Tomey AL-2000 Biometer & Pachymeter Operator Manual

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OPERATOR MANUAL
AL-2000 Biometer &amp; Pachymeter
AL-2000 Biometer &amp; Pachymeter
WARNINGS
• Read this Operator Manual carefully before using this instru ment for proper and safe operation.
• Do not use procedures other than those specified in this
manual.
• Only well-trained personnel should operate the instrument.
• Keep the Operator Manual in a place where you can easily
access it when operating the instrument.
• For any questions about the instrument or the manual, contact your Tomey representative or local distributor.
• DO NOT REMOVE THE OUTER COVER of the
instrument. If you do, you may be subjected to
direct high voltage.
• ALWAYS use a clean probe for eye measurements
(see section 10.2.1).
• NEVER use the probe if there is any visible dam age to its tip. Such use may cause an incorrect
measurement and/or damage to the cornea.
• This instrument is designed exclusively for ophthalmic use. DO NOT use the instrument for any
other purpose.
• The controlling voltage, pulse repetition frequency and pulse duration of the ultrasound output
are fixed; they CANNOT be changed.
• DO NOT use cables or memory cards other than
those specified in the manual. Such connection
may result in damage to the instrument.
WARNINGS
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AL-2000 Biometer &amp; Pachymeter
SYMBOLS USED IN THIS MANUAL
The symbols used in this manual represent the following:
• This is a precaution that, if unheeded, will result in a hazardous
situation where there is an imminent danger of serious injury
or death.
• This is a precaution that, if unheeded, may cause a hazardous
situation where there is the possibility of serious injury or
death.
• This is a precaution that, if unheeded, may cause minor or
moderate injury or property damage.
• This is a special precaution that is related, either directly or
indirectly, to personal safety or to protection of property.
SYMBOLS
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AL-2000 Biometer &amp; Pachymeter
CONTENTS
1. PRIOR TO USE
1.1 Cautionary notes .............................................................................................1
1.2 Unpacking ........................................................................................................2
1.3 Outline of operation .......................................................................................3
1.4 Software version ...............................................................................................3
2. COMPONENTS .............................................................................................................5
2.1 Front and right side of AL-2000 ......................................................................5
2.2 Back and left side of AL-2000 .........................................................................6
3. SETUP ............................................................................................................................7
3.1 Safety precautions ...........................................................................................7
3.2 Preparing for use .............................................................................................7
3.2.1 Installation site .....................................................................................7
3.2.2 Connection of accessories ...................................................................8
a) Inserting the probe holder ............................................................8
b) Connecting the biometry probe ...................................................8
c) Connecting the pachymetry probe ...............................................8
d) Connecting the power cord ..........................................................8
e) Connecting the foot switch ..........................................................9
f) Inserting and removing of the memory card ................................9
3.2.3 Chin rest installation (AL-1100) ............................................................10
a) Installing the chin rest ...................................................................10
b) Connecting the fixation lamp power plug ....................................10
4. BIOMETRY (AXIAL LENGTH MEASUREMENT) ................................................................13
4.1 Biometry mode setup.......................................................................................11
4.1.1 Turning on the power and initial adjustments ....................................11
4.1.2 Description of windows ........................................................................12
a) Measurement window ...................................................................12
b) Measurement review window (1) ...................................................13
c) Measurement review window (2) ...................................................14
4.1.3 Setting the measurement conditions ...................................................15
a) Entry of patient name &amp; ID number and physician name .............15
b) Setting the eye to be measured....................................................15
c) Setting the eye type and converted velocity.................................16
d) Setting the gain .............................................................................17
e) Setting the measurement mode....................................................17
f)
Selecting the location of the retinal waveform .............................18
4.1.4 Checking the performance....................................................................18
4.2 Performing Biometry ........................................................................................19
4.2.1 Preparation for measurement ...............................................................19
4.2.2 Measurement methods .........................................................................19
a) Probe mode ...................................................................................20
b) Methods of performing measurements.........................................20
(1) Automatic measurements modes ...........................................20
(2) Manual measurement mode ...................................................20
4.2.3 Data review and selection for IOL calculation ......................................21
a) Displaying a waveform...................................................................21
b) Selecting data for IOL power calculation .......................................21
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AL-2000 Biometer &amp; Pachymeter
c) Deleting individual measurements.................................................22
4.2.4 Caliper function ....................................................................................22
4.2.5 Deleting data.........................................................................................23
a) Deleting data for one eye .............................................................23
b) Deleting data for both eyes .........................................................23
4.2.6 Storing data ..........................................................................................23
4.2.7 Acceptable waveforms ..........................................................................24
4.3 IOL Calculation .................................................................................................25
4.3.1 Changing to IOL power calculation mode ...........................................25
a) From the biometry mode ..............................................................25
b) From the Utility mode ..................................................................25
4.3.2 Description of IOL calculation windows ...............................................26
a) Entry of data and display of calculation results ............................26
b) Display of the IOL data list ...........................................................27
4.3.3 Setting the calculation conditions ........................................................27
a) Setting the eye to be calculated ..................................................27
b) Selecting the IOL formula .............................................................28
4.3.4 Data entry for IOL calculations ............................................................28
a) Axial length (Axial) .......................................................................28
b) Keratometry readings (K1 / K2) ...................................................28
c) Desired postoperative refraction (Desired Ref. ) .........................29
d) Lens constants (Aconst, SF, ACD) ...............................................29
e) Creating the IOL data list...............................................................30
4.3.5 IOL power calculation ...........................................................................30
a) Automatic calculation.....................................................................30
b) Registration of the model name of the IOL .................................30
c) Entering IOL power .......................................................................30
4.3.6 Storing patient data .............................................................................31
5. PACHYMETRY (CORNEAL THICKNESS MEASUREMENT)...............................................33
5.1 Pachymetry mode setup...................................................................................33
5.1.1 Turning on the power and initial adjustments ....................................33
5.1.2 Description of windows ........................................................................34
a) Map mode window ........................................................................34
b) Single mode window .....................................................................35
5.1.3 Setting the measurement conditions....................................................36
a) Entry of patient name &amp; ID number and physician name .............36
b) Setting the eye to be measured....................................................36
c) Setting converted velocity and bias mode ....................................37
d) Setting automatic vs. manual acquisition ......................................38
e) Setting measurement mode and map ...........................................38
f)
Setting the measurement range....................................................38
g) Setting the data display method ...................................................39
h) Setting the data presentation mode ............................................39
5.1.4 Checking the performance....................................................................40
5.2 Performing Pachymetry ....................................................................................40
5.2.1 Preparation for measurement ...............................................................40
5.2.2 Measurement methods ..........................................................................40
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AL-2000 Biometer &amp; Pachymeter
a) Automatic acquisition in map measurement mode ......................41
b) Automatic acquisition in single measurement mode ....................41
c) Manual measurement in map measurement mode .......................42
d) Manual measurement in single measurement mode ....................42
5.2.3 Deletion of measurement data .............................................................43
a) Partial deletion of data in single measurement mode ..................43
b) Deleting data for one eye ..............................................................43
c) Deleting data for both eyes ...........................................................43
5.2.4 Storing data ..........................................................................................44
6. PRINTING..........................................................................................................................45
6.1 Initiating printing ..............................................................................................45
6.2 Printout modes.................................................................................................45
6.3 Sample printouts ..............................................................................................46
6.3.1 Sample biometry printout .....................................................................46
6.3.2 Sample IOL power calculation printout ...............................................47
6.3.3 Sample IOL power calculation printout following biometry.................48
6.3.4 Sample printout using Personal/Corresponding SF values ..................50
6.3.5 Sample pachymetry printout - map mode............................................51
6.3.6 Sample pachymetry printout - single mode .........................................52
7. UTILITIES...........................................................................................................................53
7.1 Accessing the Utility window ...........................................................................53
7.1.1 From the biometry mode ......................................................................53
7.1.2 From the pachymetry mode ................................................................54
7.2 Description of Utility windows .........................................................................55
7.2.1 Utility window for biometry mode .......................................................55
7.2.2 Utility window for pachymetry mode ...................................................56
7.3 Utility setup for biometry and IOL power calculation......................................57
7.3.1 IOL data entry .......................................................................................57
7.3.2 IOL formula setup..................................................................................58
7.3.3 Personal lens constant calculation ........................................................59
7.3.4 Display and compilation of patient data...............................................60
a) Displaying axial length data...........................................................60
b) Compiling IOL data........................................................................61
c) Displaying personal lens constants ................................................62
d) Deleting patient data.....................................................................62
7.3.5 Biometry/IOL data management ..........................................................63
7.3.6 Contact/immersion probe mode selection ...........................................64
7.4 Utility setup for pachymetry.............................................................................65
7.4.1 Map construction ..................................................................................65
7.4.2 Data display selection ...........................................................................66
7.4.3 Patient data and corneal cross-section display.....................................67
7.5 Utility setup for general items..........................................................................69
7.5.1 Physicians data entry.............................................................................69
7.5.2 Date/time setup ....................................................................................70
7.5.5 RS-232C setup.......................................................................................71
a) Pin positions of RS-232C connection terminals .............................71
b) Setting the communication conditions..........................................72
c) Transmitting data............................................................................73
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AL-2000 Biometer &amp; Pachymeter
8.
