Robotic wheelchair maps out path for mechanical engineer

UNIVERSITY PARK, Pa. — Kelilah Wolkowicz, a Penn State graduate student studying mechanical engineering, found her path at a young age. After successfully battling a brain tumor at age 11, she asked herself, “What do you do with the life you’ve been given back?"

"I wanted to do something to help people," she said.

Mechanical engineering provided that avenue, as a way to build and implement technologies to alleviate struggles that people face every day. Specifically, within the Intelligent Vehicles and Systems Group, a multidisciplinary lab in the College of Engineering, Wolkowicz helped create a robotic wheelchair.

Re-thinking the wheelchair from the ground up

With an estimated three million people in the United States relying on wheelchairs, the need for advanced technology is apparent. When designing the robotic wheelchair, Wolkowicz and other researchers carefully considered how to assist people with diverse conditions and lifestyles, including amyotrophic lateral sclerosis (ALS), Parkinson’s, or others with mobility issues.

“I’m hoping to improve the quality of life for them,” said Wolkowicz. “We don’t want a person to adapt to a wheelchair that exists; we want to create a wheelchair that adapts to the person.”

The team’s robotic wheelchair is outfitted with sensors, such as ultrasonics that are incorporated to automatically detect and avoid obstacles. As an additional safety feature, the chair also has a strip of LED lights that changes color from green to red when it detects an object in its path.

“If someone is looking at the wheelchair, it’s important that you can tell if it ‘sees’ you,” she said. “We haven’t seen any other robotic wheelchairs with that feature.”

But the team didn’t stop there. By using lasers that collect and analyze environmental information, the wheelchair can effectively create a map.

“This could help people with Alzheimer’s, who can then easily find their way if they’ve gotten lost,” she said.

Wolkowicz’s research uses a novel approach to create this "indoor GPS." By measuring ambient magnetic fields, the wheelchair detects the spatial non-uniformities due to differences between all devices that have metal, like refrigerators and computers, in addition to constructional materials used within the walls and floor of a structure. Using that data, the wheelchair can pinpoint its location in a room within a few millimeters.

“It needs some more work, but this has the potential to be one of the better indoor localization methods,” she said. “It works because every room is slightly different — even small differences in construction leads to unique magnetic fields.”

But Wolkowicz hoped to make operating a wheelchair less taxing.

“I’m trying to reduce the user input and exertion into the wheelchair,” she explained. “The downside of using a wheelchair is the person has to constantly command it.”

However, most people have a daily routine in familiar locations, like in a home or office. By enabling the wheelchair to map these locations and follow frequently used paths, the user’s need to "drive" the wheelchair can be reduced by 73 percent.

When it is being guided, the wheelchair has two joysticks, one attached to each armrest. But it also has the capability of measuring eye-gaze and arm-muscle movement. In the future, the Group plans to enable the wheelchair to measure brain activity using electroencephalogram (EEG) sensors, a breakthrough that could be extremely beneficial for users with limited mobility, including advanced ALS patients. By pioneering ways for a person’s brain to communicate directly with a device, the need for physical control lessens.

When the operator currently uses the right or left joystick, the wheelchair measures the corresponding brain activity with electrodes attached to a skullcap worn by the user.

“What we’re trying to do is use motor imagery,” Wolkowicz explained. Any joystick movements with the left hand are associated with activity in the right motor cortex, and the opposite for right hand motions. “Now, if we can measure that brain activity as someone performs or even imagines the joystick motion, the corresponding motor cortex activity can be used as the wheelchair input.”

The next steps for the project will be refining the user inputs, particularly those from brain activity.

“It’s the most difficult input to measure, so classifying those signals would be the next steps for the undergraduate and graduate students who work on this project after me,” she said.

Mapping a path for the future

While Wolkowicz is heading to Harvard for a postdoc, the next team of mechanical and electrical engineering researchers will take the helm.

“In the future, it will become more applicable to the real user, rather than just being a laboratory research project,” she said.

The potential impacts for the wheelchair will only grow with time, as the demand for wheelchairs will likely increase for the baby-boomer population.

“There will definitely be more of a need for smart wheelchairs,” she explained. “There are so many ‘smart’ products being introduced and I believe a wheelchair will be an important one.”

The interdisciplinary nature and emphasis on collaboration within the University is one Wolkowicz credits with deepening her research. Particularly in working with her advisers, Sean Brennan, professor of mechanical engineering, Jason Moore, associate professor of mechanical engineering, and Bruce Gluckman, the associate director of the Penn State Center for Neural Engineering, as well as Andrew Geronimo, assistant professor in the College of Medicine, whose expertise helped shape the project.

Fusing mechanical, electrical, neural and biomedical engineering with computer science, Wolkowicz said, “It’s a unique aspect that really added to the complexity of the wheelchair.”

She is excited to continue her work as a mechanical engineer and to bring to life technologies that can have tangible impacts on people’s health and lives.

“Every time I think I know what engineering is, the definition expands for me,” she said. “There will never stop being new things to incorporate.”

With her newly minted doctorate in mechanical engineering, Wolkowicz is poised to pioneer tech that has tangible impacts.

“This is what I went to graduate school for,” she said. “I just really want to help people, especially in the medical field.”