GE Brivo OEC 715 - DAP Accuracy Application Verification

Brivo OEC 715/785/865 Mobile C-Arm X-Ray Product Service Manual
4-60
DOSE Value Measurement:
Put the sensor of Dosimeter on the center of Image Intensifier and set Dosimeter in accumulated dose
in Gy mode. Expose about 10 seconds as the KV&mA protocol in Area_A, then input each measure
result in Aerea_2.
DOSE Accuracy Calculation:
After finishing 6 measurements, click “Calculate Error” button, system will automatically calculate and
show the “% of Dose Error and % of DAP Error” in Area_I.
The data of “% of Dose Error” shall be less than 10%, otherwise the system shall be
calibrated by “Calculate Dose Coef.”
The data of “% of DAP Error” shall be less than 10%, otherwise the system shall be
calibrated by “Calculate DAP Coef.”
4.7.2. DAP Accuracy Application Verification:
In application interface, perform below procedure to verify the DAP calibraiton result.
Dose Rate and Dose Accuracy Application Verification:
1. Create a new exam named "DOSE CHECK". Make sure the collimator is at the maximum position.
2. Put detector of Dosimeter at 30.0+/-1.0cm from the image intensifier surface in the beam axis.
Take an exposure in Auto Technique mode, observe and adjust the Dosimeter detector to the
center of I.I. Set Dosimeter to dose rate in Gy/min.
3. Take exposure with the modes and parameters listed below. When the reading of Dosimeter is
stable, record the dose rate displayed on left screen into column
Dose Rate displayed on left monitor;
record the dose rate displayed on Dosimeter into column
Dose Rate read from Dosimeter; work out
the Error and fill it into the column Error.
mode kV mA
Dose Rate
displayed
on left
monitor
(mGy/min)
Dose Rate read
from Dose
meter (mGy/min)
Error= (Dose Rate
displayed on left - Dose
Rate read from Dose
meter )/ Dose Rate read
from Dose meter <30%
normal
45
2
4. Set Dosimeter to accumulated Dose in Gy and reset Dosimeter to zero.
5. Take exposure with the modes and parameters listed below. Record the dose value displayed on
left monitor into the column Dose displayed on left monitor before exposure, take exposure and
hold on for 5~10s then stop exposure, Record the dose displayed on left screen into column Dose
displayed on left monitor after exposure; record the dose displayed on Dosimeter into column
Dose read from Dosimeter, work out the Error and fill it into the column Error.