users’ guide for the field ii program.zip_Field II_matlab例程

<html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta charset="utf-8"> <meta name="generator" content="pdf2htmlEX"> <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"> <link rel="stylesheet" href="https://static.pudn.com/base/css/base.min.css"> <link rel="stylesheet" href="https://static.pudn.com/base/css/fancy.min.css"> <link rel="stylesheet" href="https://static.pudn.com/prod/directory_preview_static/622bc08b3d2fbb00079a4027/raw.css"> <script src="https://static.pudn.com/base/js/compatibility.min.js"></script> <script src="https://static.pudn.com/base/js/pdf2htmlEX.min.js"></script> <script> try{ pdf2htmlEX.defaultViewer = new pdf2htmlEX.Viewer({}); }catch(e){} </script> <title></title> </head> <body> <div id="sidebar" style="display: none"> <div id="outline"> </div> </div> <div id="pf1" class="pf w0 h0" data-page-no="1"><div class="pc pc1 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/622bc08b3d2fbb00079a4027/bg1.jpg"><div class="t m0 x1 h2 y1 ff1 fs0 fc0 sc0 ls0 ws0">Users’ guide for the</div><div class="t m0 x2 h2 y2 ff1 fs0 fc0 sc0 ls0 ws0">Field II program,</div><div class="t m0 x3 h2 y3 ff1 fs0 fc0 sc0 ls0 ws0">version 2.70 of May 26, 1999</div><div class="t m0 x4 h3 y4 ff1 fs1 fc0 sc0 ls0 ws0">Jørgen Arendt Jensen</div><div class="t m0 x5 h3 y5 ff1 fs1 fc0 sc0 ls0 ws0">Department of Information Technology, Build. 344,</div><div class="t m0 x6 h3 y6 ff1 fs1 fc0 sc0 ls0 ws0">Technical University of Denmark</div><div class="t m0 x7 h3 y7 ff1 fs1 fc0 sc0 ls0 ws0">DK-2800 Lyngby, Denmark</div><div class="t m0 x8 h3 y8 ff1 fs1 fc0 sc0 ls0 ws0">June 23, 1999</div></div><div class="pi" data-data='{"ctm":[1.568627,0.000000,0.000000,1.568627,0.000000,0.000000]}'></div></div> </body> </html>

<div id="pf2" class="pf w0 h0" data-page-no="2"><div class="pc pc2 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/622bc08b3d2fbb00079a4027/bg2.jpg"><div class="t m0 x9 h4 y9 ff2 fs2 fc0 sc0 ls0 ws0">Contents</div><div class="t m0 x9 h5 ya ff2 fs3 fc0 sc0 ls0 ws0">1 Introduction 2</div><div class="t m0 x9 h5 yb ff2 fs3 fc0 sc0 ls0 ws0">2 Program organization 3</div><div class="t m0 x9 h5 yc ff2 fs3 fc0 sc0 ls0 ws0">3 Method of simulation 4</div><div class="t m0 xa h6 yd ff1 fs3 fc0 sc0 ls0 ws0">3.1 The spatial impulse response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4</div><div class="t m0 xa h6 ye ff1 fs3 fc0 sc0 ls0 ws0">3.2 Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4</div><div class="t m0 xa h6 yf ff1 fs3 fc0 sc0 ls0 ws0">3.3 Focusing and apodization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5</div><div class="t m0 xa h6 y10 ff1 fs3 fc0 sc0 ls0 ws0">3.4 Attenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6</div><div class="t m0 xa h6 y11 ff1 fs3 fc0 sc0 ls0 ws0">3.5 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6</div><div class="t m0 x9 h5 y12 ff2 fs3 fc0 sc0 ls0 ws0">4 Installation 7</div><div class="t m0 x9 h5 y13 ff2 fs3 fc0 sc0 ls0 ws0">5 Description of Matlab procedures 8</div><div class="t m0 xa h6 y14 ff1 fs3 fc0 sc0 ls0 ws0">5.1 List of current procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8</div><div class="t m0 xa h6 y15 ff1 fs3 fc0 sc0 ls0 ws0">5.2 Procedures for Field initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10</div><div class="t m0 xa h6 y16 ff1 fs3 fc0 sc0 ls0 ws0">5.3 Procedures for transducer deﬁnition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16</div><div class="t m0 xa h6 y17 ff1 fs3 fc0 sc0 ls0 ws0">5.4 Procedures for element manipulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58</div><div class="t m0 xa h6 y18 ff1 fs3 fc0 sc0 ls0 ws0">5.5 Procedures for ﬁeld calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65</div><div class="t m0 x9 h5 y19 ff2 fs3 fc0 sc0 ls0 ws0">6 Examples 72</div><div class="t m0 xa h6 y1a ff1 fs3 fc0 sc0 ls0 ws0">6.1 Phased array imaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72</div><div class="t m0 xa h6 y1b ff1 fs3 fc0 sc0 ls0 ws0">6.2 Linear array imaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74</div><div class="t m0 xb h6 y1c ff1 fs3 fc0 sc0 ls0 ws0">6.2.1 Computer cyst phantom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75</div><div class="t m0 xa h6 y1d ff1 fs3 fc0 sc0 ls0 ws0">6.3 Flow data generation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77</div><div class="t m0 xc h6 y1e ff1 fs3 fc0 sc0 ls0 ws0">1</div></div><div class="pi" data-data='{"ctm":[1.568627,0.000000,0.000000,1.568627,0.000000,0.000000]}'></div></div>

<div id="pf3" class="pf w0 h0" data-page-no="3"><div class="pc pc3 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/622bc08b3d2fbb00079a4027/bg3.jpg"><div class="t m0 x9 h7 y1f ff2 fs4 fc0 sc0 ls0 ws0">Chapter 1</div><div class="t m0 x9 h4 y20 ff2 fs2 fc0 sc0 ls0 ws0">Introduction</div><div class="t m0 x9 h6 y21 ff1 fs3 fc0 sc0 ls0 ws0">This is the user guide for the 2.70 version of the Field II program. This version of the program runs</div><div class="t m0 x9 h6 y22 ff1 fs3 fc0 sc0 ls0 ws0">under Matlab, and can simulate ultrasound transducers and the associated images. The focusing and</div><div class="t m0 x9 h6 y23 ff1 fs3 fc0 sc0 ls0 ws0">apodization of the transducers can be controlled dynamically, and it is, thus, possible to simulate all</div><div class="t m0 x9 h6 y24 ff1 fs3 fc0 sc0 ls0 ws0">kinds of ultrasound imaging systems.</div><div class="t m0 x9 h6 y25 ff1 fs3 fc0 sc0 ls0 ws0">This guide is intended as a presentation of the currently available routines. Little background information</div><div class="t m0 x9 h6 y26 ff1 fs3 fc0 sc0 ls0 ws0">and feedback is, therefore, welcomed. The user can consult the Web-site for the program:</div><div class="t m0 xd h6 y27 ff1 fs3 fc0 sc0 ls0 ws0">http://www.it.dtu.dk/</div><div class="t m1 xe h8 y28 ff3 fs5 fc0 sc0 ls0 ws0"></div><div class="t m0 xf h6 y28 ff1 fs3 fc0 sc0 ls0 ws0">jaj/ﬁeld/</div><div class="t m0 x9 h6 y29 ff1 fs3 fc0 sc0 ls0 ws0">where up-to-date references and papers can be found.</div><div class="t m0 xc h6 y2a ff1 fs3 fc0 sc0 ls0 ws0">2</div></div><div class="pi" data-data='{"ctm":[1.568627,0.000000,0.000000,1.568627,0.000000,0.000000]}'></div></div>