9.
10.
11.
d) Receiving data ...............................................................................74
7.5.4 Sound setup ..........................................................................................75
7.5.5 Print mode selection .............................................................................76
MEMORY CARD ..............................................................................................................77
8.1 Memory card specifications..............................................................................77
8.2 Memory card capacity and maximum number of entries ................................77
8.3 Memory card battery........................................................................................77
8.3.1 Replacing the battery.............................................................................77
8.3.2 Battery life ..............................................................................................77
8.4 Formatting the memory card ...........................................................................78
8.5 Reading the memory card on a Windows computer.......................................79
8.5.1 Rewriting the Windows PC system configuration file............................79
8.5.2 PC data: location, filename and format .................................................79
8.5.3 Removing the memory card from the comptuer ...................................79
8.5.4 Handling memory card files ...................................................................79
TECHNICAL INFORMATION ..........................................................................................81
9.1 IOL calculation formulae ..................................................................................81
9.1.1 SRK/II ......................................................................................................81
9.1.2 SRK/T ......................................................................................................82
9.1.3 Holladay..................................................................................................84
9.1.4 Hoffer Q .................................................................................................86
9.1.5 Haigis standard.......................................................................................88
9.1.6 Haigis optimized.....................................................................................90
9.2 Ultrasound velocity used in axial length measurement ...................................91
9.2.1 Normal....................................................................................................91
9.2.2 Dense cataract........................................................................................91
9.2.3 Aphakic...................................................................................................91
9.2.4 Pseudophakic .........................................................................................91
9.3 Axial length calculation in eyes with silicone oil ..............................................92
9.2.1 Normal....................................................................................................92
9.2.2 Pseudophakic .........................................................................................92
MAINTENANCE...............................................................................................................93
10.1 Replacing fuses ...............................................................................................93
10.2 Routine maintenance .....................................................................................93
10.2.1 Maintenance of the probes ..................................................................93
a) Disinfecting the probes ..................................................................93
b) Cleaning the probe handle and cord .............................................94
10.2.2 Maintenance of the main unit ..............................................................94
10.3 Replacing the printer paper ...........................................................................94
10.4 Storage ...........................................................................................................95
10.5 Packing materials ...........................................................................................95
10.6 Warranty ..........................................................................................................95
TROUBLESHOOTING......................................................................................................97
11.1 General problems............................................................................................97
11.2 Biometry function ............................................................................................97
11.3 Pachymetry function........................................................................................98
11.4 Memory card ...................................................................................................99
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AL-2000 Biometer &amp; Pachymeter
12. SPARE AND OPTIONAL PARTS ......................................................................................101
12.1 Spare parts ......................................................................................................101
12.2 Optional parts .................................................................................................101
13. SPECIFICATIONS AND MISCELLEANEOUS INFORMATION .........................................103
13.1 Specifications ...................................................................................................103
13.1.1 Biometry/IOL power calculation ....................................................103
13.1.2 Pachymetry .....................................................................................104
13.1.3 Main unit ........................................................................................104
13.1.4 Power Supply .................................................................................104
13.2 Ultrasound energy ..........................................................................................105
13.2.1 Acoustic output reporting table ....................................................105
13.2.2 Acoustic output evaluation - Biometer ..........................................106
13.2.3 Acoustic output evaluation - Pachymeter.......................................107
13.3 Sounds generated by the AL-2000 .................................................................108
AUTHORIZED TOMEY SERVICE CENTERS ............................................................................109
CONTENTS
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AL-2000 Biometer &amp; Pachymeter
AL-2000 Biometer &amp; Pachymeter
1. PRIOR TO USE
• Read this Operator Manual carefully before using the instrument
in order to operate it properly and safely.
• Do not use any procedures that are not specified in the manual.
1.1 Cautionary Notes
• Only well-trained personnel should operate this instrument.
• When installing this instrument, observe the following:
-
-
-
Do not install the instrument in a place where it might be
exposed to moisture or chemicals.
Do not install the instrument in a place where it is subject to
adverse conditions, such as direct sunlight, high temperature,
excessive humidity, dust, sulfur or salt.
Ascertain that any adverse factors such as excessive slope,
vibration and impact will not endanger the instrument (including during transportation).
Do not install the instrument in or near the storage area of
chemical substances or where any gas may be generated.
Follow frequency, voltage and allowable current (or allowable
power consumption) specifications.
Be cautious of electrical power conditions such as discharge,
polarity, etc.
Ascertain that the power source is properly grounded.
• Before using this instrument, observe the following:
-
Ascertain that all cables and cords are properly connected.
Carefully inspect the probe tip before using.
• While using this instrument, observe the following:
-
-
Always make sure that the patient is comfortable.
If any complication or abnormality is encountered, either with
the patient or the instrument, ensure the safety of the patient
by discontinuing testing.
Make sure the patient has no contact with the instrument
(other than the probe) during testing.
• After using this instrument, observe the following:
-
Be sure to clean the probes after each use (see section
10.2.1).
1.1 Cautionary Notes
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AL-2000 Biometer &amp; Pachymeter
-
When disconnecting the power cord, hold the plug, not the
cord, and do not use excessive force.
If you do not plan to use the instrument for a considerable
period of time, refer to Section 10.4 for storage instructions.
• In case of a malfunction, do not attempt to repair the instrument
yourself. Place a sign on the instrument indicating that it is malfunctioning and contact your Tomey representative.
1.2 Unpacking
When unpacking the instrument, make sure that all of the components are present and that
none of them are visibly damaged. If any items are missing or damaged, contact your Tomey
representative.
• Be sure to keep the box and the packing material for use if the
instrument is moved to another location.
List of Components:
• Main unit
• Biometry probe
• Probe holder
• Foot switch
• Power cord
• Memory card
• Biometry test piece
• Printer paper
• Dust cover
• Fuses (2)
• Operator manual
Pachymetry Components:
• Pachymetry probe
• Pachymetry test piece
1.2 Unpacking
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AL-2000 Biometer &amp; Pachymeter
1.3 Outline of Operation
The AL-2000 is an ultrasound instrument designed for measuring the axial length of the eye and
the thickness of the cornea for medical ophthalmic use.
• Ultrasound energy is emitted from the probe tip. The probe acts as both the transmitter
and receiver of ultrasound energy.
• Some of the energy is reflected back toward the probe in the form of echoes. Measurement
data can be calculated based on the time it takes the echoes to travel back to the probe
from the eye and the preset converted velocity.
• The time from the echo for the corneal epithelium to the echo for a measuring object is
measured. The length of a biological object is calculated using a set conversion value for
the speed of sound.
L = V x t/2
where L = length of the biological object
V = converted sound speed
t = measuring time
• The axial length and corneal thickness measurement are acquired automatically and do not
depend on the operator's experience and capability.
• IOL power calculation can be performed immediately after measuring the axial length. Six
standard IOL formulae are provided.
• The instrument can store axial length, corneal curvature and implanted IOL data, on the
basis of which personal lens constants may be determined.
1.4 Software Version
The version of the installed software appears on the monitor when the instrument is turned on.
1.3 Outline of Operation
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AL-2000 Biometer &amp; Pachymeter
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AL-2000 Biometer &amp; Pachymeter
2. COMPONENTS
2.1 Front and right side of AL-2000
Printer
Prints measured data and calculated results
Printer Cover
Remove the cover in order to replace the
printer paper.
Power indicator
Lit when power is on.
Probe holders
When the probes are not in use, place
them in the holders.
