There is little need to restrict mobile phone use in hospitals except within 1 metre of sensitive medical equipment, a systematic review in the Medical Journal of Australia has concluded.
Seven studies with adequate methodology tested 29 different categories of medical equipment including anaesthesia machines, defibrillators, external pacemakers, pulse oximeters, respirators and ultrasound devices. The maximum distance from a device at which electromagnetic radiation from a phone caused interference ranged from 5 cm to 200 cm at 900 MHz and 5 cm to 80 cm at 1800 MHz. Dual-band digital mobile phones in Australia operate at both 900 MHz and 1800 MHz.
"The studies confirm that electromagnetic interference (EMI) occurs when mobile phones operate close to sensitive medical equipment," the review stated. "However, clinically relevant EMI is much less frequent."
Research on the issue used a variety of methods, tested a large range of equipment and often produced conflicting results. Standardised testing, recording and reporting procedures were needed to help address the question. In the meantime, some form of restriction on mobile phone use in hospitals was probably needed, but it could be relaxed from the sometimes stringent bans that were currently applied.
The report suggested a simple '1 metre' rule, preventing use within a metre of sensitive equipment. For patients and their visitors, it would avoid confusion if phone use was restricted to designated 'mobile phone friendly zones'. The report noted that two-way radios, which produced similar levels of electromagnetic radiation, had been used in hospitals without incident for decades.
There had been only one death reported worldwide from mobile phone use, in 1996, when a respirator was switched off.
Reference
Lawrentschuk, N. Bolton, D. 2004, 'Mobile phone interference with medical equipment and its clinical relevance: a systematic review', Medical Journal of Australia, vol. 181, pp. 145-149.
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