生物医学工程专业英语.doc

Imagesofthehumanbodyarederivedfromtheinteractionofenergywithhumantissue.Theenergycanbeintheformofradiation,magneticorelectricfields,oracousticenergy.Theenergyusuallyinteractsatthemolecularoratomiclevels,soaclearunderstandingofthestructureoftheatomisnecessary.Inadditiontounderstandingthephysicsoftheatom,learningimagingjargonisalsonecessary.Forexample人体的图像来自能源与人类之间的相互作用的组织。能量可以以辐射的形式,磁场或电场,或声波能量,能量通常在分子或原子水平相互作用,所以清楚地了解原子的结构是必要的。除了了解原子的物理,学习成像术语也是必要的。例如:Tomography:across-sectionalimageformedfromasetofprojectionimages.TheGreekwordtomomeanscut.断层扫描:横断面图像由一组投影图像。希腊语tomo意味着削减。CT:Computed(orComputerized)TomographyCT:(或计算机)计算层析成象技术MR,orMRI:MagneticResonanceImaging.Thiswasfirstcallednuclearmagneticresonance(NMR),butthementionofanythingnuclearscaredpatients,sothe“N”wasdropped.先生,或MRI:磁共振成像,这是第一次被称为核磁共振(NMR),但提到任何核害怕病人,所以“N”掉了。PET1:PositronEmissionTomography.Understandingthisphenomenonrequiresacceptanceofthetheorythatthereisantimatterintheuniverse,andwhenantimattermeetsmatter,thenbothkindsofmatterareannihilated,andpureenergyisformed.宠物1:正电子发射断层扫描,理解这种现象需要接受的理论,宇宙中有反物质,反物质与物质,这两种物质是湮灭,纯粹的能量就形成了。SPECT2:SinglePhotonEmissionTomographyUltrasound:SonarinthebodySPECT2:单光子发射断层扫描超声波:声纳OCT:OpticalCoherentTomographytheuseofinfraredlighttoimage(particularity)thewallsofanart10月:光学相干断层扫描,使用红外线图像(特殊性)动脉的城墙Amodalityisamethodforacquiringanimage.MR,CT,etc.areallimagingmodalities.Modalitiesaresometimescategorizedbasedontheamountofenergyappliedtothebody.Forexample,theX-raymodalityproducesenergythatissufficienttoionizeatoms(i.e.,ejectanelectronfromanorbitofanatom,therebycreatingapositivelychargedionthatdamageshumantissue).ThemodalitiesthatcauseionizingradiationareX-rays,CT,SPECT,andPET.Non-ionizingmodalitiesincludeMRandultrasound.形态是一个方法获取图像。先生,CT,等等都是成像模式。模式有时被分类基础上的能量应用到身体。例如,x射线形态产生的能量足以电离原子(即,逐出一个电子从一个原子的轨道,从而创建一个带正电的离子,损害人体组织)。引起电离辐射x射线的形式,CT,SPECT和PET。非电离形式包括先生和超声波。Lesson8BasicKnowledgeonX-raysinMedicalRadiologyPart1X-RAYSThediscoveryandnatureofX-raysX-rayswerediscoveredbyWilhelmKonradRntgen1in1895.Theyareoftencalledroentgenrays(particularlyintheUSA).Theyareemittedfromthepositiveelectrodeinanelectricaldischargetubethroughwhichacurrentispassing.Oneoftheirfirstapplicationswasinthemedicalfield:Rntgenmadearadiographofhiswifeshandshowingthesofttissueandbonestructureandthegreatradiopacityoftheweddingring.ThepropertiesofX-raysthatareofsignificanceinmedicalradiologyare:(1)theypenetratemattertoagreaterorlesserdegree;(2)theyproduceionizationandexcitationintheatomsofmatter;(3)theyproducefluorescenceandhencevisiblelightfromcertainmaterials;(4)theyaffectphotographicemulsions2;and(5)theyproducebiologicaleffectsinlivingtissues.x射线的发现和性质x射线是由威廉康拉德伦琴发现11895年。