The upper holder is for the pachymetry probe.
The lower holder is for the biometry
probe.
Terminal for Pachymetry Probe
The probe for corneal thickness
measurement is connected here.
Terminal for Biometry Probe
The probe for axial length measurement is connected here.
Memory card
Stores acquired data.
Biometry probe
Use for axial length measurement.
Footswitch
Depress to acquire data in the manual measurment mode
Screen (touch panel)
Measurement data and other information are
displayed on the screen. The instrument is
operated by touching the keys.
2.1 Front and right side of AL-2000
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AL-2000 Biometer &amp; Pachymeter
2.2 Back and left side of AL-2000
Power supply terminal for chin rest fixation light
The power plug for the fixation light for the chinrest (AL-1100) is inserted here.
Power switch
Press the “l” side of the switch to turn on
the power. Press the “O” side to turn if off.
Contrast adjuster
Controls the contrast of the
screen.
Footswitch Terminal
The footswitch is
connected here.
Tilt stand
Tilts the instrument to achieve better
visibility of the screen, if necessary.
Power supply terminal
The power cord is connected here.
RS-232C terminal
The RS-232C cable is connected
here.
Power cord with 3-prong plug
Connection of this cord to a 3-prong
power receptacle provides power to
the AL-2000.
2.2 Back and left side of AL-2000
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AL-2000 Biometer &amp; Pachymeter
3. SETUP
3.1 Safety precautions
• ALWAYS clean the probe tip before taking a measure ment on a human eye (see section 10.2.1).
• NEVER use the probe if there is any visible damage to
its tip. Such use may cause an incorrect measurement
and/or damage to the cornea.
• This instrument is designed exclusively for ophthalmic
use. DO NOT use the instrument for any purpose
other than ophthalmic use.
• DO NOT use any cables or memory cards other than
those specified in this manual. Such use may result in
damage to the instrument.
3.2 Preparing the instrument for use
3.2.1 Installation Site
• Ascertain that the power receptacle is electrically grounded and be sure to use
the 3-prong power cord provided.
• Do not install the instrument in a location where it might be exposed to moisture
or chemicals.
• Do not install the instrument in a place where it is subject to adverse conditions,
such as direct sunlight, high temperature, excessive humidity, dust, sulfur or salt.
• Ascertain that any adverse factors such as excessive slope, vibration and impact
will not endanger the instrument (including during transportation).
• Do not put anything on top of the instrument.
• Make sure that there is no equipment that generates a strong magnetic field near
the instrument.
Strong magnetism may cause interference and may result
in incorrect measurement.
3.1 Safety Precautions
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AL-2000 Biometer &amp; Pachymeter
3.2.2 Connection of accessories
a) Inserting the probe holder
1. Insert the protruding rectangular tabs (1)
on the probe holder into the holes (2) on
the right side of the instrument.
2. Push inward on the center of the probe
holder (3) and pull it downward to lock it
in place.
b) Connecting the biometry probe
Plug the biometry probe connector (1) into
the terminal (2) labeled BIO on the right side
of the instrument. When it is properly inserted, you will hear it click.
c) Connecting the pachymetry probe
Plug the pachymetry probe connector (1)
into the terminal (2) labeled PACHY on the
right side of the instrument. When it is properly inserted, you will hear it click.
d) Connecting the power cord
Plug the power cord connector (1) into the
terminal (2) on the back of the AL-2000
3.2 Preparing for Use
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AL-2000 Biometer &amp; Pachymeter
e) Connecting the foot switch
1. Plug the connector (1) for the foot switch
to the terminal (2) labeled FOOT SW on
the back of the AL-2000. Line up the slot
of the connector with the tab on the terminal.
2. To secure the connector, turn the locking
ring (3) until you hear it click into place.
f) Inserting and removing the memory card
• Before using the memory card for the first time, set the bat tery in accordance with the Instruction Manual for Memory
Card (located in the box that contains the card). Follow the
instructions for BN-HSR series.
• Since the memory card pops quickly out of the slot when
removed, hold the edge of the card when pressing the but ton for card removal.
Inserting the card:
Hold the front of the memory card toward
you and insert it into the slot until the card is
aligned with the removal button (1).
Removing the card:
Remove the memory card by pressing the
button (2).
3.2 Preparing for Use
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AL-2000 Biometer &amp; Pachymeter
3.2.3 Chin rest installation (AL-1100)
An optional chin rest with a fixation light is available for use when measuring axial
length.
a) Installing the chin rest
The entire chin rest apparatus is shown in the
upper figure. The lower figure shows a larger
view of the top portion.
1. Grasp the slider (1) on both sides to immobilize it.
2. From the operator’s side, carefully insert the
biometry probe into the slider until it locks
into place. (Be careful not to damage the
eye contact area of the probe.)
3. Coil the probe cord twice (as shown) and
secure it with the cord hook (2). The cord
length (3) from the probe to the hook
should be approximately 20 cm to prevent
tension on the cord when the slider is
moved forward during measurement.
Make sure that the slider moves smoothly.
b) Connecting the fixation lamp power plug
Insert the power plug (1) for the chinrest fixation lamp into the terminal (2) labeled “FIX
LIGHT” on the back of the AL-2000.
The fixation lamp lights up when the AL-2000
power is turned on.
3.2 Preparing for Use
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AL-2000 Biometer &amp; Pachymeter
4. BIOMETRY (AXIAL LENGTH MEASUREMENT)
• ALWAYS clean the probe tip before taking a measurement on a human eye (see section 10.2.1).
• NEVER use the probe if there is any visible damage to its
tip. Such use may cause an incorrect measurement and/or
damage to the cornea.
• As with any ultrasound instrument, it is recommended
that the exposure be kept as low as reasonably achiev able (ALARA).
Before turning on the power:
• Make sure that the power plug is properly connected to the
receptacle.
• Make sure the biometry probe is properly connected.
4.1 Biometry Mode Setup
4.1.1 Turning on power and initial adjustments
1. Turning on the power switch (1) at the upper
left side of the instrument initiates selfchecking of the probe. If the biometry probe
is not detected (i.e., no probe or pachymetry probe connected), the message “Probe
Check ... NG” (no good) will be presented.
2. Adjust the contrast of the screen with the
contrast adjuster (2).
3. Tilt the screen forward by pulling out the
“legs” (3) on the bottom of the instrument,
if desired.
If the instrument starts up in Pachymetry mode, to change to
Biometry mode:
a. Press the UTILITY button at the bottom of the screen.
b. Press the AL button near the bottom of the screen.
c. Press the OK button to the right of the AL button.
If the screen is not touched for approximately 3 minutes, the auto matic power saving function is activated and the screen will become
dark. To re-illuminate the screen, touch it.
4.1 Biometry Mode Setup
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AL-2000 Biometer &amp; Pachymeter
4.1.2 Description of Windows
a) Measurement window
Eye type/converted velocity
Displays the eye type to be measured and
the converted velocity.
Eye (R/L)
Displays the eye to be
measured (right or left).
Patient, Physician, Date &amp; Time
Displays the patient’s name and ID number,
the physician’s name and the date and time.
Gain
Displays the gain. Press to
change (8 levels).
Measurement mode
Automatic (Hand/Chin) and
manual measurement modes
are available.
Clear key
Deletes the measurement data of both eyes.
Retinal waveform cursor selection
The waveform to the right of this
cursor is taken as the retinal
waveform.
Retake key
Deletes the measurement data
of right (R) or left (L) eye.
IOL key
Press to enter the IOL calculation mode.
Utility key
Press to display to Utility window.
Retinal waveform cursor shift key
Press to shift the position of the
retinal waveform cursor.
Edit key
Press to display the measurement review window.
4.1 Biometry Mode Setup
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AL-2000 Biometer &amp; Pachymeter
b) Measurement review window (1)
Standard deviation
Standard deviation of axial
length measurements.
Range
Difference between minimum and maximum axial length measurement.
Mean axial length
Mean of the axial length
measurements.
L
Maximum axial length.
A-mode waveform
A-mode waveform is displayed in
real time during measurement.
Memory key
Press to store data on the
memory card.
Print key
Press to obtain a printout
of the data.
Caliper key
Press to switch to caliper window.
S
Minimum axial length.
Measured data
Each row displays memory number, axial length,
anterior chamber depth and lens thickness for
each individual measurement. The last row displays the mean of all measurements.
