Compatibility of Medical Electronic Instrumentation with the EMI Environment in Hospitals

Summary form only given. The increasingly severe electromagnetic interference environment that is found in hospitals today, together with difficulties of electrical power line fluctuations, pose problems of sufficient magnitude for medical electronic instruments. The problem is a dual one: that of assuring satisfactory operation of sensitive instrumentation within this hostile environment, and the opposite one of assuring that each newly introduced instrument does not itself create additional interference to add to the prevailing environment. The paper describes several case histories that may be considered typical. Techniques of measurement of emitted interference and susceptibility are described, together with various existing standards and limits promulgated for other applications by Government agencies which may be considered for application to the hospital environment and instrumentation. The essentials of a proposed standard specifically designed for this purpose are presented, and in this connection the related work of the American National Standards Institute is discussed. The correlative topic of electrical and radiation hazards in hospitals is also discussed briefly, in relation to the general hospital electromagnetic environment.