Supine opm-meg in multilayer cylindrical shield

Abstract

Recent development of compact optically pumped magnetometer (OPM) operating in room temperature has offered a new way for magnetoencephalography (MEG). Traditional MEG and most of current OPM-MEG studies are conducted in a magnetically shielded room (MSR), which prevents MEG to be used frequently in general clinical sites due to its high cost and large space requirements. In this chapter, we review and discuss the potential of OPM-MEG with a supine subject placement strategy in a multilayer cylindrical shield. We use two-beam OPMs that are free of extra modulation for signal detection with potentially no cross-talk effect even closely attached to each other. The design of cylindrical shields with four or more layers to replace current commercial MSR is discussed. Such compact shield could largely reduce the cost of materials as well as the weight, while achieving a smaller residual magnetic field at the same time. Finally, we briefly introduce an automatic head-to-anatomy co-registration method based on optical scanning for OPMs, and preliminary multichannel auditory evoked responses as well as source imaging result are presented.