@article{3c3b7fd6069f4ba292068bc2a8d60ea6,

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, arid 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, we 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 lo estimate the Doppler angle and the flow velocity. We have verified experimentally that this method is successful for measuring constant flow in a flow phantom between 45° and 80° Doppler angle. The standard deviation of the estimated Doppler angles is less than 4.5°. This method could be implemented easily in medical Doppler ultrasound systems to automatically estimate the Doppler angle and the flow velocity.",

author = "Lee, {Bor Ray} and Chiang, {Huihua Kenny} and Kuo, {Cheng Deng} and Lin, {Win Li} and Lee, {San Kern}",

note = "Funding Information: EDICAL ULTRASOUND uses the Doppler effect, which as- sumes an infinitely wide, single-frequency ultrasound beam crossing a uniform flow to measure the flow velocity. The ultrasound beam is scattered from particles carried by the flow, and the ultrasound frequency is changed by the amount of velocity-induced Doppler shift frequency. The classic Doppler equation is given by: where fd is the energy peak frequency of the Doppler spectrum [l],8 is the Doppler angle (the beam-to-flow angle), X is the wavelength of the ultrasound, and v is the flow velocity. Sometimes, fd is referred to as the mean frequency of the Doppler spectrum [2] rather than the energy peak frequency used in this article. When the center of the sample volume is positioned at Manuscript received February 23, 1998; accepted July 21, 1998. Parts of this work were supported by the National Science Council, R.O.C., and the Veterans General Hospital and Yang-Ming Univer- sity joint research projects. B.-R. Lee and H. K. Chiang are with the Institute of Biomedical Engineering, National Yang-Min University, Taipei 112, Taiwan, Republic of China (*corresponding author's e-mail: chiang@bme.ym.edu.tw). C.-D. Kuo and S.-K. Lee are with the Taichung Veterans General Hospital, Taichung, Taiwan, Republic of China. W.-L. Lin is with the National Taiwan University, Taipei, Taiwan, Republic of China.",

year = "1999",

doi = "10.1109/58.741545",

language = "English",

volume = "46",

pages = "252--256",

journal = "IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control",

issn = "0885-3010",

publisher = "Institute of Electrical and Electronics Engineers Inc.",

number = "1",

}