方向性超声脉冲多普勒血流信号谱分析仪的研制  

The Development of a Spectrum Analyzer forUltrasonic Directional Pulsed Doppler UltrasoundBlood Flow Signal

作　　者：唐庆玉[1] 何丽静[1] 陈利建 杨福生[1] 

机构地区：[1]清华大学

出　　处：《仪器仪表学报》1985年第4期360-368,共9页Chinese Journal of Scientific Instrument

摘　　要：本仪器用微处理器控制,用快速付立叶交换(FFT)算法,处理128点复数据需250ms。与超声脉冲多普勒血流仪配合使用,建立三个心动周期的血流声谱图象需35秒。An ultrasonic directional pulsed Doppler spectrum analyzerbased on a microprocessor has been developed. The quadrature outputs from thepulsed Doppler ultrasound blood flowmeter, which contain the direction andvelocity information of the blood flow, are a Hilbert transform ?air, so tneyare employed as real part and imaginary part of a complex signal to form ananalytic signal which is just the envelope of the received signal. The powerspectrum of this analytic signal is calculated and its positive and negativefrequency components correspond to the forward and backward blood flowrespectively. To avoid the cross-talk mirroring between the two channels, cha-racteristics of the two high frequency amplifiers must be the same and sampli-ng-holders and A/D converters must work synchronously. The micro-computersystem is composed of a Z80-CPU, 2K EPROM, 34K RAM and a Z80-DMAcontroller. Two A/D converters (ADCO804) and two D/A converters(DACO832)are connected with busses as peripheral. The instrument ultilizes fast Fo-urier transform algorithm (FFT) and a hardwared multiplier to speed up theprocessing rate. A 128-point complex FFT can be completed in 250ms. Displayof a 128-point 133-line blood flow velocity sonogram can be completed in 35seconds. Clinical experiments show that some cardiovascular diseases can bedetected effectively.

关 键 词：多普勒血流 超声脉冲 反向血流 心动周期 声谱图 微处理器控制 信号谱 多谱勒 超声探头 颈总动脉 

分 类 号：R445[医药卫生—影像医学与核医学]