A Novel Head-Mounted Time-of-Flight Sensor Array for the Visually Impaired to Enhance Real-Time Spatial Awareness

A novel head-mounted assistive device was designed, developed, and validated to enhance spatial awareness for individuals with visual impairments by integrating Time-of-Flight (ToF) sensors and haptic feedback. The device leverages three VL53L1X ToF sensors arranged at constant angular offsets to provide a forward-facing with field of view of about 81°, enabling to detect obstacles approaching from any directions. Each sensor is mapped to a dedicated coin vibration motor, positioned in alignment with the person’s head to deliver directional tactile feedback. The Arduino Pro Mini microcontroller acquires the distance measurements through the I²C protocol and generates pulse-width modulated (PWM) signals to modulate vibration strength based on the obstacle proximity. This mapping lets the user perceive each area and relative distance of objects nearby without relying on vision or auditory comments. The device was assessed under indoor conditions using fixed-distance trials from 150 cm down to 15 cm in 15 cm increments. Results show a dependable detection, within this range, with dimension deviations maintained within ±1 cm. Power draw was measured at around 495 mA throughout non-stop operation, and a runtime with a 1000 mAh lithium-polymer battery validated operational intervals of 2.6 to five hours, relying on motor usage frequency. The overall tool design prioritises compactness, comfort, and real-time responsiveness, imparting a low-cost and non-intrusive solution for improving mobility and environmental consciousness among visually-impaired users in indoor environments.