Children’s Hospital Boston researchers are developing a microfluidic filtration device to rapidly pump blood out of the body and clear it of sepsis-causing pathogens before sending the blood back to the body.

Severe sepsis happens when the immune system overreacts to bacterial or fungal infections. As sepsis sets in, inflammation rapidly spreads through the body, often shutting down organs and potentially leading to death. Each year, intensive care units in the United States hospitalize nearly 750,000 patients with severe sepsis.

The device contains microscopic channels for blood and for a saline-based solution. The solution contains molecules that naturally attach to a sepsis-causing bacteria. The researchers added magnetic beads to those molecules.

When infected blood mixes with the saline solution, the molecules attach, and a magnetic field pulls the bacteria out of the blood.