Title 
Ultrasound Flow Estimation 
Author

Henze, Lasse

Supervisor

Jensen, Jørgen Arendt (Biomedical Engineering, Department of Electrical Engineering, Technical University of Denmark, DTU, DK2800 Kgs. Lyngby, Denmark)

Institution 
Technical University of Denmark, DTU, DK2800 Kgs. Lyngby, Denmark 
Thesis level 
Bachelor thesis 
Year 
2008 
Abstract 
A method for measuring the transverse velocity component is proposed. The
method measures the transit time of the blood scatterers between two, receive
beamformed lines. The transit time is estimated by correlating the beamformed
lines taken from different emissions. The largest correlating will occur when the
temporal span between the lines being correlated corresponds to the transit time
of the blood scatterers. Compensation for the axial velocity is applied. The
method has been investigated using Field simulations for a parameter study.
Using 15 emissions to create an estimate, a standard deviation of 1.64% and a
bias of 1.13% are obtained for a beam to flow angle of 90 degrees. Using the
same setup a standard deviation of 2.21% and a bias of 1.07% are obtained for
a beam to flow angle of 75 degrees. Using 20 emissions, a standard deviation of
3.4% and a bias of 2.06% are obtained for a beam to flow angle of 45 degrees.
The simulation results have been confirmed by phantom measurements. Using
20 emissions to create an estimate, a standard deviation of 3.77% and a bias
of 1.68% are obtained for a beam to flow angle of 90 degrees. For a beam to
flow angle of 75 degrees a standard deviation of 3.45% and a bias of .12% are
obtained and for a beam to flow angle of 60 degrees a standard deviation of 4.68%
and a bias of 1.45% are obtained. Invivo measurements of the common carotid
artery, the carotid bifurcation and vena jugularis have been conducted. Using the
measured velocities, the spatial pressure gradients of the carotid bifurcation have
been estimated. The estimator needs 53.75 MFLOPS for a real implementation
with a pulse repetition frequency of 4000 Hz, 50 estimates pr line and 15 emission
pr estimate. 
Pages 
123 
Admin 
Creation date: 20090625
Update date: 20090625
Source: dtu
ID: 245563
Original MXD
