Zheng Y, Kotani M, Utsukawa Y, Nakadate T
School of Information Environment, Tokyo Denki University, Chiba, Japan.
Neurol Clin Neurophysiol. 2004 Nov 30;2004:10.
For some time, we have been using a large device, in our laboratory, to measure the remanent field from magnetic contaminants in the human lung (magnetopneumography, or MPG). But this device is too large and cumbersome to transport to worksites to assess the magnetic contaminants in the lungs of workers. Further, it is inconvenient and expensive for workers of small or medium-sized companies to come to our campus to be magnetically examined. To solve this problem, we have developed a succession of portable devices which can easily be transported to worksites to perform MPG measurements. We here describe our most recent portable MPG device, and present a typical result of the MPG measurements. The lungs of many workers have so far been measured, and we find that the device can produce accurate measurements at the worksites, beyond our expectation. One reason, we find, is that the background magnetic noise at worksites usually is much less than that at our Kanda campus, located in the center of Tokyo, where the level of magnetic noise caused by subways is high. Therefore, some measurements, which are unable to be done at our campus,can be successfully completed at worksites by using this portable device. We note that the level of the magnetic noise during the recordings greatly depends on the exact location of the workplace measuring site.
一段时间以来，我们一直在实验室使用一种大型设备来测量人肺中磁性污染物产生的剩磁场（磁肺图，简称MPG）。但这种设备体积太大、过于笨重，无法运到工作场所去评估工人肺部的磁性污染物。此外，对于中小企业的工人来说，到我们校园接受磁性检测既不方便又昂贵。为了解决这个问题，我们开发了一系列便携式设备，这些设备可以轻松运到工作场所进行MPG测量。在此，我们描述我们最新的便携式MPG设备，并展示MPG测量的一个典型结果。到目前为止，已经对许多工人的肺部进行了测量，我们发现该设备能够在工作场所进行准确测量，这超出了我们的预期。我们发现，一个原因是工作场所的背景磁噪声通常比位于东京市中心的神田校园的背景磁噪声小得多，在神田校园，地铁引起的磁噪声水平很高。因此，一些在我们校园无法进行的测量，可以通过使用这种便携式设备在工作场所成功完成。我们注意到，记录过程中的磁噪声水平在很大程度上取决于工作场所测量地点的确切位置。
