便攜式數(shù)字血壓計(jì)中英文對(duì)照外文翻譯文獻(xiàn)

畢業(yè)設(shè)計(jì)（論文）PAGE58PAGE57中英文資料對(duì)照外文翻譯便攜式數(shù)字血壓計(jì)產(chǎn)品簡(jiǎn)介我們的最后一個(gè)項(xiàng)目是設(shè)計(jì)和建立一個(gè)便攜式血壓監(jiān)測(cè)裝置，可以通過(guò)一個(gè)充氣袖口測(cè)量一個(gè)人的血壓和心率。該裝置包括三個(gè)主要部分：外部硬件（如袖口，電機(jī)，閥門(mén)，和液晶顯示器）、模擬電路與單片機(jī)。模擬電路轉(zhuǎn)換的袖帶內(nèi)的壓力值形成可讀和可使用的模擬波形。單片機(jī)對(duì)樣本波形并進(jìn)行模數(shù)轉(zhuǎn)換，可以做進(jìn)一步計(jì)算。此外，單片機(jī)用按鈕控制操作設(shè)備、液晶顯示。因?yàn)槲覀冇羞@個(gè)詞'便攜式'的稱(chēng)號(hào)，用一個(gè)包就可以裝下，允許用戶(hù)把它帶到任何地方，無(wú)論何時(shí)何地進(jìn)行測(cè)量。不可否認(rèn)的是，現(xiàn)在人們更多地關(guān)注健康狀況。其中最廣泛使用的測(cè)試健康狀況的方法是衡量一個(gè)人的血壓和心率。為了人們的健康，我們決定為解決這一問(wèn)題而設(shè)計(jì)一個(gè)在現(xiàn)實(shí)生活中有益的和可用的設(shè)備。高層次的設(shè)計(jì)1）血壓測(cè)量通常當(dāng)醫(yī)生測(cè)量病人的血壓時(shí)給袖口充氣，并使用聽(tīng)診器聽(tīng)血液在病人的手臂動(dòng)脈的聲音。開(kāi)始時(shí)，空氣被輸送到收縮壓值以上。在這一點(diǎn)上，醫(yī)生什么也聽(tīng)不到，隨著壓力漸漸地被釋放，在某一點(diǎn)上，醫(yī)生會(huì)開(kāi)始聽(tīng)到心臟跳動(dòng)的聲音，這一點(diǎn)對(duì)應(yīng)的是收縮壓的值。壓力進(jìn)一步降低后，醫(yī)生將繼續(xù)聽(tīng)到的聲音（與之前聲音不同）。并在某一點(diǎn)，聲音將開(kāi)始消失，這一點(diǎn)對(duì)應(yīng)舒張壓的值。

我們使用的這種測(cè)量方法叫“示波法”。空氣將被沖入袖口20毫米汞柱左右，高于平均收縮壓（平均約120毫米汞柱）。之后，空氣會(huì)慢慢從袖口放出，導(dǎo)致在袖口的壓力慢慢減小，我們將測(cè)量在手臂袖口氣壓的微小振蕩，收縮壓是壓力脈動(dòng)開(kāi)始出現(xiàn)時(shí)，我們將使用單片機(jī)檢測(cè)該點(diǎn)，然后記錄該壓力值。然后在袖口的壓力將進(jìn)一步減少。舒張壓將采取點(diǎn)振蕩開(kāi)始消失時(shí)的點(diǎn)3）硬件框圖上面的圖顯示了我們的設(shè)備是如何運(yùn)作的。用戶(hù)將使用按鈕來(lái)控制操作整個(gè)系統(tǒng)。單片機(jī)的主要成分是控制所有操作，如電機(jī)和閥門(mén)控制，A/D轉(zhuǎn)換和計(jì)算，直到測(cè)量完成。然后是通過(guò)液晶屏輸出結(jié)果供用戶(hù)觀察。4）模擬電路模擬電路用于放大壓力傳感器的輸出信號(hào)的直流和交流成分，我們可以使用單片機(jī)來(lái)處理信號(hào)，并獲得有用的信息。壓力傳感器的生產(chǎn)應(yīng)用的差分輸入壓力和輸出電壓成正比。輸出電壓壓力傳感器，范圍從0到40毫伏。但我們的應(yīng)用希望泵手臂袖口只有160毫米汞柱（約21.33千帕），這相當(dāng)于約18mV的輸出電壓。因此，我們選擇放大電壓，直流放大器的直流輸出電壓輸出范圍從0至4V。因此，我們需要的增益約為200。然后直流放大器的信號(hào)將傳遞到帶通濾波器，直流放大器放大直流和交流信號(hào)的組成部分（它只是一個(gè)普通的放大器）。過(guò)濾器的設(shè)計(jì)有較大的增益在1-4赫茲左右，使通帶任何信號(hào)衰減，是帶通濾波器的交流分量最重要的因素，以確定何時(shí)捕獲的收縮壓/舒張壓時(shí)以確定心臟使用率。最后一個(gè)階段是交流耦合階段，我們使用兩個(gè)相同的電阻提供直流約2.5伏特的偏置電壓。使用47uF的電容耦合只有交流信號(hào)的組成部分，使我們能夠獨(dú)立的提供直流偏置電壓。硬件設(shè)計(jì)1）壓力傳感器我們使用來(lái)自摩托羅拉MPX2050壓力傳感器接受手臂袖口壓力。壓力傳感器應(yīng)用的差分輸入壓力和輸出電壓成正比。我們連接管輸入袖口和我們離開(kāi)打開(kāi)另一個(gè)輸入，通過(guò)這種方式，將是成正比的輸出電壓區(qū)別在袖口的壓力和在房間里的空氣壓力。傳輸特性如圖圖1：輸出電壓和差分輸入壓力2）直流放大器由于壓力傳感器的輸出電壓是非常小的，我們必須作進(jìn)一步的信號(hào)放大處理。我們使用ADI公司的儀表放大器AD620。電阻RG是用來(lái)確定放大器的增益。因?yàn)槲覀冃枰蠹s200的增益，我們選擇電阻RG是240歐姆。這將使我們根據(jù)公式的增益。然而，我們已經(jīng)測(cè)量從成品電路，測(cè)得的增益是213。放大器的電路圖如圖2所示。圖2：直流放大器的電路圖3）帶通濾波器作為一個(gè)活躍的兩個(gè)帶通濾波器級(jí)聯(lián)設(shè)計(jì)的帶通濾波器階段。之所以使用兩個(gè)帶通階段將提供一個(gè)比僅使用單級(jí)更大的增益和頻率響應(yīng)的濾波器將具有清晰的切斷。這種方法將提高輸出噪聲比。“兩個(gè)濾波器的原理圖如圖3所示。圖3：帶通濾波器階段第一個(gè)帶通濾波器：低頻截止高頻率截止第一個(gè)過(guò)濾器的中頻增益第二帶通濾波器：低頻截止高頻率截止第一個(gè)過(guò)濾器的中頻增益因此，對(duì)帶通濾波器階段，總增益為399.6。結(jié)合這一增益與增益從直流放大器，總交流電路增益為，選擇高和低截止頻率足夠好給我們非常干凈的交流波形。4）交流耦合級(jí)交流耦合階段是用來(lái)提供直流偏置水平。我們要的直流電平波形定位大約一半，這是2.5伏交流耦合階段示意圖如圖4所示。鑒于這種偏執(zhí)電流，這是我們更容易使用單片機(jī)上模數(shù)轉(zhuǎn)換器的微控制器處理交流信號(hào)。