麻豆传媒

Peter Coveney and Roger Highfield (Princeton University Press)

IMAGINE a future where science has created your twin. Not a flesh-and-blood twin, but one that recreates your flesh and blood, your bones, your heart, your brain 鈥� your whole body, in fact 鈥� as an exquisitely sophisticated computer model.

Your doctors can use this digital twin to work out how you will respond to a particular drug or medical procedure. They can even look further into the future, creating a 鈥渉ealthcast鈥�, a bit like the medical equivalent of a weather forecast, to predict what diseases might befall you or how your lifestyle will affect your health as you age. It is the ultimate in personalised medicine.

This is the bold vision set out in Virtual You: How building your digital twin will revolutionize medicine and change your life by Peter Coveney, director of the Centre for Computational Science at University College London, and Roger Highfield, a former science journalist (and editor of 麻豆传媒) who is now science director of the Science Museum Group, UK.

At its heart is the seismic shift under way in biomedical science as it strives to move from being a largely descriptive, experimental science to one that uses mathematics to achieve the kind of predictive power and deeper mechanistic understanding that could revolutionise medicine.

Virtual You鈥榮 scope is as epic as its vision, taking us through medical history from Vesalius to Venter, and from the Antikythera mechanism to supercomputers and beyond. This means the concepts come at you thick and fast, although as a non-mathematician, I found the explanations refreshingly clear.

Digital twins are already in widespread use in industries such as civil engineering. But these model systems are, relatively speaking, much simpler than the dizzyingly complex human body. Imagine all the parts that come together to make you work: from the 3 billion letters of your genome, the myriad molecules that make up your cells, the trillions of cells building your tissues and organs, and the environment having its input too. Now, imagine trying to create a model of this that is tailored to each unique individual and that predicts the changes that will take place over a lifetime.

Coveney and Highfield set out the challenges in the first four chapters, outlining the key components that need to come together to build a virtual you. The first one, data, is in no shortage, although we still need more. But scientists need new theories to make sense of this data and to convert it into mathematical understanding.

This is easier said than done. Changes in the systems biologists want to describe usually aren鈥檛 in direct proportion to one another, a property mathematicians describe as 鈥渘on-linear鈥�. Another complication is 鈥渆mergence鈥�, where the whole of a system is greater than the sum of its parts.

This complexity challenges mathematics and pushes computing to the limit too. By the end of chapter four, the reader is wondering whether it is, in fact, remotely possible. But having shown us what we are up against, Coveney and Highfield reveal the remarkable progress that has already been made at multiple levels of biological organisation, from Coveney鈥檚 own work on simulating the molecular biology of HIV infections, to predicting whether drugs will harm heart tissue, to attempts to model whole bacterial cells.

There is an astonishing account of how scientists have built a model for the whole heart, not only shedding light on conditions such as arrhythmias and heart failure, but also to start tailoring treatments to individual patients. Researchers are also creating models of other organs, like the lung and brain, and even starting on organ systems, such as the cardiovascular system.

But getting to the next level 鈥� a whole human individual 鈥� is going to require yet more data and a revolution in computing technology far beyond what is currently possible. Whether we will get there is an open question, but Virtual You shows us what scientists from widely differing disciplines can achieve when they all work together.

Claire Ainsworth is a science journalist based in Hampshire, UK