The Jacobs family - Jeffrey, 48-years-old, Leslie, 46-years-old, and Derek their 14-year-old son - had the devices, about the same size as a grain of rice, implanted in a procedure that took only 10 seconds in a clinic in Boca Raton, Florida.

It is hoped the procedure could eventually replace medical alert bracelets and give medical personnel invaluable details into their patients' medical problems.

However the chips could also be used to contain personal information and even a global positioning device which could track a person's whereabouts, leading to fears the chip could be used for more sinister purposes.

Potential lifesaver?

Called the VeriChip, the technology is the creation of a Florida-based company called Applied Digital Solutions (ADS).

Each chip contains a unique number and emits a radio frequency signal that transmits a brief medical message - for example a possible allergy or medical problem - and the unique number.

Using a handheld device, medical personnel can then feed the number into a web-based database that is maintained by ABS and contains more detailed information about any possible problems the implanted patient may have.

In the case of the Jacobs', the information would include Jeffrey's various medical problems, including a fused spine, a history of cancer and other serious medical problems, Reuters news agency reported.

'Great technology'

"I thought it was great technology and something that had the potential to save my father's life," he said.

"We hope it will become an emergency room protocol," his mother said later.

If they don't know your medical history, your drug allergies, they can do a lot of damage."

However at present no hospitals or medical establishments in the region carry the equipment that enables personnel to scan such implants.

ADS said that 13 out of 14 local hospitals approached have offered verbal agreements, although there has not yet been a formal hospital approval.

Ethical questions

The scheme has also attracted controversy as the chips can also be used to track individuals.

MedicAlert, an emergency medical identification company based in California, described the procedure as raising "serious medical, ethical and infrastructure questions".

"It simply is unnecessary to implant a device into a person's body when non-invasive, less expensive methods of protection exist," the company said in a statement.

However the Jacobs said that the scheme had enabled them to obtain peace of mind.