Doynov P, Cohen H D, Cook M R, Graham C
Midwest Research Institute, Kansas City, Missouri 64110, USA.
Bioelectromagnetics. 1999;20(2):101-11. doi: 10.1002/(sici)1521-186x(1999)20:2<101::aid-bem4>3.0.co;2-r.
For more than a decade, Midwest Research Institute (MRI) has investigated the effects of exposure to 60 Hz electric and magnetic fields (EMF) on human physiology, performance, and biochemistry. This accumulated experience, new research directions, and limited resources made it important to design more comprehensive and operationally cost-effective exposure facilities. Here we describe the new, integrated laboratory exposure test facilities recently constructed at MRI and present data on relevant characteristics of the exposure systems. Concentric coil systems were developed to generate uniform magnetic fields within the three new exposure rooms, with rapid cancellation of the field to ambient levels in the rest of the laboratory. Control systems are fully automated, computer-based, and independent. These provide the operational flexibility needed to present fields of different magnitudes, frequencies, and polarization. The local geomagnetic field can be modulated and/or canceled, and both AC and DC fields can be presented in various combinations. Capabilities for conducting double-blind experiments with true active-sham exposure conditions were implemented using bifilar windings and applying current flow in the opposite direction for each wire in a pair. The new facilities provide a comprehensive capability for laboratory-based human research on the potential effects of exposure to AC and DC magnetic fields.
十多年来，中西部研究所（MRI）一直在研究暴露于60赫兹电场和磁场（EMF）对人体生理、机能和生物化学的影响。这些积累的经验、新的研究方向以及有限的资源使得设计更全面且运营成本效益更高的暴露设施变得至关重要。在此，我们描述了MRI最近新建的综合实验室暴露测试设施，并展示了暴露系统相关特性的数据。同心线圈系统已开发出来，以在三个新的暴露室内产生均匀磁场，并能迅速将其余实验室区域的磁场消除至环境水平。控制系统完全自动化、基于计算机且相互独立。这些系统提供了呈现不同强度、频率和极化磁场所需的操作灵活性。当地地磁场可以被调制和/或消除，并且交流和直流磁场都可以以各种组合形式呈现。利用双线绕组并对一对导线中的每根导线施加相反方向的电流，实现了在真正的有源-假暴露条件下进行双盲实验的能力。新设施为基于实验室的人体研究提供了全面的能力，以研究暴露于交流和直流磁场的潜在影响。
