k-Wave User Forum » Topic: rps pressure of HIFU within a layered tissues

k-Wave User Forum » Topic: rps pressure of HIFU within a layered tissues http://www.k-wave.org/forum/topic/rps-pressure-of-hifu-within-a-layered-tissues Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 22:27:09 +0000 http://bbpress.org/?v=1.0.2 <![CDATA[Search]]> q http://www.k-wave.org/forum/search.php Bradley Treeby on "rps pressure of HIFU within a layered tissues" http://www.k-wave.org/forum/topic/rps-pressure-of-hifu-within-a-layered-tissues#post-6127 Wed, 06 Sep 2017 11:36:16 +0000 Bradley Treeby 6127@http://www.k-wave.org/forum/ Hi tahere, It's not a quick fix, but I'd recommend spending some time reading through the k-Wave user manual, and working through the k-Wave examples from the beginning. This should answer all your queries. After that, if you get stuck on something in particular, let us know. Brad. tahere on "rps pressure of HIFU within a layered tissues" http://www.k-wave.org/forum/topic/rps-pressure-of-hifu-within-a-layered-tissues#post-6124 Wed, 06 Sep 2017 08:27:59 +0000 tahere 6124@http://www.k-wave.org/forum/ hi again.i wnat to know the rms pressure duo to a transducer in a homogeneous tissue.for different excitation frequency of transducer in a homogeneous medium should i change the medium.alpha_coeff proportional to excitation frequency?for example for excitation frequency values equal to 1Mhz and 2Mhz should i vary the medium.alpha_coeff from .7 to 1.4? any help would be appreciated tahere on "rps pressure of HIFU within a layered tissues" http://www.k-wave.org/forum/topic/rps-pressure-of-hifu-within-a-layered-tissues#post-6123 Wed, 06 Sep 2017 06:55:51 +0000 tahere 6123@http://www.k-wave.org/forum/ hi every body .i have some question. with constant values for medium.alpha_power and medium.alpha_coeff equal to 1.05 and .45 respectively.i see with increasing the frequency of source from .25 to 1.5 Mhz the maximum value of rms pressure increases while i expect with increasing the frequency of excitation the value of rms pressure decrease.where is the problem? thanks in advance tahere on "rps pressure of HIFU within a layered tissues" http://www.k-wave.org/forum/topic/rps-pressure-of-hifu-within-a-layered-tissues#post-6122 Tue, 05 Sep 2017 14:59:06 +0000 tahere 6122@http://www.k-wave.org/forum/ hello dear bradley. i have a medium with attenuation coefficient equal to .7 db/cm/Mhz.how can i set this value in k wave?plaese help me. Bradley Treeby on "rps pressure of HIFU within a layered tissues" http://www.k-wave.org/forum/topic/rps-pressure-of-hifu-within-a-layered-tissues#post-6121 Sun, 03 Sep 2017 20:36:44 +0000 Bradley Treeby 6121@http://www.k-wave.org/forum/ Hi tahere, If I run your code, I get an error that the absorption coefficient <code>medium.alpha_coeff</code> is not defined. Brad. tahere on "rps pressure of HIFU within a layered tissues" http://www.k-wave.org/forum/topic/rps-pressure-of-hifu-within-a-layered-tissues#post-6116 Tue, 29 Aug 2017 07:05:16 +0000 tahere 6116@http://www.k-wave.org/forum/ hello again.i'm sorry to bother you. i have one more question. i simulate a section of a HIFU.I want to know the pressure in xz and yz planes perpendicular to this section of HIFU.but i receive an error message.my code and error message is shown in the below: %% matlab code clc,clear all,close all; %% h is the HIFU aperture radius(in terms of points) h=25; %% simulation settings DATA_CAST = 'single'; % set to 'single' or 'gpuArray-single' to speed up computations MASK_PLANE = 'xz'; % set to 'yz' or 'xz' to generate the beam pattern in different planes %% set the size of the perfectly matched layer (PML) PML_X_SIZE = 10; % [grid points] PML_Y_SIZE = 10; % [grid points] PML_Z_SIZE = 10; % [grid points] %% set total number of grid points not including the PML Nx = 122- 2*PML_X_SIZE; % [grid points] Ny = 122- 2*PML_Y_SIZE; % [grid points] Nz = 122- 2*PML_Z_SIZE; % [grid points] %% set desired grid size in the x-direction not including the PML x = 102e-3; % [m] %% calculate the spacing between the grid points dx = x/Nx; % [m] dy = dx; % [m] dz = dx; % [m] %% create the k-space grid kgrid = makeGrid(Nx, dx, Ny, dy, Nz, dz); %% define the properties of the propagation medium medium.sound_speed = 1578*ones(Nx,Ny,Nz);%%speed of sound in liver medium.density = 1050*ones(Nx,Ny,Nz);%density of liver medium.alpha_power = 1.5; medium.BonA =0;%medium is linear %% create the time array t_end =100e-6;%seecond kgrid.t_array = makeTime(kgrid,medium.sound_speed,[], t_end); %% HIFU generation with spheregen function a=makeSphere(102,102,102,50); a(:,:,h:end)=0; a(1:41,:,:)=0; a(61:102,:,:)=0; voxelPlot(a); source.p_mask=a; %% define a time varying sinusoidal source source_freq =25e4; % [Hz] source_mag = 0.5; % [Pa] source.p = source_mag*sin(2*pi*source_freq*kgrid.t_array); %% filter the source to remove any high frequencies not supported by the grid source.p = filterTimeSeries(kgrid, medium, source.p); %% define a sensor mask through the central plane sensor.mask = zeros(Nx, Ny, Nz); switch MASK_PLANE case 'yz' % define mask sensor.mask(Nx/2, :,:) = 1; % store y axis properties Nj = Ny; j_vec = kgrid.y_vec; j_label = 'y'; case 'xz' % define mask sensor.mask(:, Ny/2,:) = 1; % store z axis properties Nj = Nz; j_vec = kgrid.x_vec; j_label = 'x'; end %% set the record mode such that only the rms and peak values are stored sensor.record = {'p_rms'}; voxelPlot(sensor.mask); %%set the input settings input_args = {'DisplayMask',source.p_mask,'PlotLayout',true,'PMLInside', false, 'PlotPML',true, 'PMLSize', [PML_X_SIZE, PML_Y_SIZE, PML_Z_SIZE], ... 'DataCast', DATA_CAST, 'DataRecast', true, 'PlotScale', [-source_mag/2,source_mag/2]}; %% run the simulation sensor_data = kspaceFirstOrder3D(kgrid, medium,source, sensor, input_args{:}); %% reshape the returned rms and max fields to their original position sensor_data.p_rms = reshape(sensor_data.p_rms, [Nj,Nz]); %% plot the beam pattern using the pressure rms figure; imagesc(j_vec*1e3, (kgrid.z_vec - min(kgrid.z_vec(:)))*1e3, sensor_data.p_rms'); xlabel([j_label '-position [mm]']); ylabel('z-position [mm]'); title('Total Beam Pattern Using RMS Of Recorded Pressure'); colormap(jet(256)); c = colorbar; ylabel(c, 'Pressure [Pa]'); axis image; %%error message Error using set Bad property value found. Object Name : axes Property Name : 'CLim' Values must be increasing and non-NaN. Error in imagesc (line 47) set(cax,'CLim',clim) Error in kspaceFirstOrder3D>planeplot (line 1229) subplot(2, 2, 1), imagesc(y_vec, x_vec, squeeze(data(:, :, round(end/2))), plot_scale); Error in kspaceFirstOrder_plotLayout (line 179) planeplot(scale*kgrid.x_vec(x1:x2), scale*kgrid.y_vec(y1:y2), scale*kgrid.z_vec(z1:z2), double(c(x1:x2, y1:y2, z1:z2)), 'c: ', [plot_zlim(1) - plot_spc*plot_rng, plot_zlim(2) + plot_spc*p Error in kspaceFirstOrder3D (line 689) kspaceFirstOrder_plotLayout; Error in liversade (line 110) sensor_data = kspaceFirstOrder3D(kgrid, medium,source, sensor, input_args{:}); tahere on "rps pressure of HIFU within a layered tissues" http://www.k-wave.org/forum/topic/rps-pressure-of-hifu-within-a-layered-tissues#post-6115 Mon, 28 Aug 2017 13:26:17 +0000 tahere 6115@http://www.k-wave.org/forum/ hello dear professor.thanks for your fast answering.i have modeled a layered tissue with different sound speed,density and attenuation coefficient in 3 dimensional in front of a HIFU transducer.i obtain the rms pressure in the xz and yz planes perpendicular of HIFU.I have some questions. 