The noninvasive Doppler ultrasound technique is an important method to study arterial disease. Several analysis methods, based on the calculation of the characteristic indices such as S/D, PI and RI, have been used in medical clinic. Also some arterial models, such as the transmission line model of the vessel, were proposed. However, the transmission line model has to involve the simultaneous measurement of the blood flow and pressure waveforms which usually is not very easy. The transfer function model and the Laplace transform model are developed with only the maximum and/or mean velocity waveform used. Since Doppler signals are nonstationary, some flow information can not be respected only using the maximum and/or mean velocity waveform. To improve the sensitivity of diagnosis, a zero-pole analysis method using the audio Doppler signals is described in this paper.
展开▼