他们通常被称为“伦琴射线”(特别是在美国)。它们发出正极的放电管,通过它的电流通过。他们的第一个应用程序是在医学的领域:伦琴射线照片了妻子的手显示软组织和骨骼结构和大辐射不能透过的结婚戒指。x射线的特性在医学放射学的意义是:(1)他们穿透物质或多或少;(2)产生电离和激发的原子物质;(3)产生荧光,因此可见光从某些材料;(4)他们影响感光乳剂2;(5)他们在生活组织产生生物效应。WhenabeamofX-raysfromanX-raytubefallsonapatient,interactionstakeplacebetweenenergyandmatter,andpartoftheenergyisremovedfromthebeameitherbyabsorptionorbyscattering.Theenergyremaininginthebeamthatemergesunmodifiedfromthepatientcarriesinformationabouttheinternalstructuresofthebodyintheformofadistributionofintensityperpendiculartothebeamaxis.ThisdistributioninanygivenplanemaybecalledtheX-rayimage,andtheprocessmaybecalledX-rayimageformation.当一束x射线从落在一个x线管病人,能量和物质之间的相互作用发生,能量从光束的一部分通过吸收或散射。剩余的能量产生的光束从病人携带的信息修改的内部结构体的形式分布的强度垂直于声束轴线。这在任何给定平面分布可能所谓的x射线图像,这个过程可以称为x射线成像。Part2TheproductionofX-rays:X-rayspectraThiscreatesacrucialdifficultyfortheX-raytubedesigner,whomustensurethattheheatisremovedfromthebombardedarea(thefocalarea)ofthetargetsufficientlyfasttoensurethatthefocalareadoesnotbecomeexcessivelyhotandthereforedeteriorateorevenmelt.Thisisdoneinseveralways,ofwhichtwoareimportantindiagnosticradiologyandareshowninfigure1.2.First,thetargetismadeintheformofadisc(withabevelededge)whichiscausedtorotatewheneverX-rayemissionisrequired;thustheheatisspreadoutovertheperipheryofthediscfromwhichitismainlyradiatedbutpartiallyconductedaway.这将创建一个至关重要的困难x射线管的设计师,他们必须确保热量从轰炸区(焦区)中删除目标足够快,以确保核心地带不会变得过于热,因此恶化,甚至融化。这样做是在几个方面,其中两个是重要的诊断放射学和图1.2所示。首先,目标是在光盘的形式(斜边)是引起旋转时x射线辐射是必需的,因此,热量在盘的外围的主要辐射但部分进行Thenatureofthetargetmaterialisimportant.Forclinicalworktungstenisinalmostuniversalusebecauseithasahighmeltingpoint,reasonablethermalconductivity,desirablemechanicalpropertiesandahighatomicnumberwhichincreasestheefficiencyofX-rayproduction.目标材料的性质是非常重要的。临床工作钨几乎普遍使用,因为它有一个高熔点、导热系数合理,理想的机械性能和较高的原子序数增加x光生产的效率。X-raysofhighquantumenergy(hardX-rays)aremorepenetratingthanthoseoflowquantumenergy(softX-rays).Henceifafilterofaluminiumorcopperisplacedinthebeam,thesoftX-raysareattenuatedtoagreaterextentthanarethehardX-rays;thewholebeambecomesmorepenetratingandissaidtobeharder.ThistechniqueisofimportanceinclinicalradiologybecausethesoftercomponentsinaspectrumarepreferentiallyabsorbedinthesuperficiallayersofpatienttissuenearesttotheX-raytube,withunwantedbiologicaleffects.Thereforeitiscustomarypartiallytoremovethesoftcomponentsbymeansofanaluminiumfilter,thoughamoreradicalsolutionistoensurethatthepotentialdifferenceacrosstheX-raytubeisalwaysatitsmaximum,i.e.isconstantpotentialandnotpulsating.Constant-potentialgenerators,ortheirequivalent,arerapidlydisplacingtheolderpulsatingvoltagegeneratorsfromthemodernX-raydepartment.TheyhavetheoutstandingadvantagethatnotonlyislesssoftX-radiationproducedbutthattheheatthatwouldhaveaccompanieditsproductionisabsentalso,thusrenderingtheX-raytubedesigneasier.