scope:

Introduction and scope

Because the performance of electronic medical devices can be disrupted by electromagnetic (EM) energy, patient safety can potentially be put at increased risk because of the effects of electromagnetic interference (EMI). EMI is caused by an EM disturbance, which can be in the form of radiated disturbance (radio waves propagating through the air); conducted disturbance (radio waves induced on power or signal wires); AC power-line transients, surges, sags, and dropouts; and electrostatic discharge (ESD). Radiofrequency (RF) sources that emit various EM disturbances have proliferated in modern society, including healthcare facilities, creating the potential for EMI with electronic medical devices. Sources of EM disturbance include any product or device that uses electricity or can carry an electrical charge. Systems that can emit EM disturbances include, but are not limited to, the following:

a) Cellular telephones and other wireless communication devices

b) Two-way radios

c) Wireless barcode systems

d) Radiofrequency identification (RFID) systems

e) Security systems

f) Fire alarm systems

g) Nurse call systems

h) Heating, ventilation and air-conditioning (HVAC) systems

i) Motor controllers, including elevators and copiers

j) Medical devices

Concerns arise because the EM disturbance exposure might exceed the immunity designed into medical devices and systems and because some electronic medical devices currently in use have not been tested for immunity to EM disturbances. The risks faced by even those devices that comply with EMC standards seem to be increasing as the number of radio transmitter sources, including RF wireless technology, is dramatically increasing within and outside healthcare facilities. Numerous EMI incidents have been reported in the literature.