http://www.k-wave.org/forum/topic/problem-with-simulation-of-signal-from-phantom-with-nonlinear-effect Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 22:33:42 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/problem-with-simulation-of-signal-from-phantom-with-nonlinear-effect#post-8869 Tue, 25 Jul 2023 10:19:16 +0000 P.S 8869@http://www.k-wave.org/forum/ <p>My objective is to simulate echo from a phantom with two layers, for which I have set nonlinear parameters. However, when I reconstruct the B-mode image, I notice an unexpected line in the second layer, making the result look like it has three layers. I'm uncertain about what might be causing this issue in my code. Your assistance in resolving this matter would be greatly appreciated. Thank you.</p> <p>The parameters that I use are as follows:<br /> c0 = 1480; % [m/s]<br /> alpha_coeff0 = 0.5; % [dB/(MHz^y cm)]<br /> alpha_power0 = 1.9;<br /> rho0 = 1000; % [kg/m^3]<br /> BonA = 6;</p> <p>% define properties<br /> sound_speed_map = c0 * ones(Nx, Ny);%.* background_map;%;<br /> density_map = rho0 * ones(Nx, Ny).* background_map;<br /> alpha_coeff_map = alpha_coeff0 * ones(Nx, Ny);</p> <p>% make circle inclusion SoS<br /> sound_speed_map(cond1,:) = 1520;</p> <p>% assign to the medium inputs<br /> medium.sound_speed = sound_speed_map;<br /> medium.density = density_map;<br /> medium.BonA = 6*ones(Nx, Ny); </p>