The Economist 29Feb2020

TheEconomistFebruary 29th 2020 63

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I

f you travelon a modern airliner, the

chances are that each of the jet engines

powering it will have a virtual copy resid-

ing in a computer on the ground. This copy,

known as a digital twin, will be updated

constantly with information from sensors

that measure the engine’s performance

and check for signs of wear and tear. Digital

twins allow engineers to service engines as

and when needed, rather than sticking to

rigid schedules, and let them carry out pre-

ventive maintenance by fixing things be-

fore they break. Their use is increasingly

common—not only in aerospace, but also

in carmaking, construction and factory

planning. If an international team of re-

searchers have their way, similar twins will

soon keep an eye on another important

piece of equipment, the human heart.

Building a digital twin of a patient’s

heart would first require that person to don

a variety of sensors. The data from these

would then be turned by specialised soft-

ware into a computer simulation of the

pumping organ. This simulation would

show detailed information about how the

heart is working, and the way blood is flow-

ing within it. And, in the same way that dig-

ital twins in industry are employed by en-

gineers, virtual hearts could be used by

doctors to help with their diagnoses and to

determine what treatments might be nec-

essary. A twin could then keep track of how

a patient responded to those treatments.

Heart of the matter

The idea of creating digital heart-twins

comes from a cardiac-research programme

called echoes, led by Frank Rademakers of

University Hospitals Leuven, in Belgium.

Several European and American research

groups are involved, including the Univer-

sities of Sheffield and Bristol in Britain and,

in America, Harvard and Stanford, along

with firms such as ansys, a computer-

simulation company, and ge, which makes

jet engines and medical devices.

An important part of echoesis the de-

velopment of miniaturised sensors that

will allow people to wear the monitoring

equipment throughout their daily lives,

rather than just in a clinic or a doctor’s sur-

gery, says Tim Chico of the University of

Sheffield, who leads the British arm of the

project. This will permit heart function to

be simulated in a variety of circumstances,

including walking, sleeping and climbing

stairs, rather than just for the brief period

when a patient is undergoing clinical ex-

amination. Although some portable cardi-

ac devices are already available—small

electrocardiographs worn on a belt, for ex-

ample, with leads that attach to a patient’s

chest to trace the rhythm and electrical ac-

tivity of the heart—these tend to be used for

just a couple of days. Digital twins would

draw data from a broader suite of sensors,

and for longer.

Some of the monitoring could be done

by existing or adapted consumer products,

such as health apps on smartphones and

fitness trackers, adds Dr Chico. Other sen-

sors, with more sophisticated capabilities,

are being developed by echoes’ members.

These include a wearable ultrasound scan-

ner which Jan d’hooge and his colleagues at

Cardiology

The heart’s digital twin

SHEFFIELD

How virtual copies of patients’ hearts could help doctors diagnose and treat

cardiac disease

Science & technology

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