Artificial heart recipiant Barney B. Clark, left, smiles at his surgeon, Dr. William DeVries, in Salt Lake City, in this Dec. 3, 1982, file photo. Clark, who lived 112 days with the Jarvik-7 heart after the landmark surgery, had little expectation of longtime survival. "He had faced his mortality," said his widow UnaLoy Clark-Ferrar. "He knew he was going to die. He knew he had to be in that position (for doctors) to consider him. He saw it as a real opportunity for him to contribute something to medical science. That was the reason he did it." (AP Photo/FILE)