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

在本研究中，使用高温(-196ﾟC)超导量子干涉装置(SQUID)记录了心磁图和胃磁图。这是第一个多通道高T_c SQUID系统，它的操作比传统的液氦SQUID系统简单得多。1.心磁图：本研究记录了144个位置(16个通道×9个扫描)的胸壁前壁的心磁图，并在心室除极和复极时绘制了等磁图。根据毕奥-萨伐尔定律，本研究中的等磁图显示了心脏的瞬时电流源。在QRS波和T波时相，推导出的电流偶极子与传统的SQUID传感器的电流偶极子吻合得很好。2胃磁图：在本研究中，检测到了胃中磁化物质的位置运动产生的磁场。一个磁化的钢球被固定在胃管的顶端。在空腹或进食状态下，将直径1.3 mm的钢球放置在胃窦内。将磁传感器放置在上腹部区域上方，并在磁屏蔽室中测量胃运动产生的磁信号。滤除DC-0.1赫兹的磁记录带宽后，可清楚地看到反映胃运动的有规律的3周/分信号。进食后的磁场比禁食状态下的磁场大。两种状态下胃运动峰值频率差异无统计学意义。3结论：该方法有望为各种心脏和胃部疾病的诊断和治疗提供帮助。

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.