【作者】 施建；

【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】 消化道出血症严重影响着现代人们的正常生活。这种疾病的早期出血量比较少,具有很强的隐蔽性,不容易引起人们的注意。当发展到出血量较大的程度,将会对患者造成生命威胁。目前对于消化道出血的检测和定位,还没有一种十分理想的方法和器械,特别是对小肠段出血的检查。现有检测手段具有检测信息单一,检测时间短,无法全消化道连续检测的缺陷,而且大部分检测方法对病人都具有一定的副作用和创伤性。消化道出血信息包括出血存在性、出血量以及出血点位置信息,消化道出血诊疗难的原因在于出血信息掌握的不足。随着科技的发展,人们对现代医学提出了微创甚至无创的迫切要求。因此开发具有无创特性的人体消化道出血信息检测系统是医学研究的一个重要方向。本文以国家自然科学基金资助项目(NO.30570485)和国家高技术研究发展计划(NO.2004AA404013)资助项目为依托,结合工程技术与医学知识,对人体消化道出血信息及其无创获取方法进行研究,致力于解决消化道出血的检测、出血估量和出血点定位问题,为消化道出血诊疗提供新方法和新设备。本研究旨在对人体消化道疾病的诊疗起到进一步推动作用,因此具有重要的研究意义和明显的社会效益。本文具体研究工作可分为以下几个方面:1.阐述了本文的研究背景、意义、目的和主要的研究内容。介绍人体消化道的解剖结构和基本生理常识;分析消化道出血的概况和目前临床医学上对消化道出血的常规诊断方法及其不足;其原因在于对出血信息掌握的缺失,针对这一现状提出消化道出血信息无创检测微系统的构思;介绍血液检测和消化道生理信息无线遥测方面的研究现状。2.概括消化道出血信息的内容,即存在性信息、出血量信息、出血位置信息等,这些信息构成无创检测微系统的检测对象;提出系统技术方案,分析系统的血液微传感、生物无线遥测以及生物体内微系统定位三大技术模块;分析消化道出血信息无创检测微系统应能实现的功能;按照模块化和低功耗的要求设计微系统的结构,研制微系统的样机;研究出血点定位的方案和可行性,提出基于医学影像技术的辅助定位和基于磁场测量的自主定位两种方案。3.研究消化道内血液的识别和检测机理,提出血液敏感的基本要求,确定血红蛋白为血液敏感底物的电化学检测机理;通过电化学检测技术的理论研究,分析被测物质及其浓度与电极电位和电极电流的关系,并建立相应电极系统的等效电路模型。根据理论分析,为血红蛋白电化学传感器确定合适的测试方法和控制方法。4.搭建三电极测量体系,设计恒电位电路、微电流检测电路、信号发生和采集系统,对血红蛋白电化学微型传感器进行实验验证研究;实验研究包括血红蛋白氧化还原特性的验证,传感器在不同电位激励、不同浓度下的输出响应以及传感器的温度特性、pH特性和在杂质干扰下的稳定性;研究血红蛋白微型传感器微型化的组装与封装,并对MEMS技术下的芯片式传感器的技术实现进行前期研究。5.分析生物组织的电磁特性和置于生物组织内部的辐射源的电磁波在生物组织中传播的特殊性;建立置于人体内部的辐射源的电磁波在其近场和远场的能量吸收数学模型;针对典型医用频率下多种生物组织材料中电磁能量的吸收模型进行仿真,分析能量吸收和工作频率、生物组织材料以及其他一些因素的依赖关系;分析的结果用于指导系统无线通讯载波频率的选取,并在此频率下进行无线通讯模块的设计和测试。尽管本文的研究基本实现了研究目标,但系统距离实用还有很多工作要进行。在论文的最后,对论文的工作和实验结果进行总结,指出下一步的研究工作。更多还原

【Abstract】 Gastrointestinal bleeding disease is impacting people’s normal life. At the forepart of this kind of disease, the bleeding amount is little, which will hide the disease from being discerned by people. Once the bleeding amount is much enough, it will threaten people’s life. Presently, there are no very satisfactory diagnosis methods and apparatus for gastrointestinal bleeding check and localization, especially for small intestine because of their single check information, short check time, discontinuity, range restriction, side effect and invasion. The gastrointestinal bleeding information includes bleeding existence, bleeding amount and bleeding position. The lack of grasping bleeding information results in the difficulty of gastrointestinal bleeding diagnosis. As the development of technology, people have asked for more requirement on MIT (the miniature invasive technology) and NIT (non-invasive technology) from modern medicine. So the research of micro non-invasive gastrointestinal bleeding information inspecting system is an important direction in the medical field.Under the support of National Natural Science Foundation of China (NO.30570485) and The National High Technology Research and Development Program of China (NO. 2004AA404013), combining the engineering technology and medical knowledge, this paper researches the bleeding information in gastro intestine and acquiring method in order to solve the questions of detecting, amount evaluating and location of gastrointestinal bleeding. The final purpose is to get new method and device for gastrointestinal bleeding diagnosis and treatment. Addressing on promoting the level of medical care, it is valuable both in research and social benefits.The main content and contributions of this paper are summarized as follows:1. The dissertation expatiates on the background, significance, purpose and main content for research; introduces the anatomical structure and basic physiological knowledge; analyzes the overview of gastrointestinal bleeding, normal diagnosis method and their shortages. As for the lacking of bleeding information, a non-invasive micro system for inspecting the gastrointestinal bleeding information is presented.2. The dissertation generalizes the content of gastrointestinal bleeding information composed of bleeding existence, bleeding amount and bleeding position etc which are the inspected objects of the researched system. The system’s technique scheme is composed of blood micro sensing, biotelemetry and micro system localization in biotic tissue. The dissertation introduces the function of the researched micro system, designs the system structure and composition under the requirement of modularization and low consumption, and develops the prototype. The scheme and practicability on bleeding spot localization are researched by putting forward two localization methods, one of which is based on medical imaging technology, the other is based on magnetic intensity measurement.3. The dissertation researches the blood recognition and measurement in gastrointestinal tract, presents the basic requirement for sensing substrate selection, and succeeds in finding hemoglobin as the sensing substrate. By theoretic research on electrochemical measurement technology, the dissertation builds the relationship among electrode potential, electrode current and measured substrate, sets up the equivalent circuit of electrodes system. According on the theory analysis, the hemoglobin micro senor is allocated suitable measurement and control method.4. The three electrodes measurement system is designed, as well as potentiostatic ciucuit, micro current measuring circuit, signal generating and acquiring system. Under the platform some experiments are implemented for hemoglobin sensor verification including hemoglobin redox character verification, current response on different exiting potential and hemoglobin concentration, temperature dependence, pH dependence and stability on iron interference. The assembly and packaging for hemoglobin sensor both on traditional process and MEMS process are researched.5. The dissertation analyzes the electromagnetic characteristics of biotic tissue and the particularity of electromagnetic propagation in biotic tissue, and builds the power absorption models both in near filed and far filed of the radiation source which is set inside the biotic tissue. With some typical medical frequency and tissue materials the model is simulated in Matlab in order to research the power absorption depended on the frequency, tissue materials and some other factors. The research results are used to select a right frequency for wireless communication and design and test the wireless communication.Although the purpose of this dissertation has been reached, there still exists much research work to be done to make the system suitable for clinical applications.更多还原