Contents

% Using transmmit processes with a STA dataset and the USTB built-in Fresnel simulator

%   authors: Alfonso Rodriguez-Molares (alfonso.r.molares@ntnu.no)


close all;

PHANTOM

pha=uff.phantom();
pha.sound_speed=1540;            % speed of sound [m/s]
pha.points=[0,  0, 40e-3, 1];    % point scatterer position [m]
fig_handle=pha.plot();

PROBE

prb=uff.linear_array();
prb.N=128;                  % number of elements
prb.pitch=300e-6;           % probe pitch in azimuth [m]
prb.element_width=270e-6;   % element width [m]
prb.element_height=5000e-6; % element height [m]
prb.plot(fig_handle);

PULSE

pul=uff.pulse();
pul.center_frequency=5.2e6;       % transducer frequency [MHz]
pul.fractional_bandwidth=0.6;     % fractional bandwidth [unitless]
pul.plot([],'2-way pulse');

SEQUENCE GENERATION

N=128;                      % number of waves
seq=uff.wave();
for n=1:N
    seq(n)=uff.wave();
    seq(n).probe=prb;
    seq(n).source.xyz=[prb.x(n) prb.y(n) prb.z(n)];

    seq(n).apodization=uff.apodization();
    seq(n).apodization.window=uff.window.sta;
    seq(n).apodization.origin=seq(n).source;

    seq(n).sound_speed=pha.sound_speed;

    % show source
    fig_handle=seq(n).source.plot(fig_handle);
end

SIMULATOR

sim=fresnel();

% setting input data
sim.phantom=pha;                % phantom
sim.pulse=pul;                  % transmitted pulse
sim.probe=prb;                  % probe
sim.sequence=seq;               % beam sequence
sim.sampling_frequency=41.6e6;  % sampling frequency [Hz]

% we launch the simulation
channel_data=sim.go();

USTB's Fresnel impulse response simulator (v1.0.7)
---------------------------------------------------------------

SCAN

scan=uff.linear_scan('x_axis',linspace(-2e-3,2e-3,200).', 'z_axis',linspace(39e-3,41e-3,100).');
scan.plot(fig_handle,'Scenario');    % show mesh

PIPELINE

pipe=pipeline();
pipe.channel_data=channel_data;
pipe.scan=scan;

pipe.transmit_apodization.window=uff.window.tukey50;
pipe.transmit_apodization.f_number=1.7;

pipe.receive_apodization.window=uff.window.tukey50;
pipe.receive_apodization.f_number=1.7;

% beamforming
pre = preprocess.demodulation();

mid = midprocess.das();
mid.dimension = dimension.transmit();

b_data=pipe.go({pre mid});

Estimating power spectrum
Band-pass filtering
Low-pass filtering
USTB General beamformer MEX v1.1.2 .............done!

coherently compounded

cc=postprocess.coherent_compounding();
cc.input=b_data;
cc_data=cc.go();
cc_data.plot([],cc.name);

incoherently compounded

ic=postprocess.incoherent_compounding();
ic.input=b_data;
ic_data=ic.go();
ic_data.plot([],ic.name);

max

mv=postprocess.max();
mv.input=b_data;
mv_data=mv.go();
mv_data.plot([],mv.name);

Mallart-Fink coherence factor

cf=postprocess.coherence_factor();
cf.transmit_apodization=pipe.transmit_apodization;
cf.receive_apodization=pipe.receive_apodization;
cf.dimension = dimension.receive;
cf.input=b_data;
cf_data=cf.go();
cf.CF.plot([],'Mallart-Fink Coherence factor',60,'none'); % show the coherence factor
cf_data.plot([],cf.name);

uff.apodization: Inputs and outputs are unchanged. Skipping process.

Camacho-Fritsch phase coherence factor

pcf=postprocess.phase_coherence_factor();
pcf.transmit_apodization=pipe.transmit_apodization;
pcf.receive_apodization=pipe.receive_apodization;
pcf.dimension = dimension.receive;
pcf.input=b_data;
pcf_data=pcf.go();
pcf.FCC.plot([],'Camacho-Fritsch Phase coherence factor',60,'none'); % show the phase coherence factor
pcf_data.plot([],pcf.name);

uff.apodization: Inputs and outputs are unchanged. Skipping process.

Published with MATLAB® R2020b