Play Live Radio
Next Up:
0:00 0:00
Available On Air Stations
Donate today to give back in celebration of all that #PublicMediaGives. Your contribution will be matched $1 for $1.

Cellphone Medical Test Wins NPR's 'Big Idea' Contest

Catherine Wong used electrical components to build an electrocardiogram that sends data by cellphone.
Courtesy of Catherine Wong
Catherine Wong used electrical components to build an electrocardiogram that sends data by cellphone.

Most of us would like to make life better for people in developing countries. Most of us don't do anything about it. Catherine Wong is different. She's the winner of our Joe's Big Idea video contest. She not only came up with a big idea to improve health care for the poor but also built a prototype to test it.

Wong, 17, invented an electrocardiogram that transmits real-time medical data through a cellphone.

"Just the kind of technology that 'flattens the Earth' for better medical care," says Eric Topol, a cardiologist at the Scripps Research Institute in La Jolla, Calif., who reviewed Wong's video for NPR. An electrocardiogram, which measures the heart's rhythm, is a basic and widely used medical test.

Catherine set out to make an ECG for the 2 billion people in the world with no access to health care. She's a junior in high school in Morristown, N.J. Her device uses off-the-shelf electronic components to pick up the heart's electrical signals, then transmits them via cellphone to a health professional who can analyze them.

"It is a leapfrog approach that bypasses standard pieces of medical equipment that are expensive and not readily available to these populations," says Elizabeth Nabel, president of Brigham and Women's and Faulkner Hospitals and a former director of the National Heart, Lung and Blood Institute at the National Institutes of Health.

Lots of people are trying to develop mobile health tools for the developing world, Nabel noted. But she praised Wong for building a working prototype. "I give her kudos for her embracing knowledge across multiple scientific fields, her creativity, her vivid and concise presentation and her enthusiasm. (She even got the cardiology right!)"

The contest judges on NPR's Science Desk — Rebecca Davis, Michaeleen Doucleff, Dick Knox, Joe Neel and I — also liked the fact that Wong actually tested her idea. We chose her entry from the 10 contest semifinalists, who were selected by voting on YouTube, for its clear goal, scientific accuracy and feasibility.

How did she do it? I called Catherine to ask. She's intensely interested in making low-cost medical tools for the developing world — so much so that last year she built a stethoscope that could transmit data through a cellphone.

"That was successful enough that I decided that I wanted to see what other kinds of devices could be successfully ported over to a mobile phone platform," she told me. "The ECG was the next logical step."

But once she dove in, she realized she knew a lot less about electrical engineering and Java programming than she needed. "I knew what the endpoint was, but I had no clue how I was going to get there."

She turned to a physics teacher, who let her borrow equipment and talked through the many problems with her. After months of building, testing and failure, she came up with a working ECG that connected to a cellphone using Bluetooth wireless signals. The heart rhythms are displayed on the phone's screen, thanks to a Java app that she wrote.

She's not about to let the idea drop, even though she's now back in school. "I'm going to keep going on this project, making it smaller, cheaper, more durable," she said. Her dream: to actually get it working for patients in developing countries. "That's who I aimed the project at, and that's who I'm working for."

Topol and Nabel have offered to give Catherine advice on how she might make that happen. And I'm working to connect her with the folks at PopTech, a global community of innovators. One of their current projects is to develop self-testing for HIV using mobile phones.

And lest you think she's spending all of her time geeking out: When she's not playing with wire and circuits, Wong says, "I read like a fiend, attempt to fix things I've broken and continue learning to juggle badly."

Copyright 2021 NPR. To see more, visit

Joe Palca is a science correspondent for NPR. Since joining NPR in 1992, Palca has covered a range of science topics — everything from biomedical research to astronomy. He is currently focused on the eponymous series, "Joe's Big Idea." Stories in the series explore the minds and motivations of scientists and inventors. Palca is also the founder of NPR Scicommers – A science communication collective.

You make NHPR possible.

NHPR is nonprofit and independent. We rely on readers like you to support the local, national, and international coverage on this website. Your support makes this news available to everyone.

Give today. A monthly donation of $5 makes a real difference.