体表胃电图的检测、处理及胃电慢波传导的研究

【作者】 姜熙君；

【导师】 张凯；

【作者基本信息】 扬州大学 ， 生物物理学， 2007， 硕士

【摘要】 胃是人体重要的消化器官，胃部疾病也是临床上的一种常见病，尽管人们对其研究已进行了多年，但对于一些常见的胃动力障碍性、功能性疾病，仍然缺乏深刻的认识，缺乏有效的诊断和治疗手段。自美国生理学家Alvarez首次从人的腹壁体表记录到胃电活动，即胃电图(Electrogastrogram，EGG)，以来，许多学者都试图以胃电作为胃的生物功能指标，研究胃的生理和病理规律，希望将其应用于临床实践，作为胃疾病患者的诊断和疗效判定的客观指标。本文研究的主要目的就是设法检测出人体的胃电信号，研究胃电图中慢波成份的有效提取方法，建立胃电慢波传导的数学模型，最终为胃电图的临床应用提供新的概念和认知手段。本文在体表胃电图的检测、体表胃电图中慢波的提取以及胃电慢波传导模型方面进行了深入的研究，取得了一些令人满意的结果。深入阐述了胃电图的生理基础，从电生理学的角度描述胃电的产生机理、胃电慢波的功能和特点。体表胃电信号非常微弱，本文成功研制了单通道的体表胃电检测系统，可以实现体表胃电信号的实时采集、显示和存储。实验证明，系统性能稳定，隔离性、安全性好。本文还在此基础上开发出便携式长时间的胃电记录系统，系统以电池供电，以MMC卡作为胃电数据的存储器，可以实现胃电信号的便携式、长时间记录。系统功耗低，小型化，电路结构紧凑。为分析长时间的胃电参数提供了保证，也为相关医疗检测设备提供了一个大容量的存储器解决方案。本文首次将经验模态分解的方法应用于体表胃电图慢波的提取，有效地剔除了胃电中心电、呼吸等成份的干扰，提高了胃电慢波的信噪比。文中还从理论上进一步证明了该方法相对于自适应滤波和小波多尺度分解在胃电图慢波提取上更具有优越性。根据胃电信号传导的途径，本文为胃电慢波的传导建立了一个数学的模型。研究表明，通过该模型可以仿真出体表多道的EGG，并且与Chen JD等人的实验结果相一致，也进一步证实了该模型的真实可靠性。这为相关的科研人员提供一个基于计算机的胃电特性研究的平台。总之，我们的研究工作为胃的电活动的检测、胃电慢波的提取方法，特别是为胃电慢波的传导特性的研究提供了许多重要的信息，为胃电图在临床上的广泛应用提供了一些可靠依据。更多还原

【Abstract】 Stomach is an important apparatus in digestive system and gastropathy is one ofthe common diseases in the clinical. Although experts have been studying it for manyyears, some gastropathy still remains unclear. Since the firstly EGG was distilled byW.Alvarez, many specialists have persist in the research on it and tried to put EGG toclinical application. The aim of this thesis is to study the techniques of cutaneous EGGdetection, arithmetic of slow wave extraction, and construction of slow wave conductmodel. Some new concept and cognize means for the clinical application of EGG arepresented in the thesis.This thesis has paid more attention on EGG detection, slow wave extraction andthe model of slow wave conduction. And we met with some delectable results inexperiment and clinical.The cutaneous EGG is much week, so it is very difficult to detect. In this thesiswe build a cutaneous EGG recording system, and such EGG signals can be acquired,displayed and stored by the system. It has been proved that the system is reliable andisolated for the safety consideration. Base on the detection system, a portable EGGrecorder was developed in this thesis. With the consideration of low power cost, theportable EGG recorder is powered by a Li battery and taken a Multimedia Card (MMCcard) as its data memory. By creating a FAT file system on the Multimedia Card, EGGdata files can be recorded with standard format.In order to extract slow wave from EGG, we used Empirical Mode Decomposition(EMD). It can easily filter the noise of cardiac muscle or breathing effectively, andperforms well in slow wave extraction. Compared with adaptive filter and WaveletMultiresolution Decomposition (WMD), EMD provides even higher signal-to-noiseratio (SNR).In this thesis, we also construct a mathematical model for slow wave conduction. Using this model, multi-channel EGGs can be simulated from the abdomen and thisjust agrees with the experiment results reached by Chen JD in 1999. This model alsoprovides a computer-based platform for correlated researchers to study the charactersof EGG.The EGG is a noninvasive measurement and all of our work also proved that ithas attractive application in medical research and clinical diagnosis of patients withgastropathy. It has a broad prospect.更多还原