For the treatment of terminal heart failure, the therapy with left-ventricular assist devices has already been established. In the systems used today, pump speed does not adjust during physical activity so that cardiac output and exercise capacity remain markedly limited. It is the aim of this study to develop an automatic pump speed control based on filling pressure values in order to improve exercise capacity and quality of life in these patients. Different approaches are planned, to be tested in an in vitro patient simulator. The algorithms aim to match the pump speed with the increased venous return. In addition, preservation of aortic valve function should be taken into account.