Cirs Doppler String Phantom 043 User manual
900 Asbury Ave • Norfolk, Virginia 23513 • USA • Tel: 757-855-2765 • WWW.CIRSINC.COM
USER GUIDE
Doppler String Phantom
Model 043
Table of Contents
OVERVIEW ......................................................................................................................................................... 1
Features of the Doppler String Phantom .............................................................................................................. 1
Starting a Quality Assurance Program ................................................................................................................. 1
SETUP INSTRUCTIONS ..................................................................................................................................... 2
Parts List ............................................................................................................................................................. 2
Using the Diffuser Mat ......................................................................................................................................... 3
Installing the String .............................................................................................................................................. 3
Filling the Tank..................................................................................................................................................... 3
Setting up the Clamp........................................................................................................................................... 4
Connecting the Controller.................................................................................................................................... 5
SPECIAL FEATURE
Using The ECG Output ....................................................................................................................................... 5
OPERATING INSTRUCTIONS ............................................................................................................................ 6
Using Constant Speeds....................................................................................................................................... 6
Using Preprogrammed Waveforms ...................................................................................................................... 6
RS-232 INSTRUCTIONS .................................................................................................................................. 7
Introduction ......................................................................................................................................................... 7
Getting Started.................................................................................................................................................... 7
Accessing the Help Menu.................................................................................................................................... 8
Selecting Velocities and Waveforms..................................................................................................................... 9
Setting Up for Quality Control Testing .................................................................................................................. 9
Locking the Settings.......................................................................................................................................... 10
Description of Commands Available Via RS-232................................................................................................ 10
MAINTENANCE INSTRUCTIONS ................................................................................................................... 11
Making String Loops ......................................................................................................................................... 11
Ordering String Loops ...................................................................................................................................... 11
Cleaning the Doppler String phantom ............................................................................................................... 11
Calibrating the Doppler String Phantom............................................................................................................. 11
Replacing a fuse................................................................................................................................................ 12
ACCESSORIES AND PARTS............................................................................................................................ 12
Carrying Case.................................................................................................................................................... 12
Preformed String Loops..................................................................................................................................... 12
Step Up and Down Transformer ........................................................................................................................ 12
WARRANTY ..................................................................................................................................................... 13
Non-Warranty Service........................................................................................................................................ 13
APPENDIX A GRAPHS OF WAVEFORMS....................................................................................................... 14
Test Waveforms................................................................................................................................................. 14
Physiological Waveforms ................................................................................................................................... 19
APPENDIX B SAMPLE QA FORM .................................................................................................................. 26
1
OVERVIEW
Features of the Doppler String Phantom
The Doppler String phantom is a very accurate device for testing Doppler ultrasound scanners. It is especially
useful for checking sample volume registration, color registration, directional discrimination, and Doppler velocity
accuracy.
The Doppler String Phantom offers superior accuracy by using a string target that never changes (unlike sus-
pended scatterers in fluid flow phantoms) and a crystal-controlled motor. The motor speed is adjusted 1000
times per second, allowing realistic reproductions of human blood flow velocity patterns and a wide range of con-
stant velocities.
The Doppler String Phantom has been designed for ease of use. It can be set up quickly and easily with ordinary
tap water. It is simple to use and almost no maintenance is required. An RS-232 interface is also provided for
automated use, if desired. Ultrasound technologists, biomedical technicians, researchers and manufacturers all
rely on the Doppler String Phantom for hassle-free, reliable testing.
Starting a Quality Assurance Program
Each ultrasound lab will have different Quality Assurance (QA) needs depending on equipment, maintenance
agreements and applicable laws and policies. However, many technicians recommend performing QA tests
every 3 months. Of course, any time you suspect a problem with an ultrasound scanner, you will want to test it
immediately.
CIRS recommends using a standard form to record the results of your tests, so you can be sure that each testing
session is consistent and thorough. Recording your findings also provides written documentation of your QA
program. A sample QA form is provided in Appendix B of this User Guide.
2
SETUP INSTRUCTIONS
Parts List
When you unpack the Doppler String Phantom for the first time, you should find:
• Electronic Controller
• Acrylic tank with motor and pulleys attached
• Scanhead Clamp
• Set of 5 String Loops (not pictured)
• Rubber Diffuser Mat (not pictured)
• Power Cord (not pictured)
• Carrying Case (not pictured)
Figure 1: Doppler String Phantom
Electronic
Controller
Scanhead Clamp
Motor
Acrylic Tank
3
Using the Diffuser Mat
The black rubber Diffuser Mat is provided to reduce reverberations in the tank by absorbing and scattering the
ultrasound beam. Place the mat in the bottom of the tank with the ridges facing up, if desired.
