avishek-das Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 14:42:29 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/image-reconstruction-from-cylindrical-pat-scanning-of-tooth#post-7061 Fri, 27 Sep 2019 22:37:59 +0000 Avishek Das 7061@http://www.k-wave.org/forum/ <p>Hi, Brad,</p> <p>How to incorporate the timed signal (y, t) into the program.... ???? </p> http://www.k-wave.org/forum/topic/image-reconstruction-from-cylindrical-pat-scanning-of-tooth#post-7010 Thu, 22 Aug 2019 17:18:47 +0000 Bradley Treeby 7010@http://www.k-wave.org/forum/ <p>Hi Avishek,</p> <p>The best way to get started with k-Wave is to work through the examples included in the MATLAB help browser, and by reading the user manual. If you get stuck on any specifics, let us know.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/image-reconstruction-from-cylindrical-pat-scanning-of-tooth#post-6986 Sun, 28 Jul 2019 17:02:53 +0000 Avishek Das 6986@http://www.k-wave.org/forum/ <p>Dear Dr. Cox and Dr. Treeby,</p> <p>I am Avishek and I am doing postdoc research in PAT scanning. I am new to this field. Currently, I have designed an instrument which can perform 3D photoacoustic scanning of a tooth. The laser light is illuminated from the top and single element ultrasonic transducer scans the teeth with 360-degree rotation and top-down movement so that the whole tooth is covered. The setup is like this- <a href="https://www.nature.com/articles/srep21798" rel="nofollow">https://www.nature.com/articles/srep21798</a>. I have many timed-PAt signals obtained from the oscilloscope and now want to reconstruct the image. How can I obtain B-mode imaging with your k-wave program? Can you describe step-by-step? How can we incorporate the timed signal in your program. Please help. </p> http://www.k-wave.org/forum/topic/how-to-reconstruct-an-image-from-data-taken-from-pat-measurement#post-3710 Thu, 13 Jun 2013 12:43:52 +0000 bencox 3710@http://www.k-wave.org/forum/ <p>Hi Juho,</p> <p>If each row of your matrix contains a photoacoustic pressure time series recorded at one point, then you could try reconstructing the image using time reversal (see the examples <a href="http://www.k-wave.org/documentation/example_pr_3D_tr_planar_sensor.php"> such as this</a> for the details of how to set it up). Essentially, you need to associate each time series with its corresponding measurement point.</p> <p>If, in addition, your measurement points are equally spaced and lying on a plane, you could look at the examples for <a href="http://www.k-wave.org/documentation/example_pr_2D_fft_line_sensor.php">2D here</a> or <a href="http://www.k-wave.org/documentation/example_pr_3D_fft_planar_sensor.php">3D here</a> for more inspiration.</p> <p>Ben </p> http://www.k-wave.org/forum/topic/how-to-reconstruct-an-image-from-data-taken-from-pat-measurement#post-3709 Thu, 13 Jun 2013 06:05:53 +0000 julehtel 3709@http://www.k-wave.org/forum/ <p>Hi Dr. Cox and Dr. Treeby, I am a electrical engineering student from Finland. I have been trying to reconstruct an 2D image from data I have measured with PAT. The problem is that my data is in a 'matrix' and it contains only amplitude values. So that one measurement data goes on one row and the second measurement on the second when I move the sample. I have been using example_pr_2D_FFT_line_sensor as the base. So my question is that what do I need to do to get an image out of my data?</p> <p>Thank you<br /> Juho </p> http://www.k-wave.org/forum/topic/necessary-data-to-perform-image-reconstruction#post-1822 Wed, 27 Mar 2013 17:48:50 +0000 bencox 1822@http://www.k-wave.org/forum/ <p>Hi David,</p> <p>Not that I know of, unfortunately, but if you find something please post back on here. Simulating with a light model such as Monte Carlo is a good idea as a first step, as it gives you much more control so you can test more clearly what works and what doesn't, change the noise level, etc.</p> <p>Ben </p> http://www.k-wave.org/forum/topic/necessary-data-to-perform-image-reconstruction#post-1778 Wed, 27 Mar 2013 09:31:48 +0000 sturmbrig 1778@http://www.k-wave.org/forum/ <p>Hi Dr. Cox,<br /> Yes, i´m working on 2D, in fact i´m trying to simulate in MCML a multilayered sample to get the data i need (at least optical absoption and fluence) as i don´t have access to any experimental photoacoustic data. Is there any public database where i could adquire the initial pressure distribution from a real sample?