简介:EEGisthestudyoftheelectricalactivityofthebrainasdetectedby8-16pairsofsurfaceelectrodesattachedtothescalpinstan-dardizedpositions(Figure1).EEGisacrudemeasureofcere-bralfunction,reflectingtheactivityoflessthanonequarterofcorticalneuronesforalimitedperiodonly,butisthemostusefulandmostreadilyaccessibletestofcerebralactivity,ifitisusedappropriatelyanditslimitationsareunderstood.
简介:AnewmethodofphasespectralanalysisofEEGisproposedforthecomparativeanalysisofphasespectrabetweennormalEEGandepilepticEEGsignalsbasedonthewaveletdecompositiontechnique.Byusingmultiscalewaveletdecomposition,theoriginalEEGsaremappedtoanorthogonalwaveletspace,suchthatthevariationsofphasecanbeobservedatmultiscale.Itisfoundthatthephase(andphasedifference)spectraofnormalEEGsaredistinctfromthatofepilepticEEGs.Thatisthevariationsofphase(andphasedifference)ofnormalEEGshaveadistinctperiodicpatternwiththeelectricalactivityproceedsinthebrain,butdonottheepilepticEEGs.ForepilepticEEGs,onlyatthosetransientpoints,thephasevariationsareobvious.Inordertoverifytheseresultswiththeobservationaldata,thephasevariationsofEEGsinprincipalcomponentspaceareobservedandfoundthat,thefeaturesofphasespectraisincorrespondencewiththatthewaveletspace.TheseresultsmakeitpossibletoviewthebehaviorofEEGrhythmsasadynamicspectrum.
简介:IMAGINGOFEEGBYSPHERICALHARMONICANALYSISIMAGINGOFEEGBYSPHERICALHARMONICANALYSISYaoDezhong;YangShaoguo(Dep.ofAuto,UESTofChina,C...
简介:THEORYOFTHEEEGCORTICALIMAGINGTECHNIQUESTHEORYOFTHEEEGCORTICALIMAGINGTECHNIQUESDezhongYao,BingweLuoi(DepartmentofAutomationUni...
简介:Withtherapiddevelopmentofbraincomputerinterface(simplycalledBCI),electroencephalography(EEG)willbeanotherinterestingbio-electricalsignalappliedinroboticsafterEMG.Inordertorealizeitfinally,theaccuratemeasurementandpatternrecognitionofEEGsignalmustbeaveryimportantandelementaryresearchobjective.Basedonourcurrentresearchesandsomereportsfromtheotherinternationalcolleaguesinthefield,wedeeplydiscussthebasiccharacteristicsofEEGsignal,thedevelopmentandselectionofEEGmeasurementsystem,featureextractionandrecognitionmethodsofEEGsignal,andthenreviewEEG'sapplicationsinroboticsaswellasthefutureresearchtrendsinthispaper.
简介:Anewwaveletvarianceanalysismethodbasedonwindowfunctionisproposedtoinvestigatethedynamicalfeaturesofelectroencephalogram(EEG).TheexprienmentalresultsshowthatthewaveletenergyofepilepticEEGsaremorediscretethannormalEEGs,andthevariationofwaveletvarianceisdifferentbetweenepilepticandnormalEEGswiththeincreaseoftime-windowwidth.Furthermore,itisfoundthatthewaveletsubbandentropy(WSE)oftheepilepticEEGsarelowerthanthenormalEEGs.
简介:这研究的目的是根据EEG信号的复杂性措施的值识别大脑的函数和状态。30件正常样品和30件耐心的样品的EEG信号是镇定的。为未加工的数据基于预处理,为复杂性措施的一个计算程序被编译,所有样品的复杂性措施是计算的。吝啬的值和控制组的复杂性措施的标准错误作为0.33和0.10,并且正常的组作为0.53和0.08。当信心度是0.05时,为控制组的复杂性措施的正常人口平均数的信心间隔是(0.2871,0.3652),并且(0.4944,0.5552)为正常的组。正常样品和耐心的样品能清楚地是的统计结果表演由措施的价值区分了。在临床的药,结果能是是引用评估函数或状态,诊断疾病,监视大脑的康复进步。
简介:Thecombinationofelectroencephalogram(EEG)andfunctionalmagneticresonanceimaging(fMRI)isaveryattractiveaiminneuroscienceinordertoachievebothhightemporalandspatialresolutionforthenon-invasivestudyofcognitivebrainfunction.Inthispaper,werecordsimultaneousEEG-fMRIofthesamesubjectinemotionalprocessingexperimentinordertoexplorethecharacteristicsofdifferentemotionalpictureprocessing,andtrytofindthedifferenceofthesubjects’brainhemispherewhileviewingdifferentvalenceemotionalpictures.Thelatepositivepotential(LPP)isareliableelectrophysiologicalindexofemotionalperceptioninhumans.Accordingtotheanalysisresults,theslow-waveLPPandvisualcorticalbloodoxygenlevel-dependent(BOLD)signalsarebothmodulatedbytheratedintensityofpicturearousal.TheamplitudeoftheLPPcorrelatesignificantlywithBOLDintensityinvisualcortex,amygdala,temporalarea,prefrontalandcentralareasacrosspicturecontents.