4.1 Biometry Mode Setup
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AL-2000 Biometer &amp; Pachymeter
c) Measurement review window (2)
Selected measurement
Displays the waveform for the selected measurement and indicates the memory number.
Level cursor/level line
In the automatic measurement mode, the measurement data are acquired only
when there are crests rising
above the cursor level.
Display selection
The selected measurement is highlighted.
Measure key
Press to change to the
measurement window.
Measurement cursor/meas urement line
Distances are measured
from the level of this cursor.
Delete key
Deletes data.
Recall key
Press to retrieve data
that were deleted
using the Delete key.
4.1 Biometry Mode Setup
14
Memory Key
Press to store data on
the memory card.
Select key
Select Axial length
measurement to
be used for IOL
calculation.
Selection keys
Used to select the measurement data to be displayed.
AL-2000 Biometer &amp; Pachymeter
4.1.3 Setting the measurement conditions
Before measuring axial length, the following measurement conditions should be set:
•
•
•
•
•
•
Patient name, patient ID and physician name
Eye (right/left)
Eye type
Gain
Measurement mode
Retinal waveform
a) Patient name, patient ID number and physician name
Stored data are controlled by ID numbers. If you plan to
store data on the memory card, you must enter a patient ID
number.
Up to 10 letters can be entered for each
item.
1. Touch the Index key (1) on the measurement window (fig. 1) to display the
Name/ID entry window (fig. 2).
2. Touch the number keys and the alphabetic character keys (2) to enter the patient’s
name, ID number and physician’s name.
If the physician’s name is already registered in the Physician List, it can be
selected by pressing the corresponding
number (6).
To switch between letters and numbers,
use the switch-over key (3). In the event
of an erroneous entry, touch the Delete
key (4).
3. To set the entered value and advance to
the next entry, touch the Return key (5).
The cursor location indicates the category of the next entry.
4. Touch the Index key (1) again to return to
the measurement window (fig. 1).
b) Setting the eye to be measured
Touch the Eye key (1) to select the eye you
wish to measure (right or left).
The right eye (OD) or the left eye (OS) is
selected alternately each time the Eye key
is touched.
4.1 Biometry Mode Setup
15
AL-2000 Biometer &amp; Pachymeter
c) Setting the eye type and converted velocity
The AL-2000 can be set to measure the following types of eyes:
• Normal: Select when the lens nucleus of the patient’s eye is rather soft, e.g.,
incipient cataract.
• Dense cataract: Select when the lens nucleus of the patient’s eye is rather
hard, e.g., hypermature cataract.
• Aphakic: Select when the patient’s eye is aphakic.
• Pseudophakic: Select when the patient’s eye is pseudophakic.
1. Touch the Eye type key (1) on the
measurement window (fig. 1) to display
the window shown in fig. 2.
2. Select the eye type (2) by touching the
desired option.
3. Touch the Velocity key (3) to change
the converted velocity for the selected
eye type (fig. 3).
4. Enter the converted velocity using the
number keys (4). See range of converted velocities below.
In the event of an erroneous entry,
touch the Delete key (5).
5. Press the Return key (6) to set the
entered value and advance to the next
entry. The cursor location indicates the
category of the next entry.
6. Press the Velocity key to return to the
screen shown in fig. 2.
7. Press the Eye type key (1) to return to
the measurement window (fig. 1).
For aphakic eyes, ACD and LENS cannot
be measured. With a dense cataract, the
instrument sometimes does not identify a
wave shape behind the cataract due to
multiple echoes, and nothing is shown in
the LENS column.
Range of Converted Velocity
• Normal
Average axial length velocity: 1,500 m/s - 1,600 m/s
Lens velocity: 1,540 m/s - 1,740 m/s
Anterior chamber velocity: 1,430 m/s - 1,630 m/s
• Dense cataract
Average axial length velocity: 1,500 m/s - 1,600 m/s
Lens velocity: 1,540 m/s - 1,740 m/s
Anterior chamber velocity: 1,430 m/s - 1,630 m/s
4.1 Biometry Mode Setup
16
AL-2000 Biometer &amp; Pachymeter
Range of Converted Velocity (continued)
• Aphakic
Average axial length velocity: 1,430 m/s - 1,630 m/s
• Pseudophakic
IOL velocity: 800 m/s - 3,000 m/s
Average velocity (BIO): 1,000 m/s - 2,000 m/s
Anterior chamber velocity: 1,430 m/s - 1,630 m/s
IOL thickness: 0.10 mm - 4.00 mm
d) Setting the gain
Set the gain level based on the waveform
amplitude. The higher you set the gain, the
larger the amplitude will be.
1. Touch the Gain key (1) on the measurement window (fig. 1) to display the window shown in fig. 2.
2. Touch one of the Gain level keys (2) to set
the gain level. The screen will return to the
measurement window (fig. 1).
e) Setting the measurment mode
Set the measuring mode by touching the
Mode button (1). Successive presses of the
button scroll through the options. There are
two automatic modes and one manual
mode.
Automatic modes: Measurements are
acquired automatically when the probe tip is
applied to the cornea.
1. Hand-held measurement: Select if you
wish to hold the probe by hand.
2. Chin rest measurement: Select if you
wish to use the chin rest.
Manual mode: Measurements are acquired
by pressing the footswitch. Select when performing biometry on patients from whom it
may be difficult to obtain measurements.
4.1 Biometry Mode Setup
17
AL-2000 Biometer &amp; Pachymeter
f) Selecting the location of the retinal waveform
In the event that a spike occurs between
the back of the lens and the retina (e.g.,
due to a vitreous hemorrhage), manually
reposition the retinal cursor (2) by pressing
the retinal cursor shift keys (1).
The waveform to the right of this cursor
location is taken as the retinal waveform.
4.1.4 Checking the performance
Check the performance of the AL-2000 by using the biometry test piece (found in
the box containing the biometry probe). (See fig. 1.)
1. Select the following settings:
Eye type/converted veolcity: Aphakic/1,532 m/s
Gain:
8
Measurement mode:
Hand-held
2. Apply a drop of water to the upper and to the lower
test piece surfaces.
3. Apply the biometer perpendicular to the upper surface. Up to 15 measurements will be automatically
taken, each indicated by a beep. When measurement
is complete, a higher-pitched beep will sound.
4. Repeat steps 2 and 3 for the lower test piece surface.
Expected results:
Waveform:
A representative waveform is shown in fig. 2.
Average AXIAL value (shown above the waveform):
Upper surface: 22.0 mm &plusmn; 2 mm
Lower surface: 16.0 mm &plusmn; 2 mm
The biometry test piece is used only for checking the operating per formance of the instrument. It cannot be used for determining the
precision of the instrument or for calibration of the instrument.
4.1 Biometry Mode Setup
18
AL-2000 Biometer &amp; Pachymeter
4.2 Performing Biometry (Axial Length Measurement)
4.2.1 Preparation for measurement
1. Confirm that the measurement conditions have been set.
2. Anesthetize the eye with an appropriate topical anesthetic.
3. When taking measurements using the chin rest, instruct the patient to sit in front
of the chin rest. Adjust the height of the chair, the lift table and/or the chin rest to
maximize patient comfort.
When taking measurements holding the probe by hand, instruct the patient to be
seated or to lie supine.
4. If the fixation light is used to guide the direction of gaze (when using the chin
rest), set it at an appropriate height for the patient to fixate.
• If the patient is relaxed and cooperative, the measurement will be easier and more successful. Prior to taking
measurements, explain the purpose and method of measurement to the patient to reduce his/her anxiety.
4.2.2 Measurement methods
• ALWAYS clean the probe tip before taking a measure ment on a human eye (see section 10.2.1).
• NEVER use the probe if there is any visible to its tip. Such
use may cause an incorrect measurement and/or damage
to the cornea.
• ALWAYS anesthetize the eye with an appropriate topical
anesthetic before performing measurements.
• Avoid applying excessive force to the cornea during measurement. Be careful not to push the probe beyond the
allowable sliding range when using the chin rest.
• The converted velocity directly affects the measurement.
Ascertain that you have set the desired converted velocity.
• In immersion mode, the ultrasound gel must intervene between
the eye contact area of the biometer probe and the cornea so
that the distance between the probe and the cornea is approxi mately 1.8 to 3.2 mm.
• Excessive ultrasound gel may affect the accuracy of the measurement.
