A variety of surgical training applications are plausible as well. Surgeons know there is no substitute for hands-on practice and training. Consider laparoscopic procedures, which involve surgery performed through very small incisions in the body. The advantage of such procedures is that patient recovery time is greatly reduced over conventional surgery, because of the smaller trauma to the body. However, manipulation of tools through the incision, hand-eye coordination, and understanding the spatial relationships of the tools relative to the organs within the body place high cognitive demands on the surgeon.
Today, a surgeon wishing to learn laparoscopic procedures may attend a one- or two-day course designed to teach necessary skills. In the course, the surgeons-in-training begin with laparoscopic cholecystectomy trainers to familiarize themselves with the technique. These trainers are quite rudimentary, consisting of a black box in which endoscopic instruments are passed through rubber gaskets. Trainees use these instruments to practice such tasks as tying knots, grasping structures, and encircling plastic arteries. The current technology of velour-and-plastic organ models are stiffer and harder to manipulate than normal tissue; arteries are not easily transected or avulsed and do not bleed; and damaged organs do not ooze. As a result, the experience is far from realistic. Following work with the trainer, the surgeons-in-training begin practicing these techniques on pigs—the approximation to humans is better, but the anatomy is dissimilar, and the amount of experience is limited by both the cost and the availability of the pigs.
An appropriately constructed VE simulator could obviate some of these problems. For example, the abdominal simulator developed by Satava (1993b) includes several laparoscopic tools, making it possible for the surgeon to practice some (primitive) endoscopic surgical techniques. The current drawbacks of this system are the low-resolution graphics, the lack of realistic deformation of organs with manipulation, and the lack of tactile input and force feedback. However, the model sets the framework for further investigation into surgical simulators. Such a simulator could be used for initial training, as well as for the additional follow-up training, which has been shown to significantly reduce the incidence of post-surgical complications in patients operated on by surgeons with such training (William et al., 1993).
A second application to surgical training is the use of the see-through augmented-reality model to support novice surgeons in performing their first few appendectomies, cholecystectomies, or arthroscopies. After gaining