Back in the Bicycle Seat Again

September 11, 2009

For Claude Flynn, long bicycle rides in the fresh air were therapy for the mind and exercise for the body. Every Sunday, she’d ride her bike 35 to 40 miles through the rolling Chatham County countryside south of Chapel Hill, N.C. Often, she would stop in a meadow, take in the sun, listen to the birds singing and enjoy a sandwich and bottled water.

That all changed in 2003, when a car accident left her unable to flex her left knee enough to the pedal a bicycle.

"Since the accident, I haven't ridden my bike at all," said Flynn, 59, an occupational therapist assistant who hails from France. "I had assumed that I wouldn't ever be able to ride again."

However, the ingenuity of three recently graduated Pratt School of Engineering undergrads put Flynn once again behind the handlebars. "I've gotten up to about 15 miles, which is pretty good," she said. "I might try to work my way back up to 35 miles, but I don't have to do 35 to be happy. I'm just so excited to be riding again."

The students – Stephanie Tupi, Winston Lynk and Megan Toney – devised and built a modified crank arm – the metal part of the bike that 'holds' the pedal itself on one end and attaches to the main gear on the other. By altering the left crank arm, they were able to compensate for her inability to completely extend her left leg.

"We came up with a pivoting left crank arm that allows the pedal to drop to a lower height at the peak of the pedal motion," explained Lynk, a BME graduate from Coral Gables, Fla. "This decreased the degree of knee flexion she needed for pedaling." The story begins in BME 260: Devices for People with Disabilities, a course taught every year by Larry Bohs, assistant research professor in biomedical engineering. Now in its 12th year, the semester-long course matches small groups of students with a specific problem hindering the quality of life of a real person. Each team’s mission is to conceive, design and manufacture a solution.

The first thing the team did when they settled on their project was to visit Flynn at her Chapel Hill home.

bike pedal"They asked a lot questions and made measurements of my knee and its capability to move," Flynn recalls. "Throughout the whole process, there were many phone calls, e-mails and visits to my house. I was very impressed by their determination to make sure I got what I needed. They were very considerate and involved in the process. It was quite touching seeing three kids being so very thorough making sure to get everything right."

By the end of the semester, the device was complete. The team took it to Flynn’s house and installed it on her bike. "She kept going around circles in a parking lot, and we couldn't get her off,"said Toney, a BME graduate from Wrentham, Mass.

This summer, the team entered their invention into the annual competition held by the Rehabilitation and Assistive Technology Society of North America (RESNA). Out of more than 60 teams from across the country, the Duke team was honored as one the top five during a ceremony in New Orleans. Teams from Northeastern, Georgia Tech, University of North Carolina and Rice were the other winning teams. For team members, the experience of developing a device, and then completing all the work that goes into preparing the presentation for the competition, reinforced the choices they made for their future endeavors.

"I am considering working in product development and design, and after this experience, my decision was solidified," Lynk said. "What exactly I want to build I’m not sure yet, but I know I want to make things that can help people." "This class helped me to decide on a career working in assistive engineering," Toney said. "I like helping people, not just sitting in an office all day. Ultimately I'd like to develop prosthetic devices that will improve someone's quality of life."

Bohs said that his class is unique from most in that students not only get hands-on practical experience, but they also have the opportunity to work and interact with the real person who will use their device. In the process, he said, they learn about tools, materials, how to use their hands and machine tools in the course of a semester. Over the years, Bohs has made contacts with patients, therapists and teachers who provide him with ideas for individuals that could use his class' help. After a vigorous screening process, he selects those challenges that offer the most potential help for the client, as well as those offering a unique learning experience for his students.

"It's important to not only give the students a challenging project, but also one that by the end of the semester they can feel a true sense of accomplishment," Bohs said. "For me, I get satisfaction knowing we are doing something for someone that makes a difference, while hopefully awakening some new interests in the students."

For Flynn, the students' efforts truly have improved her quality of life. "Biking had always been such an important part of my life, both physically and spiritually," she said. "It was very frustrating not being able to ride. I did take up swimming, and while I enjoyed it, it just wasn't the same. Being outdoors in nature is such a totally different experience."