A Basic Study on the Measurement of Electromagnetic Fields in a New University Hospital Building Before and After the Hospital Opened

Abstract

It is well-documented that establishing electromagnetic compatibility (EMC) is important for using medical equipment and communication devices in hospitals. To evaluate the basic electromagnetic environment, measurements should be conducted over 2 periods (before and after the opening of the hospital). We measured the electric field intensity induced by electromagnetic radiation in the broadcasting spectra coming from outside the hospital at 73 locations in our new hospital building in February 2014 (before any patients came into the hospital for the very first time) and August 2014 (6 months after the opening of the hospital). Frequency modulated radio signals, ultra-high frequency television signals, aeronautical radios, community wireless systems, and cellular phone system base stations were strongly detected at the windows of the upper floors. There was no great difference in measured levels between before and after the opening of the hospital. There were no cellular phone unit signals before the hospital opened its doors to patients, but were very strongly detected 6 months thereafter. In this study, the maximum electrical intensity was 0.28 V/m from cellular phone system base stations (2.1 GHz) observed on the south end of the 4th floor before the hospital first opened. This value was lower than the EMC marginal value of the general electronic medical equipment specified in IEC 60601-2-2 (3 V/m). Therefore, electromagnetic interference with medical equipment was extremely improbable in this situation. However, there were no cellular phone system base station signals in the elevator hall, in a portion of the corridor (located in the center of hospital), and in the hemodialysis unit. Measurements 6 months after the opening of the hospital revealed very strong cellular phone unit radio waves in the hospital. To promote greater EMC safety, the hospital should prepare countermeasures to improve these conditions, e.g., installing an interior cellular phone system base station.