The dangers of brain injuries, particularly concussions, have become more clear and troubling, leading militaries, sports programs, and medical professionals to give more focus to preventing and detecting concussions. Brain injuries are still poorly understood, and nobody clearly defined what a concussion is, but what is known is that when a person has poor eye tracking ability it’s a good idea to get off the field and get help.
The brain tracks objects that we’re seeing by predicting which way they’ll go and pointing our eyes at them, allowing us to interact with a fast moving world with minimal blur. How it actually seems to work is that one part of the brain goes full speed while another puts on the brakes to create the final speed. Going too fast puts the eyes ahead of a moving target, going too slow puts them behind. Most clots following a brain injury tend to happen in the front of the brain, the same part that’s responsible for the “brakes,” so it seems like that’s the reason that following a brain injury many people’s eyes seem to jump a lot while they’re looking at something moving.
Just a few months ago the FDA cleared a system called EYE-SYNC from SyncThink, a firm based in Boston, MA, for helping to assess concussions. It relies on eye tracking built into an Oculus Rift virtual reality headset to quickly detect if a person has a poor ability keeping the eyes synced with moving objects.
We met with Jamshid Ghajar MD, PhD, Director of the Stanford Concussion and Brain Performance Center and President of the Brain Trauma Foundation, and who is also Chairman of the Board and Scientific Adviser of SyncThink. He essentially came up with the idea for the EYE-SYNC and helped turn it into reality.
He was joined by Scott Anderson, Director of Athletic Training at Stanford University who is responsible for the sports medicine aspects of athlete care and who has been working for a number of years on concussion research. He has introduced the EYE-SYNC at Stanford as a front-line tool and attests that in over a year and a half of its use for on-the-field assessment, it has really changed how head injuries are followed up on. It’s now part of Stanford’s concussion management protocol and is used on every athlete with a suspected case of concussion. The device travels with the football team and is always on the sidelines, just in case.
Dr Ghajar explained to us that in a concussion a few things are typically tested, one being balance and the other is attention. Observing a standing person with their eyes closed is a simple balance test. However, the second part, testing the attention of the eyes, is not that simple, in part because attention of the eyes is powered by two different processes. One process powers the eyes to follow the world around you as you move your head. The other tracks moving objects as your head stays still. Simply moving one’s head around while looking at a stationary object can induce nausea and other symptoms of a concussion, and it is an easy test to perform to assess the first process powering attention. It’s more difficult to assess the second attention process and to notice how accurately the eyes are following a rapidly moving object. This was the motivation to build the EYE-SYNC.
The technology really grew out of the research by the Brain Trauma Foundation that received a good deal of funding from the military. SyncThink was a spinoff of the foundation, turning an idea and prototype into an FDA cleared and fully commercialized product.
We tried the EYE-SYNC after a good night’s rest and not following any head trauma, so we were expecting good results. Once you put on the headset and the test starts, you first see a dot that disappears and then reappears in another location. This is used to calibrate the eye tracker. Following a few seconds of that is the actual test, which is just simply a red object moving along an invisible circle. This last piece is performed twice and the whole process takes only about a minute.
Below is what the test basically looks like and how the measurements are turned into a visual representation that can be readily assessed. The blue blob made of irregular streaks indicates how much difficulty the eyes had tracking the moving object.
Here is what a healthy athlete’s eyes look like from the point of view of the EYE-SYNC, and we produced very similar results:
Now take a look at results from someone following a head injury. These immediately indicate something is wrong and can be shown to the athlete to quickly stop any arguing about one’s well-being.
While there isn’t exactly a cure for concussion, exercise and lots of sleep can be very important for speeding up recovery. To help motivate a concussed athlete, the test can be taken on a regular basis to see how much progress is being made. Since it’s very objective and involves little interpretation, the athlete can quickly see how rest and exercise are actually beneficial. Importantly, the SYNC-EYE test does not require a baseline test to be taken prior to physical activity and so can’t be easily cheated on as with previously available tools (think ImPACT).
Virtual reality headsets with natively built-in eye tracking are about to start hitting the market, and the folks at SyncThink are planning on eventually switching to such devices in the future. Ideally, the headset will couple with a smartphone and the complete system will be considerably more compact and easier to bring on the field.
The technology is very convincing and is already in use not just at Stanford, but also at Oregon State, Clemson, Notre Dame, and a few other schools. Considering how fast the cost of the technology within the EYE-SYNC is dropping, there’s a good chance that high school football teams will soon be able to afford this capability for their athletes.
Here’s a short video demonstrating the test and what the system is seeing:
We’d like to thank Dr. Ghajar and Mr. Anderson for their time and the fascinating discussion we had about concussions and their management. Brain damage is a serious issue and smart people are putting modern technology to work to help reduce its consequences. We were inspired by the unexpected application of virtual reality and eye tracking technology for brain damage assessment, and are looking forward to more surprises such technology can reveal.