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VersaPulse
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Select™
SERVICE MANUAL
0621-499-01
DEC. 95
This service manual is to be used in conjunction with the operator manual for the product. The
operator manual contains important information regarding instrument description, location of
controls, specifications, and normal operating procedures.
VISIBLE AND INVISIBLE LASER RADIATION.
AVOID EYE OR SKIN EXPOSURE TO
DIRECT OR SCATTERED RADIATION.
CLASS IV LASER PRODUCT
DANGER
HOLMIUM:YAG LASER: 2.1 MICROMETERS
MAX OUTPUT 5 JOULES 250 µs PULSE
Nd:YAG LASER: 1.06 MICROMETERS
MAX. OUTPUT 2 JOULE 350 µs PULSE
DIODE LASER: 650 NANOMETERS
MAX OUTPUT 5 MILLIWATTS
2400 Condensa Street
Santa Clara, CA 95051
(408) 764-3000
VISIBLE AND INVISIBLE LASER RADIATION.
AVOID EYE OR SKIN EXPOSURE TO
DIRECT OR SCATTERED RADIATION.
CLASS IV LASER PRODUCT
DANGER
HOLMIUM:YAG LASER: 2.1 MICROMETERS
MAX OUTPUT 5 JOULES 250 µs PULSE
DIODE LASER: 650 NANOMETERS
MAX OUTPUT 5 MILLIWATTS
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This manual is copyrighted with all rights reserved. Under the copyright laws, this manual cannot be copied
in whole or part without the express written permission of Coherent, Inc. Permitted copies must carry the
same proprietary and copyright notices as were affixed to the original.
Please note that while every effort has been made to ensure that the data given is accurate, the information,
figures, illustrations, tables, specifications, and schematics are subject to change without notice.
Coherent and the Coherent Logo are registered trademarks of Coherent, Inc.
Please direct all inquiries about this manual to:
Coherent, Inc.
Technical Support B-35
2400 Condensa Street
Santa Clara, CA 95051
(408) 764-3638
© Coherent, Inc 01/94, 07/94, 08/95, 10/95, 12/95
0621-499-01
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VersaPulse Select Service Manual Disclaimer 0621-499-01 12/95
DISCLAIMER
Coherent service manuals are written specifically for use by Coherent service engineers who have received
formal training in the servicing of Coherent equipment, and by customers who have taken and passed a
Coherent certification service training course for the equipment being serviced. Information on certification
service training courses offered to customers can be obtained by contacting the Technical Training Coordina-
tor at 800-367-7899.
Coherent does not accept responsibility for personal injury or property damage resulting from the servicing
of Coherent equipment by its customers or by third parties, except where such injury or property damage is a
direct result of Coherent's negligence. Customers, by accepting the service manual, agree to indemnify
Coherent against any claims alleging personal injury or property damage resulting from the servicing of
Coherent equipment by the customer or by third parties, except where such injury or property damage is a
direct result of Coherent's negligence. These limitations include situations where Coherent personnel are
advising customers on the repair of Coherent equipment over the telephone.
The servicing of Coherent equipment by persons who have not passed a current Coherent certification
service training course for that equipment will void Coherent's product warranty.
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VersaPulse Select Service Manual Revision Information 0621-499-01 12/95
REVISION INFORMATION
This is the DEC '95 release of the Versapulse Select Service Manual. Contact Coherent Medical Group Techni-
cal Support to determine if this is the most current release of this service manual.
Each page of this manual has a MM/YY date at the bottom. This indicates the release date for the individual
page. Note that when the manual is updated, not all of the pages are necessarily updated, so some pages
may have a MM/YY earlier than the release date for the manual (the release date for the manual is the MM/
YY that appears on the cover and in the first sentence of this revision information page). The following list
provides a complete list of the release date information, by section, for this release of the service manual.
Cover page, copyright page, disclaimer page, this page, table of contents page or pages are all dated with the
release date of the manual (12/95).
SECTION 1 Pages 1-1, 01/94
Pages 1-2, 12/95
SECTION 2 Pages 2-1,4,6 12/95. All other pages 03/94.
