Minimally invasive surgery (MIS) is performed through natural body openings or small, keyhole incisions with the aid of a thin, rod-shaped probe, a small scope, and surgical instruments. Reduced trauma and shorter hospital stays have contributed to the popularity of MIS. Yet the difficult operating conditions leave surgeons with restricted vision and mobility and limited hand-eye coordination, which they must overcome by developing a keen sense of touch.
A virtual reality-based surgery simulator would allow surgeons to practice manipulating computer-generated 3-D models of human organs using their sense of touch as well as vision. Such a simulator can avert the need for cadavers and animals currently used for training, resulting eventually in highly customized training.
"The sense of touch plays a fundamental role in the performance of a surgeon," De said. "Current simulator technology can be significantly improved with the addition of touch feedback. I believe better simulator training will substantially reduce operating room errors, reduce tissue damage, speed recovery, and lead to better patient outcomes."
Surgery simulators, much like flight simulators, are based on intense computer programming. To program realism of touch feedback from a surgical probe navigating through soft tissue, De must develop efficient computer models that perform 30 times faster than real-time graphics. This requires a mathematical model that summarizes all the forces at play as simply as possible.
De has developed a novel computational technique, the Point-Associated Finite Field approach, that models human tissue as a collection of particles with distinct, overlapping zones of influence that produce coordinated, elastic movements. This technique enables his program to rapidly perform hundreds of thousands of calculations for real-time touch feedback.
"Initially, I intend to develop training for specific tasks, such as palpation, grasping, incision, and surgical cutting," De said. "Then I hope to piece individual tasks together to generate diverse procedures."
De, who works in the Department of Mechanical, Aeronautical, and Nuclear Engineering, also intends to improve the visual realism of simulator training by creating more lifelike visual perspectives, using a technique called view-dependent texture mapping. "If successful, this could become the de facto standard in surgical simulation technology," De said.
After developing a successful prototype for minimally invasive surgery, De hopes to apply the model to a much wider class of medical procedures. "The grand vision," he said, "is to develop a palpable human--a giant database of human anatomy that provides real-time interactivity for a variety of uses, from teaching anatomy to evaluating injuries in a variety of scenarios. In the long run, a better simulator could even help in the design of new surgical tools and techniques."
This NIH exploratory grant is part of an overall increase in the amount of NIH support to Rensselaer. The Institute currently has 30 active grants from the NIH totaling $24 million, an increase in five years from three active NIH grants totaling $600,000.
For a print-quality photo, go to http://www.rpi.edu/dept/NewsComm/sub/Pressimgs/Liver%20&%20Stomach.JPG
Please credit RPI/Suvranu De.
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Rensselaer Polytechnic Institute, founded in 1824, is the nation's oldest technological university. The school offers degrees in engineering, the sciences, information technology, architecture, management, and the humanities and social sciences. Institute programs serve undergraduates, graduate students, and working professionals around the world. Rensselaer faculty are known for pre-eminence in research conducted in a wide range of research centers that are characterized by strong industry partnerships. The Institute is especially well known for its success in the transfer of technology from the laboratory to the marketplace so that new discoveries and inventions benefit human life, protect the environment, and strengthen economic development.