k-Wave

1. millsmess
   

   Member
   Joined: Aug '16
   Posts: 3

   I'm running a simulation in which I specify some initial pressure conditions using source.p0, and then record sensor data using an ultrasound transducer object. I would like to create a beamformed imaged from the received data by beamforming a series of axial lines. It appears to me that the starting point of any beamformed line generated by transducer.scan_line() is centered laterally.

   Is there an easy way to beamform lines that are not centered laterally on the transducer? I guess I'm wondering if there is functionality in k-wave comparable to that provided xdc_center_focus() and xdc_focus() in Field II.

   Thanks.

   Posted 6 years ago #

2. Bradley Treeby
   

   Developer
   Joined: Mar '10
   Posts: 1,640

   Hi millsmess,

   You can adjust the focal depth and steering angle using the properties focus_distance and steering_angle, is that what you mean?

   Brad.

   Posted 6 years ago #

3. millsmess
   

   Member
   Joined: Aug '16
   Posts: 3

   Hi Brad,

   Thanks for your reply.

   No, I don't think that is what I meant. I'll try and clarify.

   We can view the final formed image as a rectangle. Each scan_line() operation forms one subset of this final rectangle. Specifically, it forms a single line of the final rectangle.

   If I understand the steering_angle parameter, it specifies the angle of the line formed. However, the pivot-point of the line, if you will, remains at the center of the transducer (I think). So, as one adjusts the steering_angle parameter, one can sweep out a portion of a circle, forming an image in that region.

   What I would like to do instead is to translate the origin of the beamformed line, so that the entire image can be formed from a collection of vertical beamformed lines.

   Since my first post above I've discovered that the Beamformation Toolbox by Svetoslav Nikolov is capable of doing this and I've got it working with k-wave. However, I would still be interested in knowing if k-wave provides a built-in way of carrying out this sort of beamforming.

   Thanks again.

   Posted 6 years ago #

4. Bradley Treeby
   

   Developer
   Joined: Mar '10
   Posts: 1,640

   Hi millmess,

   The centre is assumed to be in the middle of the active elements. So if you translate the section of active elements, then it's possible to do this. Otherwise, unfortunately, there's no way to manually adjust the beamforming weights, or adjust the centre, and it's not something we're working on. Glad you managed to get it to work with the Beamformation Toolbox!

   Brad.

   Posted 6 years ago #

5. millsmess
   

   Member
   Joined: Aug '16
   Posts: 3

   Okay, that is good to know.

   Thanks again for you help - it's really nice to be working with a piece of software where the developers are willing to spend the time to answer questions about it.

   Posted 6 years ago #

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