简介：Thispaperpresentsaflexibleandhighspeeddigitalscanconverter(DSC)withtheabilitytohandlehighfrequencyultrasoundimaginginreal-time.Thecharacteristicsinimagingsystemsuchasfocuslengthoftransducer,theswingradiusandsamplinglengthetc.couldbechangedeasilyincompliancewiththeresearcher'sapplicationbasedonthisflexibledigitalscanconverter.Linearinterpolationisemployedtoachievethecoordinatetransformationsalgorithm.Custom-builtsoftwareisprogrammedtopreliminarilyhandlethealgorithmaccordingtodifferentultrasoundimagingapplications.HighperformanceFPGAwillimplementhighspeedinterpolationcalculationbasedonthepreliminarydatawhicharestoredintheDDR2SDRAMfromthesoftware.64bit66MHzPCIisemployedtoaccomplishhighspeeddatatransmission.Experimenthasshownthatmorethan500frameratecouldbeachievedbasedonthishighspeeddigitalscanconverter.ThedesignedflexibleandhighspeeddigitalscanconvertercouldbeusedincurrentFPGAbasedhighfrequencyultrasoundimagingsystem.

简介：Low-intensityfocusedultrasoundstimulation(FUS),whichpossesseshighspatialresolutionandpenetrationdepth,hasbeendevelopingrapidlyfornoninvasivebrainneuromodulationinrecentyears.Inthisletter,alow-intensityFUSsystemwasdevelopedfornoninvasivebrainneuromodulationinvivo.Theradiusofultrasonicfocalspotwasquantitativelycalculatedintheorytoevaluatethespatialresolution.Thelocalfieldpotential(LFP)ofrathippocompuswererecordedbeforeandafterFUS.TheeffectofFUSonLFPpowerspectrumwasinvestigatedbycomputingtheLFPmeanabsolutepowerandrelativepowerwithWelchalgorithm.TheexperimentresultsshowthatnoninvasiveFUScanenhanceLFPmeanabsolutepowerandaltertheLFPrelativepoweratdifferentfrequencybands.TheresultsindicatethatFUScanmodulatebrainrhythmsandhassignificantpotentialinthemodulationofneuronalandpsychiatricdiseases.

简介：Inordertoeliminatedisplacementandelasticdeformationbetweenimagesofadjacentframesincourseof3Dultrasonicimagereconstruction,elasticregistrationbasedonskeletonfeaturewasadoptinthispaper.Anewautomaticallyskeletontrackingextractalgorithmispresented,whichcanextractconnectedskeletontoexpressfigurefeature.Featurepointsofconnectedskeletonareextractedautomaticallybyaccountingtopicalcurvatureextremepointsseveraltimes.Initialregistrationisprocessedaccordingtobarycenterofskeleton.Whereafter,elasticregistrationbasedonradialbasisfunctionareprocessedaccordingtofeaturepointsofskeleton.Resultofexampledemonstratethataccordingtotraditionalrigidregistration,elasticregistrationbasedonskeletonfeatureretainnaturaldifferenceinshapefororgan'sdifferentpart,andeliminateslightelasticdeformationbetweenframescausedbyimageobtainedprocesssimultaneously.Thisalgorithmhasahighpracticalvalueforimageregistrationincourseof3Dultrasoundimagereconstruction.

简介：High-frequencyimagetechniquehasbeenwidelyappliedinmedicaldiagnosisrecently.Forhighvoltageprotection,highspeedstageandtriggercontrolcircuitryaredifficulttoimplementahigh-frequencyultrasoundimagingsystem.Inthisstudy,weutilizedalinearservowithhighnoisetoleranceandanovelmulti-depthexpressionmethodtoovercomethoseissuesindevelopedhigh-speedimagesystem.B-modeimageofthechickenphantomby25MHztransducershowstheresolutionoflateralandaxialresolutionsareupto123μmand59μmrespectively.Inaddition,theexperimentdemonstratesthattheaxialresolutionanddepthoffield(DOF)canbeimprovedbytimegaincompensation(TGC)andmulti-depthmethod.Theresultsindicatethattheproposedsystemcouldachieveover24fpsfor1mmscandistanceand100linesperframe.Inthefuture,thedevelopedsystemispotentialforotherclinicalapplicationssuchasophthalmologyanddermatology.

简介：Intravascularultrasoundcanprovidehigh-resolutionreal-timecrosssectionalimagesaboutlumen,plaqueandtissue.Traditionally,theluminalborderandmedial-adventitialborderaretracedmanually.Thisprocessisextremelytimeconsumingandthesubjectivedifferencewouldbelarge.Inthispaper,anewautomatedcontourdetectionmethodisintroducedbasedonfastactivecontourmodel.Experimentalresultsfoundthatlumenandvesselareameasurementsafterautomateddetectionshowedgoodagreementwithmanualtracingswithhighcorrelationcoefficients(0.94and0.95,respectively)andsmallsystemdifference(-0.32and0.56,respectively).Soitcanbeareliableandaccuratediagnostictool.

简介：ImagegeometrydistortionisanimportanttechnicalstandardinB-modeultra-sounddiagnosissystem.ThispaperinvestigatesthecauseofimagedistortioninphasedarrayB-modeultrasounddiagnosissystem.Thefirstdistortioncauseisthedelayerrorofcompoundwavebind.Phasedarrayultrasoundtranduceriscomposedofmanyrectangleunits.Withcontrollinginspiringplustime,ultrasoundwave