High Resolution Scanning Magnetometry

高分辨率扫描磁力计

• 批准号: 8201288
• 负责人: Yoshio Okada
• 金额: $ 15万
• 依托单位: MOMENT TECHNOLOGIES, LLC
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2013-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8201288
• 关键词: Air; Area; Bathing; Biological; Boundary Elements; Brain; Caliber; Cells; Detection; Dimensions; Glass; Head; Human; Image; In Vitro; Laws; Magnetoencephalography; Magnetometries; Measures; Medical Research; Methods; Neurons; Neurosciences; Phase; Physiological; Population; Property; Radial; Resolution; Saline; Scanning; Silver; Slice; Source; Surface; Techniques; Testing; Tissues; base; brain tissue; cranium; design; detector; electromagnetism; magnetic field; millimeter; novel; relating to nervous system; research study; simulation; tissue culture; tool

DESCRIPTION (provided by applicant): In Phase I we propose to test the feasibility of developing a high-resolution scanning magnetometry for neuroscience based on a simple, but novel concept of primary source mirror (PRISM). The PRISM can be made with different designs, but in this project it will be an air-filled glass pipette with a small glass plate at the end with a tilt of 45o toward bottom. We claim that this mirror can be used to visualize the current distribution regardless of source orientations in an in vitro neuronal tissue with a spatial resolution as high as 10 5m when we complete the Phase II of this project. It has been well known that the magnetic field outside a conducting medium such as a bath filled with saline or the human head is solely due to currents tangential to the conducting boundary. In the case of human head, magnetoencephalography (MEG) measures only the currents tangential, but not radial, to the brain-air boundary. In the case of a neuronal tissue in a bath, the magnetic field is solely due to currents tangential, but not perpendicular, to bath surface. This fundamental limitation has restricted the use of biomagnetometry. In Phase I we will use the PRISM in a physical phantom to test whether the PRISM will make the vertically oriented currents in a bath "visible". When this mirror is submerged in a bath of physiological saline just above a neural tissue, it will produce the so- called secondary source oriented perpendicular to its surface when a population of neurons produces vertical or horizontal intracellular currents below the mirror. According to our simulation study, the horizontal component of the secondary source on the PRISM will make the vertical current "visible" to a magnetometer above the bath. We will compare the results with a realistic simulation study using a boundary element method to fully represent the experimental condition. We will further evaluate two important properties of this technique that may enable us to develop a high resolution scanning magnetometry in Phase II. We will test our claim that: (1) the spatial resolution primarily depends on the distance between the mirror and active neurons below, instead of the distance between the magnetic field sensing coils above the bath and the volume of active neurons, and (2) the spatial resolution is independent of the dection coil size (within reasonable limits). These results will enable us to develop a novel high-resolution scanning magnetometry in Phase II. PUBLIC HEALTH RELEVANCE: This simple, but novel invention will expand applications of magnetometry since it will enable us to obtain images of current distribution in biological tissues, containing currents in any directions with an unprecedent-ed level of spatial resolution. The scanning magnetometry should become an important new tool in bio-medical research in the area of direct high resolution imaging of electrical currents such as neural currents in biological tissues in vitro. This technique can be in principle applied to human MEG studies as well.

描述(由申请人提供)：在第一阶段，我们建议测试基于一种简单但新颖的初级源镜(PRISM)概念开发用于神经科学的高分辨率扫描磁学的可行性。棱镜可以有不同的设计，但在这个项目中，它将是一个充气的玻璃移液管，末端有一个向底部倾斜45度的小玻璃板。我们声称，当我们完成这个项目的第二阶段时，这个镜子可以用来可视化体外神经元组织中的电流分布，而不考虑源的方向，空间分辨率高达105m。众所周知，诸如充满生理盐水的浴缸或人头之类的导电介质外部的磁场仅仅是由于与导电边界相切的电流。以人头为例，脑磁图(MEG)只测量与脑-空气边界相切的电流，而不是径向的电流。对于浴缸中的神经细胞组织，磁场完全是由于电流与浴缸表面相切而不是垂直的。这一基本限制限制了生物磁学的使用。在第一阶段中，我们将在一个物理模型中使用棱镜来测试棱镜是否会使浴缸中垂直方向的电流“可见”。当这面镜子被浸在神经组织上方的生理盐水浴中时，当一群神经元在镜子下面产生垂直或水平的细胞内电流时，它将产生与其表面垂直的所谓二次源。根据我们的模拟研究，棱镜上二次源的水平分量将使垂直电流在浴缸上方的磁强计中“可见”。我们将使用边界元方法将结果与真实的模拟研究进行比较，以完全代表实验条件。我们将进一步评估这项技术的两个重要性质，这可能使我们能够在第二阶段开发高分辨率扫描磁学。我们将检验我们的主张：(1)空间分辨率主要取决于镜面和下方活动神经元之间的距离，而不是浴缸上方磁场感应线圈和活动神经元体积之间的距离；(2)空间分辨率与检测线圈的大小无关(在合理范围内)。这些结果将使我们能够在第二阶段开发一种新的高分辨率扫描磁学。 与公共健康相关：这项简单但新颖的发明将扩大磁测量的应用，因为它将使我们能够获得生物组织中电流分布的图像，以前所未有的空间分辨率包含任何方向的电流。在生物组织中神经电流等电流的直接高分辨率成像领域，扫描磁测技术应该成为生物医学研究中的一种重要的新工具。这项技术原则上也可以应用于人类脑磁图研究。