Electric field strengths created by electrosurgical units

The electromagnetic environment found in hospital operating rooms can be quite hostile to electronic medical devices. The electromagnetic fields existing in the operating rooms are created by both distant sources such as AM and FM broadcast towers as well as local sources such as electrosurgical units. In this paper, results are presented of electric field strengths created by a typical electrosurgical unit. The field strengths are given as a function of frequency. Electric fields as large as 44 V/m were measured 1 meter from the electrosurgical unit. Interference was observed on monitoring equipment in the operating room during operation of the electrosurgical unit. Measurement results can be used by both the manufacturers of medical equipment as well as appropriate standards organizations when evaluating how to minimize the severity of electromagnetic interference in operating rooms.<>