高量子能量(硬x射线)的x射线穿透比低的量子能量(软x射线)。因此,如果一个过滤器的铝或铜放在梁,软x射线的衰减在更大程度上比硬x射线;整个梁越来越渗透,据说是困难。这种技术在临床放射学的重要性,因为软组件优先吸收光谱中病人的表层组织最近的x射线管,不必要的生物效应。因此,是司空见惯的部分删除软组件通过一个铝过滤器,但更激进的解决方案是确保跨x射线管的电位差总是最大,即是恒定的潜力,没有脉动。定压发电机,或其等价,正在迅速取代旧的脉动电压发电机从现代x光部门。他们有突出的优势,不仅不太软x光辐射产生的热量会伴随生产也没有,因此呈现x射线管的设计更加容易。ItisoftendesirabletospecifythequalityorpenetratingpowerofabeamofX-rays.Asthisconsistsofacomplexspectrum,itcannotbedoneunequivocallyintermsofquantumenergy.Insuchacaserecourseishadtoaconceptknownastheequivalentenergyofthebeam.Thelatterispassedthroughvariousthicknessesofmatter,andthethicknessofagivenmaterial(forexample,aluminium)thatreducesthebeamtoone-halfofitsintensityisnoted.Thisiscalledthehalf-valuelayerofthebeaminthatparticularmaterial.ThemeasurementisthenrepeatedusingmonoenergeticsourcesofX-raysandthequantumenergyofthemonoenergeticX-raybeamthathasthesamehalf-valuelayerasthebeaminquestionisknownasitsequivalentenergy2.Forexample,theequivalentenergyofaspectrumproducedby100kVpacrosstheX-raytubeisabout60keV.通常需要指定质量或一束x射线的穿透能力,这包括一个复杂的光谱,它不能做明确的量子能量。在这种情况下追索权不得不是一个概念称为等效梁的能量。后者是通过各种厚度的问题,给定材料的厚度(例如,铝),降低了一半的梁的强度。这就是所谓的半值层梁在特定材料。然后重复测量使用单色的x射线的来源和量子的能量单色的x射线,相同的半值层梁的问题被称为等效能量2。例如,相当于100千伏峰值产生的光谱能量x射线管大约是60岁的凯文。CTstandsforcomputerizedtomography.Inthisprocedure,athinX-raybeamisrotatedaroundtheareaofthebodytobevisualized.Usingverycomplicatedmathematicalprocessescalledalgorithms,thecomputerisabletogeneratea3-Dimageofasectionthroughthebody.CTscansareverydetailedandprovideexcellentinformationforthephysician.CT代表电脑断层摄影术。在这个过程中,薄的x射线是旋转的身体被可视化。使用非常复杂的数学过程称为算法,计算机能够生成一个三维图像的部分通过身体。CT扫描非常详细,为医生提供良好的信息。YouwillbeaskedtolieonanarrowtablethatslidesintothecenteroftheCTscanner.Dependingonthestudybeingdone,youmayneedtolieonyourstomach,back,orside.你将被要求躺在狭窄的台上,滑向了CT扫描仪的中心。根据所做的研究,你可能需要躺在你的胃,或侧面。Youmustbestillduringtheexam,becausemovementcausesblurredimages.Youmaybetoldtoholdyourbreathforshortperiodsoftime.你仍然必须在考试期间,因为运动造成图像模糊,你可能会告诉屏住呼吸的时间。Certainexamsrequireaspecialdye,calledcontrast,tobedeliveredintothebodybeforetheteststarts.Contrastcanhighlightspecificareasinsidethebody,whichcreatesaclearerimage.某些考试需要一种特殊的染料,称为对比,交付测试开始前进入体内。对比体内可以突出显示特定的区域,形成清晰的图像。Ifyouweighmorethan300pounds,haveyourdoctorcontactthescanneroperatorbeforetheexam.CTscannershaveaweightlimit.Toomuchweightcancausedamagetothescannersworkingparts.如果你的体重超过300磅,你的医生联系考试前扫描仪操作符。CT扫描仪有重量限制。太多的重量会导致损害扫描器的工作部件。