1. Executive Summary
The subject of my internship was to design a mechanical apparatus that holds ultrasound
probes with existing resolution phantoms, in order to measure ultrasound imaging resolution
in a precise and reproducible manner. The designed apparatus needs to follow a list of
requirements such as:
The ultrasound scanning plan could be perpendicular to the phantom surface
It should intersect the reflecting objects in an optimal manner.
Also the probe should be easy to install and firmly attached to the holder and its
repositioning should be repeatable.
Before I started to design the holder,I studied the basics of ultrasound imaging and of
ultrasound phantoms. First of all I read about the resolution of an image. There are three
kinds of resolution , the spatial resolution which is divided to axial and lateral resolution, the
contrast resolution and the temporal resolution. Also I read about how the resolution
measurement tests are performed and what are the parameters that affect the image quality,
like the transducer design,the frequency, the focusing etc , and the reproducibility of the
measurements (for instance the temperature, the angle of the probe etc.)
Furthermore i make a study about the ultrasound phantoms and the different sort of them
like phantoms for training and demonstration, for general purpose and the QA phantoms.
There are a various shapes and sizes of phantoms, with different types of targets( wires,
cylindrical and spherical anthropomorphic objects, channels) designed for specific
transducers.
In addition I learned how to use the Aixplorer and made measurements for the B mode
imaging. With the use of the CIRS model 040GSE phantom and the XC6­1 probe i did
measurements for the imaging distance accuracy. In other words I measured the distance
between the most left and most right wire target. Also I measured the image penetration with
the CIRS model 040 S/N E1188­2 and with the XC6­1 transducer. The above measurements
was done once a day, for a week with the existing probe holder. The purpose was to see if
there are reproducible. As a result the measurements weren’t reproducible (Report 1).
An important part of my work was to build the first version of the apparatus​.First, I found all
the dimensions for the probe and the phantom, such as the height, the diameter of the wire
etc, and I design the holder on a paper. I presented my idea on the ultrasound staff and I
started to build the prototype.
The mechanical apparatus consist of square aluminum tubes with two different sizes b(25
mm and 20 mm with 2mm thickness).
The base is fixed in a plane(450 x 295 mm) in order to be more stable and to have a uniform
level for positioning the phantom tissue. All the tubes of the base has diameter of 25mm. In
front of the horizontal tube is fixed on the plane a second one with the same dimensions in
order to establish the desired place of the probe.
Left and right of the horizontal tube of the base are placed two smallest tubes(20 mm) which
can move inside out so they can change the length (50 mm + 70 mm). The phantom can be
placed inside in the desired position and remains stable. To stop the movement of the tubes
two screws were used.
The vertical tube of the base has 200mm height and inside of it is placed another tube which
can move inside out so that it can change the height in order to be easier the placement of
the probe.

2. The second tube has length 250mm and diameter of 20mm which only the 100mm can go
inside the first tube. At the 100mm is placed a vertical tube(40 mm) with a box in the end of
it. Inside the box is a probe mold made by silicon for the specific probe. The box can open
and close easier. As the most important probe is the XC6­1 I made a silicon for this specific
probe, but you can used it also for the SL10­2.
In the same tube is placed vertical again in a distance of 150 mm away from the first one, a
second tube(60 mm) which is purpose is to hold the cable of the probe. It consists of two
parts which when combined are form a box with a hole in the center(diameter 8.52mm). The
1​st​
part is stable in the tube and the 2​nd​
part can open and close with the use of screws.

4. The next step was to make a protocol to describe how the prototype works so everyone can
to measurements with it and to describe how you can find the axial and the lateral resolution
(Protocol for the prototype).
To check the efficiency of the prototype, I ask people in the company to do a resolution
measurement test, with and without the probe holder at the third group of 10.5 cm depth.
As a result the measurements with the use of the holder were reproducible, which was one
of the goals and the axial resolution was the best that can be achieved. Without the holder
the measurements weren’t reproducible(Report 3). The time that requires to do the
measurement was approximately 4 minutes for the both. However the prototype had some
technical problems that occurred due to assembly, such as the vertical tube wasn’t well
controlled and the right arm of the holder was hard to slide. Also the cable holder wasn’t
easy to set up and the probe repositioning wasn’t repeatable.
To eliminate these problems a new apparatus was builded with more stable and easy to
assembly materials. The second design idea is consist of optical rails that can be used for
quick and repeatable alignment. The base is an optical rail with metric and english scale. An
optical rail carrier, is used to carry the vertical tube above the base. On the vertical tube
there also an optical rail carrier which carry the probe holder. The apparatus is fixed on a big
plate, for more stability. Likewise I made a protocol, to explain how the new holder is working
and how you can performed the measurements( New Protocol).

