k-Wave User Forum » Topic: Combination of attenuation coefficients
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Bradley Treeby on "Combination of attenuation coefficients"
http://www.k-wave.org/forum/topic/combination-of-attenuation-coefficients#post-7215
Wed, 12 Feb 2020 11:42:59 +0000Bradley Treeby7215@http://www.k-wave.org/forum/<p>Hi Kris,</p>
<p>Do you have broadband signal or a single frequency / tone burst? If you can fix your frequency, then you can calculate the total attenuation in the voxel in dB/cm. Then you can convert this back to values for <code>alpha_coeff</code> by fixing <code>f</code> and <code>alpha_power</code> (e.g., to 2).</p>
<p>Hope that helps,</p>
<p>Brad.
</p>kdreher on "Combination of attenuation coefficients"
http://www.k-wave.org/forum/topic/combination-of-attenuation-coefficients#post-7139
Fri, 29 Nov 2019 15:08:21 +0000kdreher7139@http://www.k-wave.org/forum/<p>Hello,</p>
<p>I would like to combine two attenuation coefficients in one voxel for simulating with blood perfused tissue. I know that the attenuation is calculated by a = a_0 * f^y.<br />
For example: If I want to combine two substances (e.g. 99% water and 1% blood), I could define my attenuation as a_tot = 0.99 * a_0_water * f^y_water + 0.01 * a_0_blood *f^y_blood.<br />
But I can't define different y-values for different voxels and I can't analytically bring this equation to the form a_tot = a_0_tot * f^y_tot, so that I can have one y_value for all voxels.<br />
What do you think I could do to simulate this as realistically as possible?</p>
<p>Sincerely,<br />
Kris
</p>