Identification of Dipoles in Bioengineering

生物工程中偶极子的识别

• 批准号: 11650068
• 负责人: OHNAKA Kohzaburo
• 金额: $ 1.09万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650068/
• 关键词: Inverse Source Problem; Dipole Model; Poisson Equation; Boundary Integral; Charge Simulation Method; Magnetoencephalogram; 数値計算アルゴリズム

An important problem in bioengineering is to identify the activity of human brain from observation data of magnetic fields called Magneto Encephalo Gram. Many researchers assume spherically symmetric conductor model for the human head and dipole model for the activity of human brain. Our problem is to identify locations, moments, and number of dipoles in human brain from observations of magnetic induction outside of human head.Before this project, we have already proposed the following two methods.Method 1: Local search method based on weighted integrals for the two-dimensional caseMethod 2: Global search method based on an extension of observations to the interior of three-dimensional domainIn this project, we extend Method 1 to three-dimensional problem, and give error estimates of identified results. However, Method 1 needs a priori information of locations, moments, and number of dipoles. Method 2 is applicable without any a priori information of dipoles. We construct a new method combining Method 1 and Method 2. Our proposed method gives reasonable identification results with practical error estimation.At the present time, we are preparing a paper with respect to the proposed identification method. Further discussions are needed for the error caused by numerical integrations and noisy observations, and also needed for the arrangement of observation points

生物工程中的一个重要问题是从称为磁场磁场革兰氏磁场的观察数据中鉴定出人脑的活性。许多研究人员假设人头的球形对称导体模型和人脑活动的偶极模型。 Our problem is to identify locations, moments, and number of dipoles in human brain from observations of magnetic induction outside of human head.Before this project, we have already proposed the following two methods.Method 1: Local search method based on weighted integrals for the two-dimensional caseMethod 2: Global search method based on an extension of observations to the interior of three-dimensional domainIn this project, we extend Method 1 to three-dimensional problem, and give error估计结果的估计。但是，方法1需要先验信息，有关偶极子的位置，力矩和数量。方法2适用，没有任何偶极子的先验信息。我们构建了一种结合方法1和方法2的新方法。我们提出的方法通过实践误差估计给出了合理的识别结果。在当前时间，我们正在准备有关提议的识别方法的论文。需要进一步讨论数值集成和嘈杂观察引起的错误，也需要进行观察点的安排

项目成果

K.Yamatani: "An Identification Method of Electric Current Dipoles in Spherically Symmetric Conductor"J.Computational and Applied Matematics. (in press).

K.Yamatani：“球对称导体中电流偶极子的识别方法”J.计算与应用数学。

S.Kajihara: "Application of Moditied Simplex Method to Biomagnetic Inverse Problem"Biomag 2000 : Proc. 12th Internet, Conterence on Bio-magnetism, J. Nenomen, R.J.Llmonieri, and T.Katila(eds.). 729-732 (2001)

S.Kajihara：“改进单纯形法在生物磁逆问题中的应用”Biomag 2000：Proc。

Sang-Uk Rye, A. Yagi: "Optimal Control of Keller-Segel Equations"Journal of Mathematical Analysis and Applications. 256-1. 45-66 (2001)

Sang-Uk Rye，A. Yagi：“Keller-Segel 方程的最优控制”数学分析与应用杂志。

M.Ikehata: "Numerical Method for finding the Convex Hull of Polygonal Cavities using Enclosure Method"Inverse Problems. (in press).

M.Ikehata：“使用包围法寻找多边形空腔凸包的数值方法”反问题。

S. Kajihara, K. Yamatani, N. S. Yamaki, A. Arakawa, and Y. Yoshida: "Application of Modified simplex Method to Biomagnetic Inverse Problem"Biomag 2000, Proc. 12th International Conference on Biomagnetism, J. Neuromen, R. J. Limonieri, and T. Katila (eds.)

S. Kajihara、K. Yamatani、N. S. Yamaki、A. Arakawa 和 Y. Yoshida：“改进单纯形法在生物磁反问题中的应用”Biomag 2000，Proc。