Rohl D, Laun H M, Hauber M E, Stauch M, Voigt H
ISA Trans. 1975;14(2):115-7.
The susceptibility of 16 noncompetitive cardiac pacemakers to radiation from a powerful radar system was investigated in the laboratory and in the vicinity of its prototype. From comparative in vitro tests in air, fat, water, and saline it was concluded that only tests in fat or air represent the worst case condition after implantation. In air all pacemakers showed signs of interference at pulse power densities between 0.025 mW/cm2 and 62.5 mW/CM2. Three of six implanted pacemakers were triggered or inhibited depending on their mode of operation when tested at a location 1.2 km away from the radar station by the radar beam occurring every 5.5 sec. Because interfering radiation can enter the pacemaker circuitry directly along the electrode, acting as an antenna, metal encapsulation of the pulse generator does not provide sufficient shielding against microwave radiation. However, pacemakers modified by metal encapsulation and a low-pass filter at the electrode remained undistrubed at pulse power densities of greater than 10 W/cm2 when tested under worst case condition in air.
在实验室及其原型附近，对16个非竞争性心脏起搏器对强大雷达系统辐射的敏感性进行了研究。通过在空气、脂肪、水和盐水中的体外对比测试得出结论，只有在脂肪或空气中进行的测试才能代表植入后的最坏情况。在空气中，所有起搏器在脉冲功率密度为0.025毫瓦/平方厘米至62.5毫瓦/平方厘米之间时均显示出干扰迹象。当在距离雷达站1.2公里处，每隔5.5秒出现一次的雷达波束进行测试时，六个植入式起搏器中有三个根据其工作模式被触发或抑制。由于干扰辐射可沿充当天线的电极直接进入起搏器电路，脉冲发生器的金属封装并不能为微波辐射提供足够的屏蔽。然而，在最坏情况的空气中进行测试时，经过金属封装和在电极处设置低通滤波器改装的起搏器在脉冲功率密度大于10瓦/平方厘米时仍未受到干扰。
