“How a Children’s Toy Could Help Fight Malaria”

Question

by Jason Daley

One of the most basic and necessary pieces of equipment in a medical lab is a centrifuge. Often bulky and expensive, this device (in the most simple terms) spins things. And spinning things like blood can separate out its components, allowing doctors to diagnose diseases like malaria. But the lack of electricity and resources in rural regions around the world means no centrifuge. Now, a simple new 20-cent gadget could change all that, and it's based on an unusual source of inspiration: the whirligig.

"There are more than a billion people around the world who have no infrastructure, no roads, no electricity," says Manu Prakash, a physical biologist at Stanford and inventor of the new gadget. When he visited Uganda in 2013 he found that clinics either did not have centrifuges or didn't have the juice to power them. “One clinic used its broken centrifuge as a doorstop,” Prakash tells Devin Powell at Nature.

"I realized that if we wanted to solve a critical problem like malaria diagnosis, we needed to design a human-powered centrifuge that costs less than a cup of coffee,” Prakash says in a press release.

When he returned to Stanford, Parkash began brainstorming ideas with one of his post-docs, Saad Bhamla, examining at all sorts of spinning things, reports Madeline K. Sofia at NPR. They quickly began focusing on old-school, preindustrial toys like yo-yos and whirligigs.

“One night I was playing with a button and string, and out of curiosity, I set up a high-speed camera to see how fast a button whirligig would spin. I couldn’t believe my eyes,” Bhamla says in the press release. The button was rotating at 10,000 to 15,000 rpms.

The pair began prototyping small hand-powered centrifuges based on the whirligig principle. Their final model, the Paperfuge, spins at 125,000 rpm, the equivalent of a centrifuge costing $1,000 to $5,000, according to the press release.

The Paperfuge is made of a disk of paper coated in a polymer, reports Sofia. The disk is attached to two pieces of wood or PVC pipe via string. When the strings are pulled, the disk in the middle spins, acting as a centrifuge for a blood sample attached to the center of the disk. The team describes their work in the journal Nature Biomedical Engineering.

Prakash and Bhamla recently returned from successful field trials of the Paperfuge in Madagascar where they used it to test for malaria. While the gadget only takes two minutes to separate blood, reports The Economist, it takes 15 minutes of whirligigging for malaria-diagnosing separations.

Once the blood is separated, however, it needs to be examined by a microscope. Luckily, several years ago Prakash also created the Foldscope, a $1 paper microscope with optical quality similar to conventional microscopes that will begin distribution in 2018.

Answer 1

The article discusses an innovative approach to addressing the challenges of malaria diagnosis in rural areas lacking electricity and proper medical infrastructure. Manu Prakash, a physical biologist at Stanford University, along with his post-doctoral researcher Saad Bhamla, has developed an affordable and simple device called the Paperfuge. Inspired by traditional spinning toys like whirligigs, the Paperfuge is a hand-powered centrifuge that can achieve an impressive spinning speed of 125,000 revolutions per minute (rpm), making it comparable to much more expensive centrifuges often found in medical labs.

The Paperfuge is designed to be low-cost, estimated at just 20 cents, allowing it to be accessible in regions where medical resources are scarce. By pulling on strings attached to a paper disk coated with polymer, users can spin a blood sample to separate its components, which is crucial for diagnosing diseases such as malaria. Field tests conducted in Madagascar confirmed the device's effectiveness, with the separation process taking only two minutes following 15 minutes of operation.

Additionally, Prakash had previously developed the Foldscope, an affordable paper microscope that complements the Paperfuge, as blood samples need to be examined microscopically for malaria diagnosis. This combined approach offers a promising solution to improve malaria detection in rural areas, enhancing public health efforts while tackling one of the world's most persistent health challenges.