Burghoff M, Schnabel A, Drung D, Thiel F, Knappe-Grüneberg S, Hartwig S, Kosch O, Trahms L, Koch H
Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin, Germany.
Neurol Clin Neurophysiol. 2004 Nov 30;2004:67.
For many biomagnetic applications the discrimination between simultaneously active sources is required. To evaluate the performance of a given SQUID system in this respect, the angle between the signal vectors of different sources is used. If the angle reaches large values, discrimination between the multiple sources is possible. We tested this approach with the first module of a new vector magnetometer system consisting of 19 identical modules. Two examples of measurements illustrate the differentiation of multiple sources, i.e. the fetal and the mother's heart signal, and alpha rhythm and heart signal in MEG recordings. This first module of a vector magnetometer system containing 16 SQUIDs is operated at PTB in the new Berlin Magnetically Shielded Room (BMSR 2) The spatial configuration of the 16 integrated SQUID magnetometers of the module is such that all three vector components of the magnetic field can be calculated in three measurement planes at 1.5 cm, 5 cm, and 10.5 cm above the Dewar bottom, respectively. The SQUID magnetometer channels have a typical white noise level of less than 2.3 fT/square root of Hz1/2 at 1 kHz.
对于许多生物磁应用而言，需要区分同时活跃的源。为了评估给定超导量子干涉仪（SQUID）系统在这方面的性能，使用不同源的信号向量之间的夹角。如果夹角达到较大值，则有可能区分多个源。我们用一个由19个相同模块组成的新型矢量磁力计系统的第一个模块测试了这种方法。两个测量示例说明了多个源的区分，即胎儿和母亲的心脏信号，以及脑磁图（MEG）记录中的阿尔法节律和心脏信号。这个包含16个超导量子干涉仪的矢量磁力计系统的第一个模块在柏林新的磁屏蔽室（BMSR 2）中的德国物理技术研究院（PTB）运行。该模块中16个集成超导量子干涉仪磁力计的空间配置使得磁场的所有三个矢量分量可以分别在杜瓦瓶底部上方1.5厘米、5厘米和10.5厘米处的三个测量平面中计算得出。超导量子干涉仪磁力计通道在1千赫兹时的典型白噪声水平小于2.3飞特斯拉/赫兹的平方根。
