The rapid technical improvement of the extracorporeal circulation in the past decades has led to safer, more comfortable and more compatible operations in cardiac surgery and interventions which used to be an adventure are now routine practice. Although most technical variables can easily be accommo dated today, the physical influence of artificial circulation systems on blood and tissue still remains uncertain in many cases. One of our main observations in the use of the extracorporeal circulation is that the prolonged interaction with unphysiological surfaces and forces of ten releases a cascade of blood and tissue reactions, resulting in a complex type of "disease." Thus, the symptoms can range from unspecific pulmonary inflammations to a severe renal failure or from coagulation problems to a heavy cerebrovascular stroke. Based on these facts, an interdisciplinary workshop named "Current Per spectives of the Extracorporeal Circulation" took place in Duisburg, Ger many on March 26, 1999. The rationale behind the word "interdisciplinary" was to make a step for ward to establish a joint field of knowledge which would be capable of link ing the experiences and transfer the know-how of various specialists like car diac surgeons, neurologists, physiologists or the healthcare industry with their contributions to this essential topic from different perspectives."