image: Derek Wolf, right, is principal investigator of the study designing a device combining functional electrical stimulation with a passive exoskeleton device to help restore hand grasping motions.
Credit: Photo/Corrie Mayer/University of Cincinnati
For people with spinal cord injuries/diseases (SCI/D), performing daily tasks can be a challenge due to an impaired ability to grasp and manipulate objects with their hands.
University of Cincinnati researchers, in collaboration with end users in the community, have received a $200,000 grant from Paralyzed Veterans of America (PVA) to design a user-centered, easy-to-use assistive device to help restore hand grasping motions.
Study background
UC’s Derek Wolf, PhD, the project’s principal investigator, said biomedical engineers have developed many exoskeletons — robotic devices worn over the user’s hand — to assist with grasping. These devices often work well in lab settings, but few end users adopt hand exoskeletons and wear them in real-world settings for the long term.
“We make these really cool devices, but they don’t get to that next step for any number of reasons,” said Wolf, assistant professor in the Department of Mechanical and Materials Engineering in UC’s College of Engineering and Applied Science. “What we’re trying to do with this project is involve end users throughout and focus on actually making a device that will translate beyond the lab.”
The research team is aiming to combine an exoskeleton device with another technology called functional electrical stimulation (FES) that runs electricity through a paralyzed muscle to get the muscle to contract.
“If you just put an exo on someone’s hand, you’re not really taking advantage of the hand that is there, arm muscles that are there,” Wolf said. “There’s an efficiency gap when you just throw an exo on. We can use those muscles to generate force or motion.”
Wolf’s background includes expertise in FES and incorporating it into hybrid systems. While the goal is to eventually fully integrate FES with a motorized exoskeleton, this project will first try to combine FES with a passive exoskeleton that cannot move on its own.
“FES can be hard to control and get fine motor control, so our hope is to use the exo on top of it to make that control easier while the motion is still driven by the FES,” Wolf explained. “So if FES causes a finger to move, the exo is going to move with it and get a nice grasp.”
Wolf said major barriers include making interfaces user-friendly and simple for a lay person to operate, devices being cumbersome for users to quickly put on and take off by themselves, and the fact that each person’s injury and needs are unique.
“Making a device that helps a lot of people but also is able to help an individual person is a real challenge,” he said. “Our hope is that, by including users throughout, we can really do that.”
Keeping the end user in mind
As paid members of the research team for the full two years of the project, advocates Sarah Elam and Dave Reed will provide input on their needs and test prototypes and new designs so that the final product can be useful and functional for end users like themselves.
“Professor Wolf told me, ‘You can't simulate disability,’” said Elam, 48, who has multiple sclerosis and is a quadriplegic with limited use of her nondominant left hand. “That's not something they can make up using something else. It's been very important to them that I know I'm a teammate and not just the disabled person coming in to help them.”
Reed, 71, a retired UPS driver, has regained partial movement of his arms and legs and uses a power wheelchair after a C3 spinal cord injury.
“I said yes to the project because I thought it would help other people like me, and I thought it'd be interesting, from a mental health sort of view, to be part of something bigger than myself,” Reed said. “I've always liked science. I thought it'd be good to be part of a kind of science project, and I’m really looking forward to doing this.”
Reed said the research could help him with tasks like steering his wheelchair better and signing his name. Elam noted that even in the project’s early stages, it has been exciting to make progress as a team.
“In our first session, we were just working on picking up items and picking up and gripping a can and moving a can,” she said. “But there's excitement around — oh, holy crap, that worked the way we wanted it to!”
Wolf said engineers can often get caught up in an engineering challenge or big idea they believe will help users, but at the end of the project their innovations do not solve any real-world problems.
“I’m very excited to be able to have Sarah and Dave involved, to teach me and teach the students in the lab how we actually solve the things that people care about,” Wolf said. “My hope is that the two advocates actually end up developing a relationship with us and stay with us long term — where they’re guiding what the next project is, and the next project, and that every project we do is actually based on their needs and what they understand the needs of the community to be.”
Student experience
Ryan Cuda, a student pursuing his PhD in mechanical engineering, will lead much of the day-to-day design aspects of the project and said he was envisioning working on projects like this when weighing graduate programs.
“I chose UC because it offers great opportunities to work in biomechanics, and having the medical school nearby is a huge advantage for collaboration and research,” he said. “At a lot of schools and in many research programs, you do the work but never see it lead to real-world change. What matters most to me is doing research that’s truly translational — where we’re building something that can directly improve people’s lives.”
Working with Reed and Elam’s feedback and needs, Cuda and the rest of the team are currently designing the first prototype exoskeleton.
“From there, we’re working in two-month sprints: designing a prototype, gathering feedback from users, refining the design and repeating the process to keep improving with each iteration,” Cuda said.
Working on a PVA grant is personal for Cuda, who comes from a military family and planned to join the military himself before an arm injury derailed his plans.
“I understand the kind of support veterans and service members truly need, and I constantly hear about the gaps in care they’re facing,” Cuda said. “My grandpa was a member of the Veterans of Foreign Wars, and since they work closely with PVA, it’s really meaningful to come full circle and contribute to that same mission.”
Other co-investigators include Victoria Heasley, MD, who brings clinical expertise and experience with user-centered device design, and Aaron Burdette, MS, an expert on product design, usability studies and the process of getting devices approved by the Food and Drug Administration.