Optics shine at the Olympics

Alongside the buzz of athletic achievements, medals, and Parisian flair, the 2024 Olympic Games offered a less visible but no less exciting opportunity: a chance to experiment with optics.  Babak Shadgan, the medical director of Olympic wrestling competitions since the 2004 Athens Olympic Games, celebrated his sixth Olympics in that role, using his extensive knowledge to minimize athletic injuries. But the SPIE Fellow — whose expertise includes clinical biophotonics, optical diagnostics, implantable biosensors, musculoskeletal medicine, and muscle biophysics — also leverages his Olympic presence to test new technologies: he uses optics to explore and assess the physical abilities of Olympic wrestlers.

He tested his first wearable wireless near-infrared spectroscopy (NIRS) sensor on a group of athletes at the Beijing Olympic Games in 2008, used advanced IR imaging to evaluate Achilles tendinitis in an Olympic wrestler at the 2012 London Games, and applied a non-contact IR thermometer to screen athletes for the Zika virus at the 2016 Rio Games. This year, at the Paris Olympics, Shadgan tested a novel NIRS-EMG (electromyography) wearable sensor developed in his research lab — International Collaboration on Repair Discoveries’ Implantable Biosensing Laboratory — to evaluate muscle and metabolic activity.

“The fields of sports and exercise sciences are ripe for innovative applications of optics and biophotonic techniques — they offer us exciting opportunities for research and development,” says Shadgan. “Right now, in our lab, we are working on a wearable sensor that is basically a combination of NIRS and EMG sensors. It’s a compact wireless device, very wearable, that allows you to observe the electrical activity of the exercising muscle while recording the metabolic fitness of the muscle.”  In these tests, Shadgan was particularly interested in discerning the difference between muscle activity and metabolism. “Integrating NIRS and EMG sensors can provide this information for you as an observer or reviewer of the data. We are working on a calculating method, trying to use this information, this device, to find lactate threshold points during exercise — like the point where the body starts to change its metabolism from aerobic to anaerobic.”

For an athlete, he says, if you have the predictive ability to be able to tell when  you are getting to that point in advance, you could strategize your training and your exercise to get your best performance: “When you pass that threshold point, the metabolic activity is different, and you have a limited time before the lactic threshold hits, starts to accumulate, and reduces your performance.”

Shadgan first proposed using optics technology on a wrestler’s physique 20 years ago, when an athlete at the Athens Games had to drop out due to progressive leg pain resulting from chronic exertional compartment syndrome (CECS). Shadgan discovered that CECS could be diagnosed noninvasively using a NIRS sensor, and he’s applied optics solutions to his wrestling-focused work ever since, improving his devices alongside developments in optics and photonics technology.

“We’ve seen very good progress in the technology, especially in the electro-optical components that we use in our NIRS devices,” says Shadgan. “The first NIRS system that I worked with was wired, and many still are.  But by improving the components, especially the chips that we use, we have made sensors wireless as well as shrinking their size. Now they are truly wearable devices that can send data to a computer or a smartphone or a smartwatch. Developing the NIRS-EMG miniaturized, wireless, multimodal system, that’s been a major progression. We simply didn’t have that platform, those technology opportunities, ten years ago.”

Shadgan, who’s been in the sports-medicine business for 25 years, sees plenty of potential in optics and photonics still to be fulfilled in exercise and in sports monitoring. “With NIRS, you can get noninvasive, real-time information of all areas critical in exercise science. Look at the Apple Watch, Fitbit, Garmin — they are all using optical components and sensors to provide lots of information for both recreational and professional athletes.” Ultimately, says Shadgan, if we can integrate that optics and photonics technology, collecting data from the exercising muscle and the cardiovascular and cardio-respiratory system, with AI-based software that can provide predictive information during activity, “it would change the whole field of exercise science.”

Based on that information, he explains, athletes could improve their athletic performance while preventing injury: “When you pass specific thresholds during exercise, especially from aerobic to anaerobic, you gradually get susceptible to injuries. And if you understand that you are getting close to that point, then you can reduce the risk.”

That same approach could be a boon for non-athletes as well — post-trauma and post-treatment patients, for example: someone recovering from a cardiac attack and trying to get back to normal life would need to improve their body fitness.  “To manage the best way to progress or how much intensity of exercise they can tolerate and gradually increase, you need a measurement, the relevant data, right?” says Shadgan. “The data from optics techniques like near-infrared spectroscopy can be the safest real physiological information that you can get.”

Shadgan representing at the 2024 Paris Olympics.

Shadgan, an assistant professor at the University of British Columbia’s Department of Orthopaedics, has been presenting his work and research at SPIE conferences since 2008. In 2010, he was the recipient of that year’s D.J. Lovell Scholarship. Then, in 2012, he placed second in the SPIE Startup Challenge’s biophotonics division for his use of near-infrared spectroscopy to noninvasively diagnosis bladder dysfunction. In 2021, he contributed to a special guest-editorial section for the Society’s  Journal of Biomedical Optics, “Wearable, Implantable, Mobile, and Remote Biomedical Optics and Photonics.”

“SPIE had a very primary impact on my career,” he says. “I initially discovered optics through my early engagement with SPIE as a PhD student, attending Photonics West every year. There, I had the opportunity to dive into lots of interesting ideas, talking to knowledgeable people; it was always a good time for me to engage in discussion with the best optics and photonics scientists in the world.”

He began to realize that he could use optics and photonics for better, less invasive methods of diagnosis and monitoring of organ and tissue function — “like the implantable sensor that I designed for monitoring spinal cord oxygenation, hemodynamics, and spinal cord injuries” — or the NIRS sensor he’s developed for monitoring reconstructive surgical grafts: “I was able to get involved in all these areas after getting introduced to SPIE.”

He also recognized a niche area that needed filling, founding the Biophotonics in Exercise Science, Sports Medicine, Health Monitoring Technologies, and Wearables conference at Photonics West’s BiOS in 2019, a conference that he chairs and is looking forward to in early 2025.

And, now that he’s back from Paris, Shadgan can also start looking ahead to Los Angeles in 2028 — and planning his next application of optics at the Olympics.