Microwave Interference with the Function of an Implanted Cardiac Pacemaker

The effect of external microwave radiation on an implanted cardiac pacemaker is studied. Based on a clinical case history [1] indicating an effective blocking in a patient of the implanted pacing activity due to microwave radiation, the process by which microwave energy may cause this observed effect is analyzed. The problem is formulated in terms of thermoelastic theory in which the absorbed microwave energy of the biomedium containing the implanted pacemaker represents a volume of heat source and a resulting thermoelastic motion sets up acoustic waves; these in turn, cause microphonic oscillations in the pacemaker which correspond to the noisy high-frequency artifact recorded on the ECG tracings [11.