Cellular phone interference with external cardiopulmonary monitoring devices.
OBJECTIVE
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 portable telephones (4 digital, 1 analog) to assess the potential for electromagnetic 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 appropriate simulators for proper operation while the tests were under way. The screens and alarms of the medical devices were monitored while the telephones were maneuvered in the y and z planes near the devices. Clinically important interference was defined as interference that may hinder interpretation of the data or cause the equipment to malfunction.


RESULTS
Any type of interference occurred in 7 (41%) of the 17 devices tested during 54.7% of the 526 tests. The incidence of clinically important interference was 7.4%.


CONCLUSIONS
Cellular telephones may interfere with the operation of external cardiopulmonary monitoring devices. However, most of the test results showed that the interference would rarely be clinically important.
Tri
J L
JL
Telecommunications and Mobile Services, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA.
Hayes
D L
DL
Smith
T T
TT
Severson
R P
RP
D004562:Electrocardiography / Q000295:instrumentation; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004868:Equipment Failure; D006334:Heart Function Tests / Q000295:instrumentation; D006801:Humans; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D011846:Radio Waves / Q000009:adverse effects*; D013689:Telephone; D012122:Ventilators, Mechanical