Topics
1. Mechanic probes
i. transmission and reception
2. Linear array probes
i. delay time
Ii. line generation
Iii. focusing
Vi. echo generation
3. Convex probes.
4. Phase array probes
i. transmission and reception
Ii. continuous focalization in reception
ULTRASOUND PROBES
MECHANIC PROBES (transmission and reception).
Sectorial ultrasound image probes.
Though mechanic probes are not widely used as electronic ones at this time, it is useful to
know how they work for understanding better the electric ones. As was explained before
the ultrasound area is built with ultrasound lines, as seen in figure 1, the mechanic probes
generate the ultrasonic lines one by one, using only one crystal (remember that crystal in
this paper means is a quartz crystal or other combine materials, with the piezoelectric properties), though ultrasound probes may have more than one crystal depending the kind of
mechanic probe. In this paper the ultrasound area is defined by two axes, (x,y), the y-axis is
in the center of the area and has the direction other central ultrasound line emitted by the
ultrasound probe, and the x axis has a 900angle respect the y axis as is shown in figure 1, at
the left, x is negative, and positive at the right, besides all the lines emitted by the crystals
have the same strength, that is why when two lines are added, and the y components have
opposite sing, they cancel each other.
Here we explain two types on mechanic probes; one of them has a crystal which swings
as a clock pendulum, and another has three crystals going around an axis.
The one that swings has just only one crystal which at the beginning of the generated area is localized at the left of the ultrasound area where the first line has to be, as is shown in
figure1, the crystal receives the electric pulse needed for sending the ultrasonic beam,
then it waits for the echoes coming from the tissues the ultrasonic beam has passed
through, when the last echo is received, a motor moves the cryst al to the place where the
line 2 is going to be generated as shown in figure 2, the same crystal transmits