Safe wayfinding for the visually impaired remains a challenge in the built environment. Typical navigational aids feature physical modifications such as tactile warning surfaces and braille signage, as well as auditory enhancements like audible traffic signals. These provide only a minimum level of navigational support, leaving room for new solutions that offer enhanced safety and confidence.
Students at Wake Forest University, in Winston-Salem, N.C., investigated the capability of echolocation in bats and moths for inspiration in assisting the navigation of the visually impaired. Under the guidance of Wake Forest biology professor William Conner and computer-science associate professor Paul Rauca, the interdisciplinary student team developed a novel technology based on this natural approach to non-visual sensing.
Called the Human Echo Location Partner, or HELP, the device uses sonar to communicate the proximity of physical surfaces and objects to users. Worn like a watch, it can supplement conventional aids such as a cane or a guide dog. The device is composed of sonar distance sensors, mobile-phone vibrating motors, and a Lilypad Arduino microprocessor that is controlled by a custom algorithm. As a user approaches an object, the device vibrates with increased frequency, allowing the person to not only detect a physical hazard but also sense its proximity.
The technology can help the visually impaired observe the location of vertical barriers such as walls and guard rails, as well as whether they are approaching doors that are open or closed. Future versions could include spatial-hazard detection for the edges of stairways, platforms, and curbs, which can be even more dangerous. Such cases invite the development of building-integrated counterpart technologies, which could communicate with users' sonar devices to impart a more detailed navigational picture.
Blaine Brownell, AIA, is a regularly featured columnist whose stories appear on this website each week. His views and conclusions are not necessarily those of ARCHITECT magazine nor of the American Institute of Architects.
