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  • Electronic Warning System for the Visually Impaired

    By Jean Shaw
    Selected and Reviewed by Neil M. Bressler, MD, and Deputy Editors
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    Journal Highlights

    JAMA Ophthalmology, September 2021

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    How effective are electronic mobility aids for visually impaired patients? Pundlik et al. assessed a collision warn­ing device and found that it reduced the number of times patients bumped into various obstacles and hazards.

    For this double-masked study, the researchers enrolled 31 independently mobile individuals who had severe vi­sual impairments, including blindness (age range, 25-73 years). All habitually used either a long cane (n = 28) or a guide dog (n = 3) to navigate. The participants were fitted with a wearable device that included a chest-mounted video camera capable of detecting im­pending collisions and two wristbands that, when in active mode, vibrated when the collision risk was high.

    The device was programmed to switch between active and silent modes on a randomized schedule. This sched­ule was not disclosed to the participants, who were told that the device was a prototype and might not provide warn­ings in some situations. After the par­ticipants underwent training, they took the device home. They were instructed to use it—along with their habitual mobility aid—at their discretion as they went about their day. They also were told that the camera would record whenever the device was on. After four weeks, they returned the device. The primary outcome measure was the rate of contacts per 100 true hazards (as seen on video) per hour.

    A total of 368 hours of walking video data was available for analysis. The median (interquartile range) number of contacts was 9.3 (range, 6.6-14.9) in the active mode, versus 13.8 (range, 6.9-24.3) in the silent mode. Six partic­ipants reported a total of eight minor adverse events (minor contact/brush­ing against an object while walking); no serious adverse events occurred. These findings demonstrate a clear mobility benefit of using the device, the researchers said. (Also see related commentary by Gerald McGwin Jr., MS, PhD, and Cynthia Owsley, PhD, MSPH, in the same issue.)

    The original article can be found here.