SECTION 3 Pages 3-1 thru 3-10 12/95. All other pages, 03/94.
SECTION 4 Pages 4-4 Thru 4-17, 4-22 Thru 4-30, 12/95.
All other pages, 01/94
SECTION 5 All pages, 12/95
SECTION 6 All pages, 12/95
SECTION 7 FSB's released for this service manual are listed in the Versapulse Select FSB
Index. Each time an FSB for this manual is released or updated the Index is
also updated and distributed with the FSB. The current Index is placed
behind the single sheet that makes up Section 7, and the FSB's are placed in
order behind the Index. Contact Coherent Medical Group Technical Support
for the date of the most current FSB Index.
SECTION 8 Page 8-1,12, 10/95
Pages 8-2 thru 8-11, 8-13 thru 8-18, 01/94
Pages 8-19 thru 8-30, 08/95
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Table Of Contents
DISCLAIMER .................................................................................................................................................. 3
REVISION INFORMATION ........................................................................................................................ 4
1.0 GENERAL INFORMATION ............................................................................................................... 1
1.1 USE OF THIS MANUAL .......................................................................................................................1
1.2 CONVENTIONS USED IN THIS MANUAL.......................................................................................1
1.3 SERIAL NUMBERS ...............................................................................................................................2
2.0 INSTALLATION .................................................................................................................................... 1
2.1 INSTALLATION INSTRUCTIONS......................................................................................................1
3.0 CALIBRATION & ADJUSTMENT .................................................................................................... 1
3.1 OVERVIEW............................................................................................................................................1
3.1.1 Safety Precautions ..................................................................................................................................1
3.2 System Check Out ..................................................................................................................................2
3.3 Energy Monitor and Automatic Laser Calibration ..............................................................................5
3.4.1 Making Test Burns .................................................................................................................................. 7
3.4.2 Adjusting the YAG Channel Optics ....................................................................................................... 7
3.4.3 YAG Channel Check Out and Adjustment Procedure......................................................................... 8
3.5 AIMING BEAM ADJUSTMENT ........................................................................................................ 10
3.6 PERIODIC MAINTENANCE REQUIREMENTS............................................................................13
4.0 THEORY OF OPERATION .................................................................................................................. 1
4.1 INTRODUCTION ...................................................................................................................................1
4.1.1 Operational Overview ............................................................................................................................. 1
4.1.2 Functional Overview ...............................................................................................................................2
4.2 POWER SWITCHING, CONDITIONING, DISTRIBUTION ..........................................................5
4.2.1 Input Power..............................................................................................................................................5
4.2.2 Circuit Breaker on, Keyswitch off .........................................................................................................5
4.2.3 Turn on .....................................................................................................................................................5
4.2.4 Shutdown..................................................................................................................................................6
4.2.5 Low Voltage Power Supplies................................................................................................................... 6
4.3 COOLING................................................................................................................................................ 7
4.4 CONTROL ELECTRONICS .................................................................................................................9
4.4.1 Overview...................................................................................................................................................9
4.4.2 Main Processor ......................................................................................................................................10
4.4.3 Shutter / Footswitch / Remote Interlock Circuits............................................................................... 11
4.4.4 Servo Motor Control Circuit ................................................................................................................ 13
4.4.5 HVPS & PFN Control Circuits ............................................................................................................14
4.4.6 Energy Monitor Circuits.......................................................................................................................17
4.4.7 Touch Screen & Remote Control Circuits...........................................................................................18
4.4.8 Aiming Diode Laser Circuit..................................................................................................................20
