The Berlin Heart itself is external, with two tubes going into the baby's body, where one is connected to the apex of the left ventricle and the other to the aorta. It's pneumatically powered by a device that's about the size of a mini-refrigerator. The pump moves about 10 ccs of blood with each heartbeat.
It has been implanted about 108 times in young children in North America prior to Kaidence Stephenson's surgery this week.
The pump can be used as either a bridge to transplant or to give the heart enough help and rest so that it can recover. Only time will tell which it will be for Kaidence.