We devised a low-tech, low-cost, robust, and minimally obtrusive navigational travelling aid to be paired with and bolster standard white cane use for people with visual impairments. The device combines ultrasonic range detection with proportional vibrational output. The navigational aid was devised using a sensing belt equipped with independent ultrasonic sensors for distance measurements. Sensors were mounted using adjustable mobile clips to allow for user variability. The sensing belt was connected to a stimulation belt affixed to the ribcage. The stimulation belt used vibrating motors with vibration proportional to the distance between the belt wearer and surrounding obstacles sensed by corresponding ultrasonic sensors. The device was validated through preliminary testing on blindfolded, but fully sighted, persons and one blind person (all authors) in navigating a novel environment without supplemental aid. Testing sessions varied from 45 to 90 min. In preliminary tests, the devised ultrasonic-sensor-belt and vibration-actuator-equipped belt combination was capable of informing users of surrounding obstacles in real-time while navigating a hallway with several turns.
Keywords: Visually impaired persons; assistive device; sensory prostheses; tactile sensation; ultrasonic sensors.