Maximum flow velocity estimation based on Doppler spectral analysis [haemodynamics]

A novel maximum-frequency estimator based on Doppler spectral analysis is presented and demonstrated on experimental results obtained by a newly constructed versatile pulse-echo Doppler system. The system employs a fast (12-b at 20 MHz) data-acquisition system that enables recording of raw RF data, which allows computation of Doppler spectra in software. Given a Doppler spectrum, the maximum-frequency estimator makes use of the total spectral power. This feature makes the estimator less susceptible to noise. The maximum-frequency estimator has been applied to a series of pulsatile flow phantom data obtained at 3.5 MHz. Maximum-frequency curves obtained from pulsatile flow velocities in the 2 m/s range are presented. The efficacy of the estimator is further demonstrated on preliminary results obtained from data taken from a human carotid artery using a real-time scanner