%  Example of use of the Field II program running under Matlab for B-mode
%  and flow imaging
%
%  This script defines all the common parameters for the example 
%
%  Version 1.0 by Joergen Arendt Jensen, October 24, 2022
%     Initial version

%  Transducer parameters for send and receive

fs=100e6;                %  Sampling frequency [Hz]
c=1540;                  %  Speed of sound [m/s]
f0=5e6;                  %  Transducer center frequency [Hz]
M_cycles_cfm=4;          %  Number of cycles in transmit for CFM
M_cycles_B_mode=1;       %  Number of cycles in transmit for B-mode imaging
lambda=c/f0;             %  Wavelength [m]
width=lambda;            %  Width of element [m]
element_height=10/1000;  %  Height of element [m]
elevation_focus=50/1000; %  Elevation focus depth [m]
kerf=0.05/1000;          %  Kerf [m]
focus=[0 0 50]/1000;     %  Fixed initial focal point [m]
N_elements=196;          %  Number of physical elements
rec_N_active=64;         %  Number of active elements in receive
xmit_N_active=64;        %  Number of active elements in transmit
F_number_elevation = elevation_focus/element_height;  %  Elevation F-number
F_number = 2;            %  Desired F-number for imaging

%  Parameters for the flow simulation

R=5/1000;               %  Radius of blood vessel [m]
x_range=80/1000;        %  x range for the scatterers  [m]
y_range=2*R;            %  y range for the scatterers  [m]
z_range=2*R;            %  z range for the scatterers  [m]
z_offset=40/1000;       %  Offset of the mid-point of the scatterers [m]
theta=45/180*pi;        %  Angle between ultrasound beam and flow [rad]
v0=1;                   %  Largest velocity of scatterers [m/s]
blood_to_stationary= 10;   %  Ratio between amplitude of blood to stationary tissue
Tprf=1/10e3;            %  Time between pulse emissions  [s]
fprf=1/Tprf;            %  Pulse repetition frequency [Hz]

%  Imaging parameters

Ncfm=10;                %  Number of emissions for color flow mapping
no_lines_CFM=20;        %  Number of lines in image
image_width=40/1000;    %  Lateral size of image sector  [m]
focal_zones=(5:2:200)'/1000;  %  Focal zones for B-mode imaging
no_lines_B_mode=50;     %  Number of lines in B-mode image

rec_zone_start=5/1000;  %  Start for receive focusing [m]
rec_zone_stop=100/1000; %  Last receive focus [m]
rec_zone_size=2/1000;   %  Length of focal zones [m]
z_focus_transmit=40/1000;   %  Transmit focuse [m]

D=5;                    %  Sampling frequency decimation factor for display
dB_range=60;            %  Display range for B-mode image
start_depth=10/1000;    %  Start depth for displayed image [m]
end_depth=80/1000;      %  End depth for displayed image [m]