Patients' lives at risk from mobile signals

Researchers have found compelling evidence that handset signals can interfere with medical equipment more than 9ft away.

For years, patients were banned from using mobile phones in hospitals over concerns that their signals could confuse life-saving electronics.

However, following pressure from doctors and patients, a growing number of NHS trusts relaxed the rules to allow mobile phones on wards.

But in new tests carried out in a hospital, a signal from a mobile phone switched off an automatic pump used to deliver life-saving medicines, interfered with a heart monitor and confused an external pacemaker.

Although most of the effects were seen when a handset was within three feet of equipment, one phone switched off a ventilator from a distance of more than three yards while handset signals affected an electrocardiogram five feet away.

The scientists who carried out the tests want hospitals to ban mobiles from wards.

They say Health Service chiefs should not bow to pressure from doctors and patients who want to be able to use them for their own convenience.

The researchers admit that, although many phones appear to be safe to use at least a yard from less sensitive items of equipment, the risk to certain life-saving devices and from the latest complex phones is great enough to justify a ban.

Earlier this year, the Government encouraged hospitals to allow handsets, claiming there was no reason to ban them.

That followed advice from the Government's advisers in 2006 who said phones should only be banned where specialist equipment is used, such as intensive care and specialist baby wards.

Although many doctors doubt phones are dangerous, the new study, published in the online journal Critical Care, highlights the risks.

In tests carried out in hospitals, the researchers mimicked the sort of signals emitted by a range of mobile phones and found they interfered with 26 out of 61 medical devices.

Out of the 48 separate incidents recorded, a third were classed as hazardous, meaning they could cause direct harm to a patient, while half were serious.

Signals from the phones caused ventilators to switch off and restart and changed the rate they pumped air into a patient's lungs.

Twice they switched off a syringe pump - a device that deliveries medicines or fluids to a patient.

However, most hazardous incidents took place only when the simulated phone was within two inches of a piece of equipment.

Dr Erik van Lieshout, of the University of Amsterdam, said: "Our work has real implications for present restrictions of mobile phone use in patient areas.

"The one-meter rule, as the minimum distance to keep a mobile phone away from medical equipment or the bedside as proposed in the past, seems safe, although the rule does not exclude electromagnetic interference by new generation mobile phones entirely."

He warned that the ban would only work if patients and staff had access to areas in the hospital where it was safe to make a mobile phone call.

The Medicines and Healthcare Products Regulatory Agency said it received "very few reports" of incidents where mobile phones have been blamed for the malfunction of medical devices.

A spokesman said: "Areas of restriction are down to the individual hospital or trust.

"But we recommend mobile phones are not used in critical care areas such as intensive therapy units, special care baby units or where patients are attached to complex devices."

A Department of Health spokesman added: "Patients and staff should be able to use mobile phones subject to medical privacy and safety considerations. We don't see any reason for a ban."

d.derbyshire@dailymail.co.uk