GE Healthcare eXplore Locus SP User manual

Technical
Publication
Direction 5158821-100
Revision 3
GE Healthcare
eXplore Locus SP Service Guide
Copyright 2005 by GE Healthcare
All rights reserved
http://www.gehealthcare.com

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GE HEALTHCARE
DIRECTION 5158821-100, REVISION 3 EXPLORE LOCUS SP SERVICE GUIDE
- Page3
Revision History
Revision History
Effective
Date
Revision Nature of Change
March 19/05 0 Previously released under eXplore Locus SP Service &
Installation Guide (2407687).
March 24/06 1 Updates to FRUs, Calibration & Troubleshooting.
Reflects latest software release.
Apr. 2/07 2 Changes to calibration procedures.
Addition of Calibration Worksheets.
Addition of electrical block diagram.
Changes to Registry back up.
Addition of Registry Restore procedure.
Addition of Calibration Values Restore procedure.
Addition of Acquisition Computer Replacement procedures
(Dell to HP)
Major changes to Preventive Maintenance chapter.
Sept 26/07 3 Minor changes to calibration procedures.
Remove lexan collimator window if present.
Live animal handling prohibition.
Before
You
Begin
This Guide documents how to service GE’s eXplore Locus SP scanner. It is only
intended for use by GE qualified personnel who have received training on its
operation. The eXplore Locus SP may be not be used or serviced in a manner
outside manufacturer specifications.
This Guide is periodically updated. Please ensure you are using the most
current version by checking the Common Documentation Library (CDL) at:
http://apps.gehealthcare.com/servlet/
ClientServlet?REQ=Enter%2bDocumentation%2bLibrary

GE HEALTHCARE
DIRECTION 5158821-100, REVISION 3 EXPLORE LOCUS SP SERVICE GUIDE
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GE HEALTHCARE
DIRECTION 5158821-100, REVISION 3 EXPLORE LOCUS SP SERVICE GUIDE
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Contents
1 Introduction
1.1 Important Precautions .........................................................................11
1.1.1 Language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
1.2 Safety & Hazard Information ................................................................14
1.2.1 Text and Character Representation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
1.2.2 Standard Hazard Icons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
1.2.3 Lockout / Tagout (LOTO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
1.2.4 Certified Electrical Contractor Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
1.2.5 Important... X-Ray Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
1.2.6 Live Animal Handling Prohibition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1.3 Publication Conventions ......................................................................17
1.3.1 General Paragraph and Character Styles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
1.3.2 General Installation Safety Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
1.3.3 Omissions, Errors & Suggested Improvements. . . . . . . . . . . . . . . . . . . . . . . . . 18
2 Theory & Components
2.1 Basic Concepts ......................................................................................19
2.1.1 Parts of a CT Scanner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
2.1.2 Definitions of Basic Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
2.1.3 Image Creation Basics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.2 Hardware & Software Components .....................................................23
2.2.1 Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
2.2.2 Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
2.3 Managing Files....................................................................................... 27
2.3.1 File Locations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.3.2 Files Created During the Acquisition Process . . . . . . . . . . . . . . . . . . . . . . . . . . .27
2.3.3 Files Created During the Reconstruction Process . . . . . . . . . . . . . . . . . . . . . . .28

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DIRECTION 5158821-100, REVISION 3 EXPLORE LOCUS SP SERVICE GUIDE
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2.3.4 Removing Unnecessary Scan Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3 Troubleshooting
3.1 Overview................................................................................................. 29
3.1.1 Avoiding Common Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.2 Troubleshoot the System ......................................................................30
3.2.1 Visualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.2.2 System Wide Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.2.3 Reconstruction Cluster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.2.4 Reconstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.2.5 Scan Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.2.6 Fluoroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.2.7 eXplore Locus SP Electrical Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
4 Functional Checks
4.1 Overview .................................................................................................39
4.1.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.2 Perform Functional Checks ..................................................................39
4.2.1 X-Ray Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.2.2 Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.2.3 Limit Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.2.4 Comair Rotron Fan FS12B3 (Detector Fan). . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.2.5 Comair Fan 2.0625 (Fan under X-ray Source) . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.2.6 Shutter Drive Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.2.7 X-Ray Indicator Light, Small . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.2.8 Comair Blower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.2.9 Ventilator Hose (PVC, 1"IDX1.21"OD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.2.10 Interlock, D4DS Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.2.11 Interrupt Switch, 4600B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