<br /> Thanks a lot </p> http://www.k-wave.org/forum/topic/necessary-data-to-perform-image-reconstruction#post-1614 Thu, 21 Mar 2013 12:00:42 +0000 bencox 1614@http://www.k-wave.org/forum/ <p>Hi David, </p> <p>Yes, the photoacoustic initial pressure distribution is the product of the optical absorption coefficient, optical fluence, and the Grueneisen parameter. It almost certainly does vary between tissue types, and although there are not many direct experimental measurements of it, it can be calculated from other thermodynamic parameters (search Grueneisen on wikipedia, for example). It is often assumed constant, but that is not quite right. It is also temperature dependent.</p> <p>Are you working entirely in 2D?</p> <p>Ben </p> http://www.k-wave.org/forum/topic/necessary-data-to-perform-image-reconstruction#post-1613 Thu, 21 Mar 2013 10:39:37 +0000 sturmbrig 1613@http://www.k-wave.org/forum/ <p>Hi Dr. Cox, I have a 2D absoption map (i also have the data in a matrix) of a depth cut from a sample of skin tissue with a single capillary. So, i would need the absorption distribution, the grüeneisen parameter and the fluence distribution? Shouldn´t the grüeneisen parameter variate between the different components of the sample (fat,blood,etc..), would it be correct to asume it to be constant (using the mean of the diferent parts)<br /> Thanks alot<br /> David </p> http://www.k-wave.org/forum/topic/necessary-data-to-perform-image-reconstruction#post-1593 Wed, 20 Mar 2013 10:20:57 +0000 bencox 1593@http://www.k-wave.org/forum/ <p>Hi David,</p> <p>In photoacoustic tomography the data is measurements of the acoustic pressure (or some related quantity) on a surface (imaginary surface) surrounding the region of interest. The image you are trying to reconstruct is the initial pressure distribution.</p> <p>What exactly do you have a map of? The 3D optical absorption map of the sample? If so, that is related to the initial pressure distribution by a thermodynamic quantity sometimes called the Grueneisen parameter, which is often assumed constant. (In water, for example, it is about 0.11.)</p> <p>Ben </p> http://www.k-wave.org/forum/topic/necessary-data-to-perform-image-reconstruction#post-1592 Wed, 20 Mar 2013 09:50:51 +0000 sturmbrig 1592@http://www.k-wave.org/forum/ <p>Hi Dr. Cox and Dr. Treeby, I am a Telecommunications student from Spain (Universidad de Cantabria) conducting a photoacoustic tomography project as my final proyect. I have recently discovered k-wave and i´m trying to make a specific type of simulation.<br /> I aim to perform an image reconstruction using as experimental data an absorption map from a sample (knowing also the sample´s properties: sound speed,medium density..) but without having an initial pressure distribution. Would it be possible?<br /> Thanks a lot<br /> David </p> http://www.k-wave.org/forum/topic/example-to-reconstruct-image-from-pat#post-1313 Thu, 28 Feb 2013 10:55:15 +0000 Bradley Treeby 1313@http://www.k-wave.org/forum/ <p>Hi Kenichiro,</p> <p>In photoacoustic microscopy (PAM), a focused ultrasound detector is used to record the photoacoustic signals at particular spatial positions on the tissue surface (in OR-PAM the excitation laser light is also focused). The signal recorded at each spatial position is analogous to an ultrasound scan-line, where the beam-forming in the PAM case is performed directly by the use of a focused transducer. This means that no image reconstruction is required. Instead, the individual time-series recorded at each position directly become the columns of the photoacoustic image. The <a href="http://www.medphys.ucl.ac.uk/research/mle/pdf_files/Review_Roy_Soc_Interface_1.pdf">review paper</a> by Paul Beard (or equally any of the review papers by Lihong Wang) gives a good explanation of the differences between photoacoustic microscopy and tomography.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/example-to-reconstruct-image-from-pat#post-1312 Thu, 28 Feb 2013 08:29:29 +0000 kenichiro yoshimi 1312@http://www.k-wave.org/forum/ <p>Hi Dr. Treeby and Dr. Cox</p> <p>I am new to k-Wave. I am trying to use k-Wave to reconstruct an image from acoustic signals obtained by scanning with photoacoustic microscopy (PAT) such as<br /> <a href="http://en.wikipedia.org/wiki/Photoacoustic_imaging_in_biomedicine#Photoacoustic_microscopy_.28PAM.29" rel="nofollow">http://en.wikipedia.org/wiki/Photoacoustic_imaging_in_biomedicine#Photoacoustic_microscopy_.28PAM.29</a><br /> (The purpose of this scanning is to see the vasculatures in rat skin. The imaging head was directly placed on the surface of the skin with ultrasound gel asnd scanned over the ROI (5x4 mm^2) with a step size of 50 micro meter.)</p> <p>I studied the "Example: 3D Time Reversal For A Planar Sensor", but I don't know if it is applicable.<br /> Would you advise me on the proper way?</p> <p>thanks a lot. </p>