Eighteen diabetics have been implanted with microchips to help with emergency treatment.

The volunteers, from Atlanta in the USA, have agreed to have radio-frequency identification (RFID) tags implanted beneath their skin. The chips emit a signal that can be read by hospital computers, which identifies the wearer's records in the hospital database.

If the patients arrive at hospital unconscious, the chip can be read and the patient's medical records called up. Doctors will then be able to administer the correct treatment, saving valuable time.

The chips are being provided by American company Verichip, which is attempting to increase take-up of its products in hospitals. Already, 500 hospitals across the US are equipped with the readers.

A Verichip representative said: "We always knew that the diabetic community was in need of a way to communicate their medical information better and more frequently."

Such uses of RFID have been legal in America since 2004, but European legislators and campaigners are still concerned about the potential privacy violations, with the EU currently considering whether the technology should be regulated.

However, European commissioner Viviane Reding said last month that there were no plans to limit the use of the tags. She said: “My view is that we should under-regulate rather than over-regulate, so that this sector can take off."