Changes in the susceptibility of a medical device resulting from connection to a full-size model of a human

The Radiofrequency (RF) susceptibility of an apnea monitor was evaluated while connected to a saline-filled, full-size model of an adult human. Experimental measurements were performed at an outdoor electromagnetic compatibility (EMC) test facility. The RF susceptibility of the apnea monitor increased by approximately 8 to 15 dB when its fully-extended patientmonitoring leads and electrodes were connected to the model, rather than being terminated with a resistor. This increase in electric field strength susceptibility of 2.5 to 5.6 times occurred in the 63 to 100 MHz range. This frequency range includes the resonant frequency of the model, and of actual adult humans. This finding has clinical significance due to the widespread presence of high power FM radio and VHF television transmitters in the U.S. and other countries.