Senior Design Team Builds Automatic “Arm” to Assist Fellow Student
By Colleen Kearney Rich
Mason bioengineer Nathalia Peixoto lost a bet this semester, and she couldn’t be happier. Earlier this year, she bet one of the senior engineering design teams she was advising that the automatic self-feeding device they were building would never be able to feed someone rice.
Over the course of the semester, the automatic “arm” in its various iterations has served up Legos, Cheerios, and other small items. Peixoto lost the bet in April when the device did indeed finally serve up some rice.
“It was a good bet to lose,” says Peixoto, an assistant professor of electrical and computer engineering in the Volgenau School of Engineering.
The rice was part of an Iranian chicken dish prepared by one of the team members, electrical engineering major Farideh Madani, for Neima Izadi, the Mason student for whom the arm was built.
“He is from my country, so I knew what kind of food he would like,” Madani says with a smile. The food was prepared, and Izadi, a criminology, law and society major, was able to enjoy it using the new device.
In addition to Madani, the design team includes Jane Kambugu, Sidra Khan, and Kamran Mohammadi, and is led by Salma Mahmoud. All are electrical engineering majors, and all were smiling when they came to the Students as Scholars end-of-the-year event to celebrate the successful completion of their project.
But the journey to this point was not easy and involved a lot of hard work, late nights, and some last-minute creative problem solving.
In the Beginning
When the group came together in the fall, they were interested in developing something that would help someone. Bioengineering, Peixoto’s specialty, was one of the concentrations on which the engineering students could focus. It was Madani who suggested a device that could help her friend.
“He is in a wheelchair and can move his arms, but it takes a long time for him to complete the motions to eat a meal,” says Mahmoud. “We thought this device could help him enjoy a meal in the same amount of time it would take one of us.”
The time-saving and social benefits of such a device for a busy college student were clear to the group, so they decided to proceed.
How the senior engineering design projects work is the group spends one semester doing research and planning and then uses the second semester to build whatever it is they have committed to creating. The projects often involve a considerable amount of work, and it isn’t unusual for a group to be unable to complete the project or take the project as far as planned, according to Peixoto.
“It was really good that they had five people in this group,” says Peixoto, who also directs the Neural Engineering Lab on campus.
The engineering students spent last fall researching what kind of devices were already on the market and finding out more about the mechanics of wheelchairs. Over time, they came up with goals for their device: it had to be portable and discreet, it had to save time and minimize spills, it had to weigh less than five pounds, and it had to run on battery power using a rechargeable six-volt battery.
They designed it—on paper—and came up with a budget. Mohammadi even built a version of the arm for their presentation using a Lego Mindstorms kit. Their presentation was well received, and by the end of the fall semester, they were ready to move to phase two.
With construction of the device, the real work began, and everyone on the team is quick to point out that they are not mechanical engineers.
“In the beginning, we had been working pretty linearly,” says Mahmoud of the process. “One week we would work on one motor, then move on to the next. Soon it became obvious that we would never finish.”
So they divided up the tasks, trying to make sure everyone was working on something they were interested in. The project easily broke into five parts: the robotic arm, the mount that connects the device to the wheelchair, the printed circuit board (PCB), the sensor, and programming.
For many of these tasks, the students had to almost start from scratch to learn what they had to do. “Everything was a learning experience for us,” says Madani.
In terms of the fabrication of the mount and the PCB, these tasks included learning software in which they would design the piece before it went to manufacturing. Khan oversaw the design of the mount; Madani worked on the PCB.
“Three months,” Madani says as she holds one of the small green circuit boards in the palm of her hand. That’s how long it took to get the piece designed so it could go to the manufacturer. When the boards finally arrived, there was still soldering to do.
Were there hiccups in the process? You bet. For one, there was miscommunication between the team and the company that was selling them a tiny camera that was to be the “eyes” of the device and help the spoon find food. Just three weeks from their deadline, they had to come up with a better plan.
“I knew nothing about sensors except that we needed one,” says Kambugu who oversaw that portion of the project. “So I did a ton of research to figure out what kind of sensor would work best for us. Then it needed to be calibrated for this use.”
How much help was their mentor Peixoto? “A lot,” says Mahmoud with emphasis. “In the beginning, we got stuck on something I now realize is very basic, but we had spent a week trying to work out a solution.”
A simple suggestion from Peixoto got them past that first hurdle, and she has been guiding them throughout the process.
“I know they pulled many all-nighters,” says Peixoto. “I got several e-mails from them that were written at odd hours of the night saying ‘we need this….’”
Because of the nature of the group’s project, Peixoto was also able to provide some financial assistance. Peixoto and Vasiliki Ikonomidou, an associate professor also in the Department of Electrical and Computer Engineering, are coprincipal investigators on a National Science Foundation (NSF) grant specifically designed to support senior design groups that are developing projects to help other students. Their current plan is to fund one group per semester with the $100,000 grant that runs until 2016.
The Final Stretch
It was always the intention of the team that the completed device go to Izadi. It was built for him. What they didn’t anticipate was that it might have a life beyond the prototype.
Peixoto says that she and the group have been in communication with a local assistive technology company that designs custom wheelchairs. The company is interested in possibly offering the automatic arm as a feature.
In addition, they recently found out that they are finalists in the student design competition of the Rehabilitation Engineering and Assistive Technology Society of North America. They will travel to Baltimore, Maryland, in late June to compete against teams from other universities.
But for now the students are mostly relieved to be done with classes. Some graduated this semester; others still have classes to take.
“I believe we did a fantastic job in putting our ideas together and creating something useful, especially for individuals who are handicapped,” says Mohammadi. “Our advisor was also very happy with the project. That’s always a good sign.”
“The work of engineers can change lives, especially in areas such as assistive technology,” Peixoto says. “When you can see how others benefit from something you’ve created, that has a huge impact on you. These undergraduates got that.”
Would they do it again? The group members chuckle and admit that it was fun.
“Yes,” says Kambugu, “but with more time.”
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