Perhaps someday organs will be mapped using computer models, much like the weather is today. Using a computerized "digital twin" of a heart, researchers will be able to make predictions about the effect of pacemakers on an individual. "Over time, [my medical] record could be a digital twin of me," said Steve Levine, the chief strategy officer for French software company Dassault Systèmes Simulia division. The potential applications to personalized medicine are profound, because taken to its extreme, the idea could be used to research differences between individuals' organs. It sounds out there. But Dassault has already launched the Living Heart, which turns a 2-D scan of the heart into an individualized 3-D model. Each 'twin' heart consists of 208,561 digital tetrahedrons. Each one has its own biological properties. Digital twins have long been used to model bridges and cars. Why not the human body? More