CTscansandotherx-raysarestrictlymonitoredandcontrolledtomakesuretheyusetheleastamountofradiation.CTscansdocreatelowlevelsofionizingradiation,whichhasthepotentialtocausecancerandotherdefects3.However,theriskassociatedwithanyindividualscanissmall.Theriskincreasesasnumerousadditionalstudiesareperformed.x射线CT扫描和其他受到严格的监督和控制,以确保他们使用最少的辐射。CT扫描的确创造了低水平的电离辐射,这有可能导致癌症和其他缺陷3。然而,与任何个人扫描相关的风险很小。风险增加许多额外的研究。Insomecases,aCTscanmaystillbedoneifthebenefitsgreatlyoutweightherisks.Forexample,itcanbemoreriskynottohavetheexam,especiallyifyourhealthcareproviderthinksyoumighthavecancer.在某些情况下,CT扫描可能仍然做如果权衡风险极大好处。例如,它可以是风险更大没有考试,特别是如果你的卫生保健提供者认为你可能有癌症。AnabdominalCTscanisusuallynotrecommendedforpregnantwomen,becauseitmayharmtheunbornchild.Womenwhoareormaybepregnantshouldspeakwiththeirhealthcareprovidertodetermineifultrasoundcanbeusedinstead.腹部CT扫描通常不建议孕妇,因为它可能会伤害未出生的孩子。或可能怀孕的妇女应该与他们的卫生保健提供者来确定超声波可以使用。60Lesson10MagneticResonanceImagingIn1952,theNobelPrizeinPhysicswasawardedforthediscoveryofnuclearmagneticresonance,whichlaidthegroundworkforoneofthemostuniqueandimportantinventionsinmedicalimagingsincethediscoveryoftheX-ray.1952年,诺贝尔物理学奖授予了核磁共振的发现,它奠定了基础最独特和最重要的发明之一自发现x射线在医学成像。Magneticresonanceimaging(MRI)isamethodoflookinginsidethebodywithoutusingsurgery,harmfuldyesorradiation.Themethodusesmagnetismandradiowavestoproduceclearpicturesofthehumananatomy.磁共振成像(MRI)是一种方法不用手术,体内的有害染料或辐射。该方法使用磁性和无线电波产生人体解剖学的清晰照片。AlthoughMRIisusedformedicaldiagnosis,itusesaphysicsphenomenondiscoveredinthe1930sinwhichmagneticfieldsandradiowaves,bothharmlesstohumans,causeatomstogiveofftinyradiosignals.Inthe1940s,researchphysicistsfoundthatthelengthoftimetheseresponsesignalsareemittedafteranatomisstimulatedbyradiowavesvarieswidelydependinguponthesubstancebeingexamined1.Thisamazingphenomenonalsoholdstrueforbiologicaltissue.虽然核磁共振用于医学诊断,它使用一个物理现象在1930年代发现磁场和无线电波,都对人类无害,导致原子释放出微型无线电信号。在1940年代,物理学家研究发现,这些响应的时间信号发出后一个原子是由无线电波刺激变化很大取决于物质检查1。这一惊人的现象也适用于生物组织。Itwasntuntil1970,however,thatRaymondDamadian,amedicaldoctorandresearchscientist,discoveredthebasisforusingmagneticresonanceasatoolformedicaldiagnosiswhenhefoundthatdifferentkindsofanimaltissueemitresponsesignalsofdifferinglength.Healsodiscovereddifferencesinresponsesignalsbetweencancerousandnon-canceroustissue,andamongtheresponsetimesofotherkindsofdiseasedtissue.然而,直到1970年,雷蒙德Damadian医生和科学家,发现使用磁共振作为一种工具的基础医学诊断时,他发现,不同种类的动物组织发出的响应信号不同的长度。他还发现响应信号之间的差异癌变和癌变组织,以及其他类型的病变组织的响应时间。61Manyoftheproblemsencounteredwerefromtheuseoflow-fieldstrengthmagnetsandthelimitsoftheprevailingtechnologyofthetime2.However,withtheintroductionofhigh-fieldmagnetsinthemid-1980scamefasterscantimesandbettertechniques,andsoonMRIwasthesuperiorchoiceoverCTscans.遇到的许多问题都来自low-field力量的使用磁铁和当时的主流技术的限制2。