward the user. It's designed to track infrared light reflected by shiny material stuck to the wand or ring, or bounced off pea-size dots affixed to the skin or a piece of clothing, such as the brim of a hat.
Using infrared reflections, subtle movements of the hand, head, or fingers are converted by the camera into a series of three-dimensional coordinates. The NaturalPoint software, in turn, translates these coordinates into cursor actions or other user commands, such as quit or open. You can use the trackIR in place of, or in tandem with, a mouse. The software can also be configured to recognize special gestures and movements that activate more complex functions -- for example, a waggle of the finger from right to left could translate into turning an on-screen page.
It all sounds nifty. But it's no piece of cake to make trackIR work. The software installation went smoothly. But the problems started when I tried to put the camera on top of my monitor. The trackIR's three legs did not fit properly into slots on the monitor. And the foam rubber pads at the end of each leg proved no better. I looked in the instruction booklet but found no clues. Eventually, I had to tape the left and right legs to the monitor's top. On my second day of using the trackIR, I had retape the camera to prevent it from toppling off the monitor.
NOTHING BLINKED. Once I had attached the trackIR to my monitor, I plugged the cable into the USB port on my desktop PC. The computer installed the drivers for the trackIR quickly. I double-clicked on the NaturalPoint icon on my desktop to open up the program. Then I followed the instructions by placing a dot on my finger. I waved the dot in front of the trackIR while waiting for a green light on the camera to blink. This would indicate that the program was ready, an event that should have been followed by the cursor following my finger motions. Nothing blinked. Nor did the cursor move in step with my finger.
I closed the program, reopened it, and tried the whole procedure again. Nothing happened. I closed and reopened the program yet again. Still nothing. Frustrated, I visited the manual's troubleshooting section. After trying several of its suggestions, I managed to get the green light and could finally work the program. But I had spent more than an hour getting the trackIR up and running.
Next, I learned how to navigate the NaturalPoint software. A diagram on the monitor illustrated all the program's options and functions. It has slow, medium, fast, and custom settings that determine the speed and distance the cursor moves in reaction to the motions of the reflective dot, ring, or wand. Initially, I selected the slow setting. (Eventually, I moved to the medium and fast settings, but never tried the custom one.) I placed the dot on my forehead and then clicked on the icon on the left side of the monitor. I adjusted the trackIR so the dot and beam were properly aligned.
Once I became accustomed to the dot's movements, I scrolled pages up and down, moved them left and right, and highlighted copy. The trackIR requires little body movement for readable reflective motions. But getting the system to work to my satisfaction was a slow process that took hours. In fact, I believe that using speech-recognition software and a regular mouse, one can achieve the same effect with less time and effort.
IMPERFECT REFLECTORS. Each of the three reflective devices have their own problems, too. I stuck one of the reflective dots to my forehead. I felt kind of goofy, but it seemed to work O.K. But it was a hot day, and I started to sweat a bit. When the sweat from my forehead dripped onto the dot, it stopped working and had to be replaced permanently. So much for reusable dots.
Next, I tried the ring. I wore it on my right index finger and was able to perform the same functions I did with the dot by aiming the ring at the screen and slightly moving my hand. But the ring was too small for my fingers (which are large, I confess), and I never grew completely comfortable with it. Worse, to use the ring I had to move the trackIR camera from the top of the monitor to a place just above the keyboard. To secure the camera, I taped it onto a small box. And I couldn't help but think the tape companies should invest in ECT.
Finally, I pulled out the small reflective wand. Unlike the other two infrared reflectors, the wand works when a user is a good ways away from the keyboard and camera. To use the wand, you hold it between your thumb and forefinger and click a button. Audio feedback tells you when you have successfully activated the wand function on NaturalPoint. After that, any wand movements should shift the cursor onscreen and control other programmed functions. But when I stood to the right of the wand and out of the way of the trackIR camera, I got no response.
Additional features added more confusion than functionality. For example, a "Gravity" feature exists for clicking on icons such as check boxes. When this feature is active, the cursor will jump to whatever icon or button you're trying to hit and lock on for a moment. But if there are multiple check boxes in a row, say, the cursor can easily glom onto the wrong one.
MAYBE NEXT TIME. Another feature, called "dwell clicking," is supposed to give users total hands-free control of the computer. When a user clicks on the dwell-clicking icon, a bar with six buttons appears at the top of the screen. The buttons on the bar are used for double clicking, dragging, right clicking, and opening a more advanced dwell-clicking options menu. For me, this was simply too many buttons doing too many things.
Another problem was trackIR's sensitivity to direct sunlight, a condition that seemed to reduce the camera's ability to pick out motions of the reflective medium. That was a big strike in my book, since I like the sunlight coming over my shoulder while I am working. As I final test, I gave my software-guru son a chance to test drive trackIR. After four hours of trying, he, too, was exasperated.
All this isn't to say trackIR is useless. The product is inexpensive and available to just about anyone. The technology clearly has potential. And NaturalPoint did put together a relatively easy-to-use manual (save for my bad encounter with the tripod setup and the unfortunate fact that the pages were not numbered). But after using TrackIR for about 14 hours, over three days, I knew it wasn't for me. I look forward to trying the next version. But for now, I'll stick with voice-recognition software. Williams writes Assistive Technology every week, only for BW Online.
Got a comment or question? Please visit our Assistive Technology interactive forum