Simulation and implementation for blood flow velocity measurement on pulsed Doppler system using single-channel RF sampling

In this paper, we propose a new demodulation strategy "single channel slight undersampling" for a Doppler system. The proposed method can directly sample the RF signal at the sampling frequency of 4 fo/(2 k+1). The sampling frequency of A/D conversion is reduced proportionally to this factor. The efficiency of mean frequency estimator when coupled to the single channel RF sampling method is tested by computer simulation as a function of the intersequence sample delay time. The autors have compared the accuracy of the mean frequency tracking, both on the proposed method and the undersampling method. They have showed that single channel RF sampling until the delay 5/4 fo shows good results in the carotid artery. With a single channel RF sampling system, they present the estimation of the velocity of the blood flow in the carotid, as a factor of k.