Seeing the invisible: How “Digital Twins” Could Protect Athletes from Chronic Traumatic Encephalopathy (CTE)

The Big Problem:

The challenge with CTE is timing. By the time symptoms appear, the brain may already be damaged. Doctors and researchers have been searching for a way to detect early warning signs while athletes stay active when intervention can make a difference. Standard brains scans and blood tests do not yet give reliable answers, and since no single test can “prove” CTE, many players are left wondering whether the headaches and forgetfulness they feel are temporary or first signs of something far more serious.

We don’t need to wait for tragedy to act. We just need a smarter way to connect the dots.

What to look for:

To prevent or slow CTE, we first need to understand how it shows up in the body. Research suggests there are early signs of brain stress that could predict risk.

In professional sports we have already seen the implementation of ‘smart’ mouthguards. These smart mouthguards measure the velocity and intensity of hits that athletes get during games and give feedback to the user of potentially dangerous hits. (Rugby, 2023)

Another possible sign of CTE development can be seen by looking at the eyes after impacts. There is a strong link between changes in the retina and brain diseases such as Alzheimer’s (Doustar et al., 2017). Researchers (Silverstein et al., 2024) have found that there was a clear difference in the retina of people who have experienced concussions. This suggests eye scans could help identify early signs of CTE.

Researchers (Monroe et al., 2022) have also found the presence of biomarkers in saliva, specifically S100B, can suggest that there is possible brain stress or damage done. A real time tool to monitor potential markers could be an easy way to track how much pressure the brain is under (Montengiro et al., 2017) which can play a huge role in the development of a serious TBI such as CTE.

A monitoring tool could help prevent people from falling through the cracks, as never suffering a major concussion, but many small hits that are gradually harming the brain.

Each of these tools tells part of the story, but what if we combined them all?

The “Digital Twin” Idea:

In engineering, a digital twin is a computer model that mirrors a real machine, like a virtual airplane that predicts when a part might fail. (Armstrong, 2020) What if we applied the same concept to people, specifically athletes?

A digital twin for the brain would combine small everyday bits of data from smart mouth guards, salvia test, eye scans and even speech patterns to build a live picture of brain health. Instead of guessing, we could watch for early changes and give athletes clear signals of when to rest, when to test and even when to worry less.

Emerging research on digital twins in sport and medicine supports this idea. Digital twins are already being used in medicine and sports performance. Applying them to brain health is the next logical step. (Tilen Hliš, 2024) (Dylan Powell, 2021)

How it would work:

Let's break it down into simple steps.

1. Smart Mouthguards

Measure the number and force of head impacts to identify players at higher risk. (Rugby, 2023)

2. Saliva Biomarkers

Detect early brain stress by analysing proteins like S100B in saliva which is a quick and painless test. (Monroe et al., 2022) (Montengiro et al., 2017)

3. Eye Scans (Retinal imaging)

OCT-A imaging can reveal small blood vessel changes in the retina that mirror damage inside the brain. (Doustar et al., 2017) (Silverstein et al., 2024)

4. Speech and Eye Movement Apps

Track subtle changes in reaction time, speech and eye movement that can signal brain fatigue. (Lisa Graham, 2024)

When combined, it can create a personalised Digital Brain Twin and can be shown by using the traffic light system. This tool wouldn't diagnose CTE, but it would help prevent it from silently progressing.

Figure 1 A digital twin combines physical data and biology to track brain health in athletes.

Figure 2 How it works

Why it Matters:

For athletes, uncertainty is often worse than bad news. A digital twin system can give back clarity and control to their lives.

It could:

• Help doctors’ spots early signs while they are still reversible.

• Provides reliable data rather than relying on how an athlete feels.

• Guide training, rest and recovery safely.

• Reduces worry by showing real time brain health.

• Shifts focus from treating CTE after the damage to preventing it in the first place.

This could help athletes listen to their brains long before symptoms start speaking for them. (Tilen Hliš, 2024)

Challenges:

Implementing digital twins into sports comes with challenges. The first is obtaining accurate and consistent data. These systems rely on large amount of reliable data which can be difficult to gather in fast paced environments such as sports (Hliš, Fister and Fister Jr., 2024).

Another challenge lies in the complexity of the brain. Since experts are still not completely sure how CTE develops in every individual, that each digital twin would have to adapt to an athlete's specific biology, injury history and genetics. This requires time, collaboration, and ongoing research (Tudor et al., 2025).

Ethics and privacy are also critical. Brain data is deeply personal so very clear rules must be set and followed to ensure the athletes' personal data is protected and used properly. Building trust is essential (Huang, Kim and Schermer, 2021).

Devices that can be designed to be more user friendly by providing clear results along with compatibility with a range of devices, like phones and computers, can greatly limit the need for experts to be present. This will likely drive athletes to understand and trust technology (Moorthy et al., 2024).

Looking Ahead:

The idea of using digital twins to track and protect the brain health of athletes is still new, but the potential it holds is undeniable. With modern advancements and between the medical researchers, sports organisations, and technology, potential for this type of brain monitoring is not impossible. Digital twins may carry the answers to CTE and have the possibility to redefine athlete health care.

A digital twin can't stop every hit, but it can make every hit count less. Maybe one day we’ll say we didn’t just change the game, but we changed how we cared for those who play it.