简介:视频或电视录像脑电图(Video-EEG)监测是鉴别癫痫发作性质及类型的最有效的检查方法,也是国际上普遍采用的癫痫和癫痫综合征分类的重要依据之一.目前正在国内普及,其优势在于可以同步观察到病人发作症状和脑电图变化,实现了视频图像、声音和脑电三者的统一,对癫痫发作的鉴别诊断及分型均有难以取代的临床价值.目前报道的一些新的癫痫发作类型及综合征无不有赖于视频脑电图监测的证实.但是,如果没有监测到癫痫发作,与常规脑电图有何区别?过去有的报道仅"监测"数十分钟,而且90%以上未监测到发作,这就使这样一个现代化优势明显的设备成为只有经济效益的检查,失去其临床应用价值.对此,有关视频脑电图的临床应用价值做进一步探讨.
简介:InordertoexplorethecorrelationbetweentheadjacentsegmentsofalongtermEEG,animprovedprincipalcomponentanalysis(PCA)methodbasedonmutualinformationalgorithmisproposed.Aone-dimensionEEGtimeseriesisdividedequallyintomanysegments,sothateachsegmentcanberegardedasanindependentvariablesandmulti-segmentedEEGcanbeexpressedasadatamatrix.Then,wesubstitutemutualinformationmatrixforcovariancematrixinPCAandconducttherelevanceanalysisofsegmentedEEG.Theexperimentalresultsshowthatthecontributionrateoffirstprincipalcomponent(FPC)ofsegmentedEEGismorelargerthanothers,whichcaneffectivelyreflectthedifferenceofepilepticEEGandnormalEEGwiththechangeofsegmentnumber.Inaddition,theevolutionofFPCconducetoidentifythetime-segmentlocationsofabnormaldynamicprocessesofbrainactivities,theseconclusionsarehelpfulfortheclinicalanalysisofEEG.
简介:目的:了解长程数字化视频EEG与过度换气EEG的癎样放电规律.方法:评估52例颞叶癫癎患者长程数字化视频EEG与过度换气EEG的癎样放电特点.结果:过度换气EEG癎样放电检出率明显低于浅睡期EEG,差异具有极显著意义(P<0.01);但与清醒期和深睡期EEG癎样放电检出率比较差异无显著意义(P>0.05).结论:颞叶癫癎患者浅睡期EEG癎样放电率明显高于过度换气EEG,对颞叶癫癎患者进行睡眠EEG检测,有助于提高癎样放电的检出率.
简介:[摘要]:目的:分析 50例儿童失神癫痫脑电图波形典型改变特征及儿童失神癫痫的临床发作特点。方法:对我院 2015年 -2019年 50例儿童失神癫痫收集的资料进行回顾性分析。结果: 50例儿童失神癫痫异常率达 100%。结论:发作期为双侧对称、同步的 3Hz棘慢综合波或双棘慢综合波节律爆发,棘慢综合波的频率在发作期开始时稍快,平均为 3.5-4.5Hz;结束前稍慢,可达 2.5-2.8Hz,波幅以前头部最高,持续约 4-20秒,多数在 8-10秒之间,发作后背景无抑制或波率慢化现象。过度换气试验容易诱发出临床发作。
简介:摘要:癫痫是大脑异常放电引起的短暂性脑功能失调综合征,是一种常见的神经系统疾病。据统计,患病率超过 4‰。其中 1/3以上癫痫患者还可出现各种精神障碍,严重影响人们正常的生活。脑电图检查对癫痫的确诊具有重要意义,对癫痫的鉴别具有决定性作用。最初的脑电图检查主要依靠医师的肉眼观察,具有较强的主观性,近年来,国内外对于脑电信号处理方面的研究日益增多,许多经典的或现代的信号处理分析方法已开始应用于脑电信号中,为癫痫的诊断提供了更准确和客观地方法。
简介:Inrecentyears,therehavebeensignificantadvancesinwearable,mobile,dry-electrodeelectroencephalography(EEG)systems.Theseareyieldingexcitingnewpossibilitiesforscientificresearch,clinicaldiagnosticsandtherapeutics,andbrain-computerinterfaces(BCI)outsidetheclinicorlaboratory.However,thesesystemshavebeenlimitedtoahandfulofchannelsmostlyforapplicationsof