Hi,
I wonder how the elevational focus is simulated in K-Wave?
After a transducer is created by makeTransducer(), if you plot it, it is always plat even with a finite elevation_focus_distance.
Is it done with delay?
k-Wave
A MATLAB toolbox for the time-domain
simulation of acoustic wave fields
how elevational focus is simulated in K-Wave
(4 posts) (2 voices)-
Posted 11 years ago #
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Hi Bo,
Yes, the elevation focus distance is applied with delay. There is small amount of information on how this works in the k-Wave manual on pages 41-42. Essentially, in transmit, the signals driving the individual grid points that make up each transducer element in the z-direction are delayed to give the appropriate elevation focus distance. In receive, the time signals recorded at the individual grid points are similarly delayed before they are averaged to give one signal per transducer element.
The functionality of the
kWaveTransducerclass is quite new, and some of the code is reasonably complex. If you notice any strange behaviour or have any other suggestions, do let us know!Brad.
Posted 11 years ago # -
Brad,
I may be wrong but I tried to implement circular focusing transducer with delays, the results do not match up with physical lens. Basically, the focus appears to be broader and displaced a little bit. Maybe it is not a big deal but would like to let you know.
Bo
Posted 11 years ago # -
Hi Bo,
Thanks for your feedback - it would be interesting to know the reason for the difference. How did you define your circular transducer, or is that not what you mean? Also, what did you compare the results to? If you want to simulate a single element circular transducer, it might be easier to define a circular aperture using
makeDisc, and then create an input signal with the appropriate beam forming delays usingfocus.Brad.
Posted 11 years ago #
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