Imagine you have some risky surgery coming up and the procedure could be tested first on your virtual twin - a computerised recreation of your body - to see how your metabolism might react. It would be a kind of digital doppelgänger, not made of flesh and bone but bits and bytes. The doppelgänger would mirror everything from how your heart beats and your lungs work, right down to your personal DNA code. It could help to minimise the risks before surgery and anticipate any previously unexpected reactions or complications. Researchers at CompBioMed have been working on just such a project.