MORGATE BiomédicalApplications & Ressources > Fantômes d'Echographie en Mode B
IEC document 1390 A.2 Axial Resolution Model 461 and 1461
Specifications:
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Thin threads placed at 25 mm, 50 mm, 100 mm, 150 mm and 200 mm from surface.
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All threads 0.1 mm nylon.
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All markers 0.5 mm steel.
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Background:
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Attenuation 0.5 +/- 0.1 dB/cm*MHz.
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Speed of sound 1535 +/- 15 m/sec.
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Outer dimensions 230 mm * 180 mm * 95 mm
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Weight 2.7 kg
Practice:
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For Axial resolution use the nylon thread
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Select a pair of threads at relevant distance. Notice the axial resolution should not change with distance.
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Optimize the focus in the relevant distance.
Measure the distance between the threads, where they just can be distinguished from one another.
Or calculate the distance proportionally by means of the metal markers.
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For lateral resolution use the steel markers:
1) Optimise the focus of the scanner in the region of test.
2) Reduce the amplification, so that the threads just can be seen.
3) Increase the amplification 20 dB.
4) Measure the dimensions of one wire axial and lateral.
Repeat step 1 to 4 at relevant depths.
Maintenance:
Once every Month inspect the phantom.
The surface must always be covered with 1/2 - 1 cm preservative fluid. Fluid that disappears by desiccation should be replaced by distilled water.
Once every 3 month replace the preservative fluid.
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.
The phantom will not stand frost. Safe storage temperature: 0 - 45 degrees Celsius.
Prescription for preservative fluid:
906 ml Distilled Water
94 ml Glycerol (85 %) or 65 g PEG MW400
5 g Acnibio OCS
1 g Citric ascid