1)the t_end time doesn't affect rms pressure'value? 2)I can reach the intensity with below formula: intensity=(rms pressure)^2/2*acoustic impedance. the formula between acoustic radiation force(ARF) and intensity is given as below: f=2*absorption coefficient*I/sound speed. how can i obtain ARF when i put different values for different layer in my simulation. thanks for your answering in advance Bradley Treeby on "rps pressure of HIFU within a layered tissues" http://www.k-wave.org/forum/topic/rps-pressure-of-hifu-within-a-layered-tissues#post-6114 Wed, 23 Aug 2017 19:50:19 +0000 Bradley Treeby 6114@http://www.k-wave.org/forum/ Hi tahere, I'm not sure I follow what your question is. What do you mean when you say you didn't get the answer? Brad. tahere on "rps pressure of HIFU within a layered tissues" http://www.k-wave.org/forum/topic/rps-pressure-of-hifu-within-a-layered-tissues#post-6107 Tue, 22 Aug 2017 08:12:33 +0000 tahere 6107@http://www.k-wave.org/forum/ hi every one.i want to obtain the rms pressure of a HIFU with continuous excitation in the plane perpendicular to HIFU but i didnt get answer.the medium which i simulated consist of fat ,muscle,rib and liver.here is my code.i appreciate any help.i am looking forward getting answer from you as soon as possible.thanks in advance. clear all; h=50; % simulation settings DATA_CAST = 'single'; % set to 'single' or 'gpuArray-single' to speed up computations MASK_PLANE = 'yz'; % set to 'xy' or 'xz' to generate the beam pattern in different planes USE_STATISTICS = true; % set to true to compute the rms or peak beam patterns, set to false to compute the harmonic beam patterns % ========================================================================= % DEFINE THE K-WAVE GRID % ========================================================================= % set the size of the perfectly matched layer (PML) PML_X_SIZE = 10; % [grid points] PML_Y_SIZE = 10; % [grid points] PML_Z_SIZE = 10; % [grid points] % set total number of grid points not including the PML Nx = 170- 2*PML_X_SIZE; % [grid points] Ny = 170- 2*PML_Y_SIZE; % [grid points] Nz = 170- 2*PML_Z_SIZE; % [grid points] % set desired grid size in the x-direction not including the PML x = 15e-2; % [m] % calculate the spacing between the grid points dx = x/Nx; % [m] dy = dx; % [m] dz = dx; % [m] % create the k-space grid kgrid = makeGrid(Nx, dx, Ny, dy, Nz, dz); % ========================================================================= % DEFINE THE MEDIUM PARAMETERS % ========================================================================= % define the properties of the propagation medium medium.sound_speed = 1578*ones(Nx,Ny,Nz); % [m/s] medium.sound_speed (:,:,1:h)=1430; medium.sound_speed (:,:,h:h+10)=1430; medium.sound_speed (:,:,h+10:h+30)=1580; medium.sound_speed (:,:,h+20:h+30)=1580; medium.sound_speed (:,1:10,h+20:h+30)=3198; medium.sound_speed (:,20:30,h+20:h+30)=3198; medium.sound_speed (:,40:50,h+20:h+30)=3198; medium.sound_speed (:,60:70,h+20:h+30)=3198; medium.sound_speed (:,80:90,h+20:h+30)=3198; medium.sound_speed (:,100:110,h+20:h+30)=3198; medium.sound_speed (:,120:130,h+20:h+30)=3198; medium.sound_speed (:,140:150,h+20:h+30)=3198; medium.density = 1050*ones(Nx,Ny,Nz); % [kg/m^3] medium.density(:,:,1:h)=928; medium.density(:,:,h:h+10)=928; medium.density(:,:,h+10:h+30)=1041; medium.density(:,1:10,h+20:h+30)=1990; medium.density(:,20:30,h+20:h+30)=1990; medium.density(:,40:50,h+20:h+30)=1990; medium.density(:,60:70,h+20:h+30)=1990; medium.density(:,80:90,h+20:h+30)=1990; medium.density(:,100:110,h+20:h+30)=1990; medium.density(:,120:130,h+20:h+30)=1990; medium.density(:,140:150,h+20:h+30)=1990; medium.alpha_coeff = 0.45*ones(Nx,Ny,Nz); % [dB/(MHz^y cm)] medium.alpha_coeff (:,:,1:h)=.6; medium.alpha_coeff (:,:,h:h+10)=.6; medium.alpha_coeff (:,:,h+10:h+30)=.6; medium.alpha_coeff (:,1:10,h+20:h+30)=3.54; medium.alpha_coeff (:,20:30,h+20:h+30)=3.54; medium.alpha_coeff (:,40:50,h+20:h+30)=3.54; medium.alpha_coeff (:,60:70,h+20:h+30)=3.54; medium.alpha_coeff (:,80:90,h+20:h+30)=3.54; medium.alpha_coeff (:,100:110,h+20:h+30)=3.54; medium.alpha_coeff (:,120:130,h+20:h+30)=3.54; medium.alpha_coeff (:,140:150,h+20:h+30)=3.54; medium.alpha_power = 1.5; medium.BonA =0; dt_stability_limit = checkStability(kgrid, medium); % create the time array t_end =15e-6; % [s] kgrid.t_array = makeTime(kgrid,medium.sound_speed,.1, t_end); % DEFINE THE ULTRASOUND TRANSDUCER % define a curved transducer element b=spheregen(h); source.p_mask=b; % ========================================================================= % define a time varying sinusoidal source source_freq = 1e6; % [Hz] source_mag = 0.5; % [Pa] source.p = source_mag*sin(2*pi*source_freq*kgrid.t_array); % filter the source to remove any high frequencies not supported by the grid source.p = filterTimeSeries(kgrid, medium, source.p); % ========================================================================= % DEFINE SENSOR MASK % ========================================================================= % define a sensor mask through the central plane sensor.mask = zeros(Nx, Ny, Nz); switch MASK_PLANE case 'yz' % define mask sensor.mask(Nx/2, :,:) = 1; % store y axis properties Nj = Ny; j_vec = kgrid.y_vec; j_label = 'y'; case 'xz' % define mask sensor.mask(:, Ny/2, :) = 1; % store z axis properties Nj = Nz; j_vec = kgrid.z_vec; j_label = 'z'; end % set the record mode such that only the rms and peak values are stored if USE_STATISTICS sensor.record = {'p_rms'}; end voxelPlot(sensor.mask); % ========================================================================= % RUN THE SIMULATION % ========================================================================= % set the input settings input_args = {'PlotLayout',true,'PMLInside', false, 'PlotPML',true, 'PMLSize', [PML_X_SIZE, PML_Y_SIZE, PML_Z_SIZE], ... 'DataCast', DATA_CAST, 'DataRecast', true, 'PlotScale', [-source_mag/2,source_mag/2]}; % stream the data to disk in blocks of 100 if storing the complete time % history if ~USE_STATISTICS input_args = [input_args {'StreamToDisk', 100}]; end % run the simulation sensor_data = kspaceFirstOrder3D(kgrid, medium,source, sensor, input_args{:}); % voxelPlot(double(source.p_mask | cart2grid(kgrid, sensor.mask))); % ========================================================================= % COMPUTE THE BEAM PATTERN USING SIMULATION STATISTICS % ========================================================================= if USE_STATISTICS % reshape the returned rms and max fields to their original position sensor_data.p_rms = reshape(sensor_data.p_rms, [Nx, Nj]); % plot the beam pattern using the pressure rms figure; imagesc(j_vec*1e3, (kgrid.x_vec - min(kgrid.x_vec(:)))*1e3, sensor_data.p_rms/1e6); xlabel([j_label '-position [mm]']); ylabel('x-position [mm]'); title('Total Beam Pattern Using RMS Of Recorded Pressure'); colormap(jet(256)); c = colorbar; ylabel(c, 'Pressure [MPa]'); axis image; % end the example return end %%below function creates HIFU with different radius function [a] = sphreregen(h) a=makeSphere(150,150,150,50); b=zeros(size(a)); for i=1:101 b(:,:,i)=a(:,:,24+i); end b(:,:,h:end)=0; voxelPlot(b); end