Futurity reports that a group of college students has turned a salad spinner into a rudimentary centrifuge that medical clinics in developing countries could use to manually separate blood without electricity. They built it for about $30—including the spinner—using plastic lids, cut-up combs, yogurt containers, and a hot-glue gun.
The centrifuge was designed as a project for a global health class. The students were asked to develop an inexpensive, portable tool that could diagnose anemia without access to electricity.
They found that a salad spinner met those criteria. When tiny capillary tubes that contain about 15 microliters of blood are spun in the device for 10 minutes, the blood separates into heavier red blood cells and lighter plasma. The hematocrit, or ratio of red blood cells to the total volume, measured with a gauge held up to the tube, can tell clinicians if a patient is anemic. That detail is critical for diagnosing malnutrition, tuberculosis, HIV/AIDS, and malaria.
“Many of the patients seen in developing world clinics are anemic, and it’s a severe health problem. Being able to diagnose it with no power, with a device that’s extremely lightweight, is very valuable,” says Rice University engineering education professor Maria Oden.
Photo by Jeff Fitlow.