Installing the String
If your Doppler String Phantom was shipped in a custom carrying case, the string target is already installed. If
not, you will need to install the string by doing the following:
1. Loosen the adjusting screw on the two pulleys at the end of the tank opposite
the motor.
2. Take one of the string loops out of the bag and lay it over the pulley that is
attached directly to the motor (Motor Pulley).
3. Draw the string half-way around the Motor Pulley, behind the two Idler Pulleys
below the motor, and around the pair of Adjustable Pulleys at the other end of
the tank. (See Figure 2).
4. Adjusting the string tension by moving the Adjustable Pulleys until the string is
fairly tight, but not tight enough to break. The actual tension will not affect the
data.
Figure 2: String Installation
About Reverberations:
Water conducts ultrasound
more efficiently than the
human body, so it may be
necessary to reduce the
power level on your ultra-
sound scanner to a mini-
mum for best results.
FILLING THE TANK
Place the tank on a firm surface and fill it with either cold tap water or velocity-corrected fluid (see sidebar).
Fill the tank until the two small pulleys beneath the motor are just submerged. This depth works well, but it may
be changed to meet your needs.
After filling the tank, there will be dissolved air bubbles in the water. For best results, wait an hour before using
the Doppler String Phantom so the water can de-gas.
4
Setting up the Clamp
The Doppler String Phantom is shipped with a scanhead clamp system con-
sisting of a clamp (see Figure 3), an "arm" with a center joint and an arm at-
tachment fixture, which is bolted to the tank. If your Doppler String Phantom
was shipped in a custom carrying case, the clamp will have been set up at the
factory and you should skip step 1.
1. The arm attachment fixture on the tank has two sockets.
Insert one end of the arm into either of the sockets and tighten the
thumbscrew.
2. Turn the clamp adjusting knob to open or close the clamp so that it
fits your scanhead.
3. Adjust the clamp and articulated arm so that the transducer end of the
scanhead is in the water. (See Figure 4). Make sure your scanhead is at the
desired angle with respect to the string.
Note: Although the scanhead clamp can be placed in water temporarily, it should
be stored in a dry location to prevent corrosion.
Figure 3: Scanhead Clamp
Clamp
Adjusting
Knob
About Velocity Corrected
Fluid:
The speed of sound is 1480
meters per second in water
and 1540 meters per second
in the human body. Doppler
scanners are calibrated for
1540 meters per second, so
some ultrasound profession-
als prefer to use a water/gly-
col mix that also has a speed
of sound of 1540 meters per
second. This mix is called
velocity corrected fluid.
The Doppler String Phantom
has been designed to work
with either plain water or
velocity-corrected fluid (H2O/
Glycol). When you turn on
the power, the Doppler String
Phantom will ask you which
type of fluid you are using.
When set for use with water,
the Doppler String Phantom
compensates for the different
speed of sound by adjust-
ing the speed of the string
and the display indicates the
speed your scanner should
be detecting. When set for
use with velocity-corrected
fluid, the Doppler String Phan-
tom moves the string at the
actual speed indicated on the
display.
5
Connecting the Controller
You are now ready to connect the controller to the motor and the power supply.
1. Before plugging in the controller make sure the power switch on the back is turned off.
2. Plug the motor cable into the Drive Motor receptacle on the back of the controller.
3. Plug the power cable into the AC Receptacle and into an AC power source. If using in a country other than
the United States you will need to connect the transformer as well. This can be purchased for an additional
price.
SPECIAL FEATURE
Using the ECG Output
The ECG (electrocardiogram) output is an output that the user can elect to use to synchronize the waveforms to
the ultrasound scanner. It is located on the rear panel of the phantom. This is a rarely used feature that can aid
ultrasound researchers as they test new ultrasound machines. Since most users of this phantom do not deal
with that aspect it may be simply ignored.
When used, this output will generate a signal pulse at the very beginning of each test or physiological waveform.
That pulse is 10 milliseconds long and rises from zero volts up to five volts and then back down. This may be
used to tell the ultrasound researcher exactly when the waveform started and is useful for internal adjustments to
the ultrasound scanner.
Figure 4: Scanhead clamp and articulated arm
About Scanning Angles:
The best angle for most Doppler
ultrasound scans is 60°.
