bft_user_guide.html

超声仿真软件

<hr>

<H3>bft_no_lines</H3>
<hr>

  <A NAME="bft_no_lines">
</A>
  <a name="bft_no_lines"></a>

<p>
Set the number of lines that will be beamformed in parallel.
  After calling <a href="#bft_init">bft_init</a>, the number of lines 
that are beamformed in   parallel is 1. If the user wants to beamform
a whole image in one  command, he/she must set the number of lines,
and then specify the focal zones for each of the lines.

<p>

<TaBle>
<tr><td>USAGE: </td><td width="553"><tt>bft_no_lines(no_lines)</tt></td>
<tr><td>INPUT:</td><td width="553"><i>no_lines</i>  &nbsp;&nbsp;Number of lines beamformed in parallel </td>
<tr><td>OUTPUT: </td><td width="553">None
</td></TaBle>

<p>

<title> bft\_param</title>

<br><br><br><br><br>
<p>
<hr> 

<H3>bft_param</H3>
<hr>

  <A NAME="bft_param">
</A>
  <a name="bft_param"></a>

<p>
Set a parameter of the BeamForming Toolbox

<p>

<TaBle>
<tr><td>USAGE: </td><td width="553"><tt>bft_param(name, value)</tt></td>
<tr><td>INPUT: </td><td width="553">
<TaBle>
<tr><td><i>name</i> </td><td width="434">Name of  the parameter (string). Currently supported:</td>
<tr><td></td><td width="434">
<TaBle>
<tr><td align="center">name </td><td align="center">Meaning       </td><td align="center">Default value </td><td align="center">Unit </td>
<tr><td align="center">'c' </td><td align="center">Speed of sound.       </td><td align="center">1540         </td><td align="center">m/s </td>
<tr><td align="center">'fs'</td><td align="center">Sampling frequency    </td><td align="center">40,000,000   </td><td align="center">Hz </td></TaBle>
 </td>
<tr><td></td>
<tr><td><i>value</i> </td><td width="434">New value for the parameter. Must be scalar. 
          </td></TaBle>
 </td>
<tr><td>OUTPUT: </td><td width="553">None
</td></TaBle>

<p>

<title> bft\_sub\_image</title>

<br><br><br><br><br>
<p>
<hr> 

<H3>bft_sub_image</H3>
<hr>

  <A NAME="bft_sub_image">
</A>
  <a name="bft_sub_image"></a>

<p>
Subtract one low-res image from  high-res one.

<p>

<TaBle>
<tr><td>USAGE: </td><td width="553"><tt>[hi_res] = bft_sub_image(hi_res, lo_res, element, start_time)</tt> </td>
<tr><td>INPUT:</td><td width="553">
<TaBle>
<tr><td><i>hi_res</i>  </td><td width="434">High resolution RF image. One column per scan line.</td>
<tr><td><i>lo_res</i>  </td><td width="434">Low resolution RF image. One column per scan line.</td>
<tr><td><i>element</i> </td><td width="434">Number of element, used to acquire the low resolution
                    image. </td>
<tr><td><i>start_time</i>    </td><td width="434">Arrival time of the first sample of the RF lines.
          </td></TaBle>
 </td>
<tr><td>OUTPUT:</td><td width="553">hi_res - The high resolution image.
</td></TaBle>

<p>

<title> bft\_sum\_apodization</title>

<br><br><br><br><br>
<p>
<hr> 

<H3>bft_sum_apodization</H3>
<hr>

  <A NAME="bft_sum_apodization">
</A>
  <a name="bft_sum_apodization"></a>

<p>
Create a summation apodization time line.
    This function is used in the case that the individual low
    resolution images must be weighted during the summation

<p>

<TaBle>
<tr><td>USAGE: </td><td width="553"><tt>bft_sum_apodization(xdc, times, values, line_no)</tt> </td>
<tr><td>INPUT: </td><td width="553">
<TaBle>
<tr><td><i>xdc</i> </td><td width="553">Pointer to a transducer aperture.</td>
<tr><td><i>times</i> </td><td width="553">Time after which the associated apodization is valid.</td>
<tr><td><i>values</i> </td><td width="553">Apodization values. Matrix with one row for each
                   time value and a number of columns equal to the 
                   number of physical elements in the aperture. </td>
<tr><td><i>line_no</i> </td><td width="553">Number of line. If skipped, <i>line_no</i> is assumed
                    to be equal to '1'.
         </td></TaBle>
</td>
<tr><td>OUTPUT: </td><td width="553">None         
</td></TaBle>

<p>

<title> bft\_sum\_images</title>

<br><br><br><br><br>
<p>
<hr> 

<H3>bft_sum_images</H3>
<hr>

  <A NAME="bft_sum_images">
</A>
  <a name="bft_sum_images"></a>

<p>
 Sum 2 low resolution images in 1 high resolution.

