At Cedars-Sinai Medical Center in Los Angeles, the nurse assistant stopped by a patient's room to pick up some lab samples while dropping off toiletries. Then, as the helper's pixilated blue eyes flashed a heart sign to indicate the task had been completed, it summoned an elevator and quietly rolled off to the hospital's supply room to carry on with its next mission.  Meet Moxi, a robot that is helping medical staff at Cedars-Sinai and roughly two dozen other hospitals around the U.S. "I don't