Home Government Affairs Newsroom Meetings Publications	Shopping Cart Site Map

September 2001 Reporter

Replicating the Real Thing

Advancing Quality of Care at the End of Life

A Hippocratic Oath for Our Time

Current & Choice: "Physician, Heal Thy Sisters"

A Word from the President

Reporter Archive

Search the Reporter

Reporter Staff:

Rachel Muir, Managing Editor
Barbara Gabriel, Staff Writer
Saunsurae Robinson, Editorial Assistant

AAMC Newsroom

Replicating the ‘Real Thing’: How Virtual Reality Is Transforming Medical Education

By Barbara A. Gabriel

students practice procedures on computerized mannequin

USUHS medical students practice trauma skills such as intubation and IV insertion on sophisticated computerized mannequins.

Proponents of using virtual reality technology to train medical students and residents liken their efforts to those used by the military and the airline industry to train new pilots. “You wouldn’t dream of boarding a plane with a pilot whose skills have not been certified,” says Alan Liu, Ph.D., a research scientist for virtual reality at the Uniformed Services University of the Health Sciences (USUHS) in Bethesda, Md. “A pilot doesn’t say to his passengers, ‘We’re having a resident come in today to practice her skills. She hasn’t done many landings, but I’m going to watch over her shoulder to make sure she doesn’t make mistakes.’ Unfortunately, that is still somewhat the case in medical training.”

Dr. Liu, who has pioneered the creation of several virtual reality physician training tools that mimic the “real thing” as much as is technologically possible, works in the Surgical Simulation Lab of the National Capital Area Medical Simulation Center, opened by USUHS in 1999 to give medical students the opportunity to practice their skills in a virtual environment. He maintains that USUHS students — especially aspiring surgeons — who are trained with virtual reality tools will make better physicians. “A virtual environment is very forgiving,” Dr. Liu explains. “You can practice all you want; you can fumble all you want; you can kill a ‘patient’ repeatedly, learning from your mistakes. In essence, you can keep rewinding a procedure until you’re good at it.”

Dr. Liu, a computer scientist by training, is one of a growing cadre of researchers and educators who are on the cutting edge of applying virtual reality technology to medical education. Surgical rehearsal, anatomy education, and trauma skills assessment are three primary applications of virtual reality currently being studied and applied at medical schools across the country.

The ‘What if?’ Game

“The virtual environment is a safe place where students can play the ‘What if?’ game,” explains Helene M. Hoffman, Ph.D., assistant dean for curriculum and educational computing at the University of California, San Diego, School of Medicine (UCSD). She is the primary designer of the “Anatomic VisualizeR,” a virtual reality tool for teaching clinical anatomy. “Students can cut an organ in half without consequence and put it back together again at will,” says Dr. Hoffman, explaining some of the capabilities of her invention. “They can measure size and distance and create dynamic cross-sectional views. They can repeatedly dissect an area, manipulating the opacity and coloration of organs until they truly begin to understand what they see.”

The Anatomic VisualizeR can be configured for use in different settings. Students may use a head-mounted display and gloves that receive input signals as they manipulate their way around a virtual dissecting room in which they interact with 3-D anatomic and schematic models. UCSD’s virtual reality laboratory contains five such set-ups, which Dr. Hoffman admits is an insufficient number for the 125 medical students in UCSD’s anatomy class. She has therefore adapted the tool for projecting virtual reality models on an auditorium screen during class lectures. For now, this is the primary mode through which students learn from the Anatomic VisualizeR. Dr. Hoffman says that approximately half of the class will follow up by visiting the virtual reality lab and using the more sophisticated head-mounted displays.

student wearing goggles using computer model of the central nervous system

A UCSD medical student learns the inner workings of the human nervous system with the Anatomic VisualizeR, with which he can use gloves equipped with magnetic trackers to directly interact with 3-D models.

Dr. Hoffman emphasizes that tools such as the Anatomic VisualizeR should be a complement to, rather than replacement of, traditional modes of learning, such as cadaver dissection. Nevertheless, she believes that “the addition of virtual reality simulation in medicine will become a critical element of teaching, testing, and recertification.”

Anatomy in Motion

Jannick P. Rolland, Ph.D., assistant professor at the University of Central Florida’s School of Optics and director of the school’s Optical Diagnostics and Applications Laboratory, has taken anatomic virtual reality a step further with her development of the Virtual Reality Dynamic Anatomy (VRDA) tool. An instrument that allows individuals to visualize complex anatomical joints in motion, the VRDA tool uses optical motion tracking and computer-generated real-time 3-D graphics.

The animation of anatomical joint motions are created as stereoscopic images developed for the right and left eyes, which, when placed together and viewed in a lightweight head-mounted display, will render a 3-D view of the anatomical joint being examined. The motion of the joint is tracked by a “knee sock” worn by the patient and equipped with sensors that translate its movement to a computer. The result is a superimposed image of a knee joint, complete with bone and ligaments, on an external image of a person’s knee. “It’s sort of like having X-ray vision,” Dr. Rolland explains.

