The virtual anatomy practical: a stereoscopic 3D interactive multimedia computer examination program.

Continuing advances in computer visualization and interface technologies have enabled development of "virtual reality" programs that allow users to perceive and to interact with objects in artificial three-dimensional environments. Such technologies were used to create an image database and program for administering a practical examination in human gross anatomy. Stereoscopic image pairs of prepared laboratory dissections were digitized from multiple views of the thorax, abdomen, pelvic region, and upper and lower extremities. For each view, the stereo pairs were interlaced into a single, field-sequential stereoscopic picture using an image processing program. The resulting color-corrected, interlaced image files were organized in a database stored on a large-capacity hard disk. Selected views were provided with structural identification pointers and letters (A and B). For each view, appropriate two-part examination questions were spoken by a human narrator, digitally recorded, and saved as universal audio format files on the archival hard disk. Images and digital narration were organized in an interactive multimedia program created with a high-level multimedia authoring system. At run-time, 24-bit color 3D images were displayed on a large-screen computer monitor and observed through liquid crystal shutter goggles. A 90-second interval timer and tone were provided to give student users a time limit for each question comparable to that of a conventional practical examination. Users could control the program and select regional "subexams" using a mouse and cursor to point-and-click on screen-level control words ("buttons").