<p>

<TaBle>
<tr><td>USAGE  : <tt>[hi_res] = bft_sum_images(image1, ele1, image2, ele2, time) </tt></td>
<tr><td>INPUT  : 
<TaBle>
<tr><td><i>image1</i> </td><td width="5572">Matrix with the RF data for the image. The number
                   of columns corresponds to the number of lines </td>
<tr><td><i>ele1</i>   </td><td width="5572">Number of emitting element used to obtain the image.</td>
<tr><td><i>image2</i> </td><td width="5572">Matrix with the RF data for the image. The number
                   of columns corresponding to the number of lines </td>
<tr><td><i>ele2</i>   </td><td width="5572">Number of emitting element used to obtain the image.</td>
<tr><td><i>time</i>   </td><td width="5572">The arrival time of the first samples. The two images
                    must be aligned in time 
          </td></TaBle>

<p>
 OUTPUT : hi_res - Higher resolution image
</td></TaBle>

<p>

<title> bft\_transducer</title>

<br><br><br><br><br>
<p>
<hr> 

<H3>bft_transducer</H3>
<hr>

  <A NAME="bft_transducer">
</A>
  <a name="bft_transducer"></a>

<p>
  Create a new transducer definition. 
    The transducer definition is necessary for the calculation of 
    the delays.

<p>

<TaBle>
<tr><td>USAGE: </td><td width="553"><tt>xdc = bft_transducer(centers)</tt></td>
<tr><td>INPUT: </td><td width="553">
<TaBle>
<tr><td><i>centers</i> </td><td width="434">Matrix with the coordinates of the centers of 
                   the elements. It has 3 columns (x,y,z) and a
                   number of rows equal to the number of elements.
                   The coordinates are specified in [m]
         </td></TaBle>
</td>
<tr><td>OUTPUT: </td><td width="553">
<TaBle>
<tr><td>xdc </td><td width="434">Pointer to the memory location with the transducer 
               definition. Do not alter this value !!!
          </td></TaBle>

<p>
</td></TaBle>
<hr>

      <H1><A NAME="tth_chAp3">
Chapter 3     </A><br>Examples</H1>
<A NAME="chap_examples">
</A>
<hr>

<p>
        <H2><A NAME="tth_sEc1">
1</A>&nbsp;&nbsp;Using Field II simulations</H2>

<p>

<title> Phased array B-mode image</title>

<br><br><br><br><br>
<p>
<hr> 

<H3>phased array B-mode image</H3>
<hr>

  <A NAME="phased_bmode">
</A>
  <a name="phased_bmode"></a>

<p>
<font size="-2">1<tt>&nbsp;&nbsp;&nbsp;&nbsp;</tt><tt><i>%PHASED_IMAGE&nbsp;Create&nbsp;phased&nbsp;array&nbsp;B-mode&nbsp;image&nbsp;with&nbsp;BFT.</i></tt><br>
2<tt>&nbsp;&nbsp;&nbsp;&nbsp;</tt><tt><i>%&nbsp;&nbsp;&nbsp;&nbsp;This&nbsp;script&nbsp;creates&nbsp;a&nbsp;B-mode&nbsp;PSF&nbsp;line&nbsp;by&nbsp;line.&nbsp;Each&nbsp;line&nbsp;is&nbsp;</i></tt><br>
3<tt>&nbsp;&nbsp;&nbsp;&nbsp;</tt><tt><i>%&nbsp;&nbsp;&nbsp;&nbsp;calculated&nbsp;using&nbsp;CALC_SCAT&nbsp;and&nbsp;CALC_SCAT_MULTY.&nbsp;The&nbsp;rf_data</i></tt><br>
4<tt>&nbsp;&nbsp;&nbsp;&nbsp;</tt><tt><i>%&nbsp;&nbsp;&nbsp;&nbsp;from&nbsp;CALC_SCAT_MULTI&nbsp;is&nbsp;passed&nbsp;to&nbsp;&nbsp;the&nbsp;beamforming&nbsp;toolbox,</i></tt><br>
5<tt>&nbsp;&nbsp;&nbsp;&nbsp;</tt><tt><i>%&nbsp;&nbsp;&nbsp;&nbsp;and&nbsp;in&nbsp;the&nbsp;end&nbsp;the&nbsp;results&nbsp;are&nbsp;compared.</i></tt><br>