多焦视网膜电图检测系统研究与设计

【作者】 邢军智；

【导师】 张泾周；

【作者基本信息】 西北工业大学 ， 生物医学工程， 2005， 硕士

【摘要】 20世纪90年代初出现的多焦视网膜电图技术可在相对较短的时间内记录测试野内许多局部视网膜生理电响应的波形,有助于了解视网膜或视路病变的机理,从而可定量和直观评价视网膜功能,可用于一些眼病的早期诊断,是视觉电生理技术的一项重要发展。本课题在研究了多焦视网膜电图检测有关技术的基础上,利用现代计算机与信号处理技术,结合新型检测电路设计方法,完成了一种多焦视网膜电图检测系统的设计与实现。 本论文首先介绍了多焦视网膜电信号的产生机理及在临床中的应用。然后对多焦视网膜电信号检测做了分析,深入讨论了多焦视网膜电信号检测及处理的基础理论方法。以此理论为指导,本文着重研究了对多焦视网膜电信号检测与处理系统的硬件电路设计。即前置放大电路和信号处理电路设计,并对器件选择和参数确定做了具体分析,同时对数字信号处理技术在该系统中的应用进行了具体阐述。接着对多焦视网膜电图各局部区域的响应波形的分离与提取算法进行了描述,即m序列与快速Walsh变换理论及其算法。最后对设计方案进行了仿真分析与原理试验,结果表明各项技术性能指标基本满足医学临床检查与诊断要求。 本论文工作突出之处在于针对多焦视网膜电信号极其微弱且淹没在复杂背景噪声中的特点,设计并实现了视网膜电信号放大和滤波处理硬件检测电路单元,将多焦视网膜信号不失真的提取出来;并结合计算机采集和分析与处理技术,完成了数据采集与数字滤波处理算法的设计,实现了多焦视网膜电信号检测的准确、快速和智能化。本研究与设计结果对多焦视网膜电图检测技术的进一步发展具有积极的促进作用。更多还原

【Abstract】 The multifocal electroretinogram (mERG) can be used to record many focal electroretinogram responses across the test field in a relatively short period of time. Although this technique is relatively new, it has already provided insights into the mechanisms of retinal disease. It can be used in the early diagnosis and prognosis of some retinal diseases, and can be used to objectively and sensitively observe the curative effect of medicine or surgery.With the development of society and the improvement of the science technology, mERG measure instrument are widely demanded and their capabilities are required better. The author of the paper design an integrated measure system based on computer. The first part describes the biomedical signal detection and how the mERG is recorded. In the second part, signal-processing method in analog technology are illustrated and its circuitry are designed which include signal preamplifier, shielding and interference restraint. In the study of weak signal detection, some key techniques about mERG have been discussed. The digitized techniques, about signal processing, realization are also described in the third part. Digital filter is one of the most important parts of digital signal processing. The Infinite Response digital filter (IIR) can be achieved through three steps: the design of prototype of analog low-pass filter, analog-to digital filter conversion and the conversion of filter frequency band. To extract the local responses is the key part in mERG. The hexagonal array stimulated different regions of retina simultaneously. The Fast Walsh transform algorithm and the cross-correlation technique, which utilized the pseudorandom features of m-sequence, extracted the single local response from each element.This paper will help to the teaching, researching and producing process. It is fresh air to the biomedical electronics, medical instrument.更多还原