I try to simulate using 2D Transducer array for 3D
I want to put the phantom and transmit sound and recieved echo by 2D transducer (16X16) and produce 3D imaging by echo
but in the K-wave transducer class only for 1-D array
so I try to use sensor and source togheter but at this time the echo was created even sound go through heterogeneous medium
I need to move a 1-D Transducer in z-direction for 3D imaging?
Hi kimwomgom,
As you've discovered, in the current version of k-Wave (v1.0) the kWaveTransducer class only supports 1D linear arrays. One way to simulate a 2D array transducer would be to directly define the appropriate source conditions using source.u_mask and source.ux. In the simulation, each physical transducer element will likely correspond to a small group of grid points. This means your physical input signals for each physical element will need to be duplicated and carefully ordered corresponding to the ordering of the grid points belonging to the source using MATLAB's column-wise linear indexing. This is essentially what the kWaveTransducer class takes care of for 1D arrays.
If you're not yet very familiar with k-Wave, I'd suggest creating a few simple examples to get started (using a single element source for example).
Brad.
Hello,
About this topic, I wanted to clarify something. I am also trying to simulate a 2D transducer.
In the k-wave user manual, it is said that a mass source is typically vibrating pistons and is associated to monopole directivity, whilst a force source is typically a sideways oscillating rigid object and is associated to dipole directivity.
Furthermore, from what I learned, a monopole is associated to a boxed transducer, whilst a dipole is associated to an unboxed loudspeaker.
Therefore, from that, I understand that transducer elements would be boxed transducers, and therefore would act like monopole source, and thus as a mass source.
Finally, a mass source is implemented in k-Wave using source.p_mask and source.p, and not, as you say, using source.u_mask and source.ux.
Am I missing something or there is a mistake in your previous post and an ultrasound probe is actually a mass source (source.p) and not a force source (source.ux) ?
Thanks for the clarification =)
Maxime
Hi Maxine,
Good question. Physically, a single element transducer often acts like a constant velocity source in a rigid baffle (i.e., a velocity imposed as a boundary condition). This is equivalent to having a constant injection of mass in free-field (i.e., an additive mass source as defined in k-Wave).
Inside the kWaveTransducer class in k-Wave, the source is defined as a velocity source in free-field (the injection of force in free-field). This is equivalent to having a constant pressure boundary condition in an otherwise compliant plane. (See section 2.19.2.6.2 of this paper if this is getting confusing).
The choice of a pressure vs velocity source affects the directivity of the wave-field. I am not an expert in the design of diagnostic ultrasound transducer, but my understanding is the directivity doesn't match either model exactly. It's likely someone has characterised this experimentally in the past, but I don't know the relevant literature off the top of my head.
Brad.
Hello,
I am used the version-1.2.1 and i would like to simulate 2D transducer array (6x6) to characterize it as actuator. It is possible?
Regards,
Eyglis
No change in the current version I'm afraid.
Brad.
Hi,
In the new version is possible to simulate a 2D transducer array (7x7)???
Eyglis
Hi Eyglis,
We have an alpha of a new transducer class described here. This doesn't have any in-built functionality for beam-forming etc, but should let you define a 7x7 transducer array.
Brad
Thank you Brad!!!
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