Watch your head: A wearable collision warning system for the blind

We describe work in progress towards the development of a miniaturized, wearable sensor device to enhance safety during ambulation for persons who are blind. This system warns the blind user when they are about to hit an obstacle at head level, in time to avoid a collision. With respect to existing Electronic Travel Aids, this device is “minimalistic”: rather than attempting to provide rich information about the environment, the proposed system simply emits a warning signal (in acoustic and/or tactile form) when a hazard is detected. The sensor, which uses two ultrasonic transducers for obstacle localization, can be mounted on one´s shirt pocket or disguised as a brooch. Special care is devoted to optimizing the devices´ performance (in terms of range accuracy and detection/false alarm rate) and to minimizing form factor and power consumption.