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.

我们评估了是否可以通过显示电流、密度来可视化心脏电流，以及是否可以通过使用液氮的高温超导量子干涉装置（高Tc-SQUID）来推断电流的传导速度。来自心脏的磁场使用 32 通道高 Tc-SQUID（Sumitomo Electric）在磁屏蔽室中进行测量。根据磁等场图，计算心房或心室除极阶段偶极电流的三维位置。根据磁梯度在32个导联点获得矢量电流，并构建电流密度图。心房除极时的传导速度约为0.67 m/sec。在心室除极初始阶段，偶极电流的传导速度约为0.85 m/sec。在心室除极过程中获得的电流分布图中，可以分别可视化左心室和右心室电动势。与心电图不同，心磁图有助于以毫米为单位精确定位电流源，并且偶极子的传导速度可以无创地测量使用这种高 Tc SQUID 系统推导出来。以前，检测心脏磁场需要使用液氦的昂贵 SQUID 系统。然而，该系统的特点是相对较高的成本效益和优异的空间分辨率。此外，对显示心脏电流密度的地图进行的研究很少，这可能提供有关电动势的重要信息。因此，该系统可以在临床上应用，因为它有利于详细的心脏电流的检测。