【文章內(nèi)容簡介】 其中的一個分支，也顯示出極大的市場需求潛力。由于心電信號容易受外界干擾和噪聲的影響，以及心電信號容易受自身狀態(tài)變化的影響，心電波形可謂千變?nèi)f化，容易發(fā)生畸變，幅度較小，頻率較低，極易受噪聲干擾，在檢測時難度更大。心電檢測技術(shù)具有無創(chuàng)傷、觀察方便、匯報及時且能在治療的同時快速、準(zhǔn)確地提供心臟方面的變化，同時它又可以有效地提高各種疾病治療中的安全性。心電放大電路是心電放大儀的核心部分，它直接決定了心電放大儀的成敗。研究心電放大電路對于心電放儀的研制具有比較實際的意義。本課題針對心電信號的這些特性，以簡便實用可靠為原則展開研究，完成了以下工作：1．分析心電信號的特性、噪聲來源、導(dǎo)聯(lián)方法，提出設(shè)計要求及總體設(shè)計方案。2．研制硬件，設(shè)計前置電路和數(shù)據(jù)采集電路。在前置電路中，集成放大器AD620作為輸入級，該芯片極低的失調(diào)電壓及漂移和高共模抑制比保證了心電信號完好的被捕捉；隔離電路的設(shè)計可保證被測試病人的安全；通過兩級放大，成功的將信號放大1000倍，使信號由毫伏級放大到伏級，同時把信號頻率限制在0．05Hz~100Hz的通帶上，而且設(shè)計了陷波器抑制50Hz工頻干擾。致 謝畢業(yè)設(shè)計完成了，在這個過程中我學(xué)到了很多東西。論文最難的方面在于，將理論和實際相結(jié)合，完成自己的邏輯框架；最有收獲的方面是，完成整個過程，最后成了一篇文章。在論文開始的初期，我對于論文的結(jié)構(gòu)以及文獻選取等方面都有很多問題，所以閱讀了大量前輩們所做的論文，并且結(jié)合了學(xué)校關(guān)于論文格式的要求，大致的對于論文的結(jié)構(gòu)有了一定了解。值此論文完稿之際，感激之情油然而生。在此向關(guān)心過我、幫助過我的老師、同學(xué)及家人表示感謝。首先感謝我的導(dǎo)師李方偉教授，本文是在周老師的精心指導(dǎo)下完成的。從論文的選題到總體設(shè)計思想，從具體實現(xiàn)方法到實驗結(jié)果的分析論證，再到論文寫作的每個階段，處處都傾注了周老師大量的心血。然后要感謝吳德操學(xué)長在論文完成過程總給予我最有效的建議及最無私的幫助，使我的課題得以順利的進行，并以愉悅的心情完成論文的撰寫。感謝我的室友們及朋友們，他們提供了溫馨的生活環(huán)境，讓我感受到了家庭般的溫暖，生活上大家無微不至的關(guān)懷，使我每天都以充沛的精力、旺盛的戰(zhàn)斗力投入到論文完成中。最后感謝我的家人，感謝他們在我求學(xué)期間對我一貫的支持和鼓勵。拙筆難以盡表我的感激之情，再次對所有關(guān)心過、支持過、幫助過我的人們致以衷心的感謝。參考文獻[1] 劉愛琴．低功耗便攜式心電記錄儀的設(shè)計．電子技術(shù)應(yīng)用，2001，27﹝9﹞．[2] ： .[3] 黃敏松，行鴻彥，[J]．現(xiàn)代電子技術(shù)，2007(16)：187—189．[4] [J].中興通訊技術(shù)，2005.[5] [M].北京：高等教育出版社，．[6] Nazarpour,K. Ebadi, Electrocardiogram Signal Modelling Using Genetic Algorithm [J].MEMEA,2007(10).[7] Horner,Holls, Based for Fetal Electrocardiogram Extraction [J].CIC,2008(5).[8] 盧喜烈．動態(tài)心電圖[M]．天津：天津科學(xué)技術(shù)出版社，2005.[9] 周嚴(yán)．測控系統(tǒng)電子技術(shù)[M]．北京：科學(xué)出版社，2007.[10] (日)谷隆嗣．?dāng)?shù)字濾波器與信號處理[M]．北京：科學(xué)出版社，2003.[11] 蘇麗，趙國良，李東明．心電信號QRS波群檢測算法研究[J]．．8，26(4)：513517. [12] 陳天華，韓力群，[J]．微計算機信息．2008，24(6).[13] 李弼程，羅建書．小波分析及其應(yīng)用[M]．北京：電子工業(yè)出版社，2003.[14] 肖詠梅，陳杭．心電自動分析技術(shù)[J]．生物醫(yī)學(xué)工程學(xué)雜志．2000，17(3)：339—342.[15] 肖詠梅，陳杭．心電自動分析技術(shù)[J]．生物醫(yī)學(xué)工程學(xué)雜志．2000，17(3)：339—342.[16] 羅小剛，彭承琳，鄭小林等．ECG信號小波變換與峰谷檢測算法的研究[J].，2003，22(3)：165．17l.[17] 王立會，潘冬明．一種消除心電信號中工頻干擾的陷波器的設(shè)計[J].醫(yī)療設(shè)備信息．2007，22(7).[18] Ziarani，A．K．；Komd，A．；A nolllinear adaptive method of elimination of power line interference in ECG signals[J]，IEEE Trans．Biomed．Eng，2002，49(6)：540547.[19] Addison PS．Ⅵ，aVelet tmsforms and the ECG：a review．Physiological measurement,2005，26(5)：155199.[20] 謝自美．電子線路實驗．測試．設(shè)計華中科技大學(xué)出版社．2001．[21] 蔡明生．電子設(shè)計．高教出版社．2004.[22] 曹細(xì)武，鄧親愷．心電圖各波的頻率分析[J]．中國醫(yī)學(xué)物理學(xué)雜志，2001，18(1)：46—48．[23] 那文鵬，王吳．通用集成電路的選擇與使用[M]．北京：人民郵電出版社，2004．[24] 王海濤，鄭濤．心電圖的閱讀分析及測量方法Ij]．小兒急救醫(yī)學(xué)，2000，7(1)：48.[25] 王友武，王桂英，劉宏等．動態(tài)心電圖若干技術(shù)偽差分析．心電學(xué)雜志，1995，14(3)：183． 附 錄一、英文原文：Goals Of True Broad band’s Wireless Next Wave (4G5G),Eng. Albert Butare .Kigali Institute of Science Technology and Management (KIST), Kigali, Rwanda.AbstractAs access technology increases, voice, video,multimedia, and broadband data services are being integrated into the same network. Fourth Generation (4G) is the next generation of wireless networks that will replace third Generation (3G) networks sometimes in future. 