Virtual Reality in Medicine and Biology

The practice of medicine and major segments of the biologic sciences have always relied on visualizations of the relationship of anatomic structure to biologic function. Traditionally, these visualizations either have been direct, via vivisection and postmortem examination, or have required extensive mental reconstruction, as in the microscopic examination of serial histologic sections. The revolutionary capabilities of new three-dimensional (3-D) and four-dimensional (4-D) imaging modalities and the new 3-D scanning microscope technologies underscore the vital importance of spatial visualization to these sciences. Computer reconstruction and rendering of multidimensional medical and histologic image data obviate the taxing need for mental reconstruction and provide a powerful new visualization tool for biologists and physicians. Voxel-based computer visualization has a number of important uses in basic research, clinical diagnosis, and treatment or surgery planning; but it is limited by relatively long rendering times and minimal possibilities for image object manipulation.

The use of virtual reality (VR) technology opens new realms in the teaching and practice of medicine and biology by allowing the visualizations to be manipulated with intuitive immediacy similar to that of real objects; by allowing the viewer to enter the visualizations, taking any viewpoint; by allowing the objects to be dynamic, either in response to viewer actions or to illustrate normal or abnormal motion; and by engaging other senses, such as touch and hearing (or even smell) to enrich the visualization. Biologic applications extend across a range of scale from investigating the structure of individual cells through the organization of cells in a tissue to the representation of organs and organ systems, including functional attributes such as electrophysiologic signal distribution on the surface of an organ. They are of use as instructional aids as well as basic science research tools. Medical applications include basic anatomy instruction, surgical simulation for instruction, visualization for diagnosis, and surgical simulation for treatment planning and rehearsal. Infrastructure, methods and applications are discussed in this chapter.

The most complex and challenging applications, those that show the greatest promise of significantly changing the practice of medical research or treatment, require an intimate and immediate union of image and model with real-world, real-time data.