Non-cryogenic Fieldable Interleaved Magnetoencephalography and Magnetic Resonance Imaging based on Multichannel Atomic Magnetometers

该提案旨在开发第一个非低温可现场多通道系统，以使交错 超低场磁共振成像(MRI)和磁感应强度的测量 人脑的脑电图(MEG)。这两种模式的组合能够唯一地将 脑特定解剖结构的生物磁脑活动(MEG)来源(URF MRI) 卓越的时间和空间分辨率。此外，这种组合基本上消除了联合配准错误 基于常用的MEG-MRI坐标系。这项先进的生物医学技术将增强 了解人脑功能，帮助诊断和治疗多发性脑疾病，如 癫痫灶，完善神经外科手术计划。此前，脑磁图-核磁共振组合只实现了 使用多个低温超导量子干涉器件(SQUID)传感器。然而，需求 因为低温冷却和屏蔽室是一个主要缺点。我们将通过更换设备来构建更实用的设备 一种新型的原子磁强计(AMS)的鱿鱼。基于激光和碱金属蒸气电池 是目前最灵敏的无低温磁性传感器。具体目标是：(1)开发原创 紧凑型16通道AM模块，适用于MEG。它基于单个大型 蒸汽室和两束宽广的近乎平行的激光。这种新方法大大降低了成本 与商业的基于SQUID的MEG系统相比。(2)制作可穿戴的全头式脑磁图头盔。我们会 生产15-20个紧凑型AM MEG模块，用于安装在头盔上，最多可覆盖320个头盔 频道。由于激光到光纤的耦合，模块位置将根据不同的磁头几何形状进行调整 以使传感器更接近头部。这将改善本地化和敏感度。我们将获得 带有脑磁图头盔的功能性脑图。(3)构建了一种新的基于单通道超高频磁共振成像的多通道设备。 模块多通道AM耦合到多个磁通变压器(FT)。对于MRI，AM设计将修改为 允许使用正交激光束，然后施加偏置磁场以将AM调谐到目标MRI频率 大约200千赫。每个FT将由两个相连的线圈组成，一个位于人头附近，另一个位于人头附近 在AM蒸汽室附近，将MRI信号传输到AMFT线圈可以灵活地围绕 人头来增强核磁共振信号。我们将演示人类头部的超低频核磁共振测量 优化的FT阵列。(4)将全头式脑磁图头盔和超高频磁共振成像设备结合在一台仪器中。 这种组合将通过将MRI FT线圈连接到MEG头盔来实现。将安装该设备 在屏蔽室中进行可行性验证，然后在人体大小的圆柱形金属磁屏蔽中进行 支持移动应用程序。我们将对大脑活动和结构进行交错成像， 时间和空间分辨率。我们还将开发用于数据采集/分析的脑磁图和核磁共振算法，并 高精度生物磁源定位。

This proposal aims to develop a first non-cryogenic fieldable multichannel system to enable interleaved measurements of magnetic resonance imaging (MRI) in the ultra-low field (ULF) regime (<< 1 T) and magneto- encephalography (MEG) of the human brain. The combination of the two modalities is uniquely capable of linking the sources of biomagnetic brain activity (MEG) to the specific anatomical brain structure (ULF MRI) with both excellent temporal and spatial resolution. In addition, the combination essentially eliminates co-registration errors based on the common MEG-MRI coordinate system. This advanced biomedical technology will enhance understanding of human brain function, aid in diagnosis and treatment of multiple brain disorders such as the epileptic focus, and improve neurosurgical planning. Previously, the MEG-MRI combination was realized only using multiple cryogenic superconducting quantum interference device (SQUID) sensors. However, the demand for cryo-cooling and a shielded room is a major drawback. We will build a more practical device by replacing SQUIDs with a novel type of atomic magnetometers (AMs). Based on lasers and alkali-metal vapor cells, AMs are currently the most sensitive cryogen-free magnetic sensors. Specific aims are to: (1) Develop an original compact 16-channel AM module for MEG. It delivers a large number of sensing channels based on a single large vapor cell and two broad nearly parallel laser beams. This new approach leads to significant cost reduction compared to commercial SQUID-based MEG systems. (2) Construct a wearable full-head MEG helmet. We will produce 15–20 compact AM MEG modules for mounting on a helmet for full-head coverage with up to 320 channels. Due to the laser-to-fiber coupling, the module positions will be adjustable for different head geometries for closer proximity of sensors to the head. This will result in improved localization and sensitivity. We will obtain functional brain maps with the MEG helmet. (3) Construct a new multichannel ULF MRI device based on a single- module multichannel AM coupled to multiple flux transformers (FTs). For MRI, the AM design will be modified to allow orthogonal laser beams, and a bias magnetic field will be applied to tune the AM to target MRI frequencies of ~200 kHz. Each FT will be composed of two connected coils, one located near the human head and the other near the AM vapor cell, to transfer MRI signals to the AM. The FT coils can be flexibly arranged around the human head to enhance an MRI signal. We will demonstrate ULF MRI measurements of the human head with an optimized FT array. (4) Combine the full-head MEG helmet and the ULF MRI device in a single instrument. The combination will be achieved by attaching the MRI FT coils to the MEG helmet. The device will be installed in a shielded room for a proof of feasibility and then in a human-sized cylindrical mu-metal magnetic shield for enabling mobile applications. We will perform interleaved imaging of brain activity and structure with high temporal and spatial resolution. We will also develop MEG and MRI algorithms for data acquisition/analysis and high accuracy biomagnetic source localization.