title: Doppler angle and flow velocity estimations using the classic and transverse Doppler effects.
abstract: Current clinical Doppler ultrasound systems could only measure the flow vector parallel to the ultrasound beam axis, and the knowledge of the Doppler angle (beam-to-flow angle) is needed to calculate the real flow velocity. Currently, the Doppler angle is determined visually by manually aligning a vessel axis marker along the blood vessel on the duplex scan image of the ultrasound. The application of this procedure is often limited by practical constraints; therefore, measurements are not reliable. In order to overcome this problem, the authors developed a simple Doppler angle and flow velocity estimation method using a combination of the classic and transverse Doppler effects. This method uses only a single focused annular array transducer to estimate the Doppler angle and the flow velocity. The authors have verified experimentally that this method is successful for measuring constant flow in a flow phantom between 45 degrees and 80 degrees Doppler angle. The standard deviation of the estimated Doppler angles is less than 4.5 degrees . This method could be implemented easily in medical Doppler ultrasound systems to automatically estimate the Doppler angle and the flow velocity.
authors.affiliation: Inst. of Biomed. Eng., Nat. Yang-Min Univ., Taipei, Taiwan, Republic of China.
authors.forename: B R
authors.initials: BR
authors.lastname: Shi
authors.forename: H K
authors.initials: HK
authors.lastname: Chiang
authors.forename: C D
authors.initials: CD
authors.lastname: Kuo
authors.forename: W L
authors.initials: WL
authors.lastname: Lin
authors.forename: S K
authors.initials: SK
authors.lastname: Lee