Digital twins are already being used in manufacturing, industry, and aerospace. Now the European project Neurotwin wants to make virtual cop...
Digital twins, virtual copies of real things, have already become a staple of manufacturing, industry, and aerospace: There are digital twins of cities, ports, and power plants. The term was first introduced in 2010 by NASA researcher John Vickers in a report on the agency's technology roadmaps. Industry analysts estimate that the digital twin market could reach nearly $50 billion by 2026.
Digital Twins of the Brain
Soon this idea penetrated into biology. In 2016, Bill Ruh, then CEO of GE Digital, predicted that "we will have a digital twin at birth, and it will collect data from the sensors that everyone uses, and this digital twin will predict diseases, cancer and other things for us". The digital twin can provide information about a patient's individual treatment and predict how their illness might develop. It can even be used to test potential treatments instead of testing them on patients, a process that can be risky.
So far, these projects are mostly in their early stages. A research program called Echoes, which involves scientists from Europe, the UK, and the US, is working to create a digital heart. Siemens Healthineers, a German medical device company, is aiming to do the same. Dassault Systèmes, a French software company, has teamed up with the US Food and Drug Administration to endorse what it calls "The Living Heart." Austrian company Golem creates digital twins of vulnerable people living alone. The idea is that the digital twin constantly monitors their health, alerting carers if they get sick and need help.
Now researchers are aiming for the highest goal: to create a twin of the brain. The EU-funded Neurotwin project plans to create a computer model of the entire brain of an individual patient.
The Neurotwin team hopes the model can be used to predict the effect of stimulation in the treatment of neurological diseases, including epilepsy and Alzheimer's disease. They are planning a clinical trial starting next year that will create digital twins of about 60 Alzheimer's patients who will receive brain stimulation treatments optimized specifically for their brains. A second clinical trial scheduled for 2023 will be carried out in the same way, but for patients with treatment-resistant focal epilepsy. Both trials are proof of concept to determine if the approach works and can improve outcomes for these patients. If successful, the team plans to expand its technology to study other aspects of the brain, such as those
Approximately one-third of patients with epilepsy do not respond to medications. Non-invasive stimulation, in which electrical currents are delivered painlessly to the brain, has been shown to help reduce the frequency and intensity of seizures. But this technology is still quite new and needs to be improved. This is where a virtual brain can come in handy.
According to Giulio Ruffini, coordinator of the Neurotwin project, chief scientist, and co-founder of the Spanish company Neuroelectrics, which develops non-invasive treatments for neurological diseases such as epilepsy, a digital avatar is a mathematical model that runs on a computer. To create a digital twin of a patient with epilepsy, the Neurotwin team takes about half an hour of MRI data and about 10 minutes of EEG (electroencephalography) readings and uses them to create a computer model that captures the electrical activity of the brain, as well as realistically simulating the main brain tissues, including the scalp, skull, cerebrospinal fluid, gray and white matter.
The twin will include a network of built-in "neural mass models," Ruffini says. These, he says, are computational models of the average behavior of many neurons connected to each other using the patient's "connectome" - a map of neural connections in the brain. In the case of epilepsy, some areas of the connectome may become overexcited; in the case of, say, a stroke, the connectome may be altered. Once the doppelgänger is created, the team can use it to optimize stimulation of the real patient's brain, "because we can run endless simulations on the computer until we find what we want," says Ruffini. "In that sense, it's like a computational weather forecasting model."
For example, in order to improve the treatment of a patient with epilepsy, he should wear a hat every day for 20 minutes while it delivers transcranial electrical stimuli to his brain. Using a digital twin, Ruffini and his team can optimize the position of the stimulus electrodes as well as the level of current delivered.
The digital twin of any organ raises a number of ethical questions. For example, does a patient have a right to know or not to know if, say, his twin predicts that he will have a heart attack in two weeks? What happens to the twin after the death of the patient? Will he have his own legal or ethical rights?
On the one hand, virtual twins give us exciting, revolutionary opportunities to develop new treatments, says Matthias Braun, an ethicist at the University of Erlangen-Nuremberg (Germany), who has written about the ethical aspects of using digital twins in healthcare. “But on the other hand, it poses challenges for us,” he continues. For example, who should own the digital twin? The company that creates it? “Or do you have the right to say: “I refuse to use specific information or specific forecast in relation to my health insurance or use in other contexts? In order for this not to be an attack on autonomy or privacy, it is important that a particular person controls the use of [their digital twin]," he says.
Ana Myles, CEO of Neuroelectrics, says the company has already grappled with the question of what will happen to the highly personal data on which the digital twin is built. "When you do personalizations like this, you have to ask tough questions, right? Who will own the data? What are you going to do with the data?" she asks.
Researchers were brought in to analyze the ethical and philosophical components of the project, including Manuel Guerrero, a neuroethics at the University of Uppsala, Sweden. For the Neurotwin project based in Europe, the collected data will be protected by the European Union General Data Protection Regulation (GDPR). This means that any use of the data requires the consent of its owner, says Guerrero.
Guerrero and his team are also exploring whether the term "digital twin", which was first coined for production, is the most appropriate term for replicating something as complex and dynamic as a living brain or heart. Could its use lead to misunderstandings or high expectations in society? "The brain is much more complex than the other types of twins that appear in the production system, so the notion of a twin for the brain is something that is discussed in the neuroscience community," he says.
Creating a brain is many orders of magnitude more difficult than modeling a heart or kidneys, and also potentially more ethical. "We're building quite sophisticated computational models of the brain," says Ruffini. "At some point, I think it will become unclear whether this digital twin is a digital twin or is it a sentient being."
Brown believes the time has come to reflect on these difficult questions. "I think these are really important issues that we have to face now," he says. "We know what happens when you just say, 'Well, just develop the technology, and then we'll see,'" he adds, warning of the dangers of postponing the ethical and moral consequences to a later date.
But the Neurotwin team says that done right, this kind of digital replication could dramatically improve both patient outcomes and our knowledge of intractable brain diseases. "We're working to really help people suffering from brain disorders from a completely different perspective," says Mikes. "We like to call this a new category of therapeutics where you really use the power of physics and mathematics to decipher the brain."
COMMENTS