Keep Your Distance: A Playful Haptic Navigation Wearable for Individuals with Deafblindness
James Gay, Moritz Umfahrer, Arthur Theil, Lea Buchweitz, Eva Lindell, Li Guo, Nils-Krister Persson, Oliver Korn · 2020 · Proceedings of the 22nd International ACM SIGACCESS Conference on Computers and Accessibility (ASSETS 2020) · doi:10.1145/3373625.3418048
Summary
This demonstration paper presents a haptic wearable vest designed to support independent navigation for people with deafblindness — a dual sensory impairment where the combination of sight and hearing loss makes it difficult for one sense to compensate for the other. Most existing navigation assistive technologies rely on voice commands and auditory feedback, making them unsuitable for people with deafblindness. The vest uses vibrotactile feedback to convey three types of information: (1) directional cues via five vibration motors distributed 45 degrees apart across 180 degrees around the frontal waist area — whichever motor vibrates indicates the direction the user should walk; (2) proximity information through vibration frequency — 100ms pulses mean too close (under 0.5m), 500ms pulses mean optimal distance (0.5-1.5m), and 1000ms pulses mean too far (over 1.5m); and (3) semantic commands via four micro-servo tapping motors on the shoulders (two front near clavicles, two back near shoulder blades) that communicate "start walking/go" (back taps) and "stop walking" (front taps) using social haptic gestures. The system uses a fisheye camera attached to the garment connected to a Raspberry Pi 4, detecting ArUco visual markers via OpenCV to determine distance and direction. The vest is made of flexible fabric fitting various body sizes, with detachable/reconfigurable actuators, powered by a battery pack carried in a back pouch alongside the RedBear Duo microcontroller.
Key findings
Five individuals with deafblindness (2 female; mean age 46) participated in a gamified evaluation called "Keep Your Distance" where they played "secret agents" following a "suspect" (researcher holding an ArUco marker) around a pre-defined indoor route. All five participants were fully deaf (three communicated verbally with cochlear implants, two used Sign Language with professional interpreters). Visual abilities ranged from fully blind to tunnel vision with 3-7 degree fields of view and up to 70% visual acuity. To win the game, participants had to maintain an optimal distance of 0.5 to 1.5 meters from the suspect while following directional cues. All participants were able to follow the directional cues and complete the route without assistance from others. Participants reported feeling comfortable and not afraid of being misguided — one stated that "as a person living with deafblindness, you always need one hand free to touch your intervener" but the haptic vest enabled them to "navigate confidently in a new environment for the first time without the direct support of another person." Another participant noted that distance feedback "calmed me down... I knew that everything was ok." Participants suggested that the shoulder tapping sensation was "too weak and difficult to perceive" and recommended stronger haptic signals, possibly through force-based actuators or localized vibration motors.
Relevance
This paper addresses an underserved population in assistive technology research: people with deafblindness who cannot benefit from either visual or auditory navigation aids. The haptic vest approach is notable for being entirely hands-free — critical for deafblind users who need their hands for carrying a cane, touching a guide dog, or communicating with an intervener through tactile sign language. The gamified "secret agent" evaluation design is a creative approach to testing navigation technology in a non-intimidating way while collecting meaningful performance data. The three-channel information architecture (directional vibration at waist, proximity via frequency, semantic tapping on shoulders) demonstrates that complex navigational information can be conveyed entirely through touch. The COVID-19 pandemic added unexpected real-world relevance: enabling deafblind people to perceive safe distance from others without physical contact. Limitations include the small sample (N=5), indoor-only testing, reliance on ArUco visual markers rather than real-world navigation infrastructure, and the short demo format (4 pages).
Tags: deafblindness · haptic technology · vibrotactile feedback · navigation · wearable technology · sensory substitution · assistive technology · wayfinding · e-textiles