Preliminary survey of the electromagnetic interference environment in hospitals

Electric field levels were predicted using a free-space propagation model, and then measured in three major hospitals in downtown Montreal. The measurements were performed using industry-standard techniques and novel broadband, omnidirectional, triaxial, electrically small (BOTES) techniques. Although the absolute values of predictions were often unreliable, they acceptably predicted the type of electromagnetic environment observed at different hospitals. Results from both sets of measurements were closely related, suggesting continued future development of lower-cost BOTES measurement techniques. None of the fields encountered were above the limit prescribed by the Food and Drug Administration (FDA) susceptibility standard for medical devices. Correlations of survey results and of previous reports of device malfunctions in the rooms surveyed suggest that the FDA standard should be mandatory rather than voluntary