Laser Safety - GE Revolution CT User Manual

11 Laser Safety

(Reference 21CFR 1040.10 (h) 21CFR1020.33 (g)(4))
A laser alignment light system is available in order to accurately define the patient scan region.
The sagittal, coronal, and transverse alignment lights are within ±1 mm of the gantry coordinate
system (x, y and z-axis) centered at gantry isocenter.
From the gantry controls, press the laser alignment light to toggle all laser alignment lights on/off
and to move the gantry components from the park or idle position to the alignment lights
position. Alignment lights are used to establish landmark locations. Three alignment lights are
displayed: axial, sagittal and coronal. Align the laser lights with the desired anatomical
reference. A poorly positioned and centered patient can impact the mA values calculated for
AEC exposures.
The laser alignment light switch is provided as an alternative to beam attenuators.
Press the Internal and External Landmark buttons to establish the table's reference point when
positioning the patient. This reference point is normally the anatomic reference point used when
positioning the patient. For example, if the patient's anatomic reference point is the sternal
notch, then the sternal notch would be centered to the laser alignment light.
• For Internal Landmark, the gantry displays a table location of 0 mm. This sets the zero point
for which S and I scan locations are centered around.
•
For External Landmark , the gantry displays a table location approximately 240 mm from the
internal landmark, depending on table characterization.
A landmark must be set before you click [Confirm Settings]. At Done Scanning, the landmark is
cleared. For scan setup details, see the Set up and position the patient procedure.
NOTE: Closely monitor infants and infirm patients, and prevent them from accidentally staring
into the beam.
•
Keep your hands away from the gantry opening.
• Make sure the gantry covers are in place.
•
The alignment light indicator is an amber light located on the secondary gantry display on
the front and rear of the gantry directly below the primary gantry display.
Chapter 3 Safety
WARNING
THE LASER BEAM CAN CAUSE EYE INJURY.
•
TELL ALL PATIENTS TO CLOSE THEIR EYES BEFORE YOU SWITCH ON
THE ALIGNMENT LIGHTS.
•
INSTRUCT YOUR PATIENTS TO KEEP THEIR EYES CLOSED UNTIL YOU
TURN OFF THE ALIGNMENT LIGHTS.
WARNING
THE DETECTOR AND DAS ROTATE TO POSITION THE ALIGNMENT LIGHTS
OVER THE LASER PORTS.
Revolution CT User Manual
Direction 5480385-1EN, Revision 1
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