Design and validation of a pneumatic wearable haptic system for blind people assistance

Throughout the world population, about 6% of the individuals suffer from eye disease and live with low or no vision capabilities. In a world where information is mostly gathered through eyesight, visual impairment can strongly affect the life of a person in terms of independence and privacy. In recent years, many researchers have been studying different technologies to assist blind people and improve their daily experience. These devices can integrate or substitute commonly used assistive tools such as the white cane or guide dogs. ETAs transform information, that is naturally gathered through eyesight, in a form that can be felt through other senses. ETAs can rely on sensory substitution and exploit auditory or tactile cues for sensory feedback. The main problem of ETAs is the needfor unobtrusiveness and wearability in real world scenarios and for this reason different sensory feedback solutions have been studied. In this work, a wearable pneumatic device is proposed and validated. The device is developed for obstacle detection application to assist blind individuals. It relies on the range measurements from an ultrasound proximity sensor and conveys tactile cues thanks to a pneumatic feedback. The feedback is provided through a silicone chamber which is inflated with air through a pump and deflated through a valve. The system was designed from scratch in all its parts: the choice of the hardware, the development of the feedback actuator, the software interface and the project of the compact case to hold the hardware and be worn on the body. The pneumatic system was validated through a psychophysical characterization, to study its capabilities in a range of applications. A final experimental study was carried out to evaluate the usability of the device in an obstacle detection task with blindfolded participants