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At WPI, a push to make smart wheelchairs

Eye, tongue movements may help disabled navigate

All it took was the slightest rise of the eyebrows. As both brows arched upward, Ran Li brought the motorized wheelchair that he was maneuvering through the halls of Worcester Polytechnic Institute to a stop.

To turn left, Li glanced left. He looked right, and the wheelchair went right — without Li touching any of the usual controls found on a motorized wheelchair.

A senior at WPI who is studying electrical engineering, Li is part of a small team that’s working on a project to create a more intelligent wheelchair that employs new sensor technologies and control systems. The goal is create a wheelchair that can be operated by using a headband with sensors that detect body movements, such as those involved in facial expressions, and transmit those instructions to the chair.


The goal is to make a wheelchair as smart, safe, and technologically advanced as a car, giving people with severe disabilities or debilitating diseases a whole new level of mobility and freedom.

“We need to rely more on technology because of our rapidly aging population,” said Taskin Padir, an assistant professor of engineering who is leading the wheelchair project. “That technology will provide more independence.”

Sensors in a footrest of an experimental wheelchair at WPI keep it from rolling off steps and other dropoffs.Screengrab

Equally important, the WPI team is trying to make this sensor-driven wheelchair affordable by using many off-the-shelf electronics that have fallen in price, as well as standard wheelchairs that can be easily retrofitted. Even the headset the team uses for sensing facial expressions and transorming those into signals a computer can understand is widely available on the Web at $300.

In all, the equipment that WPI researchers have attached to the wheelchair adds up to about 14 pounds, bringing the chair’s total weight to 220 pounds.

Many researchers and engineers have been working on advanced technologies to reimagine the wheelchair. There are robotic systems that can be programmed to navigate around homes or health care facilities. Some designs rely on brain waves to control chairs and include sophisticated mechanical arms and hands for grabbing objects.


However, there are many obstacles to clear before these advanced systems can move from the lab to the home and to the hallways of assisted-living facilities.

“The pace of development that happens at the university is faster than in the rehab industry,” said Don Fredette, an adaptive equipment specialist at the Boston Home, a facility that cares for people with multiple sclerosis and progressive neurological diseases.

Federal safety standards for medical equipment and the limitations of most insurance policies are among the factors keeping much of the wheelchair innovation from reaching the marketplace, Fredette said.

“The hardest part is that you are dealing with something that is moving a person,” he said. “Not only do you have to keep the device from damaging things, you have to keep people safe.”

On the other hand, Fredette said, patients with debilitating medical issues are often willing to take a chance on a new technology that might improve their lives.

The Boston Home has been a test bed for some of the most cutting-edge wheelchair research. For the past five years, a Massachusetts Institute of Technology professor, Seth Teller, has been working with the facility as part of MIT’s Intelligent Wheelchair Project.

His goal is to build a completely robotic chair that can navigate and learn about a user’s home environment. Indeed, it is a much loftier goal that the current WPI project, and more difficult to achieve.


“We are working on scenarios in which the users or caregiver tells the robot, ‘Here’s how I use this appliance,’ or ‘Here I am opening this refrigerator,’ ” Teller said. Once instructed, the robotic wheelchair, equipped with a robotic arm, should be able to do it for them.

Making that happen is much more difficult than it seems.

“No one’s home is exactly like anyone else’s home,” said Teller. “That is one of the real challenges in making these machines useful.”

Indeed, the researchers and technologists who are working on improving technology for people with disabilities face many challenges.

“One thing that makes it a little bit difficult is that, relatively speaking, the market is fairly small,” said Maysam Ghovanloo, an associate professor of engineering at the Georgia Institute of Technology. “The progress is slower than the kind of technology that venture capitalists or major technology companies are pushing.”

Ghovanloo has been working for nearly a decade on a technology for using a magnet placed on the tongue as a way to remotely control a wheelchair. Using the tongue, said Ghovanloo, lets even people who have little or no facial control, or who have suffered extreme spinal cord injury, manipulate a chair.

“Unlike hands and fingers and the rest of the body connected to the spinal cord, the tongue basically has a hot line to the brain,” said Ghovanloo, whose product is undergoing additional tests before it becomes commercially available.


Although the WPI project is confined to the robotics workshops at the school for now, Padir said he is working on commercializing a version of the navigation system. He expects that it could be available in the next few years.

For many people living with immobilizing diseases or problems that resulted from spinal cord injuries, this type of technology cannot come fast enough.

“It will maintain my independence,” said Steve Saling, a resident of the Leonard Florence Center for Living, an assisted-living facility in Chelsea. He has amyotrophic lateral sclerosis, better known as ALS or Lou Gehrig’s disease. “I use a computer to speak and a wheelchair to move, and the technology available to me is nothing short of amazing.”

If the WPI project succeeds, Saling said, “such a wheelchair will revolutionize mobility for the paralyzed. I often tell people that until medicine proves otherwise, technology is the cure.”

Michael B. Farrell
can be reached at michael.farrell@globe.com. Follow him on Twitter @GlobeMBFarrell.