4.4.9 Fiber and Blast Shield Position Sense Circuits ...................................................................................21
4.4.10 Service Attenuator Circuit .................................................................................................................. 22
4.4.11 Coolant Temperature and Conductivity Monitoring Circuits......................................................... 23
4.4.12 Low Energy Attenuator Circuit .........................................................................................................24
4.4.13 DC Power Supply Voltage Monitoring Circuits.................................................................................24
4.4.14 Safety Processor....................................................................................................................................25
4.5 FLASH LAMP POWER CIRCUITS..................................................................................................27
4.6 OPTICS .................................................................................................................................................27
4.7 SOFTWARE.......................................................................................................................................... 29
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5.0 TROUBLESHOOTING ........................................................................................................................ 1
5.1 OVERVIEW.............................................................................................................................................1
5.1.1 Service Philosophy.................................................................................................................................. 1
5.1.2 Safety Precautions ..................................................................................................................................2
5.2 INTERIOR ACCESS & PART LOCATIONS .....................................................................................3
5.3 SERVICE MODE .................................................................................................................................12
5.4 FAULT ISOLATION............................................................................................................................14
5.4.1 TURN-ON AND SHUTDOWN FAULT ISOLATION ......................................................................15
5.4.2 "NO FAULT CODE REPORTED" FAULT ISOLATION ...............................................................15
5.4.3 "FAULT CODE REPORTED" FAULT ISOLATION .....................................................................15
6.0 SELECTED PARTS ................................................................................................................................ 1
8.0 SCHEMATICS AND DRAWINGS .................................................................................................... 1
VersaPulse Select Service Manual
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GENERAL INFORMATION
1-1
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1.0 GENERAL INFORMATION
1.1 USE OF THIS MANUAL
This manual contains service instructions for the Coherent VersaPulse Select series of Holmium:YAG surgical
lasers. The content of this manual is intended solely for use by Coherent Medical Group Field Service Engineers
and Coherent trained and certified customer technicians. Coherent, Inc. can not be responsible for service or
repairs attempted by uncertified persons, and the use of this manual by such persons is prohibited.
This manual is to be in conjunction with the Coherent Operator Manual for the VersaPulse Select. The operator
manual contains important information regarding instrument description, location of controls, specifications,
and normal operating procedures.
As necessary, Coherent Medical Group Service Technical Support releases Field Service Bulletins for the
Versapulse Select series. These bulletins supplement the information in this manual. As they are released, the
bulletins become a part of this manual (Section 7).
1.2 CONVENTIONS USED IN THIS MANUAL
Within the text, logic signals that are active low ("notted") will appear inside of slash marks, as illustrated below.
/BRHOK/
These signals are "active", or true, when the logic level is low. When the logic signal /BRHOK/ is low, the BRH
loop is "OK" (complete). When the logic signal /BRHOK/ is high, the BRH loop is not OK (open).
In most of the schematic diagrams such signals are indicated by the more usual solid line above the signal name,
as illustrated below.
The schematics in this manual do not include individual numbers for the logic elements or operational amplifiers
within a single component. For example, U1 below contains two operational amplifiers. The top op amp would
be referred to as U1-1 ( its output is pin 1), and the other would be referred to as U1-7.
BRHOK
GENERAL INFORMATION
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U1
2
3
1
U1
6
5
7
1.3 SERIAL NUMBERS
Serial numbers for the Versapulse Select are in the format,
MYPHWVXXXX
where M is the month produced
(a is January, b is February, etc..)
Y is the last digit of the year produced
(4 is 1994., etc..)
P is a number indicating maximum system power
(6=60w, 4=45w, 3=30w)
H is the number of laser heads installed (1, 2, 3, or 4)
W is a number indicating the mix of rods installed
(See Below)
V is a number indicating power supply configuration
(1= 208VAC single phase)
XXXX is the number of the laser built
(0001, 0002, etc..)
W: 1= Holmium only
2= Erbium only
3= Nd:Yag only
5= Nd/Ho combo
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2.0 INSTALLATION
2.1 INSTALLATION INSTRUCTIONS
These installation instructions are provided for use by Coherent Service Engineers who have completed
certification service training on the VersaPulse Select. Installation by untrained persons is a potential hazard
to the person or persons doing the installation, others present, and to the equipment itself. In addition,
improper installation is a potential hazard to the user, persons present during use, and patient.
Perform the following steps to install a VersaPulse Select system.
