In case of severe lung malfunction (ARDS), conventional artificial ventilation strategies may not be able to maintain physiological gas exchange. In these life threatening situations, extracorporeal gas exchange is one of the last available options to keep the patient alive. Until now, most centers use modified cardiopulmonary bypass devices (heart-lung machines). These devices were designed and built for permanent supervision by a trained perfusionist while in operation. In particular, control and safety concepts are tailored to constant attention of an operator. As this can not be achieved in an intensive care unit, more advanced concepts for control and patient safety are necessary. This paper describes an automation concept for advanced extracorporeal lung assist systems for long term use in the intensive care unit. A main focus will be on the modelling of the gas exchange module (oxygenator) and the derivation of controllers for oxygen and carbon dioxide concentration at the oxygenator output.