Biomedical engineers learn by building
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From left: Brent Geiger,
Timothy Rand and Tom Chia test the circuitry of a muscle-activated
massage pad prototype they built for a boy with lissencephaly,
a rare neurological disorder that severely impairs mental and
physical development.
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JPG)
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n a Thursday evening before finals last semester,
Brent Geiger found himself staring at a spaghetti bowl of black wires,
protruding at odd angles from a circuit board on a table before him.
He and his four teammates had a problem, and it wasn’t so much
that the project they had worked on all semester was due the next morning,
nor that they still had to solder all those wires into place to get
the thing working.
That night, amid the darkened labs of the Engineering
Centers Building, the problem was that none of them had ever used a
soldering gun. “We’ve designed circuits and built them on
test boards. But this was our first time to actually work on a real
board,” says Geiger. “You just have to jump in and try to
figure it out.”
Fortunately for them, jumping in is no problem around
the biomedical engineering department, where Geiger is one of 140 students
learning how to design the tools of medicine and life science research.
Majors complete a sequence of six design courses, in which they create
and build biomedical equipment for clients around the university and
in private industry. Beginning as early as a student’s third semester
on campus, those courses leave little option but to dive into unfamiliar
waters.
“In almost every other class, if you give students
a problem, they can go home and work on it, and there’s always
an answer in a book somewhere,” says John
Webster, one of six BME professors who oversee the design courses.
“This is different.”
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In the BME design
class, student Tom Chia tests the prototype's circuitry.
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The difference begins with the projects. Nothing is
in the hypothetical; these are real problems in need of real solutions.
Webster and colleagues round up more than 30 design challenges by asking
professors and other contacts in the life sciences what tools they need
to do their work better. “Most have some problem they’ve
always wanted to work on or have solved,” he says. “We say,
here’s a team that is willing to spend time on it and get the
thing done.”
On the first day of each semester, students divide
into teams of five or six and sign on for projects, which might involve
anything from designing a better IV tube to figuring out how to respirate
a blue whale. It’s pretty much a given that they will start in
over their heads, lacking the technical skills or specific knowledge
to complete the task. The whole point, says Webster, is to figure out
what they need to know and how they can learn it. “They learn
to work contacts and go places they haven’t gone before to find
answers,” he says.
In the case of Geiger’s team, that meant learning
about the life of a 12-year-old boy with lissencephaly, a rare neurological
disorder that severely impairs mental and physical development. The
students’ client, a nurse who oversees the boy’s care, had
been searching for a muscle-activated massage pad that could provide
positive feedback and pleasurable stimulation when the boy flexed a
particular muscle. Nothing like it existed on the market, and so it
fell to the students—four juniors and one sophomore—to build
one from scratch.
During fall semester, the team designed a circuit
that would pick up a signal from two electrodes wrapped around the boy’s
thigh and trigger the massage pad to turn on for two minutes. They ordered
the parts and tested them out on Geiger’s biceps muscle. They
even made a colorful slipcover to put over the pad.
Technical knowhow, though, was only part of what it
took to complete the task. “At first, when we got this project,
we really had no idea how to do it,” says Geiger. “We had
to go through the process of designing it, and you really learn a lot
by doing that.”
At most universities, hands-on design comes only after
students have completed a sequence of more traditional classes that
teach the basics of biology and engineering. Wisconsin’s curriculum
includes those classes, too, but its emphasis on design is unique—a
product of a faculty-led overhaul of the curriculum undertaken six years
ago. Now, the UW-Madison program is the only one in the country in which
students are exposed to open-ended design throughout their time on campus.
“It’s my favorite class to teach, because
it’s so creative,” says Webster. He points out that the
only lectures come at the beginning of the class, when professors offer
a few insights on teamwork and the design process. But even those paltry
touches of formality try students’ patience. “They just
hate it. They want to get into the lab and get going,” he says.
To ease the culture shock, Webster teams sophomores
with juniors, who can help them with rudimentary skills and serve as
mentors. But students say even the most experienced team members rarely
have all the answers.
“You’re thrown into a lot of new areas
where you have to learn on the fly,” says student Jon Millin.
He recalls an experience from a previous semester, when his client was
a veterinarian who wanted students to design a ventilator for use on
mammals in the field—including animals as large as blue whales.
“We had to spend all this time just researching how animals breathe,”
he says.
By the time they become seniors, students have experience
on four or five projects, and their savvy shows. In the past two years
alone, 15 student teams have disclosed their inventions to the Wisconsin
Alumni Research Foundation for patent consideration, including a new
needle insert for breast biopsies, an apparatus that measures a patient’s
ability to swallow, and a portable device that allows people with speech
disorders to regulate the volume of their voice.
Not all projects go so well. Biomedical engineering
is no different from any other tool-related endeavor in that it’s
rare that everything works perfectly the first time it’s assembled.
Most teams endure prolonged periods of trial and error before they arrive
at functional solutions. “Our credo in this class is, ‘Try
it, see what’s wrong, and fix it,’” says student Brian
Frederick, whose team hit a dead end when trying to design a restraint
that would make it easier for researchers to administer eye drops to
lab animals.
But as teammate Ross Gerber points out, you can learn
as much from the things that don’t work as the ones that do.
“When things fail, you have to look at different
concepts and try other ways,” he says. “One of the most
important lessons in engineering is to know when to give up on an idea.”
