The use of mobile digital devices as navigational aids for persons with a visual impairment is quite recent, with the first usable wearable digital devices for wayfinding developed in the late 1990s.
Based on a search of the IEEE Xplore database, our research shows that since 2000, there’s been a veritable explosion of research and development in this field, with over 7,500 engineering articles written on assistive technologies and visual impairment in the past 25 years, and over 1,300 articles on solving the problem of navigation for people who are blind or visually impaired. As well, over 600 articles on augmented reality and visual impairment have appeared in the engineering literature since 2000. Most of these articles were published within the past 5 years, and the number of articles in this area is increasing every year.
There are many technologies bundled with tablets or smartphones that can be used to build navigational aids for persons with a visual impairment, including:
- GPS, accelerometers, gyroscopes, and camera(s) to pinpoint the exact location of the user and provide information on what’s in the immediate vicinity, and assistance in getting to a destination.
- Mobile technologies and algorithms such as Simple Linear Iterative Clustering (SLIC) allow apps to carry out floor detection, object on-floor detection, and tripping hazard analysis.
- Researchers have laced specific settings with near-field communications (NFC) and radio frequency identification (RFID) tags so that the environment can send signals back to the user’s phone, confirming their location and the desired path ahead.
Once a second rear-facing camera is added to a tablet or phone, new possibilities emerge, including binocular vision, range finding, and 3D measurement of objects. Range data can be combined with sophisticated time measurements using a technique called “simultaneous localization and mapping” (SLAM) to build three-dimensional reconstruction of the local environment and locates the user within the mapped space. For example, some researchers have built SLAM-based digital hazard detection into the traditional white canes using laser beams to detect objects in the way of the user, including overhead hazards.
Despite the variety and number of studies completed or underway on developing navigational aids for blind people, many researchers still maintain that human assistance (i.e., identifying objects and pathways for a person who is visually impaired) is superior to any navigational technology available today. As Maxine Wally (2015) commented in Fortune, “as of yet, there isn’t a single app that’s able to address everything a blind person needs to navigate both indoors and outside.”
But this assessment may change soon as there are many newer techniques for visualization of the environment in development that show real promise as navigational aids for persons with visual impairment. Among the most exciting developments is the use of Google’s Tango technology to build a superior navigational aid with capabilities that outstrip all other electronic travel aids in development. Tango works by integrating three types of functionality:
- Motion-tracking: Tango uses visual features of the environment, in combination with accelerometer and gyroscope data, to closely track the device’s movements in space
- Area learning: Tango stores environment data in a map that can be re-used later, shared with other Tango devices, and enhanced with metadata such as notes, instructions, or points of interest
- Depth perception: Tango detects distances, sizes, and surfaces in the environment
Float’s new Cydalion app combines Tango technology with data collection and analysis, machine learning, and other computer vision techniques to produce an exciting new option for persons with a visual impairment, especially those whose vision loss is sufficient to classify them as “legally blind.” By adding in advanced AI algorithms, augmented reality information, knowledge maps, and the new sensory capabilities of Tango, Float has produced a navigational aid that is at the leading edge of what technology can do to assist those who need an alternative, information-rich method for navigating the world. Contact Float for a demonstration and experience the amazing capabilities of Cydalion for yourself.
(Image credit: Mike Haller)