然而,通过引入磁铁在1980年代中期更快的扫描速度和更好的技术,很快,MRI是优越的选择在CT扫描。AnotheradvantageisMRIproduceshigh-resolutionsectionalimagesinmultipleplaneswithoutmovingthepatient.Thisabilitymakesitversatileoffersspecialadvantagesforradiationandsurgicaltreatmentplanning.另一个优势是核磁共振产生高分辨率截面图像在多个飞机不动病人。这种能力使它多才多艺的辐射和外科治疗计划提供特殊的优势Lesson11UltrasonicSensorUltrasonicsensors(alsoknownastransducerswhentheybothsendandreceive)workonaprinciplesimilartoradarorsonarwhichevaluateattributesofatargetbyinterpretingtheechoesfromradioorsoundwavesrespectively.Ultrasonicsensorsgeneratehighfrequencysoundwavesandevaluatetheechowhichisreceivedbackbythesensor.Sensorscalculatethetimeintervalbetweensendingthesignalandreceivingtheechotodeterminethedistancetoanobject.超声波传感器(也称为传感器发送和接收)时的工作原理类似于雷达和声纳评价属性的目标解读回声分别从无线电或声波。超声波传感器产生高频声波和评估由传感器接收回声返回。传感器计算之间的时间间隔发送信号和接收回声来确定物体的距离。Thistechnologycanbeusedformeasuring:windspeedanddirection(anemometer),fullnessofatank,andspeedthroughairorwater.Formeasuringspeedordirectionadeviceusesmultipledetectorsandcalculatesthespeedfromtherelativedistancestoparticulatesintheairorwater.Tomeasuretheamountofliquidinatank,thesensormeasuresthedistancetothesurfaceofthefluid.Furtherapplicationsinclude:humidifiers,sonar,medicalultrasonography,burglaralarms,andnon-destructivetesting.Systemstypicallyuseatransducerwhichgeneratessoundwavesintheultrasonicrange,above20,000hertz,byturningelectricalenergyintosound,thenuponreceivingtheechoturnthesoundwavesintoelectricalenergywhichcanbemeasuredanddisplayed.这种技术可以用于测量:风速和风向风速计,丰满的一辆坦克,并通过空气或水速度。速度或方向测量设备使用多个探测器和计算速度的相对距离微粒在空气或水。测量液体的数量在一辆坦克,传感器测量液体表面的距离。进一步的应用包括:加湿设备、声纳、医学超声、防盗报警器、无损检测。系统通常使用超声波换能器产生声波的范围,20000赫兹以上,通过将电能转变为声音,然后在接收到回波将声波转化成电能,可以测量并显示出来Anultrasonictransducerisadevicethatconvertsenergyintoultrasound,orsoundwavesabovethenormalrangeofhumanhearing.Whiletechnicallyadogwhistleisanultrasonictransducerthatconvertsmechanicalenergyintheformofairpressureintoultrasonicsoundwaves,thetermismoreapttobeusedtorefertopiezoelectrictransducersthatconvertelectricalenergyintosound.Piezoelectriccrystalshavethepropertyofchangingsizewhenavoltageisapplied,thusapplying analternatingcurrent(AC)acrossthemcausesthemtooscillateatveryhighfrequencies,thusproducingveryhighfrequencysoundwaves.Detectors超声波传感器是将能量转换成超声波设备,或声波高于正常人类听觉范围。虽然技术上狗哨子是一个超声换能器,将机械能空气压力的形式转换成超声波声波,这个词更合适是指压电换能器,将电能转换成声音。压电晶体的性质变化的大小一个电压时,因此应用交流电(AC)使他们以非常高的频率振动,从而产生高频率声波探测器Althoughultrasoundisavaluabletool,itdoeshaveitslimitations.Sounddoesnttravelwellthroughairorbone,soultrasoundisnteffectiveatimagingpartsofyourbodythathavegasinthemorthatareobscuredbybone.Ratherthanusingultrasoundtoviewtheseareas,yourdoctormayinsteadorderotherimagingtests,suchasCTorMRIscans,