In 2018, Tom Finn took his father, Nigel, to a physiotherapy appointment. Nigel was living with vascular dementia, which can present with symptoms similar to Parkinson’s disease, a progressive neurological disorder characterized by motor symptoms such as tremors, rigidity and problems maintaining balance. He was losing the ability to walk.
The physical therapist told Finn about markers: colored lines placed on the floor that can help Parkinson’s patients overcome difficulty walking. Finn wasn’t convinced. He couldn’t see how some lines on the ground would help his father. But when they got home, he left some colorful exercise bands in the kitchen and watched in amazement as his father walked easily back and forth on them.
The technique, called external cues, works by using visual, auditory or tactile cues (colored tape on the floor, playing a metronome, or physical vibrations) to activate neural pathways that are not affected by the disease. “It can help people focus their attention and help them take the first step and overcome freezing,” says Claire Bale, associate director of research at Parkinson’s UK, a research and support charity in the United Kingdom.
While Finn, who worked in marketing and video production in London, was impressed by the effectiveness of this simple intervention, he thought it was too basic to be really useful. But augmented reality glasses from the likes of Magic Leap had just started hitting the market, and he wondered if they could project virtual lines onto the ground to act as signs. He founded a startup, Stroll, to try to make that vision a reality.
Two years later, Stroll was short-staffed and had around £50 in the bank, according to Jorgen Ellis. Ellis, a New Zealander with experience in furniture startups, had come to the UK looking for his next venture and wanted to get involved in something he was passionate about. His grandfather had lived with Parkinson’s for more than a decade, and when he met Finn through a mutual contact, he immediately saw the promise of the technology. He came on board as CEO and began by trying to prove that AR-based signals were scientifically valid.
Ellis and Finn soon found a group of academics at VU University in Amsterdam, led by Melvyn Roerdink, who were working on something similar. Strolll acquired their intellectual property and, with Roerdink on board as chief innovation officer, began developing and testing the technology, now called Reality DTx.
Instead of physical stripes like Finn used, Stroll’s AR software simulates colored lines on the ground in front of the user, with each line disappearing as you erase it. A clinical trial (backed by Stroll) confirmed that the signaling technology was feasible and found promising results.
It could also help with rehabilitation exercises amid a shortage of physical therapists: The software includes augmented reality games like whack-a-mole and basketball, but designed around functional movements that help people with Parkinson’s. Mark Ross, who was diagnosed with Parkinson’s eight years ago at the age of 36 and is now Stroll’s head of brand and creative strategy, says these games can help overcome the apathy and depression that are also a symptom of disease. “You may know you need to exercise… but that won’t help you get out of your chair,” he says. So the fact that it’s gamified makes doing the exercises much more engaging.
The Magic Leap headphones that the software works with cost around £3,000 ($3,800), and Stroll charges more than £300 a month for its services, but Ellis maintains this is more cost-effective than 30 half-hour in-person physiotherapy sessions . . Ultimately, the company’s goal is to be “the most widely used rehabilitation software in the world,” Ellis says. They even have a specific timeline in mind: 7 million minutes of rehabilitation with the Strolll device in one week by New Year’s Eve 2029. By then, Ellis hopes Strolll can be used for all types of neurological conditions, from strokes to multiple sclerosis. There is, he says, “almost unlimited opportunity.”
This article appears in the January/February 2025 issue of UK WIRED Magazine.