Medical Engineering: Replacing Braille?

Since Louis Braille devised his raised-dot alphabet in 1829, there has been no other practical means for the blind to read. For 17-year-old Candy Linvill, blind since the age of three, Braille’s system of dots posed little problem, but she was still confined to those books and publications that are issued in Braille. Now, because of an ingenious new device on loan from her father’s laboratory, she is freed from that limitation.

Candy recently read the adventures of Christopher Robin and the Autobiography of Malcolm X without the aid of Braille. Similarly, she can read typed letters from friends and current novels or textbooks not yet transcribed into Braille, as well as newspapers and magazines — all previously inaccessible to the blind. The machine, now being perfected by Electrical Engineer John G. Linvill and a team of researchers at Stanford University and Stanford Research Institute, electronically transforms a printed letter into one that can be felt.

Linvill’s “Opticon” (for Optical Tactical Converter) reflects an enlarged image of each letter onto a disk of light-sensitive transistors. The transistors, energized by the image, trigger a corresponding group of pins that vibrate in an outline identical to the printed letter. By lightly fingering the pins, the blind person can “see” the letter.

Line Guide. The reader rests one finger on the vibrating alphabet unit, while using his other hand to scan the line of print with a probe that picks up and transmits the image of each letter Should the probe wander off the printed line, the lack of vibrations on the pin unit tells the reader to readjust.

Linvill’s idea for the probe-pin design came from a high-speed computer that printed its answers with electrically charged pins instead of solid typeface. When he found that the blind could be taught to recognize vibrating patterns, he built the first model of his machine. Next, he and two other researchers at Stanford, James D. Meindl and James C. Bliss, made the probe sensitive to the differences in such similar-shaped letters as lower case a, e, and o, and also adjustable for various print sizes. The portable, battery-operated machine was then given to Candy for testing at home.

After two weeks’ practice, Candy is reading one word a second, but expects to go as high as her Braille rate of 150 words per minute. Although the initial cost of the device may be thousands of dollars, its developers say, mass production could bring its cost down to that of “an inexpensive TV set.”