simulate a B-mode ultrasound image of a 1mm steel ball in water using a 35MHz transducer, where the distance between the transducer and the steel ball is 20mm

Dear All,

I want to simulate a B-mode ultrasound image of a 1mm steel ball in water using a 35MHz transducer, where the distance between the transducer and the steel ball is 20mm. but i got an error when generate the image by using conv2.

"Error using conv2

N-D arrays are not supported."

thanks and regrads!

this is code:

% Set ultrasound frequency and speed of sound in water
f = 35e6; % Frequency in Hz
c = 1480; % Speed of sound in m/s

% Set size of steel ball and water medium
R = 0.5e-3; % Radius of steel ball in m
L = 2*R; % Length of water medium in m
W = 2*R; % Width of water medium in m
H = 2*R; % Height of water medium in m

% Create 3D grid for water medium
[x,y,z] = meshgrid(-L/2:L/100:L/2, -W/2:W/100:W/2, -H/2:H/100:H/2);

% Create 3D model of steel ball
ball = (x.^2 + y.^2 + z.^2 <= R^2);

% Set density of steel ball (assume 1000 kg/m^3)
rho = 1000;

% Calculate acoustic properties of steel ball
cp = sqrt((rho*f^2)/(1 + 1i*f*rho/2)); % Complex sound speed
alpha = 3*(1 - cp^2/c^2)/(4*R); % Absorption coefficient

% Generate ultrasound pulse and transmit it through water medium
t = 0:1/f:1e-6; % Time vector
pulse = sin(2*pi*f*t); % Ultrasound pulse

% Set transducer position
xt = 0;
yt = 0;
zt = 0;

% Set steel ball position
xb = 0;
yb = 0;
zb = R + 20e-3; % Add 20mm to the z-coordinate of the steel ball

% Calculate time of flight and distance between transducer and steel ball
tof = sqrt((xt - xb)^2 + (yt - yb)^2 + (zt - zb)^2)/c;
d = tof*c/2;

% Generate B-mode ultrasound image
image = conv2(pulse, ball, 'same')*exp(-alpha*d);

Error using conv2
N-D arrays are not supported.

imagesc(image);

Answer 1

[Prateek]

Hello Jenifer,

Thanks for sharing the code. The “conv2” function is not designed to compute convolution with 3-dimensional matrices. The variable “ball” in your code is a 3-dimensional matrix, and thus, the function “convn” is suggested to be used instead.

Hope this helps.

Regards,

Prateek