GE HEALTHCARE
DIRECTION 5158821-100, REVISION 3 EXPLORE LOCUS SP SERVICE GUIDE
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5 Software Set Up / Back Up
5.1 Computer Hard Drive ............................................................................43
5.1.1 Ghost an Image on C Drive & Update Software . . . . . . . . . . . . . . . . . . . . . . . . .43
5.2 Back Up & Restore ................................................................................46
5.2.1 Back Up Calibration and Registry Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
5.2.2 Restore Registry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
5.2.3 Restore Calibration Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51
5.2.4 Acquisition Computer Replacement - Transfer Critical Data . . . . . . . . . . . . . . .51
6 Field Replaceable Units
6.1 Overview .................................................................................................53
6.1.1 Lockout / Tagout (LOTO) Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
6.1.2 Left Access Panel Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
6.1.3 Right Access Panel Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . .57
6.1.4 Case Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58
6.1.5 X-Ray Shield Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
6.2 Remove / Replace FRUs .......................................................................62
6.2.1 Comair Blower and Hose Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . .62
6.2.2 Right Comair Fan Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
6.2.3 Left Comair Fan Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
6.2.4 Interlock Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
6.2.5 X-Ray Indicator Light Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . . . . .69
6.2.6 Temperature Controller Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . . 70
6.2.7 Specimen Stage, Short Limit Switch Removal / Replacement . . . . . . . . . . . . . 72
6.2.8 Magnification Stage Limit Switches Removal / Replacement . . . . . . . . . . . . . . 74
6.2.9 Filter Wheel Assembly Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . . . .75
6.2.10 Module Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
6.2.11 Rotary Stage Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77
6.2.12 Specimen Slide Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79
6.2.13 X-Ray Source Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .83
6.2.14 Shutter Drive Motor Assembly Removal / Replacement . . . . . . . . . . . . . . . . . . .86
6.2.15 Collimator Window Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
6.2.16 Detector Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90
6.2.17 Fan 2.0625 (Below X-Ray Source) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92
6.2.18 Shutter Control Assembly Removal / Replacement . . . . . . . . . . . . . . . . . . . . . .93
6.2.19 Door Interlocks Removal / Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

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DIRECTION 5158821-100, REVISION 3 EXPLORE LOCUS SP SERVICE GUIDE
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7 Calibration
7.1 Overview .................................................................................................97
7.1.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
7.1.2 Calibration Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
7.2 Detector Replacement Calibration ......................................................99
7.2.1 Mechanically Adjust Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
7.2.2 Find X-Ray Mask Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
7.2.3 Start Transform1 File Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
7.2.4 Complete Transform1 File Creation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
7.2.5 Create Transform2 & Transform4 Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
7.2.6 Calculate Central Slice of X-Ray Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
7.2.7 Verify Stage Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
7.2.8 Centre the Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
7.2.9 Calculate Source to Detector Distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
7.2.10 Edit Calibration Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
7.2.11 Calculate & Edit Magnification Difference . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
7.2.12 Perform Verification Scans (1x1, 2x2 & 4x4 Modes) . . . . . . . . . . . . . . . . . . . . 133
7.2.13 Follow Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
7.3 Stage Replacement Calibration ..........................................................146
7.3.1 Mechanically Align the Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
7.3.2 Centre the Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
7.3.3 Perform Verification Scans (1x1, 2x2, & 4x4 Modes) . . . . . . . . . . . . . . . . . . . 160
7.4 Source Replacement Calibration ........................................................169
7.4.1 Centre X-Ray Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
7.4.2 Centre the Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
7.4.3 Calculate Central Slice of X-Ray Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
7.4.4 Verify Stage Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
7.4.5 Calculate Source to Detector Distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
7.4.6 Edit Calibration Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
7.4.7 Calculate & Edit Magnification Difference . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192
7.4.8 Perform Verification Scans (1x1, 2x2, & 4x4 Modes) . . . . . . . . . . . . . . . . . . . 194
7.4.9 Follow Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
7.5 Case/Shielding Removal "Abridged" Calibration ............................207
7.5.1 Centre the Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
7.5.2 Perform Verification Scans (1x1, 2x2 & 4x4 Modes) . . . . . . . . . . . . . . . . . . . . 216
7.5.3 Edit Calibration Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
7.5.4 Follow Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224