1. Check for proper site set up. This includes proper AC service and adequate space for the console.
AC power configuration: The VersaPulse Select requires 220 VAC ±10%, 50/60 Hz, 30 amp single
phase electrical service. The power cord is a 26 foot cable with 3 conductors. A terminal board
behind the right side cover allows for tapping of the isolation transformer to the setting closest to the
incoming electrical service. The system can be hard wired to electrical service or installed to electrical
service with a plug and receptacle. The plug and receptacle are shipped in the site preparation kit.
Console dimensions and weight: The console measures 39" l x 18" w x39" h. It weighs approximately
325 lbs. A minimum of 18" of air space is required around the unit to provide adequate cooling air
circulation.
The system requires approximately 2.5 gallons of deionized water for its closed loop cooling system.
The coolant must be added as described in this procedure.
Complete specifications for the VersaPulse Select are included in the VersaPulse Select Operator
Manual. Contact Technical Support in Palo Alto, CA, if there are any questions concerning site
preparation.
2.) Check the crate/carton for any shipping damage.
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LIFTING BAR (2)
Rear lifting bolts
(2, 5/8ths)
Front lifting bolts
(2, 3/4ths)
As the bolts turn, the lifting bar is raised or lowered. The system
ships with the lifting bar up. The bar must be lowered and removed,
then the system is rolled down the wooden ramps to remve it from
the crate base.
Removable
wooden ramp (2)
FIGURE 2.1 SHIPPING CRATE
Accessories
CARDBOARD SIDE COVER
CARDBOARD TOP COVER
STRAP
STRAP
WOODEN
BASE
FOAM
WOODEN RAMPS
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The shipper is responsible for any damage to the system in shipment. If the crate/carton appears to
be damaged, report the damage to the customer and shipper.
3.) Remove the console and accessories from the crate.
Refer to drawing 2-1. Remove the straps, remove the top cover, remove the side cover, remove the
protective foam, remove the accessories box, then locate and remove the two wooden ramps stored in
the base. Lower the lift plates (2) by turning the bolt at each end of each lift plate (5/8" and 3/4"
bolts). Loosen the bolts all the way, then remove the bolts and lift plate. Remove the front fence from
the base by removing the four wing nuts that secure it to the base. Install the ramps onto the base,
then roll the unit down the ramps.
4.) Move the system to its installation location.
The VersaPulse Select rolls best when pushed from the front handles. The front wheels swivel, the
rears wheels do not.
6.) Open/remove covers and do a visual inspection of the interior.
Refer to Section 5 for information on removing the covers. Open the front cover, then remove the top
and two side covers. Inspect the interior carefully for loose or broken electrical connections, loose or
broken plumbing connections, or any indication of shipping damage.
7.) Set up for site AC.
Measure the voltage of the site electrical service at the point where the VersaPulse Select will be
connected. The three connections include an earth ground and two hot mains. Measure line voltage
across the two hot mains. Mains voltage must be between 200 and 240 VAC, 50/60 Hz. Confirm that
the circuit is rated for 30 amps.
The isolation transformer has two secondaries: one operates the turn-on circuitry and the other
provides AC to the low voltage power supply, display power supply, fan and pump. These
secondary loads (not the turn-on circuitry) are rated for 220 VAC supply input. The isolation
transformer is tapped to allow a range of AC line inputs ( 200 to 240 VAC) to be stepped up or down
to result in a secondary voltage at or near 220 VAC to these secondary loads. The various taps on the
isolation transformer are wired out to terminal board TB1 on the right side on the system. The
tapping is done by changing the connections at the terminal board.
ISOLATION
XFORMER
(primary)
MAINS ( from F2)
120
100
120
100
MAINS (from F1)
POWER CORD
TB1
MAINS TO CIRCUIT BREAKER
EARTH GROUND TO
GROUNDING STUD
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FIGURE 2-2 TB1 TAPPING
INSTALLATION
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8.) Connect to AC service.
CAUTION: Once connected to site electrical service lethal voltages are present inside the unit. The
AC power is present at the circuit breaker, main contactor and isolation transformer. In addition, the
isolation transformer secondary outputs are hot. Review and understand the safety subtopic in
Section 5 before proceeding.
The system can be hard wired to electrical service, but is more typically connected by a plug to an
electrical outlet.
