Updated

They're here. They have FDA approval. But are Americans ready to get chipped?

Getting chipped means having a radio frequency identification (RFID) chip implanted in your body. The chip — about the size of a large grain of rice — lies dormant until a special scanner is passed within six inches of the implant. Then it emits a radio signal that beams a 16-digit number to the scanner.

For security uses, that 16-digit number acts like an electronic key. For medical uses, the number is linked to medical records. Doctors to whom you've granted access — emergency room doctors, for example — can use the key to quickly get hold of your medical records.

Who would want such a thing? That depends on how you ask, says Scott Silverman, CEO of Applied Digital, which makes the FDA-approved RFID called VeriChip.

"When we first announced VeriChip, a network poll asked people if they would put one in their bodies," Silverman tells WebMD. "Only 9 percent said yes. After FDA approval, 19 percent said yes. When former HHS Secretary Tommy Thompson joined our board, the rate went up to 33 percent. But our own study shows that if you ask people whether they would have a VeriChip implant to identify their medical records in case of an emergency, the positive response goes to 80 percent."

The chip got FDA approval in October 2004. Since then, Silverman says, some 2,000 people worldwide are using them for medical or security purposes. But soon he expects that millions of people will get VeriChip implants every year.

FDA Clears Implantable Microchip for Human Use

Who Would Use RFID Implants?

Silverman says the medical chips are meant for five groups of patients:

—People with other implanted medical devices, such as defibrillators

—Heart patients, especially patients who have stents in one or more blood vessels

—People with diabetes

—Memory-impaired patients, such as people with Alzheimer's disease

—Patients who need frequent medical care

The devices won't do much good unless hospitals buy scanners. Applied Digital maintains a secure database to hold client records. But many hospitals using the system will set up secure databases to hold — and to safeguard — the medical records of patients with RFID implants.

Two hospitals already are set up to do this: New Jersey's Hackensack Hospital and Beth Israel Deaconess Medical Center in Boston.

John Halamka, MD, an emergency-room doctor at Beth Israel Deaconess, has one of the chips implanted in the back of his right arm, between the elbow and the shoulder. An account of his impressions appears in the July 28 issue of The New England Journal of Medicine.

"A small amount of anesthetic is injected before the implantation is done, so the actual implant insertion feels just like receiving a vaccine — a bit of pressure, not specific pain," Halamka writes WebMD in an email. "The chip has not had any impact on my self-image. I think of it as just another technology that provides practical value for me, such as my BlackBerry."

Halamka also writes that the chip has not set off airport security systems. Even though he's suffered "several physical impacts" while rock and ice climbing, the device is still working.

Lawmakers Propose High-Tech Medical Records

What About Privacy?

Halamka admits that the device does have privacy implications. What if unauthorized scanners track his unique 16-digit number, he worries, and use the information to target him with unwanted "spam" advertising?

To answer the ethical questions posed by RFID implants, WebMD turned to Arthur Caplan, PhD, director of the Center for Bioethics at the University of Pennsylvania.

"The core ethical issue is privacy concerns: the fear that you will be penalized if the wrong people — your boss, your insurer, maybe police agencies — get information about you," Caplan says. "But it is not clear right now how the chip technology puts that in peril."

Americans may think their medical information is top secret. But Caplan says that we have far less privacy than we think we do, given the number of people who can legitimately see our medical records. And the potential benefits of RFID implants outweigh their risks, Caplan argues.

"You are more likely to die or be harmed by lack of medical information about you than by people knowing too much about your medical information," he says. "In an emergency, it's important for doctors to know what your allergies and medical problems are, who your relatives are and how to reach them, your blood type, and so on."

But Caplan says that Americans' distrust of things like RFID implants runs deep.

"The idea of putting something in your head or in your arm frightens people and stirs up privacy worries, even if they don't make a lot of sense," he says. "Americans have an almost obsessive drive to protect their personal privacy."

Halamka, however, is already dreaming about future upgrades.

"If a chip could also serve as a GPS, reporting my location, or act as an emergency transponder, requesting rescue, I would definitely upgrade," he says.

Electronic Records, Private Lives

By Daniel J. DeNoon, reviewed by Michael W. Smith, MD

SOURCES: Halamka, J. The New England Journal of Medicine, July 28, 2005; vol 353: pp 331-332. John Halamka, MD, chief information officer, CareGroup Healthcare System; emergency medical physician, Beth Israel Deaconess Medical Center, Boston. Arthur Caplan, PhD, director, Center for Bioethics, University of Pennsylvania.Scott Silverman, CEO, Applied Digital, Delray Beach, Fla.