圖4：交流耦合級(jí)直流偏壓這個(gè)階段的交流輸出將通過(guò)在Mega32單片機(jī)的模擬-數(shù)字轉(zhuǎn)換器。實(shí)驗(yàn)室的示波器上的圖像如圖5所示。我們可以看到波形非常漂亮和干凈。圖5：交流波形附錄5英文原文附錄5英文原文PortableDigitalBloodPressureMonitorIntroductionOurfinalprojectistodesignandbuildaportablebloodpressuremonitordevicethatcanmeasureauser'sbloodpressuresandheartratethroughaninflatablehandcuff.Thedeviceisconsistedofthreemainparts:externalhardwares(suchascuff,motor,valve,andlcd),analogcircuit,andmicrocontroller.Theanalogcircuitconvertsthepressurevalueinsidethecuffintoreadableandusableanalogwaveforms.TheMCUsamplesthewaveformsandperformsA/Dconventionsothatfurthercalculationscanbemade.Inaddition,theMCUalsocontrolstheoperationofthedevicessuchasthebuttonandlcddisplay.Sincewehavetheword'portable'inourtitle,forsureallofthecomponentsareputtogetherinonepackagewhichallowsausertotakeitanywhereandperformameasurementwheneverandwhereverhe/shewants.Itisundeniablethatnowadayspeoplearemoreawareofthehealthconditions.Oneofthemostwidelyusedmethodstotestthehealthconditionsofanindividualistomeasurehis/herbloodpressuresandheartrate.We,asonesofthosewhoareconcernedabouttheirhealth,decidedtoworkonthissubjectmatterbecausewewouldliketobuildsomethingthatisusefulanduseableinreallife.HighLevelDesign1)HowbloodpressuresaremeasuredUsuallywhenthedoctormeasuresthepatient'sbloodpressure,hewillpumptheairintothecuffandusethestethoscopetolistentothesoundsofthebloodinthearteryofthepatient'sarm.Atthestart,theairispumpedtobeabovethesystolicvalue.Atthispoint,thedoctorwillhearnothingthroughthestethoscope.Afterthepressureisreleasedgradually,atsomepoint,thedoctorwillbegintohearthesoundoftheheartbeats.Atthispoint,thepressureinthecuffcorrespondstothesystolicpressure.Afterthepressuredecreasesfurther,thedoctorwillcontinuehearingthesound(withdifferentcharacteristics).Andatsomepoint,thesoundswillbegintodisappear.Atthispoint,thepressureinthecuffcorrespondstothediastolicpressure.Toperformameasurement,weuseamethodcalled“oscillometric”.Theairwillbepumpedintothecufftobearound20mmHgaboveaveragesystolicpressure(about120mmHgforanaverage).Afterthattheairwillbeslowlyreleasedfromthecuffcausingthepressureinthecufftodecrease.Asthecuffisslowlydeflated,wewillbemeasuringthetinyoscillationintheairpressureofthearmcuff.Thesystolicpressurewillbethepressureatwhichthepulsationstartstooccur.WewillusetheMCUtodetectthepointatwhichthisoscillationhappensandthenrecordthepressureinthecuff.Thenthepressureinthecuffwilldecreasefurther.Thediastolicpressurewillbetakenatthepointinwhichtheoscillationstartstodisappear.3)HardwarediagramThediagramaboveshowshowourdeviceisoperated.Theuserwillusebuttonstocontroltheoperationsofthewholesystem.TheMCUisthemaincomponentthatcontrolsalltheoperationssuchasmotorandvalvecontrol,A/Dconversion,andcalculation,untilthemeasurementiscompleted.TheresultsthenareoutputthroughandLCDscreenfortheusertosee.4)AnalogCircuitTheanalogcircuitisusedtoamplifyboththeDCandACcomponentsoftheoutputsignalofpressuretransducersothatwecanusetheMCUtoprocessthesignalandobtainusefulinformationaboutthehealthoftheuser.Thepressuretransducerproducestheoutputvoltageproportionaltotheapplieddifferentialinputpressure.Theoutputvoltageofthepressuretransducerrangesfrom0to40mV.Butforourapplication,wewanttopumpthearmcufftoonly160mmHg(Approximately21.33kPa).Thiscorrespondstotheoutputvoltageofapproximately18mV.Thus,wechoosetoamplifythevoltagesothattheDCoutputvoltageofDCamplifierhasanoutputrangefrom0to4V.Thus,weneedagainofapproximately200.ThenthesignalfromtheDCamplifierwillbepassedontotheband-passfilter.TheDCamplifieramplifiesbothDCandACcomponentofthesignal(it'sjustaregularamplifier).Thefilterisdesignedtohavelargegainataround1-4Hzandtoattenuateanysignalthatisoutofthepassband.TheACcomponentfromtheband-passfilteristhemostimportantfactortodeterminewhentocapturethesystolic/diastolicpressuresandwhentodeterminetheheartrateoftheuser.ThefinalstageistheACcouplingstage.WeusetwoidenticalresistorstoprovideaDCbiaslevelatapproximately2.5volts.The47uFcapacitorisusedtocouplingonlyACcomponentofthesignalsothatwecanprovidetheDCbiaslevelindependently.HardwareDesign1)PressureTransducerWeusetheMPX2050pressuretransducerfromMotorolatosensethepressurefromthearmcuff.Thepressuretransducerproducestheoutputvoltageproportionaltotheapplieddifferentialinputpressure.Weconnectthetubefromthecufftooneoftheinputsandweleaveanotherinputopen.Bythisway,theoutputvoltagewillbeproportionaltothedifferencebetweenthepressureinthecuffandtheairpressureintheroom.Thetransfercharacteristicisshowninfigure1.Figure1:Outputvoltagevs.Differentialinputpressure2)DCAmplifierSincetheoutputvoltageofthepressuretransducerisverysmall,wehavetoamplifythesignalforfurtherprocessing.WeusetheinstrumentationamplifierAD620fromAnalogDevices.TheresistorRGisusedtodeterminethegainoftheamplifieraccordingtotheequationRg=49.4kΩ/（G-1).Sinceweneedthegainofapproximately200,wechoosetheresistorRGtobe240ohms.Thiswillgiveusthegainof206accordingtotheequation.However,wehavemeasuredthegainfromthefinishedcircuit,andthemeasuredgainis213.Theschematicoftheamplifierisshowninfigure2.Figure2:SchematicofDCamplifier3)Band-passFilterTheband-passfilterstageisdesignedasacascadeofthetwoactiveband-passfilters.Thereasonforusingtwostagesisthattheoverallband-passstagewouldprovidealargegainandthefrequencyresponseofthefilterwillhavesharpercutoffthanusingonlysinglestage.Thismethodwillimprovethesignaltonoiseratiooftheoutput.Theschematicsforbothfiltersareshowninfigure3.Figure3:BandpassesFilterStageFirstBand-passfilter:ThelowerfrequencycutoffisThehigherfrequencycutoffisThemid-bandgainofthefirstfilterisSecondBand-passfilter:Thelowerfreque