Model 453 with oblique tube with stenosis and circular tube, with C-flex tubes
The most sold Doppler phantom
The day before use, the bottle containing artificial blood is shaken well. Immediately before use, it is shaken carefully. Avoid air bubbles. An easy way to do it is to put a coated magnet into the bottle and place it upon a magnetic stirrer.
The artificial blood is diluted 10 times or more with distilled water.
Evacuating the Doppler fluid prior to use reduces problems with air bubbles.
Apply the Doppler fluid to the reservoir and start the pump. Let it run 15 minutes to eliminate bubbles. If air should be trapped in the phantom, tilt it slightly to release the air.
Use the preservative fluid of the phantom as coupling medium. If the transducer cannot tolerate fluid, use a rubber glove.
The phantom is made of agar and is therefore mechanically fragile. Avoid pressing the transducer into the phantom during scanning.
Perform Doppler and colour flow measurements at varying velocities and depths to performance check the following:
- Fast flow limit
- Slow flow limit
- Critical angle limit at a specific velocity, e.g. 50cm/sec
- Penetration at a specific velocity, e.g. 10cm/sec
- Effect of turbulence
- Effect of clutter (use the air bubbles)
- Position of Doppler signal in B-mode image
Use the reference table to find mean velocity in cm/sec. Due to the flow profile it will differ from the velocity readout on scanner.
Dimensions: 40 * 14 * 28 cm.
Weight of phantom incl. Pump: 4 kg.
Attenuation: 0,5 dB/cm*MHz tolerance see data sheet. Different Attenuation can be made.
Sound velocity:1490 m/s tolerance see data sheet. Sound velocity can be made different.
Vessels of C-flex:
1) curved tube. Inner diameter: 3,2 mm, 0,8 mm wall thickness
2) diagonal tube. Inner diameter: 8,0 mm, 1,6 mm wall thickness.
Stenosis 3,5 mm inner diameter
Maximum pressure of fluid: 50 cm Water
Power consumption: 4 Watt AC, 230 Volt, 50 Hz.
Flow meter readout: 2 - 25 liters/hour. +/- 5% of max..
Mean velocity range: 1,1 cm/sec - 86 cm/sec
Reservoir: Holds 250 ml of artificial blood.
After use, make sure that the phantom surface is covered with ½ - 1 cm of preservative fluid to avoid drying up and fungal growth. Please notice that the lid may not be 100 % tight. Drain fluid off before transportation, but never let it stay dry more than a few days.
It is recommendable to change artificial blood after 40 hours of use.
When out of use for more than a week, the pump should be emptied and washed thoroughly with water with dish soap and finally with preservative fluid.
Check that the surface is covered with sufficient fluid once every month.
Fluid that disappears by desiccation should be replaced with distilled water.
The preservative fluid should be replaced after 3 – 6 months.
The phantom will not stand frost.
When not in use disconnect the pump from the power supply.
If particles have sedimented in the pump or it has been out of use for a long time, it may take several minutes to start. If it does not start after 5 minutes flush the funnel with water and fill it with a solution of water and small amounts of dish soap. Leave it until next day. Flush the funnel with water and start the pump again. It may be necessary to connect and disconnect the pump several times.
The Flowmeter can be dismounted and washed with soap and water if needed.
If the agar surface is attacked by fungi, clean it gently with a cotton ball soaked in soap.
Prescription for Preservative Fluid
-500 ml Distilled Water
- 2,5 g Acnibio OCS
- 0,5 g Citric ascid