November 6, 2006

C.U. Engineers Design Walker to Improve Seniors’ Mobility

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A team of master student and undergraduate engineers is hard at work on a project that could help senior citizens stay fit and safe at the same time. The project is an electronically-assisted walker with power automatic breaks. This walker would adjust to the way the owner uses it and the environment in which it is being used, providing automated help when the owner requires it.

The goal, according to Sunneth Attygalle ’07, a senior in bio-engineering at Cornell and a principal member of the team, is to create a walker that is not “completely passive” and therefore does not limit an elderly person’s “desire to go out and stay as active as they need to be.”

The team consists of four Cornell students, including team leader Sheryl Lau, a master’s student in electrical engineering. The team also includes electrical engineering master’s student Philip Wang, Attygalle, and Homer Chiang ’08, a mechanical engineer and the only junior on the team.

Prof. David Lipson, biomedical engineering, acts as faculty advisor to the group. He offers the students technical support from other faculty, including Bruce Land, John Belina, and Andy Ruina, when necessary, and is responsible for grading the students on their project at the end of the year. Despite Lipson’s active role in the project, he stressed that his job is to provide support for the team, not to lead it to any great extent.
“Teams do best when they’re largely self-directed. My goal is just to keep them from walking off a cliff when I have to,” Lipson said.

According to Attygalle, the walkers currently on the market are woefully inadequate; they put their elderly users in danger just as much as they support them.

“The elderly know they are at risk for injury, so they are afraid of falling. The walker adds a sense of security,” said Attygalle of the current models. But this sense of security is often false. “The current walkers are not very secure. The walker has its own weight and can pull on the user. The only controls are difficult-to-use brakes.”

This problem was first identified by Dr. Eli Einbinder, psychiatry, professor at Weill Medical College. Einbinder has already taken out a patent on this new electronically-assisted walker. Einbinder sought out Lipson to enlist Cornell students to develop prototypes for testing in a clinical setting. Einbinder had already observed the current walker in active use at Weill. According to Attygalle, Einbinder was struck by the “clumsiness” of the heavy, cumbersome walkers. This particular problem in the walker’s design will be addressed by the new walker, which will not only be electronic, but will also be light weight — a projected eleven pounds to the typical eighteen pounds of the current model — and collapsible.

The students engaged in this project have yet to come up with a prototype. According to Chiang, who is in charge of most of the mechanical aspects of the frame, the team’s goal is “to pump out a prototype as soon as possible.” The team has yet to come up with a complete design for the frame. They have recently begun experimenting with existing walker frames and electronic apparatus. Among the models the team is using for inspiration is a razor scooter, notable for its lightweight frame, effective braking system, and ability to fold to a very compact size. Even without a prototype, the team is still right on schedule.

Chiang claimed prototyping constitutes “only a small portion of the process. A lot of testing has to be done, a lot of iterations on the geometry have to be worked out before we can build something.” Chiang is optimistic about coming up with a design soon; he said the team is “nearing the end of the research phase.”

Part of the research for the project involved a field trip to Longview, a residential senior community, part of Ithaca college’s Ithacare program. During the trip, the team was able to get the real user perspective on the walker models currently on the market. This was an invaluable resource for the team; in Chiang’s words: “As college students, we have no idea what it’s like using a walker.” To Attygalle, “the real user perspective” is the most important part of the research process.

“Their input is the key to making this project a success,” Attygalle said.
“Patients and physicians vote with their feet. They only use something if they like it,” Lipson added. The team and their advisor both feel strongly that this walker needs to be tailored specifically to the needs of the senior community.

Attygalle has a personal reason for his involvement in this project: his grandmother in Sri Lanka has come to rely on a walker for mobility. But the walker has not succeeded in granting Attygalle’s grandmother the independence she would like: because of the limitations of the bulky, passive frame, she still “needs a lot of physical help and support. She has become very dependent on others.” Attygalle hopes this project might help her regain her independence. Einbinder suffered from a condition that impaired his mobility as a child. He too was forced to rely on a largely ineffective walker. In Lipson’s words, this left a “lasting impression upon him.”

According to Lipson, the team is making great strides toward its very personal goal.

“I was overwhelmed when I saw how quickly they were able to come up with a good understanding of the problems they needed to solve” Lipson said. He estimates that it should take three to four years to completely finish the project: that means there will have to be several changes in team members before the project’s completion.