• When performing IOL calculation (see Section 4.3), be sure to use
quality readings for accuracy.
4.2 Performing Biometry (Axial Length Measurement)
19
AL-2000 Biometer &amp; Pachymeter
a) Probe mode
There are two probe modes:
1. Contact mode
In Contact mode (fig. 1), the tip of the biometry probe is applied directly to the surface of
the cornea.
2. Immersion mode
In Immersion mode (fig. 2), ultrasound gel is
used between the probe and the cornea.
Using both probe modes, the probe should be
applied perpendicular to the corneal apex such
that the visual axis and the axis of the probe are
aligned.
See instructions in section 7.3.6 for selecting the
probe mode.
b) Methods of performing measurements
There are two automatic modes, hand-held and chin rest, and one manual mode.
Set the measuring mode by touching the Mode button (1) as described in section
4.1.3e.
(1) Automatic measurement modes (hand-held and chin rest)
a. If the chin rest is used in contact probe mode, use a slider movement of 2
to 4 mm.
b. When the probe tip is applied to the cornea, the instrument automatically
starts taking measurments. When a satisfactory measurement is taken, the
instrument makes a “beep” sound.
c. Using the hand-held method, up to 15 measurements in the range of +/0.2 mm from the average value are taken. If measurement data are largely
scattered, “ERROR” is displayed.
d. Using the chin rest method, measurements are taken until 10 measurements within +/- 0.1 mm of the average value are obtained.
e. When data acquisition is complete, a higher-pitched beep sounds and the
waveform for the measurement closest to the average value is displayed.
(2) Manual measurement mode
a. If the chin rest is used in contact probe mode, use a slider movement of 2
to 4 mm.
b. Apply the probe tip to the cornea and press the footswitch to acquire a
measurement.
c. When a satisfactory measurement is taken, the instrument makes a beep
sound. When 10 measurements have been acquired, the instrument makes
a higher pitched beep and the waveform for the measurement closest to
the average value is displayed.
4.2 Performing Biometry (Axial Length Measurement)
20
AL-2000 Biometer &amp; Pachymeter
4.2.3 Data review and selection for IOL calculation
a) Displaying a waveform
The waveforms for each eye of the current
patient measurements can be retrieved
and reviewed at any time during the measuring process.
1. Touch the Edit key (1) on the measurement window (fig. 1) to display the
measurement review window (fig 2). The
waveform for the measurement closest
to the average is displayed.
2. If you wish to review the waveform for a
particular measurement, select the
measurement by pressing the up and
down arrow keys (2). The selected data
will be highlighted and the corresponding waveform will be displayed.
3. Touch the Measure key to return to the
measurement window and display the
average waveform.
b) Selecting data for IOL power calculation
1. If you wish to use the values for an individual measurement for the IOL power
calculation rather than the average values, touch the Edit key (1) on the measurement window (fig. 1) to display the
measurement review window (fig 2). (If a
particular waveform is not selected, the
mean values are used for IOL power calculation.)
2. Touch the up and down arrow keys (2)
to select the measurement data you
wish to use.
3. Touch the Select key (3) to choose the
selected data for IOL power calculation.
4. Touch the Memory key (4) to store the
data on the memory card.
5. Touch the Measure key to return to the
measurement window.
If you wish to revert to using the mean values for IOL calculation, after returning to
the measurement window, touch the
Memory key.
See Section 4.3 for detailed instructions on
IOL calculation.
4.2 Performing Biometry (Axial Length Measurement)
21
AL-2000 Biometer &amp; Pachymeter
c) Deleting individual measurements
1. Touch the Edit key (1) on the measurement window (fig. 1) to display the measurement review window (fig 2).
2. Touch the up and down arrow keys (2) to
select the measurement you wish to
delete.
3. Delete the data by touching the Delete
key (3).
In the event that measurements are accidentally deleted, touch the Recall key (4)
to recover the data. Once you have exited the measurement review window,
however, the data cannot be recovered.
4. Touch the Measure key to return to the
measurement window.
4.2.4 Caliper Function
A reading displayed in the caliper mode is an approximation
and may be different from the actual reading.
After completing measurement, the distance between two points can be measured
on the waveform that is closest to the average waveform. In this function, a velocity of
1550 m/s is used.
1. After measurement, touch the Caliper
key (1) on the measurement window (fig.
1) to enter Caliper mode (fig. 2).
2. Press the right or left arrow key (2) to set
the point from which to start measuring,
which will be indicated by a vertical
dashed line.
3. Touch the Fix key (3) to set the location
(fig. 3, next page).
4. Touch the right or left arrow key again to
set the second measurement location,
which will be indicated by a second vertical dashed line. The distance between
the two points will be displayed in real
time.
4.2 Performing Biometry (Axial Length Measurement)
22
AL-2000 Biometer &amp; Pachymeter
4. By pressing the Fix key, the caliper can be
switched alternativey between the two
measurement locations, and the location
can be changed using the arrow keys.
5. Touch the Measure key to return to the
measurement window.
4.2.5 Deleting data
Once data have been deleted, they cannot be restored. Any deletion
must, therefore, be done carefully.
a) Deleting all data for one eye
To delete all data currently displayed for
either the right or the left eye, press the
Retake key (1) until you hear a beep.
NOTE: This deletes currently acquired data
from the screen; it does not delete stored
data from the memory card. (To delete data
from the memory card, see section 7.3.4d).
b) Deleting all data for both eyes
To delete all data for both eyes of the current patient, press the Clear key (2) until you
hear a beep sound. The patient’s name and
ID number will be deleted from the screen.
The eye type will default to Normal and the
selected eye will default to the right eye
(OD).
NOTE: This deletes currently acquired data
from the screen; it does not delete stored
data from the memory card. (To delete data
from the memory card, see section 7.3.4d).
4.2.6 Storing data
• Before storing data, make sure that a memory card is inserted
in the slot.
• All data are managed using patient ID numbers. Therefore, if
you plan to store data, you must enter a patient ID number.
• The PC memory card used with the AL-2000 is an SRAM type
card. Therefore, an SRAM type card reader, not a Flash Memory
reader, must be used. If a Flash Memory reader is used, data
stored on the memory card may be corrupted.
4.2 Performing Biometry (Axial Length Measurement)
23
AL-2000 Biometer &amp; Pachymeter
The memory card that came with the AL-2000 can store data from both eyes of 237
patients. The following binocular data will be stored:
•
•
•
•
Average axial length (Average AXIAL)
Average anterior chamber depth (Average ACD)
Average lens thickness (Average LENS)
Waveform that is closest to the average waveform
After measurements have been acquired,
press the Memory key (1) to store the data.
Be sure to enter a patient ID number when
storing data on the memory card. (See
Section 4.1.3a for details.)
To display stored axial length data, compile
IOL data and display personal lens constants, see Section 7.3.4. To display graphs
of biometry and IOL data, see Section 7.3.5.
4.2.7 Acceptable waveforms
In the automatic measurement modes, waveforms are evaluated and acquired only if
the following criteria are met:
1. The following crests rise above the level cursor:
• Normal:
• Dense cataract:
• Aphakic:
• Pseudophakic:
The crests of the back and front of the lens and of the
retina.
The crest of the front of the lens and of the retina.
The crest of the retina.
The crests of the front of the IOL and of the retina.
2. The retinal waveform stands upright.
3. The variability among measurements is low.
In immersion mode, the echo from the front of the lens is located between 1.8 mm
and 3.2 mm from the initial echo (leftmost dotted line in fig. 2).
4.2 Performing Biometry (Axial Length Measurement)
24
AL-2000 Biometer &amp; Pachymeter
4.3 IOL Power Calculation
4.3.1 Changing to IOL power calculation mode
a) From the Biometry mode
If you wish to calculate IOL power after
axial length measurement, touch the IOL
key (1) to enter the IOL power calculation
mode.
b) From the Utility mode
If you are in the Utility mode and wish to
calculate IOL power, touch the IOL key (1)
to enter the IOL power calculation mode.
4.3 IOL Power Calculation
25
AL-2000 Biometer &amp; Pachymeter
4.3.2 Description of IOL power calculation window
a) Entry of data and display of calculation results
Patient, Physician, Date &amp; Time
Displays the patient’s name and ID number,
the physician’s name and the date and time.