If the system is to be hard wired, the customer must provide an electrician to wire the cord end into
the electrical service outlet.
If the system is to be plugged into an electrical receptacle, the appropriate receptacle should already
be installed by the customer's electrician. The installing engineer connects the plug to the end of the
VersaPulse Select electrical cable.
9.) Add coolant.
Add coolant (deionized water) to the fill reservoir. The coolant will drain out of the fill reservoir and
into the main reservoir. The system uses approximately 2.5 gallons of coolant. Most of the coolant
can be added at this time - until the fill reservoir level stays up. The system coolant level will be
"topped off" after the system is turned on (in a later step).
9.) Initial power application.
CAUTION: Once the circuit breaker is turned on lethal voltages are present throughout the system.
With the side covers still removed, turn on the electrical service and turn on the circuit breaker on the
VersaPulse Select. Wait a few minutes, observing for any indication of failure of mains or turn-on
components.
10.) Initial turn on.
CAUTION:
• The system will fire during the turn-on sequence if SW3 (Autocal) on the CPU PCB is up
and the BRH plug is installed. Only those persons required should be present during this
portion of the installation
• The cooling fan blades are not covered. The fan is located on top of the heat exchanger. It
operates whenever the system is turned on. Keep tools, system parts and body parts clear of
the fan blades.
Turn the keyswitch to the START position, then release it to the ON position. The system will go
through its start up sequence. Observe for normal start up, and for any indication of leaks in the
cooling system.
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11.) Add coolant.
With the system turned on, top off the fill reservoir. Cycle the machine off and on several times,
adding coolant as necessary until the fill reservoir level stays up to approximately half full as the
system runs.
12.) Operational and Safety Checkout.
Attach a test fiber, remote interlock plug, and footswitch, then check system operation as follows:
a.) Footswitch, remote control (if included) and remote interlock plugs connect properly to jacks.
b.) Fiber attaches to the fiber port.
c.) Touch screen display matrix is operating properly.
d.) Touch screen inputs are functional.
e.) Remote control (if installed) display and input buttons are functional.
f.) Aiming beam responds to off, low, medium, and high settings.
CAUTION: The remaining operational tests include firing the system and attempts to fire the system
with one disabling condition. Select a low power setting and direct the test fiber output into a
calibrated power meter.
g.) Fire into the meter for several seconds, noting the power reading on the meter.
i.) Confirm that the total energy display value has incremented, then confirm that the value clears
back to zero when RESET is touched.
j.) Disconnect the footswitch and confirm that the "ATTACH FOOTSWITCH" message appears on the
display.
k.) Reconnect the footswitch, then disconnect the fiber and confirm that an "ATTACH FIBER"
message appears on the display. Depress the footswitch and confirm the system will not fire.
l.) Reconnect the fiber, then disconnect the remote interlock plug and confirm the " REMOTE
INTERLOCK" message appears on the display.
m.) Reconnect the remote interlock plug, then go to STANDBY. Depress the footswitch and confirm
the system will not fire.
n.) Pull the blast shield out, then confirm the "REPLACE BLAST SHIELD" message appears on the
display. Depress the footswitch and confirm the system will not fire.
o.) Reinsert the blast shield.
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13.) Confirm the power calibration.
Connect a good test fiber onto the fiber port and direct the fiber output towards the head of your
calibrated power meter, then, for each operating point, fire the system into the meter, confirming that
displayed power remains within ± 10% of the power indicated on the meter (typically, the power
calibration will be much more accurate than ±10%). If the power calibration is not better than ±10% at
all operating points, refer to Section 3 for instructions on system calibration.
14.) Check the fiber focus using a test fiber.
Two test fibers are shipped with the system. Check the fiber focus as described in Section 3, topic 3.2,
step 3.
15.) Replace all covers and prepare the system for demonstration to the customer.
16.) Demonstrate the system installation to the customer.
17.) (for U.S. Field Service) Fill out and mail the "self mailer" installation quality audit report.
