telepresence, telesurgery, and rehabilitation. Each subsection addresses a long-range vision of how VE might assist in these applications and a description of possible near-term demonstrations.
Medical education has changed little in the last 30 years, despite enormous advances in knowledge. Most medical schools emphasize learning facts by rote. Information is provided in a lecture format, and students study outlines for endless hours in the library. Little effort is expended to place the information into a context or framework that might help to structure and organize seemingly disparate facts. As a result, students must use their own, perhaps incomplete experience to begin assimilating the data and creating a logical, integrated framework of anatomy, physiology, biochemistry, genetics, and the myriad springs of subspecialized knowledge from contemporary medical research.
The teaching of anatomy is illustrative, and the application of VE and augmented reality to such teaching has great potential. The static, transparent, two-dimensional overlays typical of anatomy textbooks could someday be replaced by a virtual human. Indeed, today the National Institutes of Health is funding the Visible Human, a project to develop a complete static digital representation of an adult human. Once the data are collected, a student would be able to operate a VE system for anatomy that would illustrate the spatial interrelationships of all body organs relative to each other, selectively enabling or suppressing the display of selected body subsystems (e.g., displaying only the digestive system, viewing the complete image without the circulatory system).
A much more sophisticated version of the Visible Human would be a dynamic model that could illustrate how various organs and systems move during normal or diseased states, or how they respond to various externally applied forces (e.g., the touch of a scalpel). Thus, a student could view the heart in normal and diseased states pumping blood, or observe how the stomach wall moved while cutting it.
Today, several virtual worlds have been developed to demonstrate basic anatomy and as rudimentary models of training simulators. One is a model of the optic nerve created by VPL (VPL, Inc., 1991). This model illustrates, in three dimensions, the path of the optic nerve from the retina to the optic cortex. By pointing a finger one can fly along this path, looking to either side at adjacent structures. In this way, less effort is