HOUGHTON — Taking another step toward making affordable and durable prosthetics available to India’s low-income population, a team of Michigan Tech senior design students have redesigned and cost-optimized a prosthetic knee.
This year’s project advances the work of two previous senior design teams who have worked on the prosthetic knee. Each year, the teams have redesigned the prosthetic to make it cheaper and more functional.
“I wanted to work on an international project because it seemed like a great experience, and I felt like I could positively impact a lot of lives,” said Ruth Eischer, a biomedical engineering major. “Working on the knee joint gave me that opportunity.”
Eischer teamed up with fellow biomedical engineering majors David Weyland and Bobby Pizzey and mechanical engineering major James Hartel to create a prototype that is more accessible and functional for India’s many low-income patients.
Though there are several prosthetics on the market in India, devices can cost upward of $1,000, placing them financially out of reach for many patients. The new prototype would only cost around $100, offering a low-cost alternative.
In addition to creating a product that was more affordable and could be manufactured using local labor and materials, making the device smaller and lighter were also on the list of improvements.
For Weyland, the project was a chance to create a prosthetic that stood out from the crowd.
“Our prototype has the adaptability to match the user’s gait,” he said. “The other low-cost knees are more of a one-size-fits-all sort of thing. We really focused on differentiating ourselves so that our knee would be more efficient.”
Another change that the students made was to ensure that the knee’s capabilities would meet patients’ needs. “We made sure the knee was able to flex further by removing the pneumatic cylinder, which limited the flexibility of the previous design,” Weyland explained. “Patients who use our knee have a greater range of motion.”
The students achieved this greater flexibility by using an adjustable spring in place of the larger, more rigid cylinder. Not only does the spring give patients more control over the device, it also accommodates common practices, like sitting and squatting.
Assistant professors Mo Rastgaar and Nina Mahmoudian co-advised the team. “We were impressed with the maturity and enthusiasm that the students showed throughout this process,” said Mahmoudian. “This wasn’t an easy design. The human factor and added challenge of working within cultural constraints took this project beyond a typical design.”
However, it is the challenges that make the effort so valuable.
“It’s an important project simply because it’s so educational,” said Rastgaar. “But beyond that, students get to use the knowledge that they’ve gained for a good cause — to make the lives of others easier and better.”
The students’ clients at the All India Institute of Medical Science in New Delhi were pleased with the prototype as well. “They were very excited and surprised with what we had,” said Mahmoudian. “The product will make life much easier for many of their patients.”
The students on this team graduated this spring, but Rastgaar and Mahmoudian are already planning the challenges for next year’s seniors: a design that would allow patients to sit cross-legged or a prototype that would have the size and stability to be used by children.
Currently, there are two prototypes of the latest knee—one will remain at Michigan Tech, while the other will be sent back to India for more extensive clinical trials.
More at www.mtu.edu.