The first recipient, a 50-year-old woman, received the 92-gramme (three-ounce) pump made of plastic and titanium in late July and is now leading a nearly normal life with it at home, the University Hospital of Heidelberg said in a statement.
"It can fully replace the function of the heart's left ventricle and works particularly quietly and effectively," said the director of the cardiac surgey division of the hospital, Matthias Karck.
The device can also help patients bridge the time until a heart donor can be found for a transplant.
The pump is the fifth generation of the so-called DeBakey Heart developed by the late US cardiac surgeon Michael DeBakey in the 1990s.
It can be worn adjacent the ailing heart and allows for external electronic monitoring and adjustment.