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Clinical application of magnetocardiogram by a high temperature superconducting quantum interference device

高温超导量子干涉装置心磁图的临床应用

基本信息

批准号：
12672243
负责人：
NOMURA Masahiro
金额：
$ 1.73万
依托单位：
The University of Tokushima
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

We evaluated whether the cardiac electrical current could be visualized by displaying the current, density and whether the conduction velocity of electrical currents can be deduced obtained by a high temperature superconducting quantum interference device (high Tc-SQUID) using liquid nitrogen.Magnetic fields from heart were measured using a 32-channel high Tc-SQUID (Sumitomo Electric) in a magnetically shielded room. From the magnetic isofield maps, three-dimensional locations of dipolar currents during atrial or ventricurar depolarization phase were computed. Vector currents were obtained at 32 lead points based on the magnetic gradient, and a current density map were constructed.The conduction velocity during atrial depolarization was about 0.67 m/sec. The conduction velocity of dipolar current was about 0.85 m/sec at the initial ventricular depolarization phase. In a current distribution map obtained during ventricular depolarization, left and right ventricular electromotive forces could be visualized separately.Differing from ECG, magnetocardiography facilitates the accurate localization of the origin of electric current at mm-units, and conduction velocities of dipole can non-invasively deduced using this high Tc SQUID system. Previously, the detection of magnetic field from the heart required an expensive SQUID system using liquid helium. However, this system was characterized by its relative higher cost effectiveness and excellent spatial resolution. In addition, few studies have been done on the map which displays cardiac current density, which can potentially provide important information on electromotive forces. Therefore, this system can be clinically applied because it facilitates the detection of detailed cardiac electrical current.

我们用液氮高温超导量子干涉仪（high Tc-SQUID）测量了心脏的电流密度、电流密度以及电流的传导速度，并在磁屏蔽室中用32通道高Tc-SQUID测量了心脏的磁场。根据等场强图，计算心房或心室去极化相偶极电流的三维位置。根据磁场梯度在32个导联点获得矢量电流，并绘制电流密度图，心房除极时的传导速度约为0.67 m/sec。在心室除极初期，偶极电流的传导速度约为0.85米/秒。在心室除极过程中获得的电流分布图中，左、右心室电动势可以分别显示出来，与心电图不同，心磁图可以在毫米单位上精确定位电流的起源，并且利用这种高Tc SQUID系统可以无创地推导出偶极子的传导速度。以前，检测来自心脏的磁场需要使用液氦的昂贵SQUID系统。然而，该系统的特点是其相对较高的成本效益和良好的空间分辨率。此外，很少有研究已经完成的地图，显示心脏电流密度，这可能提供重要的信息电动势。因此，该系统可以在临床上应用，因为它有助于检测详细的心脏电流。