Simulation Of The Doppler Ultrasound Signal And Separation Methods

Doppler Ultrasound blood flow detection technology is a significant in losslessdiagnosis for the disease of blood circulation system and an important branch ofmedical ultrasound. The echo signal of the vessel wall is the largest noise when weuse the doppler ultrasound technique to detect the blood flow. The doppler bloodflow almost is submerged in the vessel wall pulsation signal. The traditional dopplerultrasound equipment directly uses high-pass filtering method to elimination the wallpulse signal and get the blood flow signal. This approach would filter the low bloodflow signal when it filters the wall beat signal. Accurate detecting the low blood flowwhich close to the wall can provide effective information for doctors to diagnoissvascular disease. Researching the separation of the ultrasound vessel wall pulsesignal and blood flow signals, as far as possible keeping low-frequency componentsin the blood flow signal, are very meaningful.In the separation method of the vessel wall signal and blood flow signal, wehave done meaningful work as like:First, we introduce some related technology of the doppler blood flow detection,including signal output, waveform evaluation and time-frequency analysis, thenresearch and analysis the simulation of doppler ultrasound blood flow signal anddoppler pulse blood vessel wall signal, then elaborate the traditional and newseparation algorithm of the doppler ultrasound blood flow and vessel wall signal,discuss the characteristics and limitations of each algorithm, then propose a newseparation method to separate the doppler blood flow and vessel wall signal.This researching propose a method which use ECG as a reference signaladaptive filtering to eliminate wall interference, and use computer simulation ofultrasound doppler signal to test the method. The method includes two aspects:First,use ECG as a reference signal of Doppler ultrasound signals in adaptive filterï¼›Second, use multi-level adaptive filter and select different reference signals in thefiltering programs. We compared this method with the high-pass filtering, the resultsshowed that: the method can effectively restrain the wall beat signal, and keep partof the low blood flow signal components.The method of useing ECG as a reference signal to adaptive filter the wallsignal, is a new method with further researching value.