Abstract
A method for determining both velocity magnitude
and angle in any direction is suggested. The method uses
focusing along the velocity direction and cross-correlation for
finding the correct velocity magnitude. The angle is found from
beamforming directional signals in a number of directions and
then select the angle with the highest normalized correlation
between directional signals. The approach is investigated using
Field II simulations and data from the experimental ultrasound
scanner RASMUS and with a parabolic flow having a peak
velocity of 0.3 m/s. A 7 MHz linear array transducer is used with
a normal transmission of a focused ultrasound field. The velocity
profile estimates from simulations have relative mean standard
deviations between
0
.
7%
and
7
.
7%
for flow between
45
◦
and
90
◦
.
The angle estimation performance is highly dependent on the
choice of the time
k
tprf
·
T
prf
(
correlation-time
) between signals
to correlate, and a proper choice varies with flow angle and flow
velocity. One performance example is given with a fixed value
of
k
tprf
for all flow angles. The angle estimation on measured
data for flow at
60
◦
to
90
◦
, yields a probability of valid estimates
between
68%
and
98%
and with standard deviations between
1
◦
and
4
◦
. The optimal value of
k
tprf
for each flow angle is found
from a parameter study to reveal the potential of the method and
with these values the performance on simulated data yields angle
estimates with no outlier estimates and with standard deviations
below 2º
Original language | English |
---|---|
Title of host publication | IEEE Ultrasonics Symposium |
Publisher | IEEE |
Publication date | 2005 |
Pages | 1339-1343 |
ISBN (Print) | 0-7803-9382-1 |
DOIs | |
Publication status | Published - 2005 |
Event | 2005 IEEE Ultrasonics Symposium - Rotterdam, Netherlands Duration: 18 Sept 2005 → 21 Sept 2005 http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=10674 |
Conference
Conference | 2005 IEEE Ultrasonics Symposium |
---|---|
Country/Territory | Netherlands |
City | Rotterdam |
Period | 18/09/2005 → 21/09/2005 |
Internet address |