Best Foot Forward

Like many engineering students, Vanderbilt University graduate student Andrew Ekelem loves to invent. Unlike many engineering students, Ekelem is currently helping to develop a device that will improve his own life by enabling him to walk.

Andrew Ekelem

Andrew Ekelem

Ekelem is part of the Powered Exoskeleton project in the university’s School of Engineering, where he is on track to receive his doctorate in 2018. The project began in 2008 as the brainchild of Michael H. Goldfarb, PhD, H. Fort Flowers Chair in Mechanical Engineering and professor of Mechanical Engineering, Electrical Engineering and Physical Medicine and Rehabilitation, and two of his students: Ryan Farris, PhD, who is now the engineering manager for the Human Motion & Control department at Parker Hannifin, and Hugo Quintero, PhD, who is now a robotics engineer for Freedom Innovations.

The three engineers designed the hardware features of the exoskeleton and formed a partnership with Parker Hannifin, which plans to release the first generation of the exoskeleton later this year once FDA approvals are finalized.

Ekelem spends his days in the lab making improvements to the exoskeleton’s controllers. Each improvement brings him one step closer to a device that will allow him to walk more freely and naturally despite an incomplete spinal injury that changed his life 5 years ago.

Not ready to give up

Andrew Ekelem, far right, is helping to create an exoskeleton he hopes will enable him to walk again.

Andrew Ekelem, far right, is helping to create an exoskeleton he hopes will enable him to walk again.

Image: Hall H, Vanderbilt School of Engineering.

In 2010, Ekelem was a physically active sophomore at University of California, Berkeley who regularly spent time snowboarding with friends.

“One weekend I worked up enough courage to try out one of the biggest jumps on the mountain,” he told O&P News. “As soon as I got off the jump, I [thought], ‘Oh no, I did that wrong.’ I landed on my shoulder, as opposed to my feet. I felt fine but actually I could not move my legs so I got helicoptered to the nearest hospital and they fused my back.”

Unfortunately, the back surgery was not as successful as physicians had hoped.

“That is why I got motivated to pursue bioengineering and improve the situation for spinal cord-injured people like myself,” he said.

After his injury, he discovered Berkeley’s human engineering lab was working on an exoskeleton project.

“I was optimistic when they fused by back. I [thought], ‘People can hurt their back and they still learn how to walk [again].’ ‘But a few days later, [I found out] the surgery was not very successful. They had to do a second surgery to remove some screws from my spinal column. I was discouraged,” Ekelem said.

But he was not ready to give up.

Ekelem’s work in the lab focuses on the use of functional electrical stimulation controls.

Ekelem’s work in the lab focuses on the use of functional electrical stimulation controls.

Image: Hall H, Vanderbilt School of Engineering.

“That was where I first [became interested in] mechatronics,” he said. “I discovered [exoskeleton engineering] at Berkeley and then I chose Vanderbilt because of its exoskeleton.”

Ekelem was interested in Vanderbilt’s lab in particular because the type of exoskeleton engineers have in the works is more compatible with his abilities than the one at Berkeley.

“I tried out the exoskeleton at Berkeley and that does not really work for me because I have a lot of tone in my leg,” he said. “They did not have a knee motor because they are going for really light, minimally actuated exoskeletons.”

Although the Berkeley exoskeleton is meant to aid people with complete spinal cord injury who have minimal spasticity or tone, the Vanderbilt exoskeleton is more versatile due to functional electrical stimulation (FES) capabilities and knee motors, which makes it more fitting for injuries like Ekelem’s.

“The other members of the lab have really helped me, and Dr. Goldfarb has been very supportive,” he said.

Expanding opportunities

Ekelem’s primary focus in the lab is the addition of FES to the exoskeleton. The first version of the exoskeleton has controls for walking, sitting and standing. Because FDA approval is needed for each set of controls, the FES will be added to a later version.

Ekelem tests his changes daily with a healthy subject and once a week with a spinal cord-injured patient.

Ekelem tests his changes daily with a healthy subject and once a week with a spinal cord-injured patient.

Image: Hall H, Vanderbilt School of Engineering.

“I [am] working on controls for FES and for stairs,” Ekelem said. “I was interested in adding FES to the exoskeleton to be able to move more freely in it and not resist it as much, to get the nice big steps like you are supposed to.”

During a typical day at the lab, Ekelem said he sets one or two goals for the controllers.

“So I will change [an aspect of a controller], write some code and test it out with a healthy subject. We will evaluate the controls and see how it feels,” he said. “Once a week we have a spinal cord-injured subject get in it and he will test it out. We keep doing this iterative process until we have the controller working as well as we want it to.”

Functional electrical stimulation controls are important because they will make the exoskeleton accessible to people with a wider variety of injuries and needs.

“There is such a wide variety of people … Some people have some movement or tone or certain reflexes, certain situations that need adjustments to the controls. I will be working on those cases,” he said.

His career plans are not set in stone, but Ekelem’s experiences in the lab have helped to steer him in the right direction.

“I kind of just want to be able to build or create anything I can imagine. I feel like that is what they do in this lab,” he said. “I definitely do like rehabilitation engineering. I am also interested in devices for daily activities: wheelchairs, crutches. I like to brainstorm different inventions.” – by Amanda Alexander

Disclosure: Ekelem reports no relevant financial disclosures.

Leave a Reply

Your email address will not be published.