Transforming and comparing data between standard SQUID and OPM-MEG systems.
Transforming and comparing data between standard SQUID and OPM-MEG systems.
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DOI：
10.1371/journal.pone.0262669
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发表时间：
2022
期刊：
影响因子：
3.7
通讯作者：
Jazbinšek V
中科院分区：
文献类型：
--
作者：
Marhl U;Jodko-Władzińska A;Brühl R;Sander T;Jazbinšek V
近年来，光泵磁强计（OPMs）变得非常灵敏，适合用于脑磁图（MEG）。这些传感器解决了目前标准MEG的操作问题，其中超导量子干涉装置（SQUID）梯度仪和磁力计正在使用。opm的主要优点是它们不需要低温冷却。因此，它们可以放置在离头皮更近的地方，而且更容易使用。在这里，我们用基于SQUID和opm的MEG系统测量了一组受试者的听觉诱发场（AEFs），以更好地了解有限传感器计数的OPM-MEG的使用情况。我们提出了一个理论框架，将受试者内部数据和等效模拟数据从一个MEG系统转换到另一个MEG系统。该方法的原理是先求解一个系统的逆问题，然后利用正演模型计算另一个系统的期望磁场。对于源重构，我们使用电流分布的最小范数估计（MNE）。比较了两种不同体积导体模型：均匀导电球模型和头部三壳模型。变换结果的特点是实测和估计磁场图之间存在相对误差和相互关系。这两种模式的结果都令人鼓舞。由于一些商用opm同时测量多个磁场分量，我们还分析了切向磁场分量的影响。总的来说，我们的双轴OPM-MEG具有15个传感器，其产生的信息与62通道SQUID-MEG相似，其视野仅限于右半球。
Optically pumped magnetometers (OPMs) have recently become so sensitive that they are suitable for use in magnetoencephalography (MEG). These sensors solve operational problems of the current standard MEG, where superconducting quantum interference device (SQUID) gradiometers and magnetometers are being used. The main advantage of OPMs is that they do not require cryogenics for cooling. Therefore, they can be placed closer to the scalp and are much easier to use. Here, we measured auditory evoked fields (AEFs) with both SQUID- and OPM-based MEG systems for a group of subjects to better understand the usage of a limited sensor count OPM-MEG. We present a theoretical framework that transforms the within subject data and equivalent simulation data from one MEG system to the other. This approach works on the principle of solving the inverse problem with one system, and then using the forward model to calculate the magnetic fields expected for the other system. For the source reconstruction, we used a minimum norm estimate (MNE) of the current distribution. Two different volume conductor models were compared: the homogeneous conducting sphere and the three-shell model of the head. The transformation results are characterized by a relative error and cross-correlation between the measured and the estimated magnetic field maps of the AEFs. The results for both models are encouraging. Since some commercial OPMs measure multiple components of the magnetic field simultaneously, we additionally analyzed the effect of tangential field components. Overall, our dual-axis OPM-MEG with 15 sensors yields similar information to a 62-channel SQUID-MEG with its field of view restricted to the right hemisphere.
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在头皮安装的磁刻摄影术中用于无效背景磁场的双平面线圈系统。
影响因子：
5.7
作者：
Holmes N;Leggett J;Boto E;Roberts G;Hill RM;Tierney TM;Shah V;Barnes GR;Brookes MJ;Bowtell R
通讯作者：
Bowtell R
影响因子：
3.7
作者：
Boto E;Bowtell R;Krüger P;Fromhold TM;Morris PG;Meyer SS;Barnes GR;Brookes MJ
通讯作者：
Brookes MJ
影响因子：
4.3
作者：
Gramfort A;Luessi M;Larson E;Engemann DA;Strohmeier D;Brodbeck C;Goj R;Jas M;Brooks T;Parkkonen L;Hämäläinen M
通讯作者：
Hämäläinen M
影响因子：
5.7
作者：
Iivanainen J;Stenroos M;Parkkonen L
通讯作者：
Parkkonen L
影响因子：
5.7
作者：
Fischl, Bruce
通讯作者：
Fischl, Bruce