Journal article · Ahead of Print article
Directional Transverse Oscillation Vector Flow Estimation
A method for estimating vector velocities using transverse oscillation (TO) combined with directional beamforming is presented. In Directional Transverse Oscillation (DTO) a normal focused field is emitted and the received signals are beamformed in the lateral direction transverse to the ultrasound beam to increase the amount of data for vector velocity estimation.
The approach is self-calibrating as the lateral oscillation period is estimated from the directional signal through a Fourier transform to yield quantitative velocity results over a large range of depths. The approach was extensively simulated using Field IIpro and implemented on the experimental SARUS scanner in connection with a BK Medical 8820e convex array transducer.
Velocity estimates for DTO are found for beam-to-flow angles of 60, 75, and 90, and vessel depths from 24 to 156 mm. Using 16 emissions the Standard Deviation (SD) for angle estimation at depths ranging from 24 to 104 mm are between 6.01 and 0.93 with a mean SD of 2.8. The mean relative SD for the lateral velocity component is 9.2% and the mean relative bias -3.4% or 4 times lower than for traditional TO.
The approach also works for deeper lying vessels with a slight increase in SD to 15.7%, but a maintained bias of -3.5% from 126 to 156 mm. Data for a pulsating flow has also been acquired for 15 cardiac cycles using a CompuFlow 1000 pump. The relative SD was here 7.4% for a femoral artery waveform.
Language: | English |
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Publisher: | IEEE |
Year: | 2017 |
Pages: | 1194-1204 |
ISSN: | 15258955 and 08853010 |
Types: | Journal article and Ahead of Print article |
DOI: | 10.1109/TUFFC.2017.2710361 |
ORCIDs: | Jensen, Jørgen Arendt |
BK Medical 8820e convex array transducer CompuFlow pump Field IIpro Fourier transform Fourier transforms SARUS scanner Transverse oscillation array signal processing biomedical transducers biomedical ultrasonics blood vessels cardiac cycle cardiology directional beamforming directional signal directional transverse oscillation femoral artery waveform lateral oscillation period medical signal processing pulsating flow synthetic aperture real-time ultrasound system ultrasonic transducer arrays ultrasound ultrasound beam vector flow vector flow estimation vector velocity estimation velocity estimation