Design & development of a bone conduction based navigation aid for the visually impaired

Blind assistive technology has been a significant area of research and development over the last decade. This paper reports the design and development details of a navigation-aid for obstacle sensing and alerting the visually impaired via bone-conduction. This device can detect head-height obstacles, at distances ranging from 0.20 to 3 meters. A microcontroller ATMEGA 328 generates impulses as alert signals for a vibrating actuator, which communicates to the brain through bone conduction. The entire module is designed to be housed in a comfortable headband, which weighs around 300gm and operates at low power with a 400mAh battery. The device was tested on more than 100 visually impaired subjects and the false positives were zero.