Researchers at the Massachusetts Institute of Technology and the National University of Singapore have developed a technology which aims to treat sepsis in the blood using microfuidic techniques. The device, which comprises a series of microfludic channels, separates circulating bacteria and inflammatory components in the blood from the healthy red blood cells using a phenomenon known as margination. Margination normally occurs in blood vessels and causes bacteria and white blood cells to move to the side of the vessel.
The microfluidic channel network measures 20 micrometers high by 20 micrometers wide and is etched onto a polymer substrate where it handles the infected blood in three separate stages. As the infected blood flows through the first stage of the microchannel system, the harmful cells are directed towards the side walls of the channel. 
At the second stage the microchannel divides into three separate channels: a central channel for the red blood cells and two side channels for redirecting the harmful cells. This filtering is repeated on the central channel in the final stage of the device to remove any remaining harmful cells in the blood.
The researchers have so far demonstrated up to 80 percent removal of the E. coli bacteria and greater than 80 percent depletion of inflammatory components from samples processed by the device. The results of these early experiments have been published online in the journal Biomicrofluidics. The researchers have also designed and tested a scaled up system consisting of six microfluidic channel networks in parallel for faster cleansing of blood samples.
Abstract in Biomicrofluidics: A microfluidics approach towards high-throughput pathogen removal from blood using margination
(hat tip: Gizmag)