Robotics, virtual worlds meet medicine

Health Industry Today, Nov, 1992 by Sharyn Rosenbaum

Technology that combines computer models and images could revolutionize surgical training and surgical procedures. Manufacturers, especially those that supply laparoscopic instruments, are likely to begin developing a marketing strategy to capitalize on the potential medical breakthroughs.

Already being explored in surgical simulations, motion measurement and patient rehabilitation, virtual reality and telepresence offer exciting opportunities in health care.

Virtual reality is a technology that enables users to interact with three-dimensional computer worlds that resemble the real world. It combines computers and sensory mechanisms to create a controlled environment. Users can interact with the virtual environment through sight, sound or touch. The technology may not only empower patients by helping them to communicate, but also may help physicians better diagnose and treat patients in the future.

Telepresence extends sensory apparatus to a remote location through robotics. The user, from a distant site, could see, feel and touch objects in the real world.

For example, a surgeon in one location could have a similar hand control, visualization and touch as if he were actually at the operation site performing a surgical procedure. He or she could actually pick up an object from a remote location and feel its weight and texture. The technology has already found a niche in pathology diagnosis, whereby a surgical pathologist has immediate access to a microscope and a slide of a patient's biopsy at a remote site.

Telepresence is being investigated for use in laparoscopic surgery. Researchers are trying to commercialize the technology so surgeons performing minimally invasive surgery could have the same freedom of movement as in open surgery.

The real-time use virtual reality technology for direct patient care is years away, but telepresence may be used sooner, according to Dr. Eric Horvitz of Stanford University School of Medicine, Palo Alto, Calif., and president of Knowledge Industries, a Palo Alto company that produces real-world reasoning systems for physicians in a variety of medical specialty areas.

"Authentic or high-fidelity virtual reality is a long way off," he said. "Current virtual reality projects stimulate the imagination about the possibilities of using the technology in medicine decades from now.

"Telepresence applications are likely to come to fruition earlier because the technology does not face the inherent computational problems associated with building rich, artificial worlds.

"For example, for generating realistic simulations of surgery, computers have great difficulty at simulating the look and feel of soggy, slippery tissue. But telepresence can make use of the world as it currently exists."

Horvitz likened the resolution and functionality of medical virtual reality systems today to that of video games. "But people are excited today about the possibilities, and today's toy-like demonstrations highlight the promise of future technology for training and patient care."

Applications abound

The technology involved in virtual reality and telepresence, Horvitz said, has applications in three areas: visualization of complex structures and anatomy; more efficient access to delicate structures; and visual integration of diverse information sources.

Through virtual reality, the user could view a high-definition image on a computer screen that mimics the actual operating field and specific anatomy. The technology could be used commercially in both surgical planning and an actual operation when its resolution is improved.

Wearing virtual reality head gear, the surgeon could have a view of the operating field that would closely represent the real thing. The surgeon could then better prepare for difficult operations and have an easier time navigating instruments during procedures.

"Virtual reality is good for the 'three Ps'--planning, performing surgery and predicting outcomes," said Dr. Joseph M. Rosen, associate professor of plastic and reconstructive surgery at Dartmouth-Hitchcock Medical Center, Lebanon, N.H. "It improves visualization and navigation and therefore improves safety and performance. It can apply to any application."

Investigators at Stanford and the National Aeronautics and Space Administration have experimented with a software prototype for operating on simulated patients.

The prototype systems enable medical students and surgeons to don virtual reality gloves and headsets and to manipulate virtual surgical tools along with structures in the abdomen. But the low resolution of the images and other factors, Horvitz said, "make the simulation a distant shadow of a real surgical experience."

The second area involves using telepresence devices to plan or perform surgeries on delicate structures. The technology would be particularly advantageous in laparoscopic surgery, where clear visualization and effective control of surgical tools are crucial.

Using a version of telepresence called micropresence, a surgeon could work on a magnified image of the real anatomy. A micropresence system electronically amplifies the size of a structure and provides a different perspective of the anatomy as the physician moves his or her head.