5.
List of the bill of materials/goods
1.Newport, Optical Rail, 3.0 in. Width,12in. Length,Model:9731,
(​http://search.newport.com/?q=*&x2=sku&q2=9731​)
2.Newport, ​76.2 mm Optical Rail Carrier, for 9731/9732 Optical Rails, M4 & M6,
Model:9742­M, (​http://search.newport.com/?q=*&x2=sku&q2=9742­M​)

6. 3.Newport, Aluminum Optical Rail, 1000 mm Length, M4 Threads, X48 Series, Model:
X48­1, (​http://search.newport.com/?q=*&x2=sku&q2=X48­1​)
4.Newport, X48 Rail Carrier, 80 mm Length, M3, M4, and M6 Thread, Model: M­CXL48­80,
(​http://search.newport.com/?q=*&x2=sku&q2=M­CXL48­80​)

7. 5.Newport, Table Clamp, For 9731/9732 Quick Release Optical Rail , Model: 9739,
(​http://search.newport.com/?q=*&x2=sku&q2=9739​)
6. Metal Plate (295x450x10)
To check again the efficiency of the apparatus, I asked people in the company to do the
resolution measurement test. First I asked them to do the resolution measurement test in the
third target group at 10.5cm depth so I could compare the results with the prototype and
after at the second target group of 6.5 cm depth. As a result the resolution in the third group
was the same for the both holders, but the test was faster. Also the holder was more stable
and easy to use and the probe repositioning was repeatable (Report 3).
The final project was to process the images which are taken from the aixplorer. With the use
of matlab a program was made to give a reproducible results for the axial and lateral
resolution. The program read the image, convert it in grayscale and compute the pixel
dimension.It finds the center point of the image, which are there where the vertical and the
horizontal wire targets are intersect. It zooms in the desired area, either the 6.5 cm depth
target group or the 10.5 cm target group and it put in every target a cross. It makes pairs
between the neighbor targets and it draw a yellow line for the axial resolution pairs and blue
line for the lateral resolution pairs. For each pair it measure the brightness. If the brightness
is zero then the targets can not be distinguished and the pair is marked with red line. When
all the computes finish it gives to the user the axial and the lateral resolution as given in the
phantom user guide.
To check the program, I took images with different gains, zoom, depths and combination of
them with the use of the holder and with the XC6­1 and SL10­2 probe and without the probe
holder. I ran these images in the program in order to find out if axial and lateral resolution
vary, if you change the default conditions(Report 2). The images without the probe holder
weren’t able to run in the program because of the rotation.

8. List of the primary objectives
Design a mechanical apparatus that hold the ultrasound probe with the existing resolution
phantoms, in order to measure the ultrasound imaging resolution in a precise and
reproducible manner.
The probe holder must satisfy the follow requirements:
➢ The ultrasound scanning plan must be perpendicular to the phantom surface
➢ The ultrasound scanning plan must intersect the reflecting objects in an optimal
manner.
➢ The probe must be easy to install on the holder
➢ The probe repositioning must be repeatable
Results
Some requirements were efficiently accomplished and some others require further
improvement
➢ The apparatus can used with XC6­1, SC6­1, SL15­4, SL10­2 and with all the kind of
phantoms that need the probe to be perpendicular on it.
➢ The apparatus consist of optical rails that can be used for quick and repeatable
alignment, so the placement of the holder can be precise and the measurements can
be reproducible.
➢ The use of the apparatus is very easy and the probe can install readily.
➢ The ultrasound scanning plan is not perfectly perpendicular to the phantom surface
List of possible improvements and recommendations
➢ The apparatus could be lighter.
➢ The probe holder could fix on the optical rail carrier with another way, in order to be
perfectly perpendicular.