http://www.k-wave.org/forum/topic/calculation-in-a-loop Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 22:28:46 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/calculation-in-a-loop#post-9135 Thu, 29 Aug 2024 08:11:40 +0000 lfura 9135@http://www.k-wave.org/forum/ <p>I would like to simulate the oscillations of the microbubbles exposed to ultrasound. So I thought that I will simulate the distribution of acoustic pressure in k-wave in every step and then take this pressure and put it into Rayleigh-Plesset equation as the external acoustic pressure. The result would be a change in the radius of the microbubble, which could be treated as a wave source and introduced as a wave source in the next step of the k-wave simulation. In this way, I wanted to link the k-wave simulations to the Rayleigh-Plesset equation in a loop for the entire simulation space. Of course, there is still the problem of scattering by the microbubble, but I wanted to leave that out for now. </p> http://www.k-wave.org/forum/topic/calculation-in-a-loop#post-9131 Wed, 28 Aug 2024 18:15:34 +0000 bencox 9131@http://www.k-wave.org/forum/ <p>Hi Ifura,</p> <p>No, it's not the same. What is it that you would like to simulate?</p> <p>Best wishes<br /> Ben </p> http://www.k-wave.org/forum/topic/calculation-in-a-loop#post-9122 Tue, 06 Aug 2024 13:54:14 +0000 lfura 9122@http://www.k-wave.org/forum/ <p>Hi, </p> <p>Is it possible in k-wave to calculate the sound pressure distribution after N time steps by running simulations in a loop after 1 time step? The loop runs kspaceFirstOrder where at each grid node the wave source is the value from the previous time step in the loop. It seems to me that this should work, but maybe I'm missing something and it's not working. I have attached my code below.</p> <p>Kind regards</p> <pre><code>pml_size = 20; % [grid points] % define the grid parameters Nx = 512 - 2 * pml_size; % [grid points] Ny = 512 - 2 * pml_size; % [grid points] dx = 10e-6; % [m] dy = 10e-6; % [m] % create the computational grid kgrid = kWaveGrid(Nx, dx, Ny, dy); %% % define the properties of the propagation medium medium.sound_speed = 1480; % [m/s] medium.density = 1000; % [kg/m^3] medium.alpha_coeff = 0.02; % [dB/(MHz^y cm)] medium.alpha_power = 1.1; % define the source parameters diameter = 4e-3; % [m] radius = 3e-3; % [m] freq = 1.05e6; % [Hz] amp = 0.1e6; % [Pa] mask= logical(zeros(Nx,Ny)); mask(Nx/2,Ny/2) = 1; source.p_mask = zeros(Nx,Ny); source.p_mask(mask) = 1; % calculate the time step using an integer number of points per period ppw = medium.sound_speed / (freq * dx); % points per wavelength cfl = 0.3; % cfl number ppp = ceil(ppw / cfl); % points per period T = 1 / freq; % period [s] dt = T / ppp; % time step [s] % calculate the number of time steps to reach steady state t_end = sqrt( kgrid.x_size.^2 + kgrid.y_size.^2 ) / medium.sound_speed; Nt = round(t_end / dt); kgrid.setTime(Nt, dt); % define the input signal input_signal = createCWSignals(kgrid.t_array, freq, amp, 0); % create the time array kgrid.setTime(1, dt); source.p = zeros(1,1); source.p = input_signal(:,1); % set the sensor mask to cover the entire grid sensor.mask = ones(Nx, Ny); sensor.record = {&#39;p&#39;}; % record one point sensor.record_start_index = 1; % set the input arguements input_args = {&#39;PMLInside&#39;, false, &#39;PlotPML&#39;, false, &#39;DisplayMask&#39;, ... &#39;off&#39;, &#39;PlotScale&#39;, [-1, 1] * amp, ... &#39;PlotSim&#39;, false, &#39;DataCast&#39;, &#39;gpuArray-single&#39;}; % run the acoustic simulation sensor_data = kspaceFirstOrder2D(kgrid, medium, source, sensor, input_args{:}); % % reshape the data p = reshape(sensor_data.p, Nx, Ny,1); %% source.p_mask = ones(Nx,Ny); f = waitbar(0); for i=2:length(input_signal) source.p = p(:,:,i-1); source.p = source.p(:); source.p(mask(:)) = input_signal(:,i); % run the acoustic simulation sensor_data = kspaceFirstOrder2D(kgrid, medium, source, sensor, input_args{:}); % % reshape the data p (:,:,i) = reshape(sensor_data.p, Nx, Ny,1); waitbar(i/(length(input_signal)),f) end close(f)</code></pre>