A Florida company is poised to become the first to sell microchips designed to be implanted into human beings, an achievement that opens the door to new systems of medical monitoring and ID screening.

Implantable chips have long been discussed by technologists and even denounced by those who object on religious grounds or fear their use by a totalitarian state. But the company that did the test, Applied Digital Solutions of Palm Beach, says the specter of terrorism is shifting attitudes. The direct union of man and computer is no longer dismissed out of hand.

‘’The bottom line is, when people are trying to regain their peace of mind, they're more open to new approaches," said Keith Bolton, Applied Digital's chief technology officer.

Applied Digital, which had revenues of $165 million last year, has made its mark by selling electronic chips that help farmers keep tabs on the health and safety of their cows and other livestock. The company also makes a monitoring bracelet for Alzheimer's patients so families can use Global Positioning satellite systems to find loved ones who might have wandered off.

Now the company sees a market among those who have artificial organs and limbs. These folks will have up to 60 words of relevant medical information implanted on chips. If the patients are brought unconscious into an emergency room, technicians equipped with special scanners will easily decipher the body's internal topography.

The chips would need approval from the Food and Drug Administration, which Applied Digital says it expects to receive by mid-year. The company says it has already secured permission from the Federal Communications Commission - necessary because the chips use radio frequencies.

Regulatory approval is not necessary overseas, however. Applied Digital expects to be selling chips in foreign countries in about 90 days. One potential market is kidnap targets, who could use these chips in combination with global positioning satellite devices.

Other potential applications would put the chips in the role of an ultimate ID., capable of performing many of the roles that are now performed by keys and ATM cards.

"I'd be shocked if within 10 years you couldn't get a chip implanted that would unlock your house, start your car, and give you money," said Chris Hables Gray, an associate professor of computer science at the University of Great Falls in Montana and author of "The Cyborg Citizen."

Indeed, an English cyberneticist, Kevin Warwick, won considerable notoriety three years ago by implanting an electronic transmitter above his left elbow. The implant opened doors and switched on lights at his British University of Reading offices. He is now working on experiments in which his nervous system is linked with a computer.

The Applied Digital volunteer, a 55-year-old New Jersey surgeon named Richard Seelig, sees himself as simply a consultant thrust by events into an unexpected role. Seelig had been working with Applied Digital since early this year. He expected to do a traditional scientific study, calling for volunteers who wanted to test out the role of chip implants. Then came the terrorist attacks on Sept. 11. Five days later, Seelig injected himself with the chips.

"I was so compelled by what had happened," he said in a phone interview. "One of the potential applications suddenly jumped out - the ability to have a secure form of identification - and I felt I had to take the next step."

So he injected one chip into his left forearm; the other went next to the artificial hip in his right leg. Each could hold the equivalent of about 60 words, although at the moment they just contain serial numbers. "There's no deformity of the skin," Seelig said. "I feel just the same as I did before."

The chips that will be marketed next year are not true tracking devices. For one thing, they have no internal power source. Their data can't be read without a scanner close at hand.

The next generation of body chips - one that transmits signals from a distance - is still several years away. At the moment this kind of tracking device would have to be about 1 inch by 1 inch, raising the likelihood of a rather unsightly bulge.

• Cyborg : cybernetic organism
• I.D : identification
• F.D.A. : Food and drug administration
• A.T.M. : Automated teller machine