A new linear method for ultrasonic flow vector measurement

In conventional ultrasound Doppler systems, the velocity component along the beam axis is obtained from the observed frequency shift. There are many methods of measuring velocity components and determining the velocity vector. However, because of the non-linear nature of signal processing, it is difficult to use these methods to estimate the individual velocities of multiple targets. We have previously proposed a method called computed velocimetry (CV) that uses a linear procedure to measure all the components of an arbitrary flow vector. The first step in this method is Fourier transformation of the received signals in the direction of the transducer array. The second step is also a Fourier transformation, but in the polar-axis directions. In this presentation, we propose another method. The first step of this new method is again a Fourier transformation, but in the direction of the time-axis. The second step is not a Fourier transformation but a projection integration in the polar-axis directions. These two steps provide the two velocity components along, and transverse to, the beam axis, as in CV, but this method reduces the required amount of calculation. The theory for this method and results of a numerical simulation are presented