GE HEALTHCARE
DIRECTION 5158821-100, REVISION 3 EXPLORE LOCUS SP SERVICE GUIDE
Page9
8 Preventive Maintenance
8.1 Preventive Maintenance (PM) Introduction .......................................229
8.1.1 Why Do Preventive Maintenance? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .229
8.1.2 Record Keeping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .229
8.1.3 Scheduling Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .229
8.1.4 Tools & Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .230
8.1.5 SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .230
8.2 Preventive Maintenance Procedures .................................................231
8.2.1 X-Ray Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
8.2.2 X-Ray Indicator Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .232
8.2.3 Reset Switch Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .232
8.2.4 Interlock Body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .232
8.2.5 Limit Switches on Magnification Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .234
8.2.6 Specimen Slide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .235
8.2.7 Limit Switches On Specimen Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .235
8.2.8 Rotary Stage Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .235
8.2.9 Filter Wheel Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .235
8.2.10 Shutter Drive Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .236
8.2.11 Rear Exhaust Fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
8.2.12 Fan Under X-ray Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .236
8.2.13 Fan Behind The Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .237
8.2.14 Comair Blower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
8.2.15 Ventilator Hose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
8.2.16 Fan Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .237
8.2.17 Equalization Bath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .238
8.2.18 Temperature Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .238
8.2.19 Cables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
8.2.20 Gantry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
8.2.21 Control Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .239
8.2.22 Acquisition Computer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
8.2.23 Perform Periodic Abridged Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
8.3 Preventive Maintenance Checklist..................................................... 241
8.3.1 Completing and Filing the Checklist. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
8.3.2 Preventive Maintenance Performance Checklist . . . . . . . . . . . . . . . . . . . . . . .242

GE HEALTHCARE
DIRECTION 5158821-100, REVISION 3 EXPLORE LOCUS SP SERVICE GUIDE
Page 10
99 Appendix
99.1 Calibration Worksheets...................................................................... 245
99.1.1 Detector Replacement Calibration Worksheets . . . . . . . . . . . . . . . . . . . . . . . . 246
99.1.2 Stage Replacement Calibration Worksheets . . . . . . . . . . . . . . . . . . . . . . . . . . 253
99.1.3 X-Ray Source Replacement Calibration Worksheets . . . . . . . . . . . . . . . . . . . 257
99.1.4 Abridged Calibration Worksheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264

GE HEALTHCARE
DIRECTION 5158821-100, REVISION 3 EXPLORE LOCUS SP SERVICE GUIDE
Page11
Chapter 1
Introduction
Purpose: This chapter informs the reader about important precautions and safety considerations. It
also provides publication conventions so that the reader can identify safety and general material
that is considered important by its format.
Please become familiar with this chapter before proceeding.
Section 1.1
Important Precautions
1.1.1 Language
WARNING • This service manual is available in english only.
• If a customer’s service provider requires a language other than english, it is the customer’s
responsibility to provide translation services.
• Do not attempt to service the equipment unless this service manual has been consulted and
is understood.
• Failure to heed this warning may result in injury to the service provider, operator or patient from
electric shock, mechanical or other hazards.

