When lungs fail because of acute respiratory distress and cannot be used to deliver oxygen to patients via conventional ventilation, extracorporeal membrane oxygenation (ECMO) has to be employed. ECMOs remove carbon dioxide from whole blood and replace it with oxygen thanks to a membrane oxygenator. While such artificial lungs are effective for short periods of time for many patients, for others this procedure is just too difficult. The gas exchange process performed by ECMOs is just too slow compared with what healthy lungs can achieve.
Now, researchers at Fraunhofer Institute for Applied Polymer Research (IAP) in Germany have created a new type of membrane that permits a much more efficient gas exchange. They have created asymmetrical membranes that have irregular pore structures that are essentially random. Near where the separation happens, the material has small cavities and below that are larger cavities that are open at the bottom. Thanks to convection and diffusion, the gas separates much faster using the new membrane design.
“Our membranes have a structure tailored to the desired membrane material,” said Murat Tutuş, a researcher at Fraunhofer IAP, in a press release. “Consequently, our membrane possesses exceptionally high gas permeability and high mechanical stability. On top of this, the membrane material is both inert and soft, just as it ideally should be for a material that comes into contact with blood. Oxygen transport was quadrupled under the defined conditions. At the same time, the manufactured membranes had a pressure stability of at least 7 bar, but generally higher than 10 bar TMP (transmembrane pressure).”
It is hoped that this new approach to building gas exchange membranes will allow for much easier oxygenation of patients with severe lung conditions, giving physicians more time to address the underlying causes of the damaged lungs.