CAL & ADJUST
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3.0 CALIBRATION & ADJUSTMENT
3.1 OVERVIEW
This section includes a System Checkout Procedure, Energy Monitor Calibration Procedure, a YAG Channel
Adjustment Procedure and an Aiming Beam Adjustment Procedure. The procedures assume the reader has
successfully completed a Coherent service training course on the Versapulse Select series.
The System Check Out, Topic 3.2, is an operational check of the system. It confirms that the system turns on
properly, responds properly to operator inputs, provides the full range of pulse energies and pulse rates, delivers
average power within ±10% of the displayed average power, delivers the multiplexed YAG beam into the center
on an attached fiber, and provides an adjustable aiming beam through the fiber. It also checks system coolant level
and consumables (i.e., air filter, DI filter and particulate filter).
The Energy Monitor Calibration Procedure, Topic 3.3, calibrates the voltage output of the three energy monitor
circuits to the field service engineer's calibrated power meter.
The YAG Channel Adjustment Procedure, Topic 3.4, is done when the System Check Out Procedure indicates
a problem with one or more of the YAG channels. It provides adjustment procedures for the channel cavities and
relay optics.
Aiming Beam Adjustment, Topic 3.5, provides information on adjusting the aiming beam optics to get the aiming
beam out through the fiber. See Section 6 for required tools.
3.1.1 Safety Precautions
Lethal voltages and laser emission are the primary dangers to the servicing engineer. In addition to the general
safety precautions which always apply when working on electronics and lasers, the servicing engineer must be
aware of the following specific precautions:
Only Coherent certified VersaPulse Select Service Engineers should attempt any service on this
system.
Even with the keyswitch and the breaker in the "OFF" position there are potentially lethal voltages
present inside the console. Always disconnect the main electrical service before working on the
console.
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Storage capacitors inside the system are capable of holding a lethal charge, even after power has
been removed from the unit. A charge level indicator bulb located on the PFN PCB mounted across
the top of the main storage capacitor flashes at a rate proportional to the level of charge on the main
charging capacitor. Do not rely on this indicator to determine that the main charging capacitor has
been discharged. Before contacting the main charging capacitor, disconnect the system from primary
power and use a shorting probe to discharge the capacitor to ground.
Do not touch the YAG Cavity Module when the system is on - IT IS A SHOCK HAZARD. The
YAG Cavity Module is electrically isolated from the chassis and can be at a voltage potential much
higher than ground.
Whenever the footswitch is pressed a single pulse is fired immediately, before the shutter opens,
to dump any charge remaining on the charge capacitor. The laser cavity that fires is the one directly
opposite the one that the servo mirror is pointing towards. The energy is dependent upon how much
charge remains on the capacitor. Since the relay mirror is not directed towards the channel, the beam
will be directed away from the first turning mirror (usually towards the mounting screws for the
plano mirrors on the OC wall.
The Ho:YAG, Er:YAG and Nd:YAG laser light is invisible to the human eye. Because the YAG
laser energy can not be seen, there is no visible indication of the primary or reflected beam. Eye
protection that attenuates the Ho:YAG, Nd:YAG and Er:YAG wavelengths to a safe level must be
worn by all persons in the area of the laser system, whenever the laser is being serviced.
The YAG laser light and its reflections are potential burn hazards and can ignite flammable
materials. Use extreme caution when operating the system with covers opened or removed. The
covers contain the beam and reflections safely within the console. Only those persons required
should be present during servicing, and eye protection that safely attenuates the Ho:YAG, Nd:YAG
and Er:YAG wavelengths must be worn by all present.
The Ho:YAG, Er:YAG and Nd:YAG laser light and its reflections are potential hazards to the eye.
Use extreme caution when operating the system with the covers opened or removed. The covers
contain the beam and reflections safely within the console. Only those persons required should be
present during servicing and eye protection that safely attenuates the Ho:YAG, Er:YAG and Nd:YAG
wavelengths should be worn by all those present.
3.2 SYSTEM CHECK OUT
This system check out confirms that the laser is functioning properly.
1.) Open the front door and defeat the door interlock, then turn the system on and allow it to go through
autocalibration. After autocalibration is completed, place the system in service mode.
