The measured and predicted electromagnetic environment at urban hospitals

The need for electromagnetic compatibility (EMC) is crucial in health care environments, since electromagnetic interference (EMI) effects on critical care medical equipment may be life-threatening. Field strength measurements, made inside and outside five Montreal hospitals at frequencies between 30-1000 MHz, were compared to fields predicted using line-of-sight, and hybrid methods. Although measured fields generally remained below 3 V/m, EMI still caused medical equipment malfunctions at the five hospitals. The line-of-sight prediction method provided a worst-case estimate of the electromagnetic environmental hazard, predicting outside fields to within 20 dB of those measured. The hybrid method predicted fields to within 10 dB