http://www.k-wave.org/forum/topic/transcranial-ultrasound-attenuation Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 23:13:01 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/transcranial-ultrasound-attenuation#post-9102 Tue, 04 Jun 2024 13:53:29 +0000 cyl 9102@http://www.k-wave.org/forum/ <p>%%<br /> % 定义网格<br /> Nx = 300; % number of grid points in the x direction<br /> Ny = 300; %number of grid points in the y direction<br /> Nz = 300; % number of grid points in the z direction<br /> dx =0.1e-3; % grid point spacing in the x direction [m]<br /> dy =0.2e-3; % grid point spacing in the y direction [m]<br /> dz =0.1e-3; % grid point spacing in the z direction [m]<br /> kgrid = kWaveGrid(Nx, dx, Ny, dy, Nz, dz);<br /> %%<br /> % define the properties of the propagation medium<br /> medium.sound_speed = 1540; % [m/s]<br /> medium.density = 1000; % [kg/m^3]<br /> medium.sound_speed = medium.sound_speed * ones(Nx, Ny, Nz); % [m/s]<br /> medium.sound_speed(:,75:80,:) = 3500 ;%填颅骨的宽度和声速<br /> medium.density = medium.density * ones(Nx, Ny, Nz); % [kg/m^3]<br /> medium.density(:,75:80,:) = 2000 ;%填颅骨的宽度和密度<br /> medium.alpha_coeff=0.05*ones(Nx,Ny,Nz); %[dB/(MHz^y cm)]<br /> medium.alpha_coeff(:,75:80,:) = 2.7; %颅骨衰减系数<br /> %%<br /> % tempo e step de simulação<br /> kgrid.makeTime(medium.sound_speed);<br /> %%<br /> % target ping signal<br /> source_strength = 1e3; % [Pa]<br /> tone_burst_freq = 1e6; % [Hz]<br /> tone_burst_cycles = 1;<br /> input_signal = toneBurst(1/kgrid.dt, tone_burst_freq, tone_burst_cycles);<br /> %%<br /> %Setting up ultrasonic transducers<br /> Transducer.number_elements=1; %阵元个数<br /> Transducer.element_width = 5e-3; %阵元宽度<br /> Transducer.element_length = 12 ;%阵元高度<br /> Transducer.element_spaceing = 0 ;%阵元间距<br /> Transducer.radius = inf;%换能器曲率半径<br /> %计算换能器总宽度<br /> transducer_width = Transducer.number_elements*Transducer.element_width;<br /> transducer_x_pos = Nx/23;%grid points<br /> transducer_y_pos = 25;%grid points<br /> transducer_z_pos = 170;%grid points<br /> Transducer.positoin = round([transducer_x_pos,transducer_y_pos,transducer_z_pos]);<br /> % 用于波束合成延迟叠加的参数<br /> Transducer.sound_speed = 1500; % 声速 [m/s]<br /> Transducer.focus_distance = 20e-3; % 焦距 [m]<br /> Transducer.elevation_focus_distance = 19e-3; % elevation plane 仰角平面焦距 [m]<br /> Transducer.steering_angle = 0; % steering angle 偏转角 [degrees]<br /> % 设置变迹 apodization<br /> Transducer.transmit_apodization = 'Rectangular';<br /> Transducer.receive_apodization = 'Rectangular';<br /> % 设置当前激活的换能器阵元 define the transducer elements that are currently active<br /> Transducer.active_elements = 1;<br /> %设置用于驱动换能器的输入信号<br /> Transducer.input_signal = input_signal;<br /> %创建换能器<br /> transducer = Transducer(kgrid, Transducer);<br /> %%<br /> %创建具有检测传感器<br /> sensor.mask = zeros(Nx,Ny,Nz);<br /> sensor.mask(Nx/2,275,170)=1;<br /> %run the simulation<br /> [sensor_data] = kspaceFirstOrder3D(kgrid , medium , Transducer, sensor,input_args{:});<br /> %计算输入信号和每个传感器位置记录信号的幅度<br /> [f_input, as_input] = spect([input_signal,zeros(1,2*length(input_signal))],1/kgrid.dt);<br /> [~,as_1]=spect(sensor_data(1,:),1/kgrid.dt);<br /> [sensor_data] = kspaceFirstOrder3D(kgrid, medium, transducer, sensor, input_args{:}); </p> http://www.k-wave.org/forum/topic/transcranial-ultrasound-attenuation#post-9100 Tue, 04 Jun 2024 13:50:02 +0000 cyl 9100@http://www.k-wave.org/forum/ <p>Hello, I am currently researching the use of a single element transducer to generate ultrasound penetration through the skull, and then testing the sound field beneath the skull to obtain the attenuation coefficient of the skull. Here is my code. Currently, I have encountered an issue: during simulation, it will display‘transducer=Transducer (kgrid, Transducer)；there is an error Cannot use a value of type kWaveGrid as an index’ , which I have researched a lot of information but still cannot solve. I hope to receive your help. Thank you. Additionally, if there are any issues with my code, I hope you can point them out. Thank you very much again </p>