<div id="pf4" class="pf w0 h0" data-page-no="4"><div class="pc pc4 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/622bc08b3d2fbb00079a4027/bg4.jpg"><div class="t m0 x9 h7 y1f ff2 fs4 fc0 sc0 ls0 ws0">Chapter 2</div><div class="t m0 x9 h4 y20 ff2 fs2 fc0 sc0 ls0 ws0">Program organization</div><div class="t m0 x9 h6 y21 ff1 fs3 fc0 sc0 ls0 ws0">The program consists of a C program and a number of Matlab m-functions that calls this program. All</div><div class="t m0 x9 h6 y22 ff1 fs3 fc0 sc0 ls0 ws0">calculations are performed by the C program, and all data is kept by the C program.</div><div class="t m0 x9 h6 y2b ff1 fs3 fc0 sc0 ls0 ws0">Three types of m-functions are found. The are used for initializing the program, deﬁning and manipu-</div><div class="t m0 x9 h6 y2c ff1 fs3 fc0 sc0 ls0 ws0">lating transducers, and for performing calculations. The initializing routines are preceeded by ﬁeld</div><div class="t m0 x10 h6 y2d ff1 fs3 fc0 sc0 ls0 ws0">, the</div><div class="t m0 x9 h6 y2e ff1 fs3 fc0 sc0 ls0 ws0">transducer commands by xdc</div><div class="t m0 x11 h6 y2f ff1 fs3 fc0 sc0 ls0 ws0">, and the calculation routines by calc . Help on use of the routines can be</div><div class="t m0 x9 h6 y30 ff1 fs3 fc0 sc0 ls0 ws0">obtained by typing help</div><div class="t m1 x12 h8 y26 ff4 fs5 fc0 sc0 ls0 ws0"><</div><div class="t m0 x13 h6 y26 ff1 fs3 fc0 sc0 ls0 ws0">routine name</div><div class="t m1 x4 h8 y26 ff4 fs5 fc0 sc0 ls0 ws0">></div><div class="t m0 x14 h6 y26 ff1 fs3 fc0 sc0 ls0 ws0">. Each of the routines are described in the following section</div><div class="t m0 x9 h6 y31 ff1 fs3 fc0 sc0 ls0 ws0">and then three examples of use are given. The ﬁrst shows how a phased array image is generated, the</div><div class="t m0 x9 h6 y32 ff1 fs3 fc0 sc0 ls0 ws0">second simulates a ﬂow system, and the last example is for a linear array system. The last example uses</div><div class="t m0 x9 h6 y33 ff1 fs3 fc0 sc0 ls0 ws0">a computer generated phantom. The m-ﬁle for this phantom is also given in the example section.</div><div class="t m0 xc h6 y34 ff1 fs3 fc0 sc0 ls0 ws0">3</div></div><div class="pi" data-data='{"ctm":[1.568627,0.000000,0.000000,1.568627,0.000000,0.000000]}'></div></div>

<div id="pf5" class="pf w0 h0" data-page-no="5"><div class="pc pc5 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/622bc08b3d2fbb00079a4027/bg5.jpg"><div class="t m0 x9 h7 y1f ff2 fs4 fc0 sc0 ls0 ws0">Chapter 3</div><div class="t m0 x9 h4 y20 ff2 fs2 fc0 sc0 ls0 ws0">Method of simulation</div><div class="t m0 x9 h9 y35 ff2 fs6 fc0 sc0 ls0 ws0">3.1 The spatial impulse response</div><div class="t m0 x9 h6 y36 ff1 fs3 fc0 sc0 ls0 ws0">The Field program system uses the concept of spatial impulse responses as developed by Tupholme and</div><div class="t m0 x9 h6 y37 ff1 fs3 fc0 sc0 ls0 ws0">Stepanishen in a series of papers [1, 2, 3]. The approach relies on linear systems theory to ﬁnd the</div><div class="t m0 x9 h6 y38 ff1 fs3 fc0 sc0 ls0 ws0">ultrasound ﬁeld for both the pulsed and continuous wave case. This is done through the spatial impulse</div><div class="t m0 x9 h6 y39 ff1 fs3 fc0 sc0 ls0 ws0">response. This response gives the emitted ultrasound ﬁeld at a speciﬁc point in space as function of time,</div><div class="t m0 x9 h6 y3a ff1 fs3 fc0 sc0 ls0 ws0">when the transducer is excitated by a Dirac delta function. The ﬁeld for any kind of excitation can then be</div><div class="t m0 x9 h6 y3b ff1 fs3 fc0 sc0 ls0 ws0">found by just convolving the spatial impulse response with the excitation function. The impulse response</div><div class="t m0 x9 h6 y3c ff1 fs3 fc0 sc0 ls0 ws0">will vary as a function of position relative to the transducer, hence the name spatial impulse response.