A new chest-mounted video camera and vibrating wristband system could reduce collisions for visually-impaired people by 37 per cent, its developers claim.
A new study showed that the device works for blind people, visually impaired people and those using a long cane or guide dog compared to mobility aids alone.
There are about 360,000 people in the UK registered as blind or partially sighted, according to the NHS, with long canes and guide dogs the most common aides.
People who have visual impairments are at a significantly higher risk for collisions and falls, say the team from Mass General Brigham in Boston, Massachusetts.
While some electronic devices are marketed direct-to-consumer claiming to warn wearers of surrounding objects, there has been little evidence of their effectiveness in actual daily mobility settings, until now.
The team discovered that a chest-mounted, early warning device could reduce collisions and falls by up to 37 per cent in those with visual impairments.
This is one of the first randomised-controlled trials to look at the potential benefit of the devices at home and outside of a controlled lab environment.
A close-up of the image processing unit of the wearable collision device. A new study showed that the device works for blind people, visually impaired people and those using a long cane or guide dog compared to mobility aids alone
‘Independent travel is an essential part of daily life for many people who are visually impaired, but they face a greater risk of bumping into obstacles when they walk on their own,’ said Gang Luo, study author.
‘Although many blind individuals use long canes to detect obstacles, collision risks are not completely eliminated,’ said Luo, who is also an associate professor of ophthalmology at Harvard Medical School.
‘We sought to develop and test a device that can augment these everyday mobility aids, further improving their safety.’
The experimental device, and data recording unit were enclosed in a sling backpack with a chest-mounted, wide-angle camera on the strap, and two Bluetooth-connected wristbands worn by the user.
The camera is connected to a processing unit that captures images and analyses collision risk based on the relative movement of incoming and surrounding objects in the camera’s field of view.
If an imminent collision is detected on the left or right side, the corresponding wristband will vibrate; a head-on collision will cause both wristbands to vibrate.
Unlike other devices that simply warn of nearby objects whether or not a user is moving toward the objects, this device analyses relative motion.
It only warns of approaching obstacles that pose a collision risk, and ignoring objects not on a collision course.
The new study included 31 blind and visually impaired adults who use either a long cane or guide dog (or both) to aid their daily mobility.
After being trained to use the device, they used it for about a month at home in conjunction with their typical mobility device.
It had been set to randomly switch between active mode, in which the users could receive vibrating alerts for imminent collisions, and silent mode, in which the device still processed and recorded images, but did not give users any collision warnings
The silent mode is equivalent to the placebo condition in many clinical trials.
Gang Luo, PhD, displays the camera on the strap of wearable collision device. The camera is connected to a processing unit that captures images and analyses collision risk based on the relative movement of incoming and surrounding objects
The wearers and researchers would not know when the device modes changed during the testing and analysis.
The effectiveness of the device was evaluated by comparing collision incidents that occurred during active and silent modes.
The study found that the collision frequency in active mode was 37 per cent less than that in silent mode.
Long canes are one of the most effective and affordable mobility tools for a person who is blind or visually impaired, but they have limitations.
Canes primarily detect hazards on the ground that are within reach; however, hazards above ground level are often missed.
Additionally, the range of long cane sweeping can be restricted in busy environments, such as cities, in order avoid hitting nearby pedestrians.
Guide dogs are highly effective, but hard to come by and cost-prohibitive for many, as training a guide dog typically costs $45,000-$60,000.
Alex Bowers, PhD, a clinical researcher and one of the co-authors of the paper, said the video recording from the study also provides rich data about daily life mobility of people with visual impairments.
This can, in turn help researchers better understand the challenges of collision detection for people with visual impairments.
‘Long canes are still very helpful and cost-effective tools that work well in many situations, but we hope a wearable device like this can fill in the gaps that the cane might miss,’ Dr Bowers said.
Adding it would provide a more affordable, easier to obtain option than a guide dog.
Next, they hope to leverage ongoing improvements in mobile processing power and cameras to make the device smaller and more cosmetically appealing.
With additional funding, the team hopes that such a device could be submitted to the US Food and Drug Administration for approval so that it could be commercially available for people with low vision.
‘Dr Luo and his team are making great contributions to supporting and ensuring travel independence in our low-vision community,’ said Joan W. Miller, MD, Chief of Ophthalmology at Mass Eye and Ear, Massachusetts General Hospital.
The findings have been published in the journal JAMA Ophthalmology.