Throwback Thursday: U.S. Signal Corps Sensory Aid
|The Signal Corp Sensory Aid is a black metal |
box about nine by nine by three inches, with two
lenses on the front and a curved handle on top.
One of the more interesting stories that we tell is how military technologies like sonar and radar began to be applied to blindness after World War II.
This is a pioneering electronic obstacle detector, designed by Lawrence Cranberg at the U.S. Army Signal Corp Engineering Lab in 1943. Twenty-five experimental units were manufactured by RCA, and in 1950, Haverford College was contracted to field test them by the Veterans Administration. That study led directly to the development of more advanced models including the space age Laser Cane.
Cranberg's device sent out a beam of light, which, when reflected off an obstacle or object, was detected by the machine. A vibrating button in the handle would suggest the distance from the object by changing its frequency. This and many other travel aids are part of our AER Warren Bledsoe Orientation and Mobility Archives Collection.