http://www.k-wave.org/forum/topic/ultrasound-heating-and-intensity Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 22:33:31 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/ultrasound-heating-and-intensity#post-8624 Fri, 07 Oct 2022 14:01:26 +0000 bencox 8624@http://www.k-wave.org/forum/ <p>Hi s148275, </p> <p>You could output the intensity directly using <code>sensor.record = {&#39;I_avg&#39;}</code> or <code>... = {&#39;I&#39;}</code>. The 2 comes from the fact that the absorption coefficient for intensity is twice the pressure absorption coefficient (which is the one usually quoted) when they are given in Nepers/m.</p> <p>Interestingly, they are the same if given in dB/m as the definition of the decibel for the intensity uses 10log_10 and for the pressure is 20log_10.</p> <p>Best wishes<br /> Ben </p> http://www.k-wave.org/forum/topic/ultrasound-heating-and-intensity#post-8617 Tue, 04 Oct 2022 14:26:47 +0000 s148275 8617@http://www.k-wave.org/forum/ <p>I am a bit confused about the equation that needs to be used for the heating rate Q. From my simulation I get the outputs: <code>sensor_data.p</code>, <code>sensor_data.ux_non_staggered</code> and <code>sensor_data.uy_non_staggered</code>. The following code is used to get the average intensity:<br /> <pre><code>ux_sgt = fourierShift(sensor_data.ux_non_staggered, 1/2) uy_sgt = fourierShift(sensor_data.uy_non_staggered, 1/2) Ix = sensor_data.p .* ux_sgt Iy = sensor_data.p .* uy_sgt I = sqrt(Ix^2+Iy^2) I_avg = mean(I, ndims(I))</code></pre> <p>If I want to find the heat deposition Q, what is the equation that I need to use? For now I am using:<br /> <pre><code>alpha_np = db2neper(alpha_coeff_p_db,alpha_power) ... * (2 * pi * f0).^alpha_power; Q = alpha_np .* I_avg;</code></pre> <p>However, sometimes <code>Q=2*alpha_np*I_avg</code> is used. What is the case here and why?</p> <p>Thanks in advance! </p>