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Section 1.2
Safety & Hazard Information
1.2.1 Text and Character Representation
Different paragraph and character styles are used to indicated potential hazards. Paragraph
prefixes, such as hazard, caution, danger and warning, are used to identify important safety
information. Text (Hazard) styles are applied to the paragraph contents that is applicable to each
specific safety statement.
EXAMPLES OF HAZARD STATEMENTS USED
CAUTION
Pinch Points
Loss of Data
Sharp Objects
Caution is used when a hazard exists that can or could cause minor injury to self or others
if instructions are ignored. They include for example:
• Loss of critical patient data
• Crush or pinch points
•Sharpobjects
DANGER
EXCESSIVE
VOLTAGE
CRUSH
POINT
DANGER IS USED WHEN A HAZARD EXISTS THAT WILL CAUSE SEVERE
PERSONAL INJURY OR DEATH IF INSTRUCTIONS ARE IGNORED. THEY
CAN INCLUDE:
• ELECTROCUTION
• CRUSHING
• RADIATION
WARNING
ROTATING
EQUIPMENT
BARE WIRES
WARNING IS USED WHEN A HAZARD EXISTS WHICH COULD OR CAN CAUSE SERIOUS
PERSONAL INJURY OR DEATH IF INSTRUCTIONS ARE IGNORED. THEY CAN INCLUDE:
• Potential for shock
• Exposed wires
• Failure to Tag and lockout system power could allow for un-command motion.
NOTICE
Equipment
Damage
Possible
Notice is used when a hazard is present that can cause property damage but has absolutely
no personal injury risk.They can include:
• Disk drive will crash
• Internal mechanical damage, such as to the x-ray tube
• Coasting the rotor through resonance.
It’s important that the reader not ignore hazard statements in this document.

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1.2.2 Standard Hazard Icons
Several different graphical icons (symbols) are used to make you aware of specific types of hazards
that could possibly cause harm.
Some others make you aware of specific procedures that should be followed.
1.2.3 Lockout / Tagout (LOTO)
NOTICE
Equipment
must be locked
out during
servicing and
parts
replacement
All energy sources for equipment on which work will be performed and on which injury could occur
due to unexpected energization, startup or release of stored energy shall be deactivated. This
includes opening electrical circuits, closing and bleeding pressurized hydraulics and pneumatics,
blocking springs or counterweights and discharging capacitors (for example).
1. LOTO indicates that the energy source is Locked Out and that an Authorized Employee is
actively working on the machine, equipment, process, or circuit. LOTO is limited to one shift or
the amount of time the person is actively working on the system. If the job is not finished and
the system is not ready to be put back in use, the authorized person shall apply the Transition
LOTO or the Out of Service LOTO, whichever is appropriate for the situation.
2. When applying LOTO the following six step process (which is described in detail in the training)
must be followed:
a. Prepare for shutdown.
b. Shutdown machine or equipment.
c. Isolate machine or equipment.
d. Apply lockout and tagout device.
e. Isolate stored energy.
ELECTRICAL MECHANICAL RADIATION
LASER HEAT PINCH
AVOID STATIC
ELECTRICITY
TAG AND LOCK OUT WEAR EYE
PROTECTION
LASER
LIGHT
Signed Date
TAG
&
LOCKOUT
EYE
PROTECTION

