And now a new medical device inspired by a children's toy. NPR's Madeline Sofia reports on this low-cost diagnostic tool that could help save lives around the world.

MADELINE SOFIA, BYLINE: The inspiration for the low-tech medical innovation was the whirligig. Maybe you played with one as a kid. It's a disk with a string running through the center, pull the string and the disk spins. Manu Prakash is a biomedical engineer at Stanford University. Most people look at the whirligig and see a toy, Prakash saw potential. Laboratory Centrifuge

MANU PRAKASH: Nobody had really thought hard about, how does this very simple thing actually work?

MARTIN: Prakash thought he could turn the toy into something health care workers in developing countries desperately needed - a centrifuge, a cheap lightweight centrifuge that didn't require electricity. Centrifuges are machines that spin things like blood samples. The machine spins so fast that the blood separates into different cell types. It's the first step in diagnosing malaria and other diseases.

PRAKASH: It is an incredible tool that's very, very important to have, and it's just - it was completely missing, and most of the time you don't even have power.

SOFIA: So Prakash built a hand-powered centrifuge called the Paperfuge. Based off the whirligig, it's made from a string that passes through a central paper disk that's loaded with blood samples. Pull the string and the blood samples spin just like in the traditional expensive centrifuge, and it really spins.

PRAKASH: To the best of my knowledge, this is the fastest spinning object using human power.

SOFIA: The Paperfuge has already been used to help diagnose malaria in Madagascar, and Prakash is busy at work designing Paperfuges that can be used to test for other diseases. Madeleine Sofia, NPR News.

MARTIN: Is Madeline Sofia is a producer on NPR's special project Joe's Big Idea.

(SOUNDBITE OF HADOKEN SONG, "CLOUD RULER TEMPLE")

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