IOL constants
• A-const: SRK II, SRK/T, Haigis standard
• a0, a1, a2: Haigis optimized
• Surgeon factor (SF): Holladay
• Postoperative anterior chamber
depth (ACD): Hoffer-Q
Calculation data
• Axial: Axial length
• K1, K2: Keratometry readings
• Desired Ref: Desired postoperative refraction.
Eye (R/L)
Displays the eye for which
IOL power is to be calculated (right or left).
IOL Model/
Manufacturer
Enter and display
IOL model name
and manufacturer.
IOL &amp; predicted
postop refraction
Calculated IOL power
and predicted postoperative refraction.
IOL Formulae
Displays the selected IOL
calculation formula.
Delete key
Deletes incorrect data.
Print key
Initiates
printout.
Calculation results
Displays results of IOL
power calculation
Number keys
Enter numerical
values using
these keys.
Implanted IOL
Displays model name
and refractive power
of selected IOL.
Return key
Registers
entered data.
Utility key
Changes to Utility window.
Measure
Changes to axial length
measurement mode.
4.3 IOL Power Calculation
26
Memory key
Stores calculation results
on the memory card.
AL-2000 Biometer &amp; Pachymeter
a) Display of IOL data list
A, B, C
Indicate display location of
selected lenses.
IOL data selection key
Selects the desired IOL data.
IOL data
Lists entered IOL models and displays
lens constants for each model.
4.3.3 Setting the calculation conditions
a) Setting the eye to be calculated
Touch the Eye key (1) to select the eye for
which you wish to calculate IOL power
(right or left).
The right eye (OD) or the left eye (OS) is
selected alternately each time the Eye key
is touched.
4.3 IOL Power Calculation
27
AL-2000 Biometer &amp; Pachymeter
b) Selecting the IOL formula
To select the desired IOL formula, consecutively touch the Formula key (2) to scroll
through the formulas that have been selected using the IOL Formula utility (see section
7.3.2). Up to five formulae may be selected.
Six pre-set formulae are available: SRK II,
SRK/T, Holladay, Hoffer-Q, Haigis standard
and Haigis optimized (see section 7.3.2.)
4.3.4 Data entry for IOL calculation
a) Axial length (Axial)
Following axial length measurement, the
data will be automatically entered.
Therefore, no data entry is required.
If axial length measurement has not been
performed using the AL-2000, follow these
steps to enter axial length:
1. Prepare to enter axial length by touching
the Axial key (1). The databox will be
reverse highlighted.
2. Touch the number keys (2) to enter the
axial length value. The acceptable range is
15 - 40 mm.
In the event of an erroneous entry, touch
the Delete key (3).
3. Complete the data entry by touching
either the Return (4) or the Axial (1) key.
b) Keratometry readings (K1/K2)
1. Prepare to enter the K values by touching
K1 (1). The databox will be reverse highlighted.
2. Touch the number keys (2) to enter the
first K value. The acceptable range is
30.00 - 60.00 D or 5.00 - 11.00 mm.
In the event of an erroneous entry, touch
the Delete key (3).
3. Complete the data entry by touching the
Return key (4) or the K1 key (1).
4. Touch the K2 key (5) to enter the second
K value and proceed with the same procedure as for K1.
Note: Either the flat K or the steep K may
be entered first. Values may be entered in
either diopters or millimeters.
4.3 IOL Power Calculation
28
AL-2000 Biometer &amp; Pachymeter
c) Desired postoperative refraction (Desired Ref.)
1. Prepare to enter the desired postoperative refraction by touching the Desired
Ref. key (1). The databox will be reverse
highlighted.
2. Touch the number keys (2) to enter the
data. The acceptable range is -10.00 +10.00 D.
In the event of an erroneous entry, touch
the Delete key (3).
3. Complete the data entry by touching
either the Return key (4) or the Desired
Ref. key (1).
d) Constants (Aconst., SF, ACD)
Values for A constant, Surgeon’s Factor and Anterior Chamber Depth constant
may be entered on the IOL calculation window, or stored IOL models with preentered constant values may be selected from the IOL data list (see Section
7.3.1). IOL power may be calculated for up to three different lens models.
To enter values on the IOL calculation window:
1. Prepare to enter values by touching the
Lens A key (1), the Lens B key (2) or the
Lens C key (3). The databox will be reverse
highlighted.
2. Touch the number keys (4) to enter values.
The acceptable ranges are:
Aconst: 100.00 - 130.00
SF:
-5.00 - +10.00
ACD:
0.00 - 10.00
(For the Haigis optimized formula, a0,
a1 and a2 must be entered using the
IOL Data Entry utility; see section 7.3.1.)
In the event of an erroneous entry, touch
the Delete key (5).
3. Complete the data entry by touching the
Return key (6).
To select pre-entered lens models from the
IOL data list:
1. Prepare to enter a lens model by touching
the Lens A key (1), the Lens B key (2) or the
Lens C key (3).
2. Select the IOL with the desired parameters
from the IOL list (7) using the up/down
arrow keys (8).
3. Touch the Return key (9) to enter the selection. The constant value and the name of
the IOL model and manufacturer will be displayed for the selected IOL.
4.3 IOL Power Calculation
29
AL-2000 Biometer &amp; Pachymeter
4.3.5 IOL power calculation
a) Automatic power calculation
When all necessary values have been
entered, IOL power calculations will be performed automatically and results will be displayed.
Seven IOL power options (1) and the resulting refraction for each (2) will be displayed
for each lens. The IOL power that produces
the refractive result closest to the specified
desired refraction (Desired Ref.) will be highlighted.
In the calculation process, small errors may occur due to the number of
significant figures.
In some IOL formulas, an imaginary number may be generated due to
square root calculations and the result may be displayed as an ERROR.
b) Registration of the IOL model name
If you wish to store the IOL model that you
have selected for the patient:
1. Touch the Implanted IOL Model key (1).
2. Touch the highlighted area where IOL
model and manufacturer name are displayed (2) to store the IOL model name.
The IOL model name will be stored on the
memory card and may be used for statistical data analysis (provided that IOL power
is also stored, as described below).
c) Entering IOL power
If you wish to store the IOL power of the
lens that you have selected for the patient:
1. Touch the IOL Power key (1).
2. Enter the IOL power using the number
keys (2). The acceptable range is 0.01 50.00 D.
In the event of an erroneous entry, touch
the Delete key (3).
3. Touch the Return key (4) or the IOL key
(1) to register the IOL power.
The IOL power will be stored on the memory card and may be used for statistical
data analysis (provided that IOL Model is
also stored, as described above).
4.3 IOL Power Calculation
30
AL-2000 Biometer &amp; Pachymeter
4.3.6 Storing patient data
• Before storing data, make sure that a memory card is inserted in
the slot (see section 3.2.2f).
• All data are managed using patient ID numbers. Therefore, you
must enter a patient ID number before storing data (see section
4.1.3).
• The PC memory card used with the AL-2000 is an SRAM type card.
Therefore, an SRAM type card reader, not a Flash Memory reader, must be used. If a Flash Memory reader is used, data stored on
the memory card may be corrupted.
The memory card that came with the AL-2000
can store data from both eyes of 237 patients.
Touch the Memory key (1) to store the following
data:
•
•
•
•
•
•
Axial length (AXIAL)
Keratometry values (K1/K2)
Desired postoperative refraction (Desired Ref.)
Lens constants (Aconst, SF, ACD*)
Model name of IOL (IOL Model)
Refractive power of IOL (IOL Power)
*The anterior chamber depth value (2) is used
only for the Haigis standard and Haigis optimized formulas.
NOTE: In the Data Management utility (see section 7.3.5), patient data are compiled according
to IOL Model name. Therefore, if you plan to perform statistical analysis of surgical outcomes, be
sure to enter the Implanted IOL model (and
power) before storing patient data.
4.3 IOL Power Calculation
31
AL-2000 Biometer &amp; Pachymeter
4.3 IOL Power Calculation
32
AL-2000 Biometer &amp; Pachymeter
5. PACHYMETRY (CORNEAL THICKNESS MEASUREMENT)
• ALWAYS clean the probe tip before taking a measure ment on a human eye (see section 10.2.1).
• NEVER use the probe if there is any visible damage to its
tip. Such use may cause an incorrect measurement and/or
damage to the cornea.
• As with any ultrasound instrument, it is recommended
that the exposure be kept as low as reasonably achievable (ALARA).
Before turning on the power:
• Make sure that the power plug is properly connected to the
receptacle.
