Scientist Creates Simulators to Aid Medical Training
By Rudi Williams
American Forces Press Service
FOREST GLEN, Md., Nov. 17, 2000 The need for research animals and cadavers as teaching tools for medical students will not go away anytime soon, but Alan Liu creates products that may one day dramatically reduce the need.
Computer scientist Alan Liu works with Air Force 2nd Lt Christina Waite in the Virtual Reality Lab at the National Capital Area Medical Simulation Center in Forest Glen, Md. As project scientist for virtual reality surgical simulation development at the Uniformed Services University for the Health Sciences in Bethesda, Md., Liu creates simulators that may one day reduce the need for research animals and cadavers in teaching medicine. Waite is a third year medical student at the university. Photo by Rudi Williams.
(Click photo for screen-resolution image);high-resolution image available.
Among a host of other developments, Liu has created what is believed to be the world's first prototype diagnostic peritoneal lavage and pericardiocentesis simulator with force-feedback.
"No other known simulators for these procedures exist," said Liu, project scientist for virtual reality surgical simulation development at the Uniformed Services University for the Health Sciences in Bethesda, Md., the military's premier medical school. He's also project scientist of virtual reality engineering at the Surgical Simulation Laboratory in Forest Glen.
Creating the simulators helps the university advance as a center for innovative medical education, Liu said. Also, the simulation lab contains leading-edge simulators from military- and other government-sponsored research initiatives and commercial vendors, he added.
"Developing this capability gives university medical students an opportunity to go beyond using the traditional anesthetized animal or cadaver model of education," he noted. "These simulators provide the students a unique opportunity to train firsthand using state-of-the-art equipment."
However, today's simulators are not sophisticated enough to completely eliminate the need for research animals and cadavers, Liu said.
"A task must be pretty well understood before realistic simulation can be built for it," he noted. "Research, almost by definition, means you're exploring something you don't understand very well yet.
The American College of Surgeons has permitted these simulators to be used in place of live, anesthetized animals to teach the advanced trauma life support course at the military medical university.
"The simulators are also being evaluated by industry as potentially marketable medical training devices," Liu said.
Before coming to the university, Liu was the senior scientist responsible for coordinating a joint research initiative between the National Institutes of Health and the Center for Information Enhanced Medicine.
Born in Singapore, Liu came to America at age 26 to work on an advanced degree in computer science. When he left the University of North Carolina at Chapel Hill five years later, he was armed with a doctorate in computer science. He also graduated with honors with a bachelor of science in computer science from the National University of Singapore and a master's in computer science from the University of North Carolina.
Liu said he "sort of fell into" the virtual reality business after spending many hours studying virtual reality at the University of North Carolina. He said the university is one of five academic institutions funded by the National Science Foundation as a science and technology center for computer graphics.
As project scientist of virtual reality engineering at the Surgical Simulation Laboratory, Liu is responsible for the design and development of virtual reality-based simulators to support training objectives at the university. He's also responsible for developing and coordinating collaborations with academic institutions and commercial partners.
"It's more a collaborative effort than an individual's idea," Liu explained. "Usually, there will be a requirement for a particular type of simulator. I work with the medical staff at the simulation center, and we try to define the particular education object. Then we identify the individual tasks that make up the entire simulation and refine it to the point where we're comfortable with the description. Then we start writing code for it.
"I did my thesis research on computer-guided neurosurgery, then did some work on using virtual reality for surgery planning at the National Institutes of Health, then continued by doing work on building virtual reality-based surgery trainers."
His fascination with computers started when he was about 15 and his father brought home a book on basic programming for the Atari computer.
"I was fascinated," Liu said. "Here was a book that taught how to make computers work for you. I remember plowing through half the book that first day. I was trying to write programs even though I had no way to run them. It was like a game."
Around the same time, his school acquired an Apple computer. "The programming language was essentially the same and I could use the machine," said Liu, who pointed out that the education system in Singapore doesn't translate exactly to the American system. "I haven't looked back since."
"I still have that book," said Liu, who attended Raffles Junior College in Singapore at age 17. "I keep it in my bookcase as a reminder of how it all started."
Liu has published more than 15 articles pertaining to computer-based simulators, eliminating the need for animals and cadavers in advanced trauma life support, three- dimensional reconstruction, scientific visualization, and a host of other subjects.
Using simulators in teaching lets medical instructors do things that can't be done with animals or cadavers. "However, simulator technology is still very limited and can't do many things animals or cadavers can do with very little effort," Liu said. "For example, it's hard to reproduce tissue texture and to simulate the way tissues stretch and contract when pulled."