Oculometer provides dynamic measurement of subject's look direction, and its outputs can be used to generate visual display of his look pattern and/or to cause equipment operation associated with his lookpoint at given times. Measured eye-direction information could be used as control input at man/machine interface

Bowen, H. D.

Holt, J. D.

Leavitt, L. D.

English

NASA Technical Reports Server

April 1974	 B73-10514 
NASA TECH BRIEF 
Langley Research Center	
/	 £ 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Eye-Controlled "Teletypewriter" 
.
Experimentation with an oculometer at Langley 
Research Center has led to the development of a 
"teletypewriter" system remotely controlled by eye 
movement. The oculometer provides a dynamic measure-
ment of a subject's look direction, and its outputs can be 
used to generate a visual display of his look pattern 
and/or to cause an equipment operation associated with 
his lookpoint at given times. In the case of the 
"teletypewriter," a sketch of a typewriter keyboard was 
mounted in front of the subject and the keyboard 
characters became target lookpoints. Thus by looking at 
a specific character or letter, the subject could cause the 
"teletypewriter" to type that letter on its page copy. 
The oculometer is a device that operates at a distance 
from the eye and requires no head-mounted equipment. 
It will track the subject's eye throughout a 1-ft3 
(0.003-rn3 ) motion box with an accuracy of approxi-
mately 10. The sensing unit contains a tungsten filament 
lamp which, after being filtered, provides infrared 
illumination of the eye. This unit also contains a 
silicon target vidicon which, when operating with a 
standard 525-line TV scan, transforms an enhanced 
picture of the eye into a video signal. A signal 
processor, consisting of a minicomputer with a special 
interface section, analyzes this video signal and de-
termines what portion of the keyboard sketch the 
subject is observing. 
The output signals of the processor can be used to 
bring about an equipment operation such as typing on 
the "teletypewriter." Several methods of implementing 
print commands can be used. One simple method is 
printing whatever character the subject is regarding at 
the end of a discrete time interval. To give the operator 
variable-speed typing control, a print switch could be
actuated as soon as he fixates on a letter. In the case of a 
handicapped person, a special-purpose switch could be 
used (e.g., a switch that is breath or toe operated). 
The function of this system is simply to report 
where or at what a subject is looking. There are 
possible applications in which the measured eye-direction 
information could be used as a control input at the 
man/machine interface. Such applications potentially 
would benefit operator unloading, hands-free control, 
and speed of response. 
Note: 
Requests for further information may be directed to: 
Technology Utilization Officer 
Langley Research Center 
Mail Stop 139-A 
Hampton, Virginia 23665 
Reference: B73-10514 
Patent status: 
Inquiries concerning rights for the commercial use of 
this invention should be addressed to: 
Patent Counsel 
Langley Research Center 
Code 456 
Hampton, Virginia 23665 
Source: James D. Holt and Laurence D. Leavitt 
Langley Research Center 
and Hubert D. Bowen of 
LTV Aerospace Corp. 
under contract to
Langley Research Center 
(LAR-1 1564) 
Category 02,03 
This document was prepared under the sponsorship of the National 	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United Stales	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States	 will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19730000514 2020-03-17T07:33:01+00:00Z


Eye-controlled ''teletypewriter''

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server