简介:Inthispaper,weestablishasurfaceelectromyography(sEMG)signalmodelandstudythesignaldecompositionmethodfromnoisybackground.Firstly,singlefiberactionpotential(SFAP),motorunitactionpotential(MUAP)andmotorunitactionpotentialtrain(MUAPT)aresimulatedbasedonthetripolarsignalsourcemodel,andthenthesEMGisobtained;secondly,thesimulatedsEMGsignalisextractedfromthemixedsignalsthatconsistsofwhitenoises,powerfrequencyinterferencesignalandelectrocardiosignalbyindependentcomponentanalysis(ICA)algorithms;lastly,thespikescorrespondingtoeachmotorunitactionpotentialfromthesimulatedsEMGsignalsweredetectedbyapplyingthewavelettransform(WT)method.SimulationresultsshowedthatsEMGmodelcoulddescribethephysiologicalprocessofsEMG,ICAandWTmethodscouldextractthesEMGsignalanditsfeatures,whichwilllayafoundationforfurtherclassifyingtheMUAP.
简介:ImagegeometrydistortionisanimportanttechnicalstandardinB-modeultra-sounddiagnosissystem.ThispaperinvestigatesthecauseofimagedistortioninphasedarrayB-modeultrasounddiagnosissystem.Thefirstdistortioncauseisthedelayerrorofcompoundwavebind.Phasedarrayultrasoundtranduceriscomposedofmanyrectangleunits.Withcontrollinginspiringplustime,ultrasoundwave
简介:Diastemaoftenoccuredinmaxillarycompletedentureresinbaseintheclinic,although"Lucitone199"hadbeenusedwithmoretensilestrength.Mechanicalex-perimentshaveprovedthehightransversetensilestress(σ_x~+)concentratinginanteri-orteethregionandtheirpalatalsurfaceofmaxillarycompletedentureresinbasewhileitwasexposedtoverticalloadingincenterocclusion.Settingstrengtheningnetinresinbasehasachievedbetterresults.Forevaluatingpurpose,twentykinds