Improved Spatial Resolution in Magnetoencephalography with an Optically Pumped Magnetometer Array

使用光泵磁力计阵列提高脑磁图的空间分辨率

• 批准号: 9552418
• 负责人: Peter D. D. Schwindt
• 金额: $ 69.98万
• 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 2019-03-26
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9552418
• 关键词: Acoustic Stimulation; Adult; Affect; Anterior; Area; Auditory; Auditory area; Brain; Brain Diseases; Brain imaging; Calibration; Child; Clinical; Communication; Cortical Column; Data; Development; Diagnosis; Discrimination; Early identification; Electroencephalography; Epilepsy; Frequencies; Functional Imaging; Functional Magnetic Resonance Imaging; Goals; Head; Helmet; Human; Individual; Lead; Longevity; Magnetism; Magnetoencephalography; Measurement; Measures; Neurons; Neurosciences; Noise; Operative Surgical Procedures; Optics; Outcome; Participant; Patients; Photic Stimulation; Positioning Attribute; Premature Infant; Pump; Research; Resolution; Scalp structure; Shapes; Signal Transduction; Source; Stimulus; System; Techniques; Temperature; Testing; Time; Variant; Visual; aged; attenuation; base; brain dysfunction; brain surgery; cost; cryogenics; design; developmental disease; flexibility; frontal lobe; human imaging; improved; insight; interest; magnetic field; millimeter; millisecond; neuroimaging; pediatric patients; prevent; relating to nervous system; response; sensor; signal processing; simulation; somatosensory; source localization; superconducting quantum interference device; temporal measurement; tool

Project Summary/Abstract The fixed helmet design of commercially available magnetoencephalography (MEG) systems utilizing superconducting quantum interference device (SQUID) magnetometers is designed to fit the 95th percentile of head size and therefore gives suboptimal measurements of the MEG signals for most subjects, especially children. A small head size will result in a gap between the helmet and head of several centimeters, and since the MEG signal amplitude decays as 1/r3, where r is the distance from the neuronal source, this large gap can result in signal attenuation by a factor of ~10. Therefore, placing the sensors on to the head will lead to increases in signal amplitude. Additionally, if sensors are placed on or near the scalp, high spatial frequency variations in the magnetic field will be detectable. Combining these factors, substantially improved spatial resolution in localizing neuronal sources will be enabled. Recent developments in sensor design now makes optically pumped magnetometers (OPMs) ideal for application to the field of MEG, and since they operate above room temperature and can be constructed as individual sensor modules, the sensor layout can be flexible. The long-term goal of this research is to develop a full-head MEG system based on OPMs that can conform to any head size to give the largest possible signal while at a reduced cost compared to cryogenic MEG. The objective of this proposal is to develop a 72-channel OPM MEG system giving partial head coverage to demonstrate improved spatial resolution in the measurement of nearby neuronal sources within the human brain. The system will be rapidly reconfigurable to concentrate the array coverage on an area of interest. Our central hypothesis is that the close proximity of the OPM array will allow a new level of spatial resolution for MEG. In Specific Aim 1, our current OPM-based MEG array with 20 channels will be expanded to a reconfigurable 72-channel system. The reconfigurable array will accommodate varying head sizes, particularly that of small adults and children, and the number of sensors will allow the array to be concentrated over two sections of the brain simultaneously. In Specific Aim 2, analysis techniques specific to the reconfigurable array will be developed. When the array is repositioned for each new subject, real-time array calibration is required for accurate magnetic source localization and external noise suppression. In addition, data simulation will optimize the positioning of the array and reveal the possible improvements in source localization due to access to signals of higher spatial complexity. In Specific Aim 3, the source localization precision between our OPM MEG array and a commercial SQUID-based MEG array will be compared. Tasks involving auditory and visual stimulation will allow us to study spatial variation of brain activity due to changing stimulus parameters. With the expected improvements in signal size and spatial resolution, higher fidelity MEG measurements for people of all head sizes ranging from premature infants to the largest adults are enabled, with broad ranging applications in neuroscience and in understanding and treating brain dysfunction.

项目摘要/摘要 利用市售磁脑摄影（MEG）系统的固定头盔设计 超导量子干扰装置（squid）磁力计设计为适合第95个百分点 头大小，因此给出了大多数受试者的MEG信号的次优测量 孩子们。头部尺寸很小会导致头盔和几厘米的头部之间的缝隙，并且 MEG信号振幅衰减为1/r3，其中r是距神经元来源的距离，这个较大的间隙可以 导致信号衰减约为10。因此，将传感器放在头上将导致 信号振幅增加。此外，如果传感器放置在头皮上或附近，则高空间频率 可以检测到磁场的变化。结合这些因素，大大改善了空间 将启用有关本地化神经元来源的分辨率。传感器设计的最新发展现在 光学泵送磁力计（OPMS）非常适合应用于MEG领域，并且由于它们运行 高于室温，可以作为单个传感器模块构造，传感器布局可以是 灵活的。这项研究的长期目标是开发基于OPM的全头MEG系统 符合任何头部尺寸，以降低成本，以发出最大可能的信号 梅格。该提案的目的是开发一个72通道OPM MEG系统，使部分头部 在测量附近神经元来源中，覆盖范围可以改善空间分辨率 人脑。该系统将迅速重新配置，以将阵列覆盖集中在 兴趣。我们的中心假设是OPM阵列的近距离将允许新的空间水平 梅格的决议。在特定目标1中，我们当前基于OPM的MEG阵列将扩展到20个渠道 可重新配置的72通道系统。可重新配置的阵列将容纳不同的头大小， 特别是成年人和儿童的，传感器的数量将允许阵列集中 大脑的两个部分同时。在特定目标2中，分析技术特定于 将开发可重新配置的阵列。为每个新主题重新定位阵列时，实时数组 准确的磁源定位和外部噪声抑制需要校准。此外， 数据模拟将优化数组的定位，并揭示源的可能改进 由于获得了较高的空间复杂性信号而导致的本地化。在特定的目标3中，来源本地化 将比较我们的OPM MEG阵列与基于商业鱿鱼的MEG阵列之间的精确度。任务 涉及听觉和视觉刺激将使我们能够研究随着变化而研究大脑活动的空间变化 刺激参数。信号大小和空间分辨率的预期改善，较高的保真度MEG 启用了从早产婴儿到最大成年人的所有头大小的人的测量 在神经科学以及理解和治疗脑功能障碍中的广泛应用。