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，我们建议测试基于简单但新颖的主源镜像概念（PRISM）的神经科学扫描磁力测定法的可行性。棱镜可以通过不同的设计制成，但是在这个项目中，它将是一个充满空气的玻璃移液器，末端有一个小玻璃板，倾斜45o。我们声称，当我们完成该项目的II期时，该镜像可用于可视化电流分布，而空间分辨率高达10 5M，而无需在体外神经元组织中的源分布。众所周知，导电介质外的磁场，例如装有盐水或人头的浴室，仅是由于电流与导电边界相切。就人头而言，磁脑电图（MEG）仅测量脑空气边界的切线（而不是径向）。在浴中的神经元组织的情况下，磁场仅是由于电流切线而不是垂直于浴场。这种基本限制限制了生物磁法的使用。在第一阶段，我们将使用物理幻影中的棱镜来测试棱镜是否会使浴中的垂直方向电流“可见”。当将此镜子浸入神经组织上方的生理盐水浴中时，当神经元的群体在镜子下方产生垂直或水平的细胞内电流时，它将产生所谓的二级源垂直于其表面。根据我们的仿真研究，棱镜上的二级源的水平成分将使垂直电流“可见”到浴缸上方的磁力计。我们将使用边界元素方法将结果与逼真的仿真研究进行比较，以完全表示实验条件。我们将进一步评估该技术的两个重要特性，这些特性可能使我们能够在II期中开发高分辨率扫描磁力测定法。我们将测试我们的说法：（1）空间分辨率主要取决于下面的镜像和活性神经元之间的距离，而不是浴场上方的磁场感应线圈和活动神经元的体积之间的距离，以及（2）空间分辨率与二型线圈尺寸无关（在合理的限制内）。这些结果将使我们能够在II期中开发新的高分辨率扫描磁力测定法。 公共卫生相关性：这项简单而新颖的发明将扩大磁力测定法的应用，因为它将使我们能够获得生物组织中当前分布的图像，其中包含任何方向上的水流，并具有空间分辨率的空间分辨率。扫描磁力测定应成为在体外直接高分辨率成像的直接高分辨率成像的生物医学研究中的重要新工具，例如生物组织中的神经电流。该技术原则上也可以应用于人类MEG研究。