Resolving subjects and measuring observer/subject distances with a thermal tactile imager

Visually-impaired people have difficulty detecting objects beyond the reach of a cane. We functionally coupled a far-infrared camera to a linear array of tactile elements to create a thermal tactile viewer that enhances environmental awareness. Users may scan such a device across a scene to spatially locate people. We observed in a series of acuity-measuring tasks, at twenty feet of observer/subject separation, observers could resolve two people standing four inches apart (a separation angle of 1°) and locate the angular position of people within a room with 78% accuracy. Additionally, when employing a technique involving two sweeps from two observation points separated by approximately an arm span, subjects correctly reported observer/subject separation distance with 60% accuracy. These observations suggest the technique of information transfer provided by a thermal tactile viewing device provides the fundamental acuity required for an assistive locating device.