Mon Feb 28 - The war in Iraq is producing a group of young combat veterans who face a lifelong struggle to cope with physical wounds so severe, they might not have lived through previous conflicts.

The nation's system of veterans' health care is already seeing the first of those men and women, saved by modern battlefield medicine but in need of long-term rehabilitation. While their numbers are not nearly as large as the injured from Vietnam or World War II, the severity of their wounds is often greater than from previous wars.

"What is important is the really more profound nature of their injuries," says Tony Principi, the Veterans Affairs secretary during President Bush's first term.

While armored vehicles and jackets sometimes protect vital organs, the car bombs and booby-trap explosions so common in Iraq have left American soldiers with catastrophic amputations and serious brain trauma.

"The nature of their injuries is different in some ways from what we've been dealing with before," says Stephan Fihn, the VA's acting chief research and development officer. "They are a group of people who are going to be alive for a long time. Our goal is to return them to a functional and productive and fulfilling existence."

The biggest difference now, Fihn says, is the incidence of multiple amputations from bomb blasts, as opposed to the bullet or fragment wounds to the chest or stomach more common in previous wars. The blasts have also left some soldiers with significant brain trauma.

The VA is financing research into a variety of new technologies to help amputees, including high-tech prosthetic limbs and regeneration of tissue. A study underway at the VA's center in Providence, in collaboration with Brown University and Massachusetts Institute of Technology, is exploring the potential for restoring greater function after limb loss.

One project seeks to build "biohybrid" limbs, in which a prosthetic would be implanted in tissue and become an integral part of the patient. Another goal is to develop a system in which a patient's brain signals could direct movement of a computerized limb.

"Some of these things seem like science fiction," Fihn says. "Our hope is that there are early payoffs for these soldiers coming back home as well as the larger disabled population."

Amputee veterans are already getting some high-tech prosthetic limbs with microprocessor-controlled knee functions.

Erick Castro, who turns 25 today, has one to replace his left leg, which was blasted from the hip by an anti-tank weapon when his cavalry regiment was ambushed Aug. 25, 2003, between Ramadi and Fallujah.

Castro uses a cane to help him walk. If he needs to move faster, he takes off the limb and uses a set of lightweight titanium crutches. He's back home in California now and studying mechanical engineering at Santa Ana Community College.

"It's never going to be the same," he says. "I can't go for a run or just get up and go. I have to plan how I'm going to do this. I have to give myself extra time. ... Slowly, I have to readjust, to the best of my abilities."