page_title: Robert Ledley
section_title: Other NBRF computing projects
hierarchical_section_title: Robert Ledley / National Biomedical Research Foundation / Other NBRF computing projects
caption_attribution_description: Operation of National Biomedical Research Foundation (NBRF) BAT, a device used for interacting with objects rendered by computers in 3 dimensions. The BAT is shown here being used with a stereo display.
context_page_description: Robert Steven Ledley, professor of physiology and biophysics and professor of radiology at Georgetown University School of Medicine, pioneered the use of electronic digital computers in biology and medicine. In 1959, he wrote two influential articles in Science: "Reasoning Foundations of Medical Diagnosis" and "Digital Electronic Computers in Biomedical Science". Both articles encouraged biomedical researchers and physicians to adopt computer technology. In 1960 he established the National Biomedical Research Foundation, a non-profit research organization dedicated to promoting the use of computers and electronic equipment in biomedical research. At the NBRF Ledley pursued several major projects: the early 1960s development of the Film Input to Digital Automatic Computer, which automated the analysis of chromosomes; the invention of the Automatic Computerized Transverse Axial whole-body CT scanner in the mid-1970s; managing the Atlas of Protein Sequence and Structure; and the establishment of the Protein Information Resource in 1984. Ledley also served as editor of several major peer-reviewed biomedical journals.
context_section_description: From 1979 to 1980, Ledley and Golab developed the Computerized Electro Neuro Ophthalmograph (CENOG). This machine enabled healthcare providers to automatically analyze ocular motility, an important factor in the diagnosis of neurological and ophthalmic disorders. CENOG generated considerable media attention in the early 1980s, largely because it served as a demonstration of the feasibility of automated medical diagnosis.
  While at the NBRF, Ledley also carried out work related to computer design. In 1970, when Moore’s Law was still a relatively new idea, and when the most powerful computers had 1,000 to 2,000 logic gates, Ledley wrote a paper titled “Realization of a Billion-Gate Computer” in which he speculated on the capabilities of a transistorized computer that had 1,000,000,000 logic gates. He proposed that such a machine would: 1) have no fixed logic design; 2) be capable of redesign some of its own components; 3) be able to “self-heal.” Billion-transistor microprocessors have been commonplace in personal computers since 2010, though these machines are not as dynamic (in terms of logic structure) as Ledley had predicted.
  In the late 1980s, Ledley lead the team that developed the Bat, a three-dimensional mouse that allowed users to interact with objects in three-dimensional space (generated using stereo images).
caption: The NBRF "Bat," a 3-D mouse (left) used for interacting with stereo images (right).
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