Measurement accuracy of the flow velocity in pulsed ultrasound Doppler velocimeter.

This paper presents a numerical simulation method for evaluating the measurement accuracy of the high-frequency pulsed ultrasound Doppler velocimeter (PUDV). The frequency distribution of the Doppler signal from a sample volume is calculated by dividing the sample volume into small cells and using the statistics of the velocities of the cells. The distribution is used to analyze the accuracy of the poststenotic velocity measurements of a 20-MHz 80-channel PUDV. The target flow field is obtained by solving Navier-Stokes equations numerically. It was shown that the velocities evaluated by the zero-cross and Fourier transform methods agreed well with the given velocities, and that flow separation was successfully detected. It was also shown that the tube diameter should be at least twice as large as the diameter of the sample volume to obtain accurate measurements.