摘要
心磁图的原理是对心动周期中 ,心脏电活动引起的微小磁场进行测定。极为敏感的探头是一个超导量子介入装置(SQUID) ,它在低温保持器中使用液氦冷却( -269℃) ,能够以二维分辨率探测和量化非常微弱的磁信号。在过去 ,由于仪器内噪声和外部电磁源对其精确性和稳定性都有巨大影响 ,因此大部分系统要求检查室内设有特殊的且造价很高的磁屏蔽设施。SQUIDMCG1通过选择特殊材料制作检查床和低温保持器 ,确保最大限度降低系统内噪。任何可能由螺丝或漆料中所含微粒引起的磁干扰都被有效避免。探头部分复杂精密的主动和被动磁屏蔽技术的发展 ,使该系统能够在普通的无屏蔽的房间内进行安装。它的可自动移动检查床与固定探头的结合可以记录出20×20cm心脏电磁活动图。
The principle of magnetocardiography is based on the measurement of minimal magnetic field,caused by the electrical activity of the heart during the cardiocycle.Extremely sensitive sensors,Superconductive Quantum Interference Device (SQUID),cooled in a cryostat with liquid helium(-269℃),can detect and quantify the very weak magnetic signals with 2 dimensional resolution.However,in the past the intrinsic noise of the equipment and external electromagnetic sources used to have a big influence on the accuracy and stability of the measurement.In the past,most of the systems required a special and very expensive magnetic shielding of the examination room. The magnetocardiograph MCG1 from SQUID ensures maximum intrinsic noise reduction by using specially selected materials for the table and the cryostat.Any magnetic disturbance,caused by metal screws or particles in the paint,is avoided.The development of a sophisticated active and passive magnetic shielding of the detector allows installing the system even in tegular,unshielded rooms.The automatically moving patient table,in combination with a rigid detector,gives the possibility of recording20×20cm maps of the electromagnetic activity of the heart.
出处
《医疗设备信息》
2001年第3期1-4,共4页
Information of Medical Equipment
关键词
生物磁学
心磁图
超导量子干涉仪
Biomagnetism
Magnetocardiography
Superconductin quantum Interference device(SQUID)