4G is intended to provide high speed, high capacity, low cost per bit, IP based is all about an integrated, global network that’s based on an open system approach. The goal of 4G is to “replace the current proliferation of core cellular networks with a single worldwide cellular core network standard based on IP for control, video, packet data and VoIP. But while 3G haven’t quite arrived, researchers want to contribute their ideas to the development of an asyet undefined wireless world that could bee operational by around 2010. This paper deals with the fundamentals and issues of networks, technologies, spectrum, standards,terminals, services of 4G and about the visions that the network operators and service providers see for the evolution of 4G mobile systems and where is future research from their perspective necessary?Keywords：Wireless, 4G, WOFDM, MCCDMA, LASCDMA,UWB.I. INTRODUCTIONWhile carriers and handset manufacturers obviously have their hands full with 3G, some panies are already looking beyond this next generation of wireless technology and networks. 4G is simply an initiative by academic Ramp。D labs to move beyond the limitations and problems of 3G which is having trouble getting deployed and meeting its promised performance and throughput .While this 3G has not pletely reached researchers and vendors are expressing growing interest in 4G why? Two main areas are addressed in these initiatives: An increase of capacity in the radio link and seamless mobility across heterogeneous access networks. Section 2 discusses about the issues of 3G that has created interest towards 4G developments. Section 3 about evolution and parison,Section 4 describes about the goals and the vision, section 5 explains about some of the technologies for 4G, and in other following sections the applications, the research and other issues for 4G developments are discussed.II. WHY THE LEAP TOWARDS 4G?3G networks are in a very painful phase of their development, with early trials yielding disappointing results, costs ballooning, technical glitches, and network operators being forced to deflate expectations based on unrealistic hype. Despite the hype surrounding the higherspeed 3G mobile networks now under construction, the reasons for the leap towards 4G are:A. PerformanceIndustry skeptics say that users will not be able to take advantage of rich multimedia content across wireless networks with 3G. 4G munications will feature extremely highquality video equal to that of highdefinition television. In addition, it will enable wireless downloads at speeds exceeding 100 Mbps, about 260 times than 3G wireless network.B. InteroperabilityThere are multiple standards for 3G making it difficult to roam and interoperate across networks. We need a global standard that provides global mobility and service portability so that service provider would no longer be bound by singlesystem vendors of proprietary equipment.C. Networking3G are based on primarily a widearea concept. We need hybrid networks that utilize both wireless LAN (hot spot) concept and cell or basestation WAN design. With 4G,the world would have base stations everywhere, ensuring phone users