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f. Verify Isolation
3. Temporary removal of LOTO and re-energization of a machine or equipment may be
performed when power is needed for testing or positioning. When testing you must:
a. Ensure the machine is operationally intact.
b. Notify all Authorized or Affected Employees who are working on the equipment or are in
the area that the equipment is going to be tested and to move to a safe area.
c. Verify controls are in the "off" position.
d. Remove LOTO Locks and tags.
e. Energize and proceed with testing.
f. After testing, de-energize, verify system isolation, and re-apply LOTO Locks and Tags.
4. When removing Lockout/Tagout the following steps must be followed:
a. Communicate to all Affected Employees.
b. Verify the safety of the area.
c. Ensure the safety devices and guards are in place.
d. Return system functions.
e. Remove your lock and tag.
f. Communicate system re-energization.
g. Re-energize and test equipment.
1.2.4 Certified Electrical Contractor Statement
All electrical Installations that are preliminary to positioning of the equipment at the site prepared
for the equipment shall be performed by licensed electrical contractors. In addition, electrical feeds
into the Power Distribution Unit shall be performed by licensed electrical contractors. Other
connections between pieces of electrical equipment, calibrations and testing shall be performed by
qualified GE Medical personnel. The products involved (and the accompanying electrical
installations) are highly sophisticated, and special engineering competence is required. In
performing all electrical work on these products, GE will use its own specially trained field
engineers. All of GE’s electrical work on these products will comply with the requirements of the
applicable electrical codes. The purchaser of GE equipment shall only utilize qualified personnel
(i.e., GE’s field engineers, personnel of third-party service companies with equivalent training, or
licensed electricians) to perform electrical servicing on the equipment.
1.2.5 Important... X-Ray Protection
CAUTION X-ray equipment if not properly used may cause injury. Accordingly, the instructions herein should
be thoroughly read and understood by everyone who will use the equipment before you attempt to
place this equipment in operation. The General Electric Company, Medical Systems Group, will be
glad to assist and cooperate in placing this equipment in use.
Although this apparatus incorporates a high degree of protection against x-radiation other than the
useful beam, no practical design of equipment can provide complete protection. Nor can any
practical design compel the operator to take adequate precautions to prevent the possibility of any
persons carelessly exposing themselves or others to radiation.
It is important that anyone having anything to do with x-radiation be properly trained and fully
acquainted with the recommendations of the National Council on Radiation Protection and
Measurements as published in NCRP Reports available from NCRP Publications, 7910 Woodmont

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Avenue, Room 1016, Bethesda, Maryland 20814, and of the International Commission on
Radiation Protection, and take adequate steps to protect against injury.
The equipment is sold with the understanding that the General Electric Company, Medical Systems
Group, its agents, and representatives have no responsibility for injury or damage which may result
from improper use of the equipment.
Various protective materials and devices are available. It is urged that such materials or
devices be used.
1.2.6 Live Animal Handling Prohibition
Live animal handling for installation, testing, or service of equipment
is NOT permissible. Live animal handling must remain in control of
the customer.
Section 1.3
Publication Conventions
1.3.1 General Paragraph and Character Styles
Prefixes are used to highlight important non-safety related information. Paragraph prefixes (such
as Purpose, Example, Comment and Note) are used to identify important but non-safety related
information. Text styles are also applied to text within each paragraph modified by the specific
prefix.
EXAMPLES OF PREFIXES USED FOR GENERAL INFORMATION
Purpose: Introduces and provides meaning as to the information contained within the
chapter, section or subsection, such as used at the beginning this chapter for example.
Note: Conveys information that should be considered important to the reader.
Example: Used to make the reader aware that the paragraph(s) that follow are examples of information
possibly stated previously.
Comment: Represents “additional” information that may or may not be relevant.

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1.3.2 General Installation Safety Measures
GENERAL RULES
• Only qualified service personnel with proper training can perform installation and servicing.
• Personal Protection Equipment (PPE) is required and must be worn (safety glasses, gloves,
proper shoes, etc.).
• Follow the Lockout/Tagout safety procedures.
• All fasteners must be tightened according to their torque specification.
• Dispose of the wastes from the installation properly.
• Push any one of the Emergency Stop button during an emergency.
• Report any existing or potential safety issues to GE Healthcare.
• Handling of live animals during servicing is prohibited.
1.3.3 Omissions, Errors & Suggested Improvements
Contacting GE Healthcare:
Toll Free: 1-800-526-3593
Email: PCIServiceEngin[email protected]
Mail: GE Healthcare
1-1510 Woodcock Street
London, ON
Canada N6H 5S1

