The artificial organs program in Berlin started more than 20 years ago. The main emphasis in the circulatory assist and replacement devices program was and still is on the development of an electro-pneumatic total artificial heart (TAH) system. Additionally, a temporary assist system and investigations in the field of biomaterials are included in the research activities. Topics of the program are: interactions between natural and artificial materials, blood pump development and in vitro fatigue testing, driving units and energy transmission, measurement equipment needed for the surveillance and automatic control of the TAH system, in vivo studies of the response of the circulatory system and the organs, in vivo reliability, and training of the staff for clinical readiness. The joint efforts of engineers of different disciplines and medical doctors, working together in the department of experimental surgery, supported in the past by industrial partners, resulted after extensive in vitro and in vivo investigations in the clinical application of temporary assist devices and the realization of a percutaneous portable, electro-pneumatic total artificial heart system.