People with low vision usually rely on dogs or canes to detect obstacles at ground level. But what about higher ones such as street signs or tree branches? Computer scientists at the University of Washington think they have the answer, according to this IEEE Pervasive Computing article (PDF format, 4 pages, 390 KB). They've designed a cheap wearable device which alerts visually impaired people that they're about to hit an inanimate object. Their prototype device consists mainly of a video camera mounted on headset glasses and a laptop carried in a backpack which uses specialized software to detect potential collisions. The device, which is still in an experimental stage, should cost less than $1,000, but weighs about 15 pounds, so I'm not sure if it will ever turn into in a commercial product. Read more...
Here are some details about this prototype device.
Working under the direction of Eric Seibel, assistant director of the Human Interface Technology Laboratory (HITL), students Robert Burstein, Ryland Bryant, and Cameron Lee created a low-cost, wearable vision aid that alerts its users of stationary objects that are near enough for a collision.
One of the groupís main design objectives was to create something that could be developed inexpensively. The prototype combines a video camera, a scanner headset, a laptop computer, and software. Bryant says the scannerís parts cost just a few dollars, "although it still takes a little machining in manufacturing."
The more expensive components are the laser diode, which costs about US$400, and the laptop. Seibel notes that many people with impaired vision use computers for work, school, and email, so the laptop could serve multiple purposes.
But the prototype is quite heavy. The fully loaded backpack is weighing about 15 pounds, with 470 grams for the glasses alone.
||This picture shows one of the patients testing the equipment. (Credit: HITL)|
I'll skip some details, but here is how the software works.
Once the software determines that an object is too close (too bright), it sends a signal to the processor to display the appropriate warning icon, which is reflected onto a mirror in front of the personís left eye. At that point, the person should be within armís length of the object and can reach out and feel it to determine what to do.
But why displaying icons to visually impaired people?
Designed to operate with a person walking at a standard pace, the device has a working range of about 10 feet. Bryant explains the rationale for an icon warning system: "We went with a visual display as opposed to an auditory cue because we didnít want to obstruct our subjectís hearing," he says. "They tend to rely on that a lot."
So far, it's just a proof-of-concept, and even if it's proven useful, I seriously doubt it can become a commercial product until its weight is significantly lowered.
But if you're interested by this project, you should visit this page about wearable low vision aid at the Interface Technology Lab, where I found the picture above.
Sources: IEEE Pervasive Computing, July - September, 2004; Human Interface Technology Laboratory at the University of Washington website