Advances of cardiovascular engineering prompt one to consider innovative device technology - that is, the development of new replacement heart valves or engineering of a totally implantable energy source for an artificial heart. However, these kinds of advances have often proved unable to achieve a long-lasting benefit as the cardiovascular field has matured so fast. Cardiovascular engineering has matured to the point where a major innovation must not only function, but must continuously function better than existing devices. This is difficult to accomplish in the complex cardiovasculature...