Cellular Phone Interference with Medical Instruments
David Adler, Yona Mahler, Avi Israeli
Medical Engineering Dept., and Administration, Hadassah-University Hospital, Ein Kerem, Jerusalem
Cellular telephones and other telecommunication equipment occasionally cause malfunctioning of medical equipment, including life-support equipment. We review such malfunctioning and relate it to Israeli and worldwide standards, analyzing the characteristics of the interference in terms of amplitude and frequency. The results of a controlled study of interference by cellular telephones and portable 2-way radios with medical devices in our clinical departments are also presented. The levels of background environmental electromagnetic noise at several sites in both Hadassah hospitals (Ein Karem and Mount Scopus) were measured, as well as signal levels of cellular telephones and other communication equipment at various distances and in various areas. We recommend 2 different levels of restrictions on the use of this equipment within the hospital.
These include prohibition of the use of wireless telecommunication equipment in intensive care areas and operating theaters. In all other areas it is recommended to turn off the cellular telephone within 1 meter of medical devices and not to transmit (but only to receive) calls with a portable 2-way radio within a 5 meter distance of medical devices.