A new study published in Critical Care indicates that the signal generated by mobile phones can interfere with hospital equipment, even to the point of inhibiting its function, from a range of up to three meters.
The UK Government has suggested mobiles should be allowed in hospitals, though many trusts have maintained their ban on the basis that scientific study is lacking, and even where they are allowed they should be kept at least a meter from critical equipment.
The new study generated two GPRS signals at 900MHz, and one 3G signal, and exposed 61 different bits of life-support kit to see what would happen. Only 26 bits of kit were affected, and only a third of incidents could be classified as "hazardous", but that would be little consolation if you're the poor chap depending on one of them.
Most incidents occurred when the source was within 3cm of the kit, but in one instance a ventilator failed with the signal (one of the GPRS sources) three meters away.
The GPRS signals were held at 2W, while the 3G signal was only 0.2W and generated proportionally less interference. These are the maximum allowed by the respective standards, but again, that's little consolation.
The news will be welcomed by Patientline, who holds the monopoly for pay-phones in UK hospitals and could do with some good news, though it stops short of recommending a building-wide ban and only concludes that mobiles should be kept at least one meter from a critical bedside.®