In 2018, Tom Finn took his father Nigel to a physiotherapy appointment. Nigel was living with vascular dementia, which can manifest with symptoms similar to Parkinson's disease, a progressive neurological disorder characterized by motor symptoms such as tremors, stiffness and trouble with balance. He was losing the ability to walk.
The physiotherapist told Finn about cue markers – colored lines laid out on the floor that can help Parkinson's patients overcome difficulty walking. Finn wasn't convinced. He could not understand how a few lines on the floor would help his father. But when they reached home, he laid out some colorful exercise bands in the kitchen and watched in surprise as his father moved back and forth with ease.
The technique, called external cues, works by using visual, auditory, or tactile cues – colored tape on the ground, playing a metronome, or physical vibration– Engaging nerve pathways not affected by the disease. “It can help people focus their attention and help them take the first step and overcome a blockage,” says Claire Bell, associate director of research at Parkinson's UK, a research and support charity in the UK.
While Finn—who worked in marketing and video production in London—was surprised by the effectiveness of this simple intervention, he thought it was too basic to be truly helpful. But augmented reality glasses like Magic Leap were just beginning to hit the market, and he wondered whether they might be able to project virtual lines onto the ground to act as signs. He founded a startup, Stroll, to try to turn that vision into reality.
According to Jorgen Ellis, after two years, Stroll had no staff and about £50 in the bank. Ellis, a New Zealander with a background in furniture startups, came to the UK in search of his next venture and wanted to get involved in something he felt passionate about. His grandfather had suffered from Parkinson's for more than a decade, and when he met Finn through a mutual connection, he immediately saw the promise of the technology. He came onboard as CEO and tried to demonstrate that AR-based signals were scientifically valid.
Ellis and Finn soon found a group of academics led by Melvin Roerdink at VU University in Amsterdam who were working on something similar. Stroll acquired its intellectual property, and with Roerdink as chief innovation officer they began developing and testing the technology, now called Reality DTX.
Instead of the physical bands used by Finn, Stroll's AR software simulates colored lines on the floor in front of the wearer, with each line disappearing as they clear it. A clinical trial (supported by Stroll) confirmed that the cueing technique was feasible and yielded promising results.
It can also help with rehabilitation exercises amid a shortage of physiotherapists: The software includes AR games like Whack-a-Mole and basketball, but is designed based on functional activities 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 head of brand and creative strategy for Stroll – says these games can help overcome the apathy and depression that can be a symptom of the disease. There are symptoms also. “You probably know you need to exercise… but it's not going to get you out of your chair,” he says, so the fact that it's gamified makes exercising more appealing.
The Magic Leap headset software runs at a cost of around £3,000 ($3,800), and Stroll charges more than £300 per month for his services – but Ellis argues that this is comparable to 30 half-hour sessions of individual physical therapy. Is more cost effective. , Ultimately, Ellis says, the company aims to become “the most used rehabilitation software in the world.” He also has a specific timeline in mind: 7 million minutes of rehabilitation with the Stroll device a week by New Year's Eve 2029. By then, Ellis hopes that strol could be used for all kinds of neurological conditions, from stroke to multiple sclerosis. There is “almost limitless opportunity,” he says.
This article is published in the January/February 2025 issue Wired UK Magazine.