Children’s Toy Inspires Life-Saving Healthcare Tool

Sometimes the simplest concepts can make the greatest impact, says Manu Prakash SM ’05, PhD ’08, professor of bioengineering at Stanford, as he explains a new tool—based on a centuries-old children’s toy—that could revolutionize healthcare. His love of toys and the help of his team, which includes two MIT undergrads, helped moved the project along.

The idea first hit him on a trip to Uganda in 2013, while distributing and testing an ultra low-cost microscope designed by his lab at Stanford, when he realized that a key element in diagnosing illnesses was missing: a centrifuge. The expensive machine that spins liquid samples at high speeds to separate fluids of different densities to allow for microscopic diagnoses are not an option in much of the developing world because of their reliance on electricity. And, as a result, many treatable diseases go undiagnosed. Prakash set out to create a device that would replicate the centrifuge and sell for less than a dollar without the requirement of electricity.

For him, toys were a natural place to look for inspiration. “I started working on yoyos,” says Prakash. “I tend to look for inspiration in places with unconventional physical phenomena that might be useful, and I have a fascination with toys.” The yoyo was not fast enough and required too much skill so they stocked up on other toys and devices to try. “When postdoc in the lab, Saad Bhamla decided to image the whirligig, we got a number that was around 8,000 rpms and we knew we had something very special.”

They studied the whirligig design for eight months before coming up with the paperfuge—a small, inexpensive device made of polymer-coated paper, string, and PVC pipe or wood tubes. By attaching blood samples to a paper disc with string through the center and pulling the strings, the disc rotates at speeds up to 125,000 rpms—the fastest for any human-powered device—causing cells to separate for diagnostic processing just like in the more expensive electrical centrifuge.

Prakash says the next big push on paperfuge finally came along because of the help of MIT undergrads—Brandon Benson ’17 and Chew Chai ’17 and Stanford undergrad Aanchal Johari who were all interning in labs at Stanford in summer 2015 and caught wind of the research. “We learned about Manu and his balance between rigorous research and global development work,” says Benson. “We heard about his project and realized that we were working right outside his lab at Stanford and became really excited.”

Even before becoming officially involved, Benson and Chai started working with Bhamla via Skype calls and did preliminary modeling on the whirligig toy. They sent Prakash a four-page report summarizing their results as part of their application to intern in his lab in summer 2016, and they were quickly added to the team.

To test the design, Prakash and his team focused on malaria, one of the deadliest diseases in the developing world and one that commonly goes undiagnosed. They traveled to Madagascar—the fifth poorest country in the world, with largely insufficient infrastructure and access to electricity—for three weeks in December 2016 and distributed hundreds of paperfuges. “That was a phenomenal experience and we learned a lot from it,” says Prakash. “When you hand over the tool to somebody that works in those conditions, that’s when it starts to become clear where the value of the tool is.”

“We’re designing with very specific applications in mind. We have one paperfuge that’s designed for stool samples, another one for urine, another for blood with various parasites in mind. But this is much more of a platform or design principal. We’re going to share this more broadly with partners who would like to test it and take it to the field.”

Prakash, who grew up in India and studied at the Indian Institute of Technology in New Delhi, knows what living in a country without proper healthcare is like and he has long been motivated to use his knowledge and resources to improve that situation. After studying at MIT, he became a fellow at Harvard Society of Fellows before starting his lab at Stanford in 2011.

“I told myself, I’m going to spend a big portion of my time focused on frugal science and building tools for a broader context of people and that’s what we’ve done. I have lived in places where healthcare is a huge challenge and I understand that challenge and I care about, at least, making a dent in that.”