Floridian: Creating the virtual patient

Creating the virtual patient

Researchers around the world are using male and female bodies digitized in thousands of pictures to make the ultimate medical guinea pig.

By SUSAN ASCHOFF, Times Staff Writer

TAMPA -- A global effort to create a virtual human so real it bleeds will make for better doctors and healthier patients, scientists say. But first researchers must figure out what they want their gigabyte offspring to do for the cause of medicine.

The project was conceived almost 15 years ago and today includes researchers from the University of South Florida, dozens of medical schools and more than 40 countries. The goal is to take a standardized male and female anatomy, digitized for the computer and accessible by Internet, and make it more than pretty pictures.

Virtual human can be a stand-in cadaver for medical students or the proverbial guinea pig in a laboratory. It can be the first to "wear" experimental military gear. Surgeons can use it for a practice run before operating on a live patient.

Scientists envision a day when every newborn will get his or her own virtual human, a cyber clone to guide medical care from cradle to grave.

But first the space-age specimen must be taught what it can do.

"We can make 3-D reconstructions of anything we can slice. We already had the software," says Dr. Don Hilbelink, professor of anatomy at USF's School of Medicine. "But they're just pictures."

The challenge, he says, is to make virtual human real.

USF is among dozens of universities and companies working with the images to create everything from med school courses to crash test dummies. Researchers will compare notes on their work at the fourth annual Visible Human conference in October in Colorado.

Hilbelink's focus is the bones and tendons of the hand and wrist, his specialty. This semester he will work at the University of Michigan, a leader in putting virtual human in med school classrooms.

It all began when the National Library of Medicine, seeing an increasing need for electronic images that could be used like a textbook, decided in 1989 to create anatomically detailed, three-dimensional representations of the male and female bodies for the computer. The plan was called the Visible Human Project.

It took years to find the first model, a 38-year-old man on death row.

In 1993, convicted murderer Joseph Paul Jernigan, who had agreed to donate his body to science, was executed in Texas. Scientists at the University of Colorado froze the body, cut it into six blocks and sliced the blocks into 1-millimeter increments. MRI and CT data were collected on the cadaver, then the slices. The process yielded more than 1,800 cross-sectional, digitized color images.

Two years later, a 59-year-old Maryland woman who died of heart failure was sliced into 1/3-millimeter increments, the smaller samples reflecting advancing technology.

The Visible Human became Virtual Human. It was the first time an individual had been rendered in its entirety and its pieces for manipulation on the computer. The pictures were released worldwide via the Internet in 1994 and 1995.

But as in the body itself, the devil proved to be in the details.

"Researchers are saying, now that we have him, what can we do with him? What is the end use going to be?" says USF graduate student Mark Coty.

Coty and Hilbelink, who teaches gross anatomy, the class in which medical students dissect cadavers, focused on the hand and wrist. Building 3-D models from the photos, they put the images in a Computer Assisted Drawing, or CAD, format to permit manipulation and reflect the body's own properties.

Coty says USF is one of the few, if not only, virtual human participants to use it.

Imagine a video game, Coty continues. A video game is a simulation. A character runs into a wall and the wall bends and the character bounces off. But in a CAD-based video game, the impact would vary depending on how fast the character was walking, how much he weighed, the construction materials used in the wall, and so on.

The difference takes anatomy from colored drawings to the space age, says Hilbelink.

"What we decided to do is literally reverse engineering of the body," he says. "The models will be in a computer file, and we can insert them into a program and apply pressures and forces on those models, like an engineer on a bridge."

Virtual surgery is already performed with a wand or stylus. The user designates the tool as a scalpel to cut a 3-D image. By further refining and expanding the data in the system, the "skin" will open to a depth corresponding to the stylus' pressure, and the surgeon will feel the difference between bone and muscle as he cuts.

"It doesn't bleed yet," Hilbelink says, but soon the computerized incision could spray digital droplets of blood.

For a person with chronic wrist pain, for example, images of their bones and joints could be rendered in 3-D, measured and manipulated against norms to determine the precise misalignment requiring surgery, Hilbelink says. A doctor examines x-rays or scans to find problems. A computer can do it with infinitely more precision.

Coty, a Ph.D. candidate in medical sciences with a master's degree in biomedical engineering, tested the biochemical properties of 152 pieces of flexor tendons from pigs as a reference for how human tendons behave. The data will be incorporated with the wrist and hand images.

At the University of Michigan, researchers want to replace human cadavers with virtual ones and create the next generation of anatomy training. Project director Brian D. Athey says the computer does what the human brain cannot: simultaneously visualize the anatomy in various planes. The university is working on a tool, called a browser, that would allow cuts at any angle to give interior views of the body far beyond the cross-sections typical today. In another technique, a doctor could visually navigate an individual's aorta, riding it like a stream through its branches and curves.

Walter Reed Army Institute for Research hopes to improve the care of battlefield casualties by training its medics with the virtual human. At Boston University, researchers are using it to study the properties of airways and lung tissue to enhance treatment of asthma and pulmonary disease.

NASA wants to use it to make a better space suit.

Some of the technology's most promising applications are virtual reality systems for education.

"We should be able to make 3-D, virtual people who are representative of endless variations" in body type, age and condition, then put them in a computer for treatment, Hilbelink says. In the future, digital libraries available online could let students try their hand at repairing knee cartilage or a damaged heart on virtual patients.

Hilbelink says that with enough data, the virtual human will be like a spread sheet: When one number is changed, so is every other number. Doctors and researchers could watch the ripple effect of anything done to the body, good or bad, before trying it on humans.

"And without using one rat," Coty says.

Researchers around the world are using male and female bodies digitized in thousands of pictures to make the ultimate medical guinea pig.