Cellular phone interference with external cardiopulmonary monitoring devices

Objectives: To determine the potential effect (electromagnetic interference ) of cellular telephones on external cardiopulmonary monitoring devices. Methods: For this study, we tested 17 different medical devices with 5 port able telephones (4 digital, 1 analog) to assess the potential for electroma gnetic interference. The telephones were tested in a normal operating mode to simulate a typical hospital environment with patients or their families using their cellular phones. The medical devices were connected to the appr opriate simulators for proper operation while the tests were under way. The screens and alarms of the medical devices were monitored while the telepho nes were maneuvered in the y and z planes near the devices. Clinically impo rtant interference was defined as interference that may hinder interpretati on of the data or cause the equipment to malfunction. Results: Any type of interference occurred in 7 (41%) of the 17 devices tes ted during 54.7 % of the 526 tests. The incidence of clinically important i nterference was 7.4%, Conclusions: Cellular telephones may interfere with the operation of extern al cardiopulmonary monitoring devices. However, most of the test results sh owed that the interference would rarely be clinically important.