Quatech Audio/Video Capture USB 2.0 Specifikace stáhnout pdf (Strana 256)

9-54 z.one ultra and z.one ultra sp OPERATOR MANUAL

Registration

Accuracy in

For CD scanning of Gammex Model 1425A Doppler Flow Phantom with a sound

speed of 1540 cm/sec, the registration error between CD and 2D mode is

generally less than 1.0 mm.

PW Doppler

Velocity

Measurement

Accuracy

While CD gives an indication (at many points simultaneously) of the presence or

absence of flow and its dynamic behavior during the cardiovascular cycle, PW

Doppler provides a more precise quantification of flow velocity within the PW

sample volume.

Velocity

Accuracy in PW

Doppler

PW Doppler velocity measurements were calibrated using a Gammex flow

phantom with a small sample gate placed at the center of a diagonal flow tube and

a Doppler angle of 50°. Maximum flow velocity measurements generally fall within

±10% of the phantom's calibrated velocity readings for volume flow rates from

0.5-1.0 meters/sec.

Angle

Estimation

The precision of angle estimation is ± 0.5°. As with most electronically steered

systems, the major error in angle estimation occurs through operator error in

adjusting the angle calipers. Therefore, the operator should exercise care in the

use of the angle calipers to achieve accuracy in their placement.

OB Tables

Accuracy

All OB tables are implemented in software such that for the same input values, the

output values (e.g., gestational age in weeks and days) match exactly the tables

published in authoritative reference works.

All supplied OB tables have been verified independently by ZONARE test group.

The verification process involves manually entering each of the data points from

the source into the z.one system, and then verifying the output against that

expected based on the corresponding table reference work.

Diagnostic

Calculation

Accuracy

All vascular, OB, and GYN calculations are implemented using standard

geometric formulas and double-precision float point precision. The accuracy of the

displayed output should be limited only by the display format and precision.

The diagnostic calculation packages (e.g.,%stenosis) have been verified

independently by the

ZONARE test group. The verification process involves

manual entry of a set of randomly selected input values within the range of

possible input values.

Numeric

Display

Precision

For display on the LCD monitor, all measurements and calculation results are

generally rounded to a maximum of 2 digits after the decimal place. This policy

ensures consistency between measured quantities (e.g., distance) and calculated

values (e.g., area).

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