Fujita Atsushi, Hirota Izuo, Kawahara Yoshinobu, Omori Hideki
Home Appliance & Housing Electronics Research Laboratory, Corporate Engineering Division, Matsushita Home Appliances Company, Matsushita Electric Industrial Co., Ltd., 1-2 Kamisu-cho, Toyonaka-city, Osaka, Japan.
Bioelectromagnetics. 2007 Oct;28(7):538-45. doi: 10.1002/bem.20339.
We have developed an intermediate frequency (IF) magnetic field exposure system for in vitro studies. Since there are no previous studies on exposure to heating-frequency magnetic fields generated from an induction heating (IH) cook top, there is a strong need for such an exposure system and for biological studies of IF magnetic fields. This system mainly consists of a magnetic-field-generating coil housed inside an incubator, inside which cultured cells can be exposed to magnetic field. Two systems were prepared to allow the experiment to be conducted in a double-blind manner. The level of the generated magnetic field was set to 532 microT rms in the exposure space, 23 kHz, 80 times the value in the International Commission on Non-ionizing Radiation Protection (ICNIRP) guidelines, with a spatial field uniformity better than 3.8%. The waveforms were nearly sinusoidal. It was also confirmed that the parasitic electric field was 157 V/m rms and the induced electric field was 1.9 V/m rms. The temperature was maintained at 36.5 +/- 0.5 degrees C for 2 h. Furthermore, leaked magnetic flux density was 0.7 microT rms or lower at extremely low frequency (ELF) and IF in the stopped system when the other system was being operated, and the environmental magnetic flux density was 0.1 microT rms or lower at the center of the coils. As a result, it was confirmed that this system could be successfully used to evaluate the biological effects of exposure to IF magnetic fields.
我们开发了一种用于体外研究的中频（IF）磁场暴露系统。由于此前尚无关于暴露于感应加热（IH）炉灶产生的加热频率磁场的研究，因此迫切需要这样一种暴露系统以及对中频磁场的生物学研究。该系统主要由置于培养箱内的磁场产生线圈组成，培养箱内的培养细胞可暴露于磁场中。制备了两个系统，以便能够以双盲方式进行实验。在暴露空间中产生的磁场水平设定为532微特斯拉均方根值，频率为23千赫兹，是国际非电离辐射防护委员会（ICNIRP）指南中规定值的80倍，空间场均匀性优于3.8%。波形近乎正弦波。还证实寄生电场为157伏/米均方根值，感应电场为1.9伏/米均方根值。温度在36.5±0.5摄氏度下保持2小时。此外，当另一个系统运行时，在停止运行的系统中，极低频（ELF）和中频下的漏磁通密度为0.7微特斯拉均方根值或更低，线圈中心处的环境磁通密度为0.1微特斯拉均方根值或更低。结果证实，该系统可成功用于评估暴露于中频磁场的生物学效应。
