An assistive haptic-based obstacle avoidance system for individuals with profound visual impairment

In this paper, we present a haptic-based wireless electronic system that helps users with profound visual impairment avoid obstacles and map their surroundings through an unknown landscape. Our aim has been to design a lightweight and low-cost system that can easily and discretely be worn by the user. The system comprises two parts: 1) the “sensor module”which is laser-based and can be worn on the belt, and 2) two “haptic modules” which can be worn on each wrist with its vibrators directly placed on the skin. These two parts communicate wirelessly which makes it comfortable for the user to wear the system. The sensor module creates a representation matrix of the surrounding objects, and as an object gets closer, a higher pulse-width-modulation (PWM) duty cycle (i.e., a higher vibratorypower) is delivered by the corresponding vibrator(s), indicating its direction and proximity. This obstacle avoidance system was tested on seven individuals between 50 and 78 years of age (mean=63.5, SD=9.3 years) with profound vision impairment. The participants were instructed to walk through two path configurations: one with and another without the proposed assistive system. According to our results, significantly (p<0.05) shorter time(Median = 64s (IQR 32-81) versus Median = 95s (IQR 51-134) was needed and slightly fewer collisions occurred once they used this assistive system. The participants stated that they found the haptic signals intuitive and easy to understand. Hardware schematics and codes are publicly available for future development.