Privacy advocates are concerned that an implantable microchip designed to help doctors tap into a patient's medical records could undermine confidentiality or could even be used to track the patient's movements.
``If privacy protections aren't built in at the outset, there could be harmful consequences for patients,'' said Emily Stewart, a policy analyst at the Health Privacy Project.
The Food and Drug Administration said Wednesday that Applied Digital Solutions of Delray Beach, Fla., could market the VeriChip, an implantable computer chip about the size of a grain of rice, for storing medical information.
With the pinch of a syringe, the microchip is inserted under the skin in a procedure that takes less than 20 minutes and requires no stitches. Silently and invisibly, the dormant chip stores a code that releases patient-specific information when a scanner passes over it.
The VeriChip itself contains no medical records, just codes that can be scanned and revealed in a doctor's office or hospital. With that code, doctors can unlock part of a secure database that holds the patient's medical information, including allergies and prior treatment. The electronic database, not the chip, would be updated with each medical visit.
The microchips have already been implanted in 1 million pets. But the chip's possible use to track people's movements -- in addition to speeding delivery of medical information to emergency rooms -- has raised alarm.
The company's chief executive officer, Scott R. Silverman, said chips implanted for medical uses could also be used for security purposes, like tracking employee movement through nuclear power plants.
Stewart said that to protect patient privacy, the devices should reveal only vital medical information, like blood type and allergic reactions, needed for health care workers to do their jobs.
An information technology guru at Detroit Medical Center said he will lobby for his center's inclusion in a VeriChip pilot program.
``One of the big problems in health care has been the medical records situation. So much of it is still on paper,'' said David Ellis, the center's chief futurist and co-founder of the Michigan Electronic Medical Records Initiative.
``It's part of the future of medicine to have these kinds of technologies that make life simpler for the patient,'' Ellis said. Strong encryption algorithms will ensure hackers can't nab medical data, he said.
The Health and Human Services Department on Wednesday announced $139 million in grants to help make real President Bush's push for electronic health records for most Americans within a decade.
William A. Pierce, an HHS spokesman, could not say whether VeriChip and its accompanying secure database of medical records fit within that initiative.
``Exactly what those technologies are is still to be sorted out,'' Pierce said. ``It all has to respect and comport with the privacy rules.''
To kickstart the chip's use among humans, Applied Digital will provide $650 scanners for free at 200 of the nation's trauma centers.
In pets, installing the chip costs owners about $50. For humans, the chip implantation cost would be $150 to $200, said Angela Fulcher, an Applied Digital spokeswoman.
Ultimately, the company hopes patients who suffer from such ailments as diabetes and Alzheimer's or who undergo complex treatments, like chemotherapy, would have chips implanted.