http://www.k-wave.org/forum/topic/defining-an-ultrasound-transducer-example-question Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 22:02:37 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/defining-an-ultrasound-transducer-example-question#post-9099 Tue, 04 Jun 2024 13:31:14 +0000 cyl 9099@http://www.k-wave.org/forum/ <p>Hello, I would like to know how your problem was resolved </p> http://www.k-wave.org/forum/topic/defining-an-ultrasound-transducer-example-question#post-8968 Wed, 29 Nov 2023 19:50:28 +0000 Bradley Treeby 8968@http://www.k-wave.org/forum/ <p>You can get the full source code for all the examples, just open the k-Wave help in the MATLAB help browser. </p> http://www.k-wave.org/forum/topic/defining-an-ultrasound-transducer-example-question#post-8966 Tue, 28 Nov 2023 17:25:15 +0000 Muhammad 8966@http://www.k-wave.org/forum/ <p>Hi, I was trying to work through this example on the k-Wave website: <a href="http://www.k-wave.org/documentation/example_us_defining_transducer.php" rel="nofollow">http://www.k-wave.org/documentation/example_us_defining_transducer.php</a> but am having issues replicating their results. The code I used is:<br /> <pre><code>% create the computational grid Nx = 128; % number of grid points in the x (row) direction Ny = 128; % number of grid points in the y (column) direction Nz = 128; dx = 0.1e-3; % grid point spacing in the x direction [m] dy = 0.1e-3; % grid point spacing in the y direction [m] dz = 0.1e-3; % grid point spacing in the z direction [m] kgrid = kWaveGrid(Nx, dx, Ny, dy, Nz,dz); % define the properties of the propagation medium medium.sound_speed = 1500 * ones(Nx, Ny); % [m/s] medium.sound_speed(1:Nx/2, :) = 1800; % [m/s] medium.density = 1000 * ones(Nx, Ny); % [kg/m^3] medium.density(:, Ny/4:Ny) = 1200; % [kg/m^3] kgrid.makeTime(medium.sound_speed) % define properties of the input signal source_strength = 1e6; % [MPa] tone_burst_freq = 0.5e6; % [Hz] tone_burst_cycles = 5; % create the input signal using toneBurst input_signal = toneBurst(1/kgrid.dt, tone_burst_freq, tone_burst_cycles); % scale the source magnitude by the source_strength divided by the % impedance (the source is assigned to the particle velocity) input_signal = (source_strength ./ (medium.sound_speed * medium.density)).* input_signal; % physical properties of the transducer transducer.number_elements = 72; % total number of transducer elements transducer.element_width = 1; % width of each element [grid points] transducer.element_length = 12; % length of each element [grid points] transducer.element_spacing = 0; % spacing (kerf width) between the elements [grid points] transducer.radius = inf; % radius of curvature of the transducer [m] % calculate the width of the transducer in grid points transducer_width = transducer.number_elements * transducer.element_width + (transducer.number_elements - 1) * transducer.element_spacing; % use this to position the transducer in the middle of the computational grid transducer.position = round([1, Ny/2 - transducer_width/2, Nz/2 - transducer.element_length/2]); % properties used to derive the beamforming delays transducer.sound_speed = 1540; % sound speed [m/s] transducer.focus_distance = 20e-3; % focus distance [m] transducer.elevation_focus_distance = 19e-3; % focus distance in the elevation plane [m] transducer.steering_angle = 0; % steering angle [degrees] % apodization transducer.transmit_apodization = &#39;Rectangular&#39;; transducer.receive_apodization = &#39;Rectangular&#39;; % define the transducer elements that are currently active transducer.active_elements = zeros(transducer.number_elements, 1); transducer.active_elements(21:52) = 1; % append input signal used to drive the transducer transducer.input_signal = input_signal; % create the transducer using the defined settings transducer = kWaveTransducer(kgrid, transducer); % create a sensor mask covering the entire computational domain using the % opposing corners of a rectangle sensor.mask = [1, 1, Nx, Ny].&#39;; % set the record mode to capture the final wave-field and the statistics at % each sensor point sensor.record = {&#39;p_final&#39;, &#39;p_max&#39;, &#39;p_rms&#39;}; % run the simulation [sensor_data] = kspaceFirstOrder3D(kgrid, medium, transducer, sensor, input_args{:});</code></pre> <p>But I get the following error:<br /> <pre><code>Arrays have incompatible sizes for this operation. Error in DefiningAnUltrasoundTransducerExample (line 28) input_signal = (source_strength ./ (medium.sound_speed * medium.density)).* input_signal;</code></pre> <p>In the example, the computational grid and medium properties are not shown so I used the values shown in other examples in the same section so I assume my issue is related to something the top sections. Thanks in advance for any help. </p>