If the system fails to pass autocalibration, there is something wrong; continue on to step 2 to gather
more information about why the system failed autocalibration.
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2. Check rod calibration values.
Go to the second service screen and note the cap voltage values displayed for each of the four
channels at minimum (low point) and maximum (high point).
The HVPS maximum output is 1500 VDC, so each rod must be capable of making its
maximum pulse energy (high point) at less than 1500 VDC. Typical values at high point are
from 1280 to the low 1400's. Typical voltages for low point are in the 700 to 900 VDC range.
For Nd:YAG the typical values at high point are from 500 to 800 VDC, and typical low point
values are from 200 to 400 VDC.
As the rod temperature increases (during use), its output will tend to drop off for a given cap
voltage. The software compensates for this effect, so as the rod temperature increases, it is
normal to see the cap charge voltage required at a particular pulse energy increase. Since the
system goes through its autocalibration at turn on, when the rods tend to be cooler, the cap
charge voltages found during autocal will tend to be lower than those that might be required
during sustained, high duty cycle operation. Thus, a channel with a cap charge voltage in the
mid to high 1400's @ 2.8 Joules at turn on may require a cap charge voltage higher than the
HVPS can provide to make 2.8 Joules during operation.
If the system has failed to complete autocalibration or channel performance appears poor, perform
the YAG Channel Adjustments (Topic 3.4).
3. Inspect debris shield and clean/replace as required.
4. Check the power supply voltages, coolant temperature and coolant conductivity.
5. Check the fiber focus using a test fiber.
If the system passes autocalibration and channel performance appears normal (service screen min/
max cap charge values are good), check for proper alignment of the beam into the fiber. This is done
using a special test fiber (0621-675-01). The fiber proximal end is coated with a red ink (Berol 8800
red marker) that records an impression of the YAG beam footprint where it enters the end of the
fiber. The laser is fired into the test fiber, then the fiber end is examined using a hand held 100X
microscope. A good alignment will result in a "concentric" footprint, i.e., the footprint will be
approximately centered in the fiber core and be well away from the cladding that surrounds the fiber.
a.) Install a test fiber in the 100X fiber examination microscope and examine its surface to confirm that
it is unused.
b.) Install the test fiber at the fiber port, then turn on the system and go to service mode.
c.) Turn on all the rods, select 850 cap volts and a pulse rate of 20 Hz.
d.) Fire the laser for approximately one second.
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e.) Remove the fiber and examine it in the microscope. The burn and cladding will be easily
visualized if the other end of the test fiber is pointed towards a light source. The burn should be
approximately centered in the fiber optic and be well away from contact with the fiber cladding, as
shown in the drawing below. If the system fails this check, perform the YAG Channel Adjustments
(Topic 3.4.).
* If spot size is large, check individual YAG channels for proper alignment. Spot size should be less
than 210 µm in diameter and no closer than 70 µm from the cladding.
6. Confirm the calibration
Once the system passes steps 1 through 3, attach an Infratome fiber (nonsterile fibers for service
purposes are available through Technical Support) to the fiber port and direct its output into a
calibrated power meter. Go to user mode and fire the system to confirm that the measured power (as
seen on the power meter) is within ±10% of displayed average power across the range of pulse
energies and pulse rates.
7. Check consumable parts. Replace as necessary.
Check/replace the air filter. The air filter is mounted on the bottom of the system, held in place by a
removable bracket. A dirty filter should be cleaned or replaced.
Replace the DI filter after 6 months of use, or when the system has coolant conductivity faults.
Check/replace the coolant particulate filter. Replace the filter when it is visibly discolored.
8. Perform functional and safety checks.
a.) Attach a fiber.
ACCEPTABLE
NOT ACCEPTABLE
NOT ACCEPTABLE
Examining the test fiber end with the 100x microscope - The footprint will not always be circular,
but it should be approximately centered in the fiber and away from contact with the cladding.