• Make sure the pachymetry probe is properly connected.
5.1 Pachymetry Mode Setup
5.1.1 Turning on power and initial adjustments
1. Turning on the power switch (1) at the upper
left side of the instrument initiates selfchecking of the probe. If the pachymetry
probe is not detected (i.e., no probe or biometry probe connected), the message
“Probe Check ... NG” (no good) will be presented.
2. Adjust the contrast of the screen with the
contrast adjuster (2).
3. Tilt the screen forward by pulling out the
“legs” (3) on the bottom of the instrument,
If the instrument starts up in Biometry mode, to change to
Pachymetry mode:
a. Press the UTILITY button at the bottom of the screen.
b. Press the PACHY button near the bottom of the screen.
c. Press the OK button to the right of the AL button.
If the screen is not touched for approximately 3 minutes, the auto matic power saving function is activated and the screen will become
dark. To re-illuminate the screen, touch it.
5.1 Pachymetry Mode Setup
33
AL-2000 Biometer &amp; Pachymeter
5.1.2 Description of Windows
Patient, Physician, Date &amp; Time
Displays the patient’s name and ID number,
the physician’s name and the date and time.
a) Map mode window
Measuring range
Displays the measurement range.
Converted velocity/Bias value
Displays the converted velocity and the
bias rate or compensated bias value.
Eye (R/L)
Displays the eye to be
measured (right or left).
Measurement mode
Displays the measurement mode.
Measurement method
Displays the method
of measurement.
Selected value
Displays the measurement
that is currently selected.
Clear key
Deletes the measurement data of both eyes.
Print key
Press to initiate printing.
Utility key
Press to display the Utility window.
Memory key
Stores the data on
the memory card.
Method of data presentation
Indicates whether the value is an
actual value or a biased value.
Retake
Deletes the measurement data
of right (R) or left (L) eye.
Map display
Displays the measurement data
in order of selected elements.
5.1 Pachymetry Mode Setup
34
Display of data
Indicates whether the average values, minimum values or latest
(most recent) values are displayed.
AL-2000 Biometer &amp; Pachymeter
b) Single mode window
Memory number
Displays the measurement number.
Delete key
Deletes the selected
measurement.
Measurement data
Displays the measurement data.
Standard deviation
Displays the standard devation of
the pachymetry measurements.
Mean
Displays the mean of the
pachymetry measurements.
5.1 Pachymetry Mode Setup
35
AL-2000 Biometer &amp; Pachymeter
5.1.3 Setting the Measurement Conditions
Before measuring corneal thickness, the following measurement conditions should
be set:
•
•
•
•
•
•
•
•
Patient name, patient ID and physcian name
Eye (right/left)
Converted velocity and bias mode
Acquisition mode
Measurement mode
Measurement range
Measurement display
Data presentation mode
a) Patient name, patient ID number and physician name
Stored data are controlled by ID numbers. If you plan to store
data on the memory card, you must enter a patient ID number.
Up to 10 letters can be entered for each
item.
1. Touch the Index key (1) on the measurement window (fig. 1) to display the
Name/ID entry window (fig. 2).
2. Touch the number keys and the alphabetic character keys (2) to enter the patient’s
name, ID number and physician’s name.
If the physician’s name is already registered in the Physician List, it can be
selected by pressing the corresponding
number (6).
To switch between letters and numbers,
use the switch-over key (3). In the event
of an erroneous entry, touch the Delete
key (4).
3. To set the entered value and advance to
the next entry, touch the Return key (5).
The cursor location indicates the category of the next entry.
4. Touch the Index key (1) again to return to
the measurement window (fig. 1).
b) Setting the eye to be measured
Touch the Eye key (1) to select the eye you
wish to measure (right or left).
The right eye (OD) or the left eye (OS) is
selected alternately each time the Eye key
is touched.
5.1 Pachymetry Mode Setup
36
AL-2000 Biometer &amp; Pachymeter
c) Setting converted velocity and bias mode
Bias may be applied in the following two ways:
• Percentage:
A percentage of the actual value is calculated.
•
Plus/minus:
A compensating value is added to or subtracted from the actual value.
1. Touch the converted velocity key (1) on
the measurement window (fig. 1) to
access the setting window (fig. 2).
2. Enter the converted velocity by touching the number keys (2). The acceptable range is 1,200 - 2,000 m/s.
In the event of an erroneous entry,
touch the Delete key (3).
3. Touch the Return key (4) to set the
entered value.
4. Select either percent bias (%) or
plus/minus bias (&micro;m) at the bottom of
the window (5).
5. When setting percent bias, enter the
bias rate by touching the number keys
(2). When setting the plus/minus bias,
enter the compensating value by
touching the number keys (2). The
acceptable ranges are:
Bias rate (%):
60 - 130%
Compensating value: -600 - +450 &micro;m
In the event of an erroneous entry,
touch the Delete key (3).
6. Touch the Return key (4) to set the
entered values.
7. Touch the converted velocity key (1) to
return to the measurement window
(fig. 1).
The bias value (% or &micro;m
m) can be changed after the measurement has been performed.
5.1 Pachymetry Mode Setup
37
AL-2000 Biometer &amp; Pachymeter
d) Setting automatic vs. manual acquisition
There are two data acquisition modes:
• Auto:
The data are automatically acquired when all criteria are met.
•
Manual:
If data acquisition is difficult or erratic, data may be acquired manually using
the footswitch.
Touch the Auto/Manual key (1) to select the
desired measurement mode. Automatic mode
and manual mode are alternately set each
time the key is touched.
e) Setting the measurement mode and the map
There are two measurement modes:
• Map mode (fig. 1):
Measurements are acquired from an
array of locations which are set in the
Utility mode (see Section 7.4.1). Two
map arrays (MAP 1 and MAP 2) can be
registered.
• Single mode (fig. 2):
Single mode is used to acquire multiple
thickness measurements from a single
point on the cornea.
Consecutively press the Mode key (1) to
select MAP 1, MAP 2 or Single mode.
f) Setting the measurement range
Press the Range key (1) to set the measuring
range. Consecutively press the key to scroll
through the following range settings:
150 - 350 &micro;m
300 - 1,200 &micro;m
1,000 - 1,500 &micro;m
The message “Out of range” is presented
when an echo is acquired that is out of the
currently set range. Touch the Range key to
change the range and resume measurement.
5.1 Pachymetry Mode Setup
38
AL-2000 Biometer &amp; Pachymeter
g) Setting the data display method
There are two ways that the measurement
data may be displayed: actual value or
biased value.
Set the display method by pressing the data
display key (1). Consecutively press the key
to alternate between actual value display
and bias value display.
h) Setting the data presentation mode
You may select which measurement data
you would like to display from the following three options:
• Latest:
The most recently acquired measurement at each point.
• Minimum:
The minimum of all measurements
taken at each point.
• Average:
The mean of all measurements taken at
each point.
Set the value to be displayed as follows:
1. Press the Utility Key at the bottom of
the Pachymetry measurement window
(fig. 1) to display the Utility window (fig.
2).
2. Press the Data Selection key (2) to display the Data Selection window (fig. 3).
3. Press the desired data display option
(LLatest, Minimum or Average) by touching the adjacent key (3). The screen will
return to the pachymetry Utility window
(fig. 2).
4. Press the Measure key (4) on the Utility
window to return to the Pachymetry
measurement window.
The data presentation mode (5) is displayed
at the upper right of the measurement window (fig. 1).
5.1 Pachymetry Mode Setup
39
AL-2000 Biometer &amp; Pachymeter
5.1.4 Checking the performance
Check the performance of the AL-2000 by using the pachymetry test piece (found
in the box containing the pachymetry probe).
1. Select the following settings:
Converted veolcity:
1,640 m/s
Acquisition mode:
Automatic
Measurement mode:
Single
Measurement range:
300-1,200 &micro;m
Data display method:
Actual value
Data presentation mode: Average
2. Immerse the test piece under water.
3. Apply the pachymetry probe perpendicularly in one of the holes in the test piece.
4. Take 10 series of measurements, as
described in section 5.2.2b, and select
the 5 smallest values. The range of these
values should be less than 10 &micro;m.
5. Take the average of these 5 values.
6. Repeat steps 3, 4 and 5 for the other
test piece hole.