</div><div class="t m0 x9 h6 y3d ff1 fs3 fc0 sc0 ls0 ws0">The received response from a small oscillating sphere can be found by acoustic reciprocity. The spatial</div><div class="t m0 x9 h6 y3e ff1 fs3 fc0 sc0 ls0 ws0">impulse response equals the received response for a spherical wave emitted by a point. The total received</div><div class="t m0 x9 h6 y3f ff1 fs3 fc0 sc0 ls0 ws0">response in pulse-echo can, thus, be found by convolving the transducer excitation function with the</div><div class="t m0 x9 h6 y40 ff1 fs3 fc0 sc0 ls0 ws0">spatial impulse response of the emitting aperture, with the spatial impulse response of the receiving</div><div class="t m0 x9 h6 y41 ff1 fs3 fc0 sc0 ls0 ws0">aperture, and then taking into account the electro-mechanical transfer function of the transducer to yield</div><div class="t m0 x9 h6 y42 ff1 fs3 fc0 sc0 ls0 ws0">the received voltage trace. An explanation and rigorous proof of this can be found in 4 and 5.</div><div class="t m0 x9 h6 y43 ff1 fs3 fc0 sc0 ls0 ws0">Any excitation can be used, since linear systems theory is used. The result for the continuous wave case</div><div class="t m0 x9 h6 y44 ff1 fs3 fc0 sc0 ls0 ws0">is found by Fourier transforming the spatial impulse response for the given frequency. The approach</div><div class="t m0 x9 h6 y45 ff1 fs3 fc0 sc0 ls0 ws0">taken here can, thus, yield all the diffent commenly found ultrasound ﬁelds for linear propagation.</div><div class="t m0 x9 h9 y46 ff2 fs6 fc0 sc0 ls0 ws0">3.2 Simulation</div><div class="t m0 x9 h6 y47 ff1 fs3 fc0 sc0 ls0 ws0">A number of different authors have calculated the spatial impulse response for different transducer ge-</div><div class="t m0 x9 h6 y48 ff1 fs3 fc0 sc0 ls0 ws0">ometries. But in general it is difﬁcult to calculate a solution, and especially if apodization of the trans-</div><div class="t m0 x9 h6 y49 ff1 fs3 fc0 sc0 ls0 ws0">ducer is taken into account. Here the transducer surface does not vibrate as a piston, e.g. the edges</div><div class="t m0 x9 h6 y4a ff1 fs3 fc0 sc0 ls0 ws0">might vibarte less then the center. The simulation program circumvents this problem by dividing the</div><div class="t m0 x9 h6 y4b ff1 fs3 fc0 sc0 ls0 ws0">transducer surface into squares and the sum the response of these squares to yield the response. Thereby</div><div class="t m0 x9 h6 y4c ff1 fs3 fc0 sc0 ls0 ws0">any tranducer geometry and any apodization can be simulated. The approach is described in reference 6.</div><div class="t m0 x9 h6 y4d ff1 fs3 fc0 sc0 ls0 ws0">The time for one simulation is also of major concern. As the squares making up the tranducer apertue</div><div class="t m0 x9 h6 y4e ff1 fs3 fc0 sc0 ls0 ws0">are small, it is appropriate to use a far-ﬁeld approximation, making simulation simple. Another issue in</div><div class="t m0 x9 h6 y4f ff1 fs3 fc0 sc0 ls0 ws0">keeping the simulation time down is to use a low sampling frequency. Often spatial impulse responses</div><div class="t m0 xc h6 y1e ff1 fs3 fc0 sc0 ls0 ws0">4</div></div><div class="pi" data-data='{"ctm":[1.568627,0.000000,0.000000,1.568627,0.000000,0.000000]}'></div></div>