I have a few questions to try and get started on a (potentially lofty) goal. At the moment, we are using single element transducers to do low frequency neuromodulation. Clearly the skull causes both attenuation and distortion of ultrasound (assumption is that gray/white matter soft tissue has neglect-able impact). I am (first) trying to both estimate the intracranial pressure map and extent of skull distortion of the beam for this single transducer setup. Then, I would like to be able to do the same for a 4 element phased array that will allow beam steering etc...
In this paper (http://iopscience.iop.org/article/10.1088/1741-2552/aa843e/pdf) they did something similar for the single transducer setup.
How would I best get started to replicate that? Is this under the
Heterogeneous Propagation Medium Example"? I have gone thru the example code already and ran it successfully and altered the transducer freq, etc.. Nonetheless, I am not sure how to program in the parameters (speed of sound, density, attenuation) for all of the layers (bone, etc). Furthermore, I am unsure what the appropriate initial pressure setting should be.
Furthermore, how would I go about defining the grid such that the transducer source/face would be parallel to the skull at a desired point?
Thank for taking the time to field these questions.
An aside, this is all for neuroresearch at Arizona State. If you have the time to discuss more on phone/Gchat, we would be happy to collaborate on this (jmfine@asu.edu).
The end game is to actually use the 4channel system, calculate the distortion, then correct for it with the phased array.
Justin Fine, PhD.