This new type of ECG test would need to undergo randomised, controlled trials to ensure that it provides better readings than those recorded by current equipment.

British Heart Foundation spokeswoman

But the team at Brighton, led by Professor Terry Clark, said ECGs could distort electrical measurements because the contacts on the skin drain the current slightly.

Their device measures the "displacement current".

Unlike the standard measurement of the current produced by moving electrons, displacement current is a measure of the changing electric field in the air, generated by the shifting voltages on the skin surface.

Though it works well remotely, the sensor is also effective close to the body.

The Brighton-based researchers are testing a finger sensor that makes contact with the skin but is electrically insulated from it.

Using this device, heart signals that would normally be impossible to pick up without surgery, such as the His-Purkinje discharge - a weak current that travels from the atrium to the ventricle - have been detected.

This signal would normally need electrodes placed within an artery to detect it.

Professor Clark told BBC News Online: "It's a new age as far as sensing the electrical dynamics of the body is concerned."

Positive response

Experts have cautiously welcomed the development.

Ary Goldberger, a cardiologist at Harvard Medical School in Massachusetts, said the Brighton team's work needed to be independently verified, but agreed it could be the basis of a major medical advance.

The sensor could lead to DIY monitors, and could help in the monitoring of burns victims who cannot be touched.

A spokeswoman for the British Heart Foundation said: "The ECG test is a well established, quick and simple way of recording the rhythm and electrical activity of the heart.

"As with any piece of technology, it is always interesting to see new developments - especially those which are finding ways of eliminating any errors or inaccuracies.

"However, this new type of ECG test would need to undergo randomised, controlled trials to ensure that it provides better readings than those recorded by current equipment.

"In the meantime, patients should be assured that doctors can gain accurate assessments of the heart's electrical activity using the established equipment."

The research is also published in the journal Measurement Science and Technology.