In addition to teaching medical students dynamic anatomy, Dr. Rolland says that the VRDA tool may be used by physicians evaluating individual patients. The tool is not only capable of visually projecting a generic version of a knee’s anatomy, but it can also superimpose the image of an individual patient’s knee with information translated from an MRI into a 3-D image. She points out that such technology could be invaluable for physicians evaluating patients undergoing physical rehabilitation. “This tool can provide a visual image of a patient’s knee without requiring him or her to undergo repeated X-rays,” Dr. Rolland explains. She adds that surgeons may also use this tool to capture and examine the internal anatomy of a patient before operating.

Dr. Rolland says that as the VRDA tool becomes more refined over the next several years, it may eventually make cadaver dissection obsolete. “If it doesn’t replace it completely, it will at least minimize the number of cadavers we use,” she says. “Dissection may become a supplement to virtual reality training, rather than the other way around.”

Dummy Science

Most medical students have been exposed to scenarios in which they are asked to diagnose a “simulated patient,” an actor who manifests the symptoms of a specific illness. But there is an obvious limit to how much a student can practice on this type of “patient.” For example, students cannot unnecessarily intubate actors. To assist students with learning advanced life support skills and assessment, the University of Kansas School of Medicine, Wichita Campus, has invested in “Ernie,” a state-of-the-art human simulator. Melody Brownell, Ph.D., manager of educational technology at the Kansas medical school, says that Ernie provides a dose of “virtual reality” in his very human responses to what medical students do to him.

Remotely operated by a laptop computer, Ernie is capable of teaching students how to intubate, perform a bronchoscopy, insert an IV, inject medication, and even defribrillate. Dr. Brownell programs Ernie to help students deal with different scenarios, such as what to do when a patient’s pharynx or tongue swells during intubation. Ernie’s anatomically correct lungs cause his chest to rise and fall when breathing is restored, and he can be attached to monitors that alert students to his status. “And,” says Dr. Brownell, “he can die.” He can bleed, too. When a needle is inserted into Ernie’s arm to set up an IV, students know they’ve hit a vein when a spurt of red “blood” is emitted.

“Our primary goal with Ernie is to use him to teach our third-year medical students basic trauma skills before their clerkships,” explains Dr. Brownell. “Students and residents may also use Ernie to practice specific skills.” A complete activity log is kept by Ernie’s computer while a student is working with him, allowing the student to review his or her performance by checking Ernie’s vital signs. “Ernie will soon be incorporated into the clinical skills assessment we already do with actors,” Dr. Brownell says.

From Animal to Virtual Models

Back at Dr. Liu’s Surgical Simulation Lab, Ernie, whose commercial name is SimMan, is one of three human-like mannequins on which students practice their skills. In a full-scale mockup of an operating room, students can work with these “dummies” who, in addition to Ernie’s capabilities, can do things such as recognize and accordingly respond to more than 80 different types of injected drugs.

In the Simulation Lab’s virtual reality room, Dr. Liu says the equipment allows students to “go completely virtual.” In a “triage simulator,” students don a head-mounted display and gloves to become immersed in a virtual mass casualty event. “One scenario is a small plane crash at a busy intersection,” he explains. “The student needs to quickly assess the situation, identify as many wounded individuals as possible, determine how badly people have been hurt, and prioritize who should receive medical treatment first.”

Dr. Liu has created two needle insertion simulators to train students for specific procedures that can be life-saving at the scene of an emergency where sophisticated hospital equipment is unavailable. One, the Diagnostic Peritoneal Lavage simulator, is used to detect and relieve internal bleeding without the use of imaging technology, such as a CT scan. The simulator has force feedback to mimic the effect of pushing a needle into the body while avoiding the danger of perforating the intestines or bowels. Dr. Liu explains that it’s a simple procedure, but one that can have fatal consequences if not performed accurately. “Students currently practice on animals such as goats and pigs, but human anatomy is completely different. Having a human model to work with can refine a student’s motor skills and make animals unnecessary.”

With the permission of the American College of Surgeons, USUHS has conducted “Advanced Trauma Life Support,” a course that typically depends upon the use of animal models and cadavers, entirely with virtual reality tools. “It was done to evaluate the feasibility of using simulators compared with traditional teaching methods,” Dr. Liu says. “It was a one-time experiment, but so far the results have been promising.”

Despite these advances, Dr. Liu says simulation technology is still at the “Wright brothers” stage. Among the technology’s greatest challenges is in the area of haptics — an individual’s ability to touch something and be convinced that it is a real object. Dr. Liu says this essential ability of surgeons is somewhat accomplished with “phantom” technologies, which are capable of tracking an individual’s position in space and exerting reaction forces if his or her hand touches something solid in a virtual reality environment. Such tools are in use at the USUHS Surgical Simulation Lab, but Dr. Liu admits, “We have a long way to go before we can simulate the effect of detecting if something is soft, hard, smooth, or lumpy. We’re just not there yet.” He pauses. “But we will be.”