Teaching Anatomy and Physiology Using Computer-Based, Stereoscopic Images
Perry, Jamie, Kuehn, David, Langlois, Rick, Journal of College Science Teaching
Byline: Jamie Perry, David Kuehn, and Rick Langlois
Learning real three-dimensional (3D) anatomy for the first time can be challenging. Two-dimensional drawings and plastic models tend to over-simplify the complexity of anatomy. The approach described uses stereoscopy to create 3D images of the process of cadaver dissection and to demonstrate the underlying anatomy related to the speech mechanisms.
Virtual Reality (VR) programs (e.g., The Visible Human Project), stereoscopic, three-dimensional (3D) visual anatomy systems (e.g., Interactive Stereoscopic Virtual Reality and 3D Explorer-The Skull), and computer-generated, 3D models (e.g., Voxel Man Gallery, MPIRE, and Visible Human 3D Anatomical Structure Viewer) have been reportedly successful in biomedical instruction (Frisby 1993; Ribas, Bento, and Rodrigues 2001), simulating surgical procedures (Satava 1993; Ribas, Bento, and Rodrigues 2001; Henn et al. 2002) and diagnosis of medical conditions (Oyama 1998). Advancements in 3D technology in the medical field are important, then, as success in most disciplines of medical sciences is contingent on the mastery of complex 3D anatomy. This is also true in the area of speech science, where the focus is on anatomy related to respiration, phonation, and articulation.
Undoubtedly, learning through exploration of a human-cadaver specimen offers one of the best pedagogical experiences. It allows students to appreciate the layering of muscle architecture, and the relative sizes, forms, and shapes of structures from multiple views. However, large class sizes, increasing costs, and limited access to cadaver specimens often minimize the laboratory experience for students. Instead, some universities use animal specimens in the laboratory. While this allows students to appreciate internal anatomy, the size, shape, and orientation of the structures in lower animals are not parallel to those of the human body, and few generalizations can be made from lower animals to the human body.
When universities choose to teach without a human or animal specimen, actual observation and manipulation of the anatomy are impossible. For instance, undergraduate students learning anatomy for the first time rely primarily upon two-dimensional (2D) drawings or photographs in textbooks and atlases. Such media are valuable because they offer simple, concrete, and clearly delineated depictions of the muscle structures. However, 2D drawings can, at times, grossly underestimate or simplify complex human anatomy. Qualities such as the depth, texture, and thickness of a single muscle, and the layering of structures cannot always be appreciated. Additionally, printed drawings or photographs are not practical for showing the numerous steps involved in dissection.
Though 3D modeling can be a powerful learning tool, the major disadvantage of computer-generated models is that their production requires access, knowledge, and skill with a modeling software program-unskilled rendering artists may be unable to realistically apply surface textures such as luster, sheen, and roughness.
The introduction of VR brought another kind of 3D learning to the classroom. There are several different types of VR programs, such as interactive, 3D-rendered models; 3D-interactive models generated using magnetic resonance imaging and computerized tomography; and stereoscopic, interactive surgical-instruction tools. The major disadvantages of such programs are the relatively high costs of the software and the often technically advanced equipment, making VR systems unfeasible at some universities. In addition, the perceptual cues used to create computer-generated models do not include the depth cue that is created through binocular vision. Stereoscopic imaging, however, has been reported by many authors and credited for its relative cost efficiency and improved 3D comprehension, particularly for the instruction of anatomy (Trelease 1998; Ribas, Bento, and Rodrigues 2001; Henn et al. …