The string target in the
Doppler String Phantom is set
at an angle, so that a scanhead
aimed straight down will be at
a 60° angle to the string. Of
course, you should scan at the
angle that is needed for your
tests.
6
OPERATING INSTRUCTIONS
Using Constant Speeds
The Doppler String Phantom can be set for constant string speeds ranging from 20 to 200 cm/sec. Constant
speeds are useful for a quick check to verify that your scanner is reporting correct image registration and target
velocity for the scanning angle you’re using. You can also detect false data caused by a broken transducer or a
loose connection.
1. After setting up the Doppler String Phantom, turn on the power switch (located on the back of the controller).
The display reads UP=H2O DOWN=H2O/GLYCOL.
2. If the tank is filled with water, press UP. If the tank is filled with velocity-corrected fluid, press DOWN.
(See About Velocity-Corrected Fluid on page 4 for more information.)
The display reads SELECT A FUNCTION.
3. Press CONST. SPEED; then press UP or DOWN to select the desired speed.
Note: Holding down either the UP or DOWN button causes the display to scroll faster.
The motor starts automatically.
4. To reverse the direction of simulated flow, press FLOW REV at any time.
An arrow in the bottom right corner of the display indicates the flow direction.
5. To change functions (for example, to switch from constant speeds to test waveforms), press ESCAPE.
The display reads SELECT A FUNCTION.
Using Preprogrammed Waveforms
The Doppler String Phantom has several preprogrammed waveforms to help you test your ultrasound scanner
under realistic conditions with velocity fluctuations you might expect in a patient. Each waveform has 1000 data
points to provide accurate simulations. The waveforms are divided into two groups: test waveforms and physi-
ological waveforms. Graphs of all the waveforms are included in Appendix A of this User's Guide.
The test waveforms are:
• Sine waves with peak speeds of 100, 150, and 200 cm/sec
• Triangle waves with peak speeds of 100, 150, and 200 cm/sec
• Stepped ramp wave with stops at 1, 20, 40, 60, 80, and 100 cm/sec
The physiological waveforms are:
• Adult common carotid
• Adult aortic
• Adult femoral
• Pediatric umbilical
• Stenotic common carotid
• Pediatric renal
• Pediatric ductus arteriosus
• Pediatric middle cerebral
• Pediatric descending thoracic
7
After setting up the Doppler String Phantom, turn on the power switch (located on the back of the controller).
The display reads UP=H2O DOWN=H2O/GLYCOL.
1. If the tank is filled with water, press UP. If the tank is filled with velocity-corrected fluid, press DOWN.
(See About Velocity-Corrected Fluid on page 4 for more information.)
The display reads SELECT A FUNCTION.
2. Press TEST or PHYSIOLOGICAL to select a waveform group.
The display shows a waveform.
3. Press UP or DOWN to select a waveform. (See Appendix A for graphs of waveforms.)
4. Press EXECUTE to start the motor.
5. To select a different waveform, you may press UP or DOWN at any time while the motor is running.
6. To reverse the direction of simulated flow, press FLOW REV at any time.
An arrow in the bottom right corner of the display indicates the flow direction.
7. To change functions (for example, to switch from physiological waveforms to constant speeds), press
ESCAPE. The display reads SELECT A FUNCTION.
RS-232 INSTRUCTIONS
Introduction
The remote control software allows all of the same functions that are available from the front panel. It is primarily
a serial communications feature for use with automatic testing equipment, but may be used by anyone wanting
to control the phantom for standardized testing. It may be controlled by a laptop, desktop, or a process control
computer.
To establish the link between the Doppler String Phantom controller and your computer, any common RS-232
communications program such as Pro-Comm Plus, Teraterm Plus, Microsoft Hyperterminal, etc., may be used.
The communications program must be set to 9600, N, 8, 1. Use hardware flow control. If your computer does
not have an RS-232 port, you can use an adapter available locally that will convert a standard USB port to RS-
232.
Getting Started
To begin using the remote control feature:
1. Ensure the Doppler String Phantom controller is powered off (rear panel switch).
2. Plug the power cable into the AC Receptacle and into an AC power source. The label on the AC
Receptacle indicates 120 volts. If using with 220 volts, use step down controller (Model 901-C, sold sepa-
rately).
3. Plug the custom RS-232 cord (supplied with the Doppler String Phantom) into the RS-232 receptacle
on the back of the controller.
4. Plug the motor cable into the Drive Motor receptacle on the back of the controller.
5. Start the communications program.
6. Turn on the power on the controller (rear panel switch).
Table of contents
Other Cirs Industrial Equipment manuals
