Tom in 2018 Finn took his father Nigel to his physiotherapy appointment. Nigel was living with vascular dementia, which can cause symptoms similar to Parkinson’s disease, a progressive neurological disease characterized by motor symptoms such as tremors, stiffness and balance problems. He was losing his ability to walk.
The physiotherapist told Finn about cue markers, colored lines placed on the floor that can help people with Parkinson’s disease overcome walking difficulties. Finn wasn’t sure. He couldn’t see how a few lines on the floor would help his father. But when he got home, he laid out colored exercise bands in the kitchen and watched in amazement as his father moved on and off them with ease.
This technique, called extrinsic cueing, works by using visual, auditory or tactile stimulation (colored tape on the floor, playing a metronome or physical vibrations) to connect nerve pathways that are not affected by the disease. “It can help people get over the freeze by focusing their attention and taking that first step,” says Claire Bale, deputy director of research at Parkinson’s UK, a UK research and support charity.
Finn, who worked in marketing and video production in London, was surprised by the effectiveness of this simple intervention, but thought it was too basic to be really helpful. But augmented reality glasses like Magic Leap are just starting to hit the market, and we wondered if they could project virtual lines onto the ground to act as clues. He founded the startup Stroll to make that vision a reality.
According to Jorgen Ellis, two years later Stroll had no employees and about 50 pounds in the bank. Ellis, a New Zealander with a background in furniture startups, came to the UK looking for his next venture and wanted to get involved in something he was passionate about. His grandfather had suffered from Parkinson’s disease for over 10 years and when he met Finn through mutual contact he immediately saw the potential of the technology. He joined as CEO and set out to prove that AR-based queuing was scientifically sound.
Ellis and Finn soon found a group of scholars at VU University in Amsterdam, led by Melvyn Roerdink, who were doing similar research. Stroll acquired the intellectual property and began developing and testing the technology, now called Reality DTx, with Roerdink appointed as chief innovation officer.
Instead of the physical band Finn uses, Stroll’s AR software simulates colored lines on the floor in front of the wearer, each line disappearing when erased. Stroll-supported clinical trials have confirmed that the cueing technique is feasible and have found promising results.
Rehabilitation exercises may also be helpful amid a shortage of physical therapists. The software includes AR games like whack-a-mole and basketball, but is designed around functional movements that benefit people with Parkinson’s disease. Mark Ross, who was diagnosed with Parkinson’s disease eight years ago at the age of 36 and is now head of brand and creative strategy at Stroll, says such games can help overcome the apathy and depression that are also symptoms of Parkinson’s disease. “You may know you need to exercise, but that doesn’t help you get out of your chair,” he says. So the fact that it’s gamified makes exercise much more appealing.
A Magic Leap headset running on software costs around £3,000 ($3,800), and Stroll charges more than £300 a month for the service. However, Ellis claims this is more cost-effective than 30 30-minute sessions of in-person physical therapy. . Ultimately, the company’s goal is to become “the most used rehabilitation software in the world,” Ellis says. They even envision rehabilitating 7 million minutes using the Stroll device in a week by New Year’s Eve 2029. By then, Ellis hopes Stroll can be used for all kinds of neurological diseases, from stroke to multiple sclerosis. He says there are “almost limitless opportunities.”
This article appeared in the January/February 2025 issue. WIRED British magazine.
