A Cryogen-Free, Low-Cost Atomic Magnetometer Array for Magnetoencephalography

用于脑磁图的无制冷剂、低成本原子磁力计阵列

• 批准号: 8471703
• 负责人: Peter D. D. Schwindt
• 金额: $ 76.52万
• 依托单位: SANDIA CORP-SANDIA NATIONAL LABORATORIES
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8471703
• 关键词: Accounting; Acoustic Nerve; Algorithms; Area; Auditory; Brain; Cells; Child; Clinical; Collaborations; Comparative Study; Computer software; Cost Savings; Coupled; Dementia; Devices; Electroencephalography; Elements; Epilepsy; Evaluation; Finland; Freedom; Frequencies; Functional Magnetic Resonance Imaging; Glass; Goals; Head; Helium; Helmet; Human; Image; Individual; Lasers; Lead; Left; Liquid substance; Location; Magnetism; Magnetoencephalography; Measurement; Measures; Mental Depression; Mental disorders; Metals; Mind-Body Method; Modeling; Modification; Neurons; Noise; Performance; Persons; Positioning Attribute; Radial; Research; Research Infrastructure; Resolution; Schizophrenia; Signal Transduction; Site; Source; Subject Headings; Surface; System; Techniques; Temperature; Validation; Work; auditory stimulus; base; cost; cryogenics; design; human subject; improved; instrument; magnetic field; median nerve; meter; millisecond; nervous system disorder; neural circuit; neuroimaging; optical fiber; programs; prototype; quantum; relating to nervous system; response; sensor; simulation; somatosensory; success; superconducting quantum interference device; tool

DESCRIPTION (provided by applicant): Functional neuroimaging has led to important advances in understanding neural circuits and has emerged as an important technique in the study of psychiatric and neurological disorders such as schizophrenia, dementia, depression, and epilepsy, where anatomical imaging is negative or shows only nonspecific findings. Magnetoencephalography (MEG) is the only noninvasive functional neuroimaging technique able to directly measure neural activity with sub-centimeter spatial and millisecond temporal resolution, but its potential as a research and clinical tool has yet to be realized on a large scae due to its high acquisition and operating costs. A large portion of the cost results from the use o superconducting quantum interference device (SQUID) magnetic sensors that must be cooled with liquid helium. The cryogenic infrastructure results in a bulky MEG system that requires installation of a large magnetically shielded room to achieve acceptably low background levels and that has a fixed sensor array geometry that cannot be adjusted for head size. The goal of the proposed work is to develop a small, low-cost MEG system using an array of atomic magnetometers (AMs) as replacements for SQUIDs. AMs can achieve sensitivities comparable to SQUIDs but do not require cryogenic cooling. AMs detect magnetic fields by measuring, via laser interrogation, the interaction between a magnetic field and atoms contained within a glass cell. Recently, we developed a compact optical fiber-coupled AM and used it to detect MEG signals from human subjects. Based on these preliminary studies, we propose to develop a 36-channel array of AMs with partial-head coverage (roughly 12 cm X 12 cm) that is able detect and localize neuronal activity. In Specific Aim #1, we will design critical components of the proposed AM MEG system, including the individual AMs that serve as array elements and a person-sized magnetic shield to contain the AM-array and the human subject. Commercially available magnetic source localization software will be adapted to our array geometry. One AM will be constructed and its performance will be verified at go/no-go specifications of >100 Hz bandwidth and 20 fT/Hz1/2sensitivity. In Specific Aim #2, the AM MEG system will be constructed and its source localization accuracy will be determined by detecting an MEG phantom with the AM array geometry reconfigured to mimic a variety of head sizes. Human studies will commence only after demonstrating sub-centimeter spatial resolution. In Specific Aim #3, the AM system will be compared to a commercial SQUID MEG system by measuring the evoked response in human subjects from median nerve and auditory stimuli with both systems. A successful comparison will identify a neural source in terms of strength and location to within one standard deviation error between the two systems. The results of the proposed work are expected to clear the path for developing a full-head- coverage low-cost AM MEG system that can be adapted to accommodate a wide variety of head sizes.

描述（由申请人提供）：功能性神经影像学已经在理解神经回路方面取得了重要进展，并在精神病和神经系统疾病的研究中成为一种重要技术，例如精神分裂症，痴呆，抑郁症，抑郁症和癫痫病，在解剖学成像是阴性或仅显示非特异性发现的情况下。磁脑摄影（MEG）是唯一一种能够通过次级空间和毫秒的时间分辨率直接测量神经活动的非侵入性功能神经影像学技术，但是由于其高收购和运营成本，其作为研究和临床工具的潜力尚未实现在大型SCAE上。大部分成本是由使用o超导量子干扰装置（squid）磁性传感器所产生的，必须用液体氦气冷却。低温基础架构导致了一个庞大的MEG系统，该系统需要安装大型磁性屏蔽室以达到可接受的低背景水平，并且具有无法调整头部大小的固定传感器阵列几何形状。建议的工作的目的是使用一系列原子磁力计（AMS）作为鱿鱼的替代品开发一个小型低成本的MEG系统。 AM可以达到与鱿鱼相当的敏感性，但不需要低温冷却。 AMS通过激光审问测量磁场与玻璃单元中包含的原子之间的相互作用来检测磁场。最近，我们开发了一个紧凑的光纤耦合AM，并将其用于检测来自人类受试者的MEG信号。基于这些初步研究，我们建议开发具有部分头部覆盖率（大约12 cm x 12 cm）的36通道AM阵列，该AM能够检测和定位神经元活性。在特定的目标＃1中，我们将设计提出的AM MEG系统的关键组件，包括用作阵列元素的单个AM和人尺寸的磁性屏蔽，以包含AM-Argray和人类受试者。市售的磁源定位软件将适应我们的阵列几何形状。将构建一个AM，并在> 100 Hz带宽和20 ft/hz1/2sensitive的GO/NO-GO规格中验证其性能。在特定的AIM＃2中，将构建AM MEG系统，并通过检测具有AM阵列几何形状重新配置以模拟各种头大小的MEG Phantom来确定其源定位精度。人类研究只有在证明亚中心空间分辨率后才开始。在特定的目标＃3中，通过测量两个系统中正中神经和听觉刺激的人类受试者的诱发反应，将AM系统与商业鱿鱼MEG系统进行比较。成功的比较将在强度和位置方面确定神经来源，以在两个系统之间的一个标准偏差误差范围内。预计拟议工作的结果将清除开发全面覆盖的低成本AM MEG系统的路径，该系统可以适应以适应各种头大小。