一、引言心脏起搏器是向心脏发送电脉冲的人工装置。因起搏器的感知电路监护着心脏发出的电讯号,故它也能感知外来的干扰信号。该信号与心电活动十分相似。无线电或微波调幅的电磁信号会进入起搏器,并被它解调而产生干扰信号。电磁信号会直接感应到非屏蔽的电子元件上,或穿过金属壳小孔而进入起搏器。这种耦合的第一个机理特性能用起搏器的金属屏敝加以缩小;而第二个机理特性只能在起搏器上加一新电路方能控制。实验已表明,单极的起搏器对于通过导管耦合的电磁干扰 I. INTRODUCTION Pacemaker is an artificial device that sends electrical pulses to the heart. Because the pacemaker’s sensing circuit monitors the heart’s electrical signals, it can also sense external disturbances. This signal is very similar to ECG activity. Radio or microwave amplitude modulation of the electromagnetic signal into the pacemaker, and it is demodulated to produce interference signals. Electromagnetic signals will be directly sensed to non-shielded electronic components, or through the metal shell holes into the pacemaker. The first mechanism characteristic of this coupling can be reduced with the metal shield of the pacemaker; the second mechanism characteristic can only be controlled by adding a new circuit to the pacemaker. Experiments have shown that unipolar pacemakers are susceptible to electromagnetic interference through catheter coupling