【作者】 何文辉；

【导师】 颜国正；

【作者基本信息】 上海交通大学 ， 精密仪器及机械， 2007， 博士

【摘要】 本文在国家教育部博士点基金(项目编号:20040248033)、国家自然科学基金(项目编号:30570485)和国家863计划(项目编号:2006AA04Z368)的资助下,研制了人体胃肠道无创诊查系统,并对系统中生物遥测胶囊的磁定位技术作了比较深入的研究,力图找到一种原理可行,满足实用要求,使用方便可靠的磁定位方法。本文研究了了生物遥测胶囊的总体设计方案。为了简化设计和便于功能扩展,生物遥测胶囊共分为电源管理模块、无线通讯模块、信号处理模块和微型传感器模块。本文还详细介绍了各模块的原理与实现、生物遥测胶囊的组装方式及实验情况。本文分析了生物遥测胶囊的超声波定位和磁定位技术,并重点探讨了磁定位方法。生物遥测胶囊的磁定位包括静磁定位和交变磁定位两类方法,而磁标记法是静磁定位的典型方法,本文在磁场及磁检测的相关理论研究的基础上,较深入地探讨了生物遥测胶囊的磁标记定位问题。本文结合生物遥测胶囊自身结构特点,通过磁场有限元法的计算,选用了磁性很强的NdFeB45作为磁性材料,采用φ9×5mm的圆柱形永久磁体作为磁标记物封装在生物遥测胶囊内,定位时,通过在体外布置四个三轴传感器构成传感器阵列对磁标记物进行位置检测,然后通过改进的牛顿-拉斐森(Newton-Raphson)算法求解高次非线性超静定方程组,解出生物遥测胶囊的位置坐标。针对生物遥测胶囊的电源部分为两节氧化银纽扣电池,而这种电池的金属外壳为高导磁率的Co-Ni-Fe合金钢带的情况,本文通过相关电磁理论,采用磁场叠加原理,推导出了电池对磁场分布影响的数学模型,完善了生物遥测胶囊磁标记定位理论。本文还详细论述了磁标记定位法的实验情况,并开发了利用磁阻传感器进行磁标记定位的相关电路。作为利用静磁定位的重要方法,本文提出了三线圈脉冲激磁定位的新方法,实验表明,这种方法可以运用到生物遥测胶囊的定位中,而且对比磁标记法,分析了这种方法具有的优点。本文还讨论了利用电涡流对生物遥测胶囊定位的可能性。为此,本文提出了探头激磁线圈与检测线圈分开设置,且探头激磁采取内外双线圈激磁,三个线圈同轴安装的特殊新型电涡流探头结构,这种结构有利于对目标物的远距离定位,本文推导了这种探头的理论计算公式,分析了这种探头应用到生物遥测胶囊定位中的优缺点。另外,线圈感应定位法有抗干扰能力强,检测距离远的特点,作为交变磁定位,本文也对此作了简要分析。更多还原

【Abstract】 Supported by the Research Fund for the Doctoral Program of Higher Education (No.20040248033), the National Natural Science Foundation of China (No. 30570485) and the 863 program (No.2006AA04Z368), this thesis develops the noninvasive detecting system for gastrointestinal tract and researches magnetic localization for the biotelemetric capsule. The thesis tries to find a magnetic localizing method which is feasible, practical and portable in principle.The thesis investigates collectivity project of the biotelemetric capsule. For simplification and extensing its functions easily, the biotelemetric capsule includes power module, RF communication module, signal processing module and sensors module.The thesis analyzes ultrasonic localization and magnetic localization technology for the biotelemetric capsule, and the magnetic localization technology is the key. The technology includes two ways of static magnetic localization and alternating magnetic localization. Magnetic mark method is a typical static magnetic localization method. The thesis discussed magnetic mark localization for detecting the biotelemetric capsule in GI based on magnetic field theory and magnetic detecting technology. The thesis analyzes the biotelemetric capsule’s structure, too. According to magnetic finite element method, the thesis draws a conclusion which is a adaptive magnetic mark with profile dimension ofφ9×5mm, NdFeB45 material and cylindrical permanent magnet for localization. The four tri-axis sensors are fixed outside body for localization, and then the coordinate values of the biotelemetric capsule are solved by improved Newton-Raphson method. But there are two battery cells with high magnetic permeability metal shell. The thesis deducted calculating equation for the cells’affection via relative magnetic theory.The thesis discusses experiments of magnetic mark localization in detail, too. Besides, the author develops relative electrical circus to detect magnetic field utilizing magnetoresistive sensors.As a practice of static magnetic localization, the thesis developed tri-coil pulse inductive magnetic field method for the biotelemetric capsule’s localization. The relative experiment indicates the method can localize the biotelemetric capsule, and the thesis compared it with the magnetic mark method and analyzes its advantages.Besides, the thesis discusses eddy current for localizing capsule. In order to make the method be realization, the author developed a tri-coil eddy current detector to detect long distance. The thesis deducted calculating equations for designing the detector. It has strong antijamming ability though it is very difficult to detect the capsule continuously, and the thesis analyses its localization effect. Excluding theses methods, the coil magnetic induction method has strong antijamming ability and is able to detect the biotelemetric capsule in long distance, too. As an alternating magnetic localization method, the thesis analyzes the method simply.更多还原