Starck J, Rimpiläinen I, Pyykkö I, Esko T
Finnish Institute of Occupational Health, Department of Physics, Vantaa, Finland.
Scand Audiol. 1996;25(4):223-6. doi: 10.3109/01050399609074958.
The noise generated by stimulating coils may jeopardize the hearing of the patients as well as the hearing of the examiner. To evaluate the potential risk caused by the impulse noise of stimulating coils, we examined the A-weighted peak sound pressure levels from five different types of magnetic stimulator coils. At a distance of 10 cm, with 100% stimulation intensity, the coils with Dantec and Magstim stimulators created maximum peak sound pressure levels of 110 dB. Correspondingly, Cadwell MES-10 created maximum peak sound pressure levels of 132 dB. The decrease in the peak levels followed the distance rule quite closely. At a distance of 40 cm, the decrease in peak level was on average 14 dB (range -1-(+)1 dB). Based on American Conference of Governmental Industrial Hygienists (ACGIH) threshold limits of impact noise, the permitted maximum daily number of magnetic stimuli would be 1000 to 10,000. The permitted number of daily stimuli may be difficult to exceed in clinical practice. We consider the risk as small for the patients that are being examined and the operator using magnetic stimulation. The potential risk can be further diminished by even very light weighted hearing protectors providing proper attenuation to the coil impulses.
刺激线圈产生的噪音可能会损害患者以及检查者的听力。为了评估刺激线圈的脉冲噪声所造成的潜在风险，我们检测了五种不同类型磁刺激器线圈的A加权峰值声压级。在距离10厘米处，以100%的刺激强度，丹泰克（Dantec）和马格思蒂姆（Magstim）刺激器的线圈产生的最大峰值声压级为110分贝。相应地，卡德韦尔（Cadwell）MES - 10产生的最大峰值声压级为132分贝。峰值水平的降低与距离规则相当吻合。在距离40厘米处，峰值水平平均降低14分贝（范围为-1 -（+）1分贝）。根据美国政府工业卫生学家会议（ACGIH）的冲击噪声阈值限制，磁刺激的每日允许最大次数为1000至10000次。在临床实践中，每日允许的刺激次数可能很难超过。我们认为对于接受磁刺激检查的患者和操作人员来说，风险较小。即使是非常轻便的听力保护器，只要能对线圈脉冲提供适当的衰减，也可以进一步降低潜在风险。
