脑磁图仪的前世今生与未来

Magnetoencephalography:the past,present and future

脑磁图仪通过记录大脑神经活动在头皮外产生的磁场来进行脑活动的成像,它具备超高的时间分辨率和较高的空间分辨率,是一种重要的无创脑功能成像技术。文章介绍了脑磁信号的神经生理起源、生物物理特征及其与脑电信号的联系和区别,回顾了当前基于超导量子干涉仪的脑磁图设备与相关技术,并针对制约当前超导脑磁图发展的技术瓶颈,介绍了基于原子磁强计的新型脑磁探测技术及国内相关研究的最新进展,指出了脑磁图在脑科学研究及临床应用中不可或缺的地位和其硬件技术未来发展的方向。

Magnetoencephalography(MEG)is a non-invasive functional brain imaging technique that detects and maps the magnetic fields generated by neural activities.It has a combination of ultra-high temporal resolution and relatively high spatial resolution.In this paper,the neurophysiological and biophysical basis of MEG signals is described.While sharing some similarities with electroencephalography,MEG has different distinct features.We first review the current traditional MEG system that employs a superconducting quantum interference device(SQUID)and related technologies.In response to its limitations,a new technique to detect magnetic fields in the brain has been developed based on the optically-pumped magnetometer(OPM).From this we observe that MEG is an irreplaceable functional brain imaging modality for both neuroscience research and clinical applications,and that OPM technology has the great potential to open up a new avenue for the future development of MEG.