Chen Yi-Mei, Liu Zhi-Peng, Yin Tao
Institute of Biomedical Engineering, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300192, China.
Annu Int Conf IEEE Eng Med Biol Soc. 2012;2012:1173-6. doi: 10.1109/EMBC.2012.6346145.
High-frequency transient weak magnetic field is always involved in researches about biomedical engineering field while common magnetic-field sensors cannot work properly at frequencies as high as MHz. To measure the value of MHz-level weak pulsed magnetic-field strength accurately, this paper designs a measurement and calibration method for pulsed magnetic-field. In this paper, a device made of Nonferromagnetic material was independently designed and applied to pulsed magnetic field measurement. It held an accurately relative position between the magnetic field generating coil and the detecting coil. By applying a sinusoidal pulse to the generator, collecting the induced electromotive force of the detector, the final magnetic field strength was worked out through algorithms written in Matlab according to Faraday's Law. Experiments were carried out for measurement and calibration. Experiments showed that, under good stability and consistency, accurate measurement of magnetic-field strength of a sinepulse magnetic-field can be achieved, with frequency at 0.5, 1, 1.5 MHz and strength level at micro-Tesla. Calibration results carried out a measuring relative error about 2.5%.
高频瞬态弱磁场一直是生物医学工程领域研究的内容，而普通磁场传感器在高达兆赫兹的频率下无法正常工作。为了准确测量兆赫兹级弱脉冲磁场强度的值，本文设计了一种脉冲磁场的测量与校准方法。本文自主设计了一种由非铁磁材料制成的装置，并将其应用于脉冲磁场测量。它在磁场产生线圈和检测线圈之间保持精确的相对位置。通过向发生器施加正弦脉冲，收集探测器的感应电动势，根据法拉第定律，通过Matlab编写的算法计算出最终的磁场强度。进行了测量和校准实验。实验表明，在良好的稳定性和一致性下，可以实现对频率为0.5、1、1.5兆赫兹且强度水平为微特斯拉的正弦脉冲磁场强度的精确测量。校准结果的测量相对误差约为2.5%。
