简介:在医药Doppler超声系统,是的一个高通行证的过滤器通常采用了过滤墙喧嚷部件,将移开未经触动的Doppler超声血表明的低速度血flow.To摘录的信息,一条新奇途径基于空间地选择的噪音过滤被建议。墙信号被空间地选择的噪音过滤第一从小浪估计空间关联性质。然后,墙喧嚷被降噪消除剩余血流动信号的技术的小浪阀值确切获得。最后,未经触动的血流动信号被从混合信号减去墙信号完成。这条途径被用于模仿的计算机并且在vivo颈动脉Doppler超声信号。实验结果证明基于的小浪空间来临能确切提取血流动信号,并且比高通行证的过滤的在吝啬的绝对错误完成大约45%更低的结果。这条途径被期望是一个有效方法在Doppler超声系统移开墙喧嚷。
简介:Dopplereffectwidelyexistsinthesignalfromthemovingacousticsource.Inordertosolvesuchproblemsasfrequencyshiftandfrequencybandexpansion,atimedomaincorrectionmethodispresentedinthispaper.First,thediscretetimevectorforinterpolationandtheamplituderestorationformulaisderivedbasedonthemovingrelationshipandtheMorseacoustictheory,thentheamplitudeweightsarecorrectedandthedistortionsignalisinterpolated.Everypointofthediscretesignalisoperatedseparatelyintimedomain.Comparedwiththeexistingfrequencydomainmethods,thismethoddoesnotneedtoknowthecharacteristicfrequencybeforehandandwouldnotbeinfluencedbytheblendingofthefrequencyband.Hence,thismethodcanbeemployedtocorrectmultiplefrequencysignalsanditisalsoasimpleandeffectiveDopplereffectreductionmethod.