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Chapter 2
Theory & Components
Section 2.1
Basic Concepts
This section describes the basic components of the x-ray assembly, and explains how they work
together to produce a projection. It describes some concepts that will help you to understand the
choices that are available to you when you set up and perform a scan.
2.1.1 Parts of a CT Scanner
The tube emits x-rays. The current affects the intensity of the x-ray beam, and the voltage affects
the peak of the x-ray energy spectrum of the beam and the distribution of x-rays across energies.
If the x-ray beam were light, the current would affect the brightness of the light, and the voltage
would affect the color.
The filter controls the energy spectrum of the x-rays. The metal filters in the micro CT scanner are
like the colored filters used in cameras which block certain components of white light. When the x-
ray beam passes through it, the filter preferentially blocks lower-energy x-rays from the beam,
allowing a more uniform beam to pass through.
The shutter controls the length of time of each exposure. The shutter in the Micro CT assembly
has the same function as the shutter on a camera. In a camera, the shutter interval determines how
long the film is exposed to the light, and a correct shutter interval prevents the film from becoming
over-or under-exposed. In the eXplore Micro CT scanner, the shutter interval determines how long
the detector is exposed to the x-ray beam in each interval of data acquisition.
The specimen is the object that is being imaged. In a film camera, light bounces off the object,
comes through the aperture, and exposes the film to create an image. In a micro CT scanner, the
x-rays come out of the x-ray tube, go through the object, and act on the scintillator to create a
radiographic projection, which is a map of the beam attenuation properties of different areas of the
object. The projection is recorded by the camera.
The detector is like the film in a camera. The eXplore Micro CT system’s detector has two
components, a scintillator and a CCD camera, which are connected with fiber optics. The scintillator
is a thin screen of cesium iodide, which luminesces when exposed to x-rays. The camera behind it
records the image that is projected onto the scintillator. The projection is saved in digital format.

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2.1.2 Definitions of Basic Concepts
The following sections describe some basic concepts related to creating a projection of a specimen
using x-rays.
ATTENUATION
The attenuation coefficient can be understood as the x-ray stopping power of an object.
When x-rays pass through an object, the object attenuates the beam. This means that the beam of
x-rays is reduced in intensity as individual photons are absorbed or scattered by the object.The
process is similar to the way that light passes through a translucent object. If light is shone through
glass, most of the light comes through to the other side. Very little is absorbed or scattered by glass.
If light is shone through thick fabric, only a small amount of light will come through. The rest will be
reflected back, absorbed, or scattered.
Different materials have different attenuation properties. Bone, a dense material, has a high
attenuation coefficient. X-rays will lose a great deal of intensity when they pass through bone. Fat,
a low density material, has a low attenuation coefficient. X-rays will not lose much intensity when
they pass through fat.
Attenuation varies directly with the atomic weight of the substance being subjected to x-rays. The
atomic weight is generally related to material density.
SCATTER
In the eXplore Micro CT scanner, the x-ray beam does not travel through a vacuum, devoid of any
matter except the specimen. Both the air in the scanner and any water in the specimen vial are in
the path of the x-ray beam.
The x-ray beam, the specimen, and the medium surrounding the specimen all consist of particles.
These particles interact in a manner similar to billiard balls on a table. The x-ray particles are moving
in a straight line, and the object particles fixed in position. When the x-rays go towards the object,
some of the x-ray particles miss and pass through empty space, some of them hit object particles
and are deflected slightly, and some of them hit object particles and bounce back. The x-ray
particles that pass through are detected. The particles that hit and are deflected are also detected,
but they are a form of noise that we call scatter.
Every micro CT projection contains a small amount of scatter noise.