Doppler angle and flow velocity estimations using the classic andtransverse Doppler effects

摘要

Current clinical Doppler ultrasound systems could only measure thenflow vector parallel to the ultrasound beam axis, and the knowledge ofnthe Doppler angle (beam-to-flow angle) is needed to calculate the realnflow velocity. Currently, the Doppler angle is determined visually bynmanually aligning a vessel axis marker along the blood vessel on thenduplex scan image of the ultrasound. The application of this procedurenis often limited by practical constraints; therefore, measurements arennot reliable. In order to overcome this problem, the authors developed ansimple Doppler angle and flow velocity estimation method using ancombination of the classic and transverse Doppler effects. This methodnuses only a single focused annular array transducer to estimate thenDoppler angle and the flow velocity. The authors have verifiednexperimentally that this method is successful for measuring constantnflow in a flow phantom between 45° and 80° Doppler angle. Thenstandard deviation of the estimated Doppler angles is less thann4.5°. This method could be implemented easily in medical Dopplernultrasound systems to automatically estimate the Doppler angle and thenflow velocity