Ultrasound based assistive mobility devices for the visually-impaired

This paper proposes two assistive mobility devices for individuals with visual impairments. These devices use ultrasound technology for the detection of the obstacle distance and a vibration motor - based tactile interface system that generates different vibration patterns as a function of obstacle distance to alert the user. The main device consists of an ultrasound sensor and associated control board mounted on goggles along with a tactile interface mounted on an armband. The auxiliary device consists of an ultrasound sensor mounted on a conventional cane which detects below-knee obstacles. The electronic circuitry present in the two devices has been explained in detail. Working prototypes of both these parts of the device have been developed and tested for desired results.