Irnich W, Batz L, Müller R, Tobisch R
Department of Medical Engineering, Justus-Liebig University, Giessen, Germany.
Pacing Clin Electrophysiol. 1996 Oct;19(10):1431-46. doi: 10.1111/j.1540-8159.1996.tb03155.x.
The topic of interference of pacemakers by mobile phones has evoked a surprisingly strong interest, not only in pacemaker patients, but also in the public opinion. The latter is the more surprising, as in the past, the problem of interference has scarcely found the attention that it deserves in the interest of the patient. It was the intention of our investigation to test as many pacemaker models as possible to determine whether incompatibility with mobile phones of different modes may exist, using an in vitro measuring setup. We had access to 231 different models of 20 manufacturers. During the measurements, a pulse generator together with a suitable lead was situated in a 0.9 g/L saline solution, and the antenna of a mobile phone was positioned as close as possible. If the pulse generator was disturbed, the antenna was elevated until interference ceased. The gap in which interference occurred was defined as "maximum interference distance." All three nets existing in Germany, the C-net (450 MHz, analogue), the D-net (900 MHz, digital pulsed), and the E-net (1,800 MHz, digital pulsed) were tested in succession. Out of 231 pulse generator models, 103 pieces corresponding to 44.6% were influenced either by C- or D-net, if both results were totaled. However, this view is misleading as no patient will use C- and D-net phones simultaneously. Separated into C- or D-net interference, the result is 30.7% for C or 34.2% for D, respectively, of all models tested. The susceptible models represent 18.6% or 27% of today's living patients, respectively. All models were resistant to the E-net. With respect to D-net phones, all pacemakers of six manufacturers proved to be unaffected. Eleven other manufacturers possessed affected and unaffected models as well. A C-net phone only prolonged up to five pacemaker periods within 10 seconds during dialing without substantial impairment to the patient. Bipolar pacemakers are as susceptible as unipolar ones. The following advice for patients and physicians can be derived from our investigations: though 27% of all patients may have problems with D-net phones (not C- or E-net), the application should generally not be questioned. On the contrary, patients with susceptible devices should be advised that a distance of 20 cm is sufficient to guarantee integrity of the pacemaker with respect to hand held phones. Portables, on the other hand, should have a distance of about 0.5 m. Pacemaker patients really suffering from mobile phones are very rare unless the phone is just positioned in the pocket over the pulse generator. The contralateral pocket or the belt position guarantees, in 99% of all patients, undisturbed operation of the pacemaker. A risk analysis reveals that the portion of patients really suffering from mobile phones is about 1 out of 100,000. Nevertheless, it would be desirable in the future if implanting physicians would use only pacemakers with immunity against mobile phones as guaranteed by the manufacturers.
手机对起搏器的干扰这一话题引发了超乎想象的强烈关注，不仅起搏器患者如此，公众舆论亦是如此。后者更令人惊讶，因为过去干扰问题鲜少得到应有的、关乎患者利益的关注。我们此次调查的目的是，利用体外测量装置，尽可能多地测试起搏器型号，以确定不同模式的手机与之是否存在不兼容性。我们能够获取20家制造商生产的231种不同型号的产品。测量过程中，将一个脉冲发生器与一根合适的导线置于0.9 g/L的盐溶液中，并将手机天线尽可能靠近放置。若脉冲发生器受到干扰，就抬高天线直至干扰停止。干扰发生的间距被定义为“最大干扰距离”。德国现有的三种网络，即C网（450 MHz，模拟）、D网（900 MHz，数字脉冲）和E网（1800 MHz，数字脉冲）依次进行了测试。在231种脉冲发生器型号中，若将受C网或D网影响的结果合并计算，有103台（占44.6%）受到了影响。然而，这种观点具有误导性，因为没有患者会同时使用C网和D网手机。若分别按C网或D网干扰计算，在所有测试型号中，受C网干扰的占30.7%，受D网干扰的占34.2%。这些易受干扰的型号分别占目前在世患者的18.6%或27%。所有型号对E网均有抗性。就D网手机而言，六个制造商生产的所有起搏器均未受影响。其他十一个制造商既有受影响的型号，也有未受影响的型号。一部C网手机在拨号时，在10秒内最多只会延长五个起搏器周期，对患者并无实质性损害。双极起搏器与单极起搏器一样易受影响。从我们的调查中可以得出以下针对患者和医生的建议：尽管所有患者中有27%可能会在使用D网手机（而非C网或E网手机）时遇到问题，但一般而言，其使用通常不应受到质疑。相反，对于使用易受干扰设备的患者，应告知他们，手持手机时，20厘米的距离足以确保起搏器的完整性。另一方面，对于便携式手机，距离应约为0.5米。真正因手机而受影响的起搏器患者极为罕见，除非手机恰好放在脉冲发生器上方的口袋里。在所有患者中，对侧口袋或腰带位置能保证99%的患者起搏器正常运行不受干扰。风险分析表明，真正因手机而受影响的患者比例约为十万分之一。然而，未来如果植入医生仅使用制造商保证对手机具有抗干扰能力的起搏器，将会是理想之选。
