Guy Hotson, a doctoral student in electrical engineering at the Johns Hopkins University Applied Physical Lab in Baltimore, tele-operates a prosthetic limb using the cyber glove on his left hand. Signals from his hand go into a computer which then sends them to the limb.

BALTIMORE — After Darth Vader lopped off Luke Skywalker's hand in the movie “The Empire Strikes Back,” Rebel Alliance doctors installed a prosthetic that immediately moves and feels just like a human hand.

Science fiction is coming closer to reality at Johns Hopkins, where researchers recently adapted a brain mapping technology to enable a patient to independently move individual fingers on a prosthetic arm just by thinking about it.

While such technology is far from practical application in patients, the breakthrough by biomedical engineers and physicians from the Johns Hopkins University and its School of Medicine is the latest advancement in a growing field of research into mind-controlled movement of artificial limbs.

The Johns Hopkins researchers said their work, published in the Journal of Neural Engineering, is the first to accomplish such precise, individualized motion of the fingers and shows promise for one day providing amputees with prosthetics that more closely mimic the movements of real hands and arms.

While prosthetics have improved in recent years, they still can be bulky and hard to maneuver. The fingers on existing prosthetics move as one unit, or in unison, opening and closing together, like when grasping a soda can.

“We still have a bit of a ways to go before we get this in a practical clinical setting fully restoring the natural dexterity of people — but I think that day is coming,” said Guy Hotson, an electrical and computer engineering graduate student at Johns Hopkins who was lead author on the study.

There are more than 100,000 people in the United States with amputated hands or arms who could potentially benefit from such prosthetics, according to the Amputee Coalition, an education, support, and advocacy organization.

“The mind control research is very cutting edge,” said George Gondo, the coalition's director of research and grants. “It is really exciting to see improvement and to see actual results from the research.”

Funded by the National Institute of Neurological Disorders and Stroke, the experiment used a modular prosthetic arm developed by Johns Hopkins Applied Physics Laboratory. Considered the world's most sophisticated upper-extremity prosthesis, the arm can perform almost all of the same movements as a human arm and hand.

The lab's research and development of the arm itself was funded under the Revolutionizing Prosthetics program of Defense Advanced Research Projects Agency with the intent of restoring limb function to wounded military members.

The prosthetic arm still needs years of development, the researchers said. For one, it needs to connect to a computer running the software to work.

“Most of what is being done here is not built into the arm,” said Dr. Nathan Crone, professor of neurology at the Johns Hopkins University School of Medicine who was part of the study. “Some day when this is used by patients it will probably require some faster computing and eventually it could fit in the arm. Right now it would require some kind of computing pack somebody would carry around. You need the computer near the arm in order for it work.”