Recording of biomagnetic fields, especially magnetocardiogram and magnetogastrogram, using a high-temperature (-196ﾟC) superconducting quantum interference device

本研究采用高温（-196℃）超导量子干涉器件（SQUID）记录了心脏磁图和胃磁图。这是第一个多通道高tc SQUID系统，其操作比使用液氦的传统SQUID系统简单得多心磁图：本研究记录前胸壁144个位置（16通道* 9次扫描）的心磁图，绘制心室去极化期和复极化期等磁图。在本研究中检查的等磁图通过应用“Biot-Savart定律”来指示心脏的瞬时电流源。在QRS波和T波相位，推导出的电流偶极子与传统SQUID传感器的偶极子吻合较好胃磁图：在本研究中，检测胃中位置磁化物质运动产生的磁场。一个磁化的钢球被固定在胃管的尖端。在禁食或喂食状态下，将外径1.3 mm的钢球放置于胃窦内。在胃上区上方放置一个磁传感器，在磁屏蔽室内测量胃运动产生的磁信号。将DC-0.1 Hz的磁记录带宽滤除后，可以清晰地看到指示胃运动的规律的3周期/分钟信号。进食后的磁场比禁食时更大。两种状态下胃动力峰值频率差异无统计学意义结论：该方法有望为各种心脏和胃疾病的诊断和治疗做出贡献。

In the present study, magnetocardiogram and magnetogastrogram were recorded using a high-temperature (-196ﾟC) superconducting quantum interference device (SQUID). This is the first multi-channel high-Tc SQUID system and its operation is much simpler than that of the conventional SQUID system that uses liquid helium.1 Magnetocardiogram : In this study, magnetocardiogram were recorded in 144 positions (16 channels * 9 scans) of the anterior chest wall and isomagnetic maps were constructed at the ventricular depolarization and repolarization phases. The isomagnetic maps examined in this study indicated the instantaneous current source of the heart by applying the "Biot-Savart Law". At the phase in QRS and T waves, the deduced current dipoles were coincide well with those from the conventional SQUID sensor.2 Magnetogastrogram : In this study, a magnetic field generated by the movement of magnetized material positional in the stomach was detected. A magnetized steel ball was attached to the tip of a stomach tube. The steel ball (OD,1.3 mm) was positioned in the antrum in a fasting or fed state. A magnetic sensor was placed above the epigastric region and magnetic signals produced by gastric motility were measured in magnetically shielded room. After the magnetic recording bandwidth at DC-0.1 Hz was filtered out, the regular3-cycle/min signal, which indicated gastric motility, was clearly visible. the magnetic field was larger after ingestion of food than in the fasting state. The peak frequency of gastric motility was not statistically different between the two states.3 Conclusions : This new method is expected to contribute to the diagnosis and the management of various cardiac and gastric disorders.