http://www.k-wave.org/forum/topic/how-can-i-adjust-heterogeneous-medium-properties-over-time Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 01:51:32 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/how-can-i-adjust-heterogeneous-medium-properties-over-time#post-8264 Thu, 22 Jul 2021 10:04:11 +0000 keniiyoshi 8264@http://www.k-wave.org/forum/ <p>Dear Professor Treeby,</p> <p>Thank you very much for pointing out about the time scale.</p> <p>For now, I am aiming to make the time scale of the dynamic property to be between the order of milliseconds to seconds for physicsl experiments. Since the propagation time for a thin hologram is in the order of microseconds, I will go ahead and run property changes in separate simulations. This will significantly simplify my approach.</p> <p>Sincerely,<br /> Ken Iiyoshi </p> http://www.k-wave.org/forum/topic/how-can-i-adjust-heterogeneous-medium-properties-over-time#post-8251 Wed, 21 Jul 2021 15:29:42 +0000 Bradley Treeby 8251@http://www.k-wave.org/forum/ <p>Hi Ken,</p> <p>What's the time scale of the changes? If it's &gt;&gt; than the acoustic propagation time across the hologram, I would just run it as separate simulations. If the changes are on the same time scales, you could look at hacking the time loop so that the sound speed and density values change with each time step. Note, I've never looked into it, but I assume there will actually be some extra terms in the wave equation if the medium properties change with time. No idea if these will be important in practice.</p> <p>Hope that helps,</p> <p>Brad </p> http://www.k-wave.org/forum/topic/how-can-i-adjust-heterogeneous-medium-properties-over-time#post-8240 Mon, 19 Jul 2021 15:03:11 +0000 keniiyoshi 8240@http://www.k-wave.org/forum/ <p>Dear K-Wave community,</p> <p>Thank you very much for sharing this software! I hope this can accelerate my PhD research in mid-air haptics.</p> <p>I would like to simulate a dynamic ultrasound hologram that can create a focal point from single source, as opposed to phased transducer arrays. My approach for this is to model the hologram as a dynamic boundary between two heterogenous sources. </p> <p>However, in <code>kspaceFirstOrder2D()</code>, inputs <code>medium.sound_speed</code> and <code>medium.density</code> must be given as matrices with the same dimensions as <code>kgrid</code>, which limit me from changing the properties over time. What parts of this function should be modified to accomodate such a feature?</p> <p>Sincerely,<br /> Ken Iiyoshi </p>