Cladding
Core
Footprint
FIGURE 3.1 EXAMINING THE TEST FIBER BURN
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b.) Confirm that the aiming beam is visible at the fiber output and that the aiming beam intensity
properly responds to touch screen intensity control.
c.) Place the system in STANDBY, then depress the footswitch. Confirm the system does not fire.
d.) Go to READY and fire the system a number of times, verifying that the system displays the
cumulative energy. Stop firing, then press "clear" and verify the counter returns to zero.
e.) Unplug the footswitch and verify the system goes to STANDBY and displays "Attach footswitch".
f.) Open the front door and verify the system shuts down. Defeat the interlock and confirm that the
system turns back on.
g.) Remove the fiber optic. Verify that the system goes to STANDBY and "Attach fiber" is displayed.
Replace the fiber optic and verify that the fault clears.
h.) Remove the blast shield. Verify that the system goes to STANDBY and "Install blast shield" is
displayed. Replace the fiber and confirm that the fault clears.
i.) Check the operation of the keyswitch. It should turn the system on, turn the system off, and only
be removable when the system is switched off.
j.) Confirm that the emergency off button shuts the system down.
3.3 ENERGY MONITOR AND AUTOMATIC LASER CALIBRATION
The energy monitor calibration adjusts the three energy monitor circuits to output 2.2 volts per Joule of energy
as measured on a calibrated power meter at the output of an attached fiber. The automatic laser calibration (also
referred to as "autocalibration" and "autocal") is run to allow the system to determine and store the capacitor
voltages required to provide the maximum and minimum pulse energies for each rod.
1. Set up.
Open the front door of the VersaPulse Select and defeat the door interlock. Connect a known good
test fiber to the fiber port and direct its output into a calibrated power meter. Connect an oscilloscope
probe to CPU PCB TP2 (ENERGYI).
2. Turn on the system and go to service mode.
3. Turn off three rods, leaving one on. Select 40 Hz, then go to READY.
4. Adjust the cap voltage for a fiber output of 10 watts (1 Holmium head).
Fire the laser into the power meter, adjusting cap voltage up/down to get 10 watts of average power
at the power meter. Once the charge voltage is set to provide a consistent power meter reading of 10
watts, stop firing and leave the cap charge at that setting.
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The system software has a 2.2 volts/Joule conversion factor written into it, so the energy monitor
circuit must be calibrated to output 2.2 volts for a 1 Joule pulse. With 40 Hz selected, but only one
rod on, the actual pulse rate will be 40/4 = 10 Hz. Since 1 Watt= 1 Joule/sec, 10 Watts = 10 Joules/
second,i.e. each pulse is 1 Joule.
5.) Calibrate ENERGY II.
Attach the scope probe to TP3.
Fire the laser, adjusting CPU PCB R8 to adjust the amplitude of the positive pulses on the oscilloscope
screen to approximately 2.22 volts (the pulse will be about 2 mseconds in width, with a relatively
"square" profile). Once the pulses are of the correct amplitude, release the footswitch.
6.) Calibrate ENERGY I
Move the probe to TP2, then adjust as in step 5 above, using CPU PCB R7.
7.) Calibrate ENERGY III
Move the probe to TP4, then adjust as in step 5 above, using CPU PCB R9.
8.) Turn all the rods back on, then confirm the calibration.
Turn the system back on (CPU PCB SW3 in its up position so the system will go through its
autocalibration), then fire the laser into the power meter across its range of operating points,
confirming that delivered power as measured by the power meter is always within ±10% of selected
power.
3.4 YAG CHANNEL ADJUSTMENTS
When properly adjusted the YAG channel will meet each of the following three criteria.
•␣The cavity HR will be positioned to direct the YAG output to the center of the first relay mirror, and
the cavity OC will be positioned to provide maximum power for that HR position.
• The first relay mirror and second (plano) relay mirror will direct the YAG energy off the two
folding mirrors so that it is centered through the wedge optic apertures and centered into the
proximal end of the fiber.
• Each YAG beam will be coaxial with the other YAG channels, confirmed at the second wedge optic
aperture and at the fiber port.
The adjustment procedure for a single channel follows. The procedure is a complete check out and alignment for
a single channel. The procedure is meant to be done in the order given, from beginning to end.
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