GE Vscan Air, Руководство пользователя

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Appendix
8-16
Vscan Air
–
User Manual
Direction GP092020-1EN Rev 18
Measurement accuracy
Measurement accuracy
The following information is intended to provide guidance to the
user in determining the amount of variation or measurement
error that should be considered when performing clinical
measurements with this equipment. Error can be contributed by
equipment limitations and improper user technique. Be sure to
follow all measurement instructions and develop uniform
measurement techniques among all users to minimize the
potential operator error. Also, in order to detect possible
equipment malfunctions that could affect measurement
accuracy, a quality assurance (QA) plan should be established
for the equipment that includes routine accuracy checks with
tissue mimicking phantoms.
Please be advised that all distance related measurements
through tissue are dependent upon the propagation velocity of
sound within the tissue. The propagation velocity usually varies
with the type of tissue, but an average velocity for soft tissue is
assumed. This equipment is designed for, and the accuracy
statements listed on are based on, an assumed average velocity
of 1540 m/s..
Table 8-1: Measurement accuracy - Curved array (deep scanning) transducer
Measurement Unit Useful range Accuracy
Distance
Axial cm or mm 2mm-200mm ±1mm or ±3% whichever is
greater
Lateral cm or mm 4mm-100mm ±2mm or ±5% whichever is
greater
Circumference (ellipse) cm or mm 10mm-300mm ±5% or ±2mm whichever is
greater