Delaware Assistive Technology Initiative

Dr. Kurt Manal, Assistant Research Professor Department of Mechanical Engineering University of Delaware

Would Mark Zuckerberg, the founder of Facebook, be a billionaire if not for something as simple as a computer mouse? Maybe, but I doubt Facebook would have caught on if users had a difficult time navigating the endless cascade of member pages. Accessing Facebook and, in a broader sense, surfing the Internet are made easy by the point-and-click functionality of a computer mouse. What if you could not use a computer mouse? Could you still use a computer? Sure, but it would involve many, many key strokes to complete simple mouse-driven actions. This was frustrating for a friend of mine who was diagnosed with Amyotrophic Lateral Sclerosis (ALS), commonly known as Lou Gehrig’s Disease. He loved reading the New York Times online-edition but found it increasingly difficult to click on the many links as his disease progressed. Loss of fine-motor control in his hand and fingers limited his ability to move the mouse and control his computer. This is where my interest in assistive technology started.

The Mouth Mouse beside a dime to show scale.

Assistive technologies that allow people with disabilities to control computers and other electronic systems have tremendous potential to improve quality-of-life. The ability to control such systems can have a significant effect on one’s mental health and sense of well-being. As we become increasingly reliant on computers for recreation, education and workplace productivity, there is a growing need to develop alternate computer input technologies to make the full potential of personal computing for people with disabilities truly accessible. There are many assistive devices on the market ranging in complexity (and cost) from something as simple as a pointing stick to high-tech computerized eye-tracking systems. I had the opportunity to help my friend try a number of these devices over the years as his disease progressed. Periodically he would have to change to a new input device as his function deteriorated. Somewhere during this time it occurred to me that none of the devices he had tried or that I had seen were tongue-controlled.

Using the tongue may seem odd, but the tongue is an ideal controller because it is fatigue resistant, has excellent tactile sensitivity and it can be moved very accurately. It was easy to test the feasibility of using a tongue as a controller; I simply slid my tongue along the touch pad of my laptop and, not surprisingly, it worked. It was a little awkward, I admit, but it got me thinking about how to get the touch pad in my mouth. Ideally, whatever I came up with would have to be comfortable so that an individual could use it for extended periods of time. A custom fit dental retainer was an obvious choice. I had a retainer fabricated and then I laminated pressure sensitive sensors to the arch. The sensors were arranged in a diamond pattern similar to points on a compass. By applying pressure to the front-most sensor (akin to North on a map), the mouse pointer moves upwards on the computer screen. The sensors are spaced close enough together so that two can be depressed at the same time allowing for diagonal movements. Because the sensors are pressure sensitive, the pointer speed is controlled by simply pressing down more or less forcefully. I thought an appropriate name would be the “Mouth Mouse.” I can honestly say the Mouth Mouse is an intuitive input device and easy to use. Unfortunately, by the time a functional prototype was working, the Mouth Mouse was no longer a viable option for my friend and he never got to read the New York Times with his tongue.

Kurt Manal using the Mouth Mouse

Although the idea for the Mouth Mouse was motivated by a friend with ALS, I hope that one day it will help provide the access that many people with disabilities seek. For example, X10 software allows one to control household lighting and temperature using home-automation products. In addition to computer access and home-automation, it is foreseeable that the Mouth Mouse could be used as a controller for a motorized wheelchair and many other electronic devices. As for my friend with ALS, he’s still using assistive technology to access his computer. In fact, he was featured on 60 Minutes in 2008. For the latest in high-tech assistive technology, you can read about my friend and see how he uses brain waves to control his computer at www.cbsnews.com/stories/2008/10/31/60minutes/main4560940.shtml.

Dr. Kurt Manal is an assistant research professor in the department of mechanical engineering at the University of Delaware. The “Mouth Mouse,” which allows one to control a computer by sliding the tongue along the roof of the mouth, has received a notice of allowance for patent application and is available for licensing through the University of Delaware’s Intellectual Property & Technology Transfer Office.