相关实验视频
Updated: Jun 24, 2025

09:32
Cortical Source Analysis of High-Density EEG Recordings in Children
Published on: June 30, 2014
21.3K
在3层BEM模型中的二极管源重建的准确性与5层BEM-FMM模型相比
Guillermo Nuñez Ponasso1, Ryan C McSweeney1, William A Wartman1
1Dept. of Electrical and Computer Engineering, Worcester Polytechnic Institute, Worcester, MA, USA.
bioRxiv : the preprint server for biology
|June 3, 2024
概括
现实的5层模型提高了脑电图 (EEG) 源重建的准确性,特别是适应性网状精细化 (AMR). 简化的三层模型提供了良好的定位,但不太准确的定位,突出了临床应用中需要详细模型的需求.
科学领域:
- 神经科学是一个神经科学.
- 生物物理学的生物物理.
- 计算建模 计算建模
背景情况:
- 电脑电图 (EEG) 对于理解大脑活动至关重要.
- 精确的来源重建依赖于精确的头部建模.
- 目前的模型的复杂性各不相同,影响空间精度.
研究的目的:
- 为了比较简单的三层和现实的五层边界元素方法-快速多极方法 (BEM-FMM) 模型之间的二极管适配的空间精度.
- 评估适应性网状精细化 (AMR) 对模型准确性的影响.
主要方法:
- 15名受试者的模拟无噪声256通道EEG数据使用5层 (7区) 网格生成.
- 使用BEM-FMM与AMR和没有AMR进行了前向建模.
- 用FieldTrip MATLAB工具箱进行双极合适.
主要成果:
- 平均位置误差为~4毫米,方向误差为~20°.
- 在没有AMR的情况下,与5层模型相比,3层模型显示出更大的差异 (~8毫米的位置误差).
- 在5层模型中,AMR显著提高了准确性.
结论:
- 低分辨率的三层模型提供了良好的二极管定位精度,但更不准确的方向.
- 在某些应用中,需要现实的5层模型来准确重建源.
- 用高分辨率模型提高前置EEG计算的准确性至关重要.
相关概念视频
Calculations of Electric Potential II
1.7K
An electric dipole is a system of two equal but opposite charges, separated by a fixed distance. This system is used to model many real-world systems, including atomic and molecular interactions. One of these systems is the water molecule, but only under certain circumstances. These circumstances are met inside a microwave oven, where electric fields with alternating directions make the water molecules change orientation. This vibration is equivalent to heat at the molecular level.
Consider a...
Consider a...
1.7K
Diamagnetic Shielding of Nuclei: Local Diamagnetic Current
849
An applied magnetic field causes the electrons present in the molecule to circulate, setting up a local diamagnetic current within the molecule. The local diamagnetic current arising from circulating sigma-bonding electrons induces a magnetic field, Blocal that opposes the applied magnetic field, B0. The effective magnetic field experienced by these nuclei is given by the difference between the applied and local magnetic fields in a phenomenon called local diamagnetic shielding. Essentially,...
849
Diamagnetism
2.4K
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
2.4K
Potential Due to a Magnetized Object
282
Magnetic dipoles in magnetic materials are aligned when placed under an external magnetic field. For paramagnets and ferromagnets, dipole alignment occurs in the direction of the magnetic field. However, the dipoles align opposite to the field in the case of diamagnets. This state of magnetic polarization due to the external field is called magnetization. Magnetization is defined as the dipole moment per unit volume. It plays a similar role to polarization in electrostatics.
The vector...
The vector...
282
Induced Electric Dipoles
4.2K
A permanent electric dipole orients itself along an external electric field. This rotation can be quantified by defining the potential energy because the external torque does work in rotating it. Then, the potential energy is minimum at the parallel configuration and maximum at the antiparallel configuration. While the former is a stable equilibrium, the latter is an unstable equilibrium.
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
Since the absolute value of potential energy holds no physical meaning, its zero value can be chosen as per...
4.2K
Electric Dipoles and Dipole Moment
5.1K
Consider two charges of equal magnitude but opposite signs. If they cannot be separated by an external electric field, the system is called a permanent dipole. For example, the water molecule is a dipole, making it a good solvent.
Theoretically, studying electric dipoles leads to understanding why the resultant electric forces around us are weak. Since electric forces are strong, remnant net charges are rare. Hence, the interaction between dipoles helps us understand electrical interactions in...
Theoretically, studying electric dipoles leads to understanding why the resultant electric forces around us are weak. Since electric forces are strong, remnant net charges are rare. Hence, the interaction between dipoles helps us understand electrical interactions in...
5.1K

