Low Cost Blood Test

A centrifuge is a device that fractionates blood. Blood fractionation separates blood into plasma, white blood cells, and red blood cells. Fractionated blood is easier for researchers to analyze. Unfortunately, centrifuges can be pricey and bulky. They also require electricity. As a result developing countries and field-hospitals can’t utilize them. Recently, however, scientists at Stanford have developed an inexpensive alternative.

Inspired by a Children’s Toy

Manu Prakash is a bioengineering professor at Stanford University. He and his team traveled to Uganda and spoke with healthcare workers. The team discovered that the workers had a centrifuge, but they were using it as a doorstop. With no electricity, the device was useless to them. Prakash returned home and decided to explore children toys for inspiration. He eventually found a toy called a whirligig or buzzer. It spins much faster than a yo-yo, so it made sense to explore it as an option.

The Paperfuge

The paperfuge works just like a whirligig. A string runs through the middle of the paper disc. Handles are attached to either end of the string. When a person pulls on the handles, the disc in the middle rotates quickly. Prakash and his team found that their device makes 125,000 revolutions per minute. That number is one of the fastest rotational speeds ever recorded for a human powered device.

While the device’s disc is made out of paper, it is coated with polymer to make it less likely to break. Healthcare workers can attach blood samples to the disc and then pull on the strings to separate the blood. Prakash and his team traveled to Madagascar to test the device. It worked just as they planned.

Inexpensive Tool

One of the most important aspects of the paperfuge is its cost. It can be produced for as low as 20 cents per device. The disc itself can even be created with a 3D printer, so it’s easy to produce a large number of the devices. So far the device has only been used to detect malaria. Since it’s shown success Prakash and his team plan to test the device with other diseases. To learn more about Manu Prakash visit his Stanford profile.