Expected results (see NOTE below):
Shallower hole (D1): 465 &micro;m &plusmn; 50 &micro;m
Deeper hole (D2):
850 &micro;m &plusmn; 50 &micro;m
NOTE: The expected results are for an
ambient room temperature of 24
degrees C (75 degrees F). Compensate
for higher (lower) temperature by adding
(subtracting), as follows:
D1: 1 &micro;m per degree
D2: 2 &micro;m per degree
The biometry test piece is used only for checking the operating per formance of the instrument. It cannot be used for determining the
precision of the instrument or for calibrating the instrument.
5.2 Performing Pachymetry
5.2.1 Preparation for measurement
1. Confirm that the measurement conditions have been set.
2. Anesthetize the eye with an appropriate topical anesthetic.
3. Instruct the patient to sit back or to lie supine to maximize patient comfort.
If the patient is relaxed and cooperative, the measurement will be
easier and more successful. Prior to taking measurements, explain
the purpose and method of measurement to the patient to reduce
his/her anxiety.
5.2 Performing Pachymetry
40
AL-2000 Biometer &amp; Pachymeter
5.2.2 Measurement methods
• ALWAYS clean the probe tip before taking a measurement on a
human eye (see section 10.2.1).
• NEVER use the probe if there is any visible damage to its tip. Such
use may cause an incorrect measurement and/or damage to the
cornea.
• ALWAYS anesthetize the eye with an appropriate topical anesthet ic before performing measurements.
• Avoid applying excessive force to the cornea during measurement.
• If the cornea is dry, wet it to avoid corneal injury.
• The converted velocity directly affects the measurement. Ascertain
that you have set the desired converted velocity.
• The instrument can be set to display actual or baised values.
Ascertain that the desired data display method is set.
a) Automatic acquisition in map measurement mode (MAP 1, MAP 2)
When using either of the two map arrays,
pachymetry is performed as follows:
1. Apply the pachymetry probe perpendicular
to the cornea at the location corresponding
to the reverse-highlighted location on the
map array.
2. When the measurement conditions are satisfactorily set, a beep will indicate that the
instrument is ready to acquire data, following which measurements will be automatically acquired.
3. When 20 measurements have been
acquired, a prolonged beep will indicate
that measurement at this location has been
completed.
Data acquisition can be concluded before 20
values have been obtained by lifting the
probe off the cornea.
4. Remove the probe from the cornea, place
the probe at the next location, which is highlighted in reverse on the map array, and
repeat steps 2 and 3.
5. Measure each corneal location as described
above.
6. If you would like to re-test any locations,
touch the location on the screen to reversehighlight it and re-acquire measurements.
5.2 Performing Pachymetry
41
AL-2000 Biometer &amp; Pachymeter
b) Automatic acquisition in single measurement mode
1. Apply the pachymetry probe perpendicular
to the cornea at the desired location.
2. When the measurement conditions are satisfactorily set, a beep will indicate that the
instrument is ready to acquire data, following which measurements will be automatically acquired.
3. When 20 measurements have been
acquired, a high-pitched beep will indicate
that measurement at this location has been
completed.
Data acquisition can be concluded before 20
values have been obtained by lifting the
probe off the cornea.
4. Measurement may be repeated up to 10
times. The average for each series of values
will be displayed in each data slot.
5. If you would like to replace any of the measurements, touch the data slot on the screen
to reverse-highlight it and re-acquire measurements.
c) Manual acquisition in map measurement mode
1. Apply the pachymetry probe perpendicular
to the cornea at the location corresponding
to the reverse-highlighted location on the
map array.
2. When the measurement conditions are satisfactorily set, a beep will indicate that the
instrument is ready to acquire data.
3. Press the footswitch to take measurements.
The instrument will beep each time a measurement is taken.
4. When 10 measurements have been acquired,
a higher-pitched beep will indicate that
measurement at this location has been completed.
Data acquisition can be concluded before 10
values have been obtained by lifting the
probe off the cornea.
5. Remove the probe from the cornea, place it
at the next location, which is high-lighted in
reverse on the map array, and repeat the
above steps.
6. Measure each corneal location as described
above.
7. If you would like to re-test any location,
touch the location on the screen to reversehighlight it and re-acquire measurements.
5.2 Performing Pachymetry
42
AL-2000 Biometer &amp; Pachymeter
d) Manual acquisition in single measurement mode
1. Apply the pachymetry probe perpendicular
to the cornea at the desired location.
2. When the measurement conditions are satisfactorily set, a beep will indicate that the
instrument is ready to acquire data.
3. Press the footswitch to take measurements.
The instrument will beep each time a measurement is taken.
4. Remove the probe from the cornea, move to
the next location and repeat the above steps.
5. Repeat the above procedure up to 10 times.
6. If you would like to re-test any location,
touch the data slot on the screen to reversehighlight it and re-acquire measurements.
5.2.3 Deleting data
a) Partial deletion of data in single measurement mode
Once data have been deleted, they cannot be restored. Any deletion
must, therefore, be done carefully.
Data for a particular location can be deleted
as follows:
1. Touch the memory number (1) to select
the data to be deleted.
2. Press the Delete key (2).
3. Next, press the OK key (3) to proceed
with the deletion.
To discontinue deletion, press the Cancel
key (4).
b) Deleting all data for one eye
To delete all data currently displayed for
either the right or the left eye, press the
Retake key (1) until you hear a beep.
NOTE: This deletes currently acquired data
from the screen; it does not delete stored
data from the memory card. (To delete data
from the memory card, see section 7.3.4d).
5.2 Performing Pachymetry
43
AL-2000 Biometer &amp; Pachymeter
c) Deleting all data for both eyes
To delete all data for both eyes of the current patient, press the Clear key (2) until you
hear a beep sound. The patient’s name and
ID number will be deleted from the screen.
NOTE: This deletes currently acquired data
from the screen; it does not delete stored
data from the memory card. (To delete data
from the memory card, see section 7.3.4d).
5.2.4 Storing data
• Before storing data, make sure that a memory card is inserted in the
slot (see section 3.2.2f).
• All data are managed using patient ID numbers. Therefore, you must
enter a patient ID number before storing data (see section 5.1.3a).
• The PC memory card used with the AL-2000 is an SRAM type card.
Therefore, an SRAM type card reader, not a Flash Memory reader,
must be used. If a Flash Memory reader is used, data stored on the
memory card may be corrupted.
The memory card that came with the AL-2000
can store data from both eyes of 237 patients.
In map measurement mode, data from up to
25 points is stored (fig. 1).
In single measurement mode, up to 10 measurements are stored (fig. 2).
In both measurement modes, after measurements have been acquired, press the Memory
key (1) to store the data.
A patient ID number must be entered in order
to store data on the memory card. (See section
5.1.3a for details.)
To display stored pachymetry data and to view
cross-sectional diagrams of the cornea, see
Section 7.4.3.
5.2 Performing Pachymetry
44
AL-2000 Biometer &amp; Pachymeter
6. PRINTING
6.1 Initiating Printing
After biometry measurement, IOL calculation
or pachymetry measurement, touch the Print
key (1) to initiate printing.
6.2 Printout Modes
There are two printout modes, standard and simple. Sample printouts are shown in Section
6.3. (See Section 7.5.5 to select the desired mode.)
Standard:
Includes date, patient name and ID number, physician name and all data.
Simple:
Includes no identifying information and, for some printouts, provides an
abbreviated version of the data. The simple printout mode uses less paper.
6.1 Initiating Printing
45
AL-2000 Biometer &amp; Pachymeter
6.3 Sample Printouts
6.3.1 Sample biometry printout
a) Standard mode
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(19)
(20)
(21)
(22)
Time/Date
Patient name
Patient ID number
Physician name
Eye (Right/Left)
Measurement mode
Eye type
Average axial length velocity
Lens velocity
ACD velocity
Gain
Average axial length
Standard deviation of axial
length data
Difference between minimum and maximum axial
length
Memory number
Measurement data (axial
length/ACD/lens thickness)
Mean measurement data
values
Memory number of the displayed waveform
Waveform
Selection cursor for retinal
waveform
Selection cursor for retinal
echo
Scale (2 mm/div)
b) Simple mode
6.3 Sample Printouts
46
AL-2000 Biometer &amp; Pachymeter
6.3.2 Sample IOL power calculation printout
a) Standard mode
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
Time/Date
Patient name
Patient ID number
Physician name
Eye (Right/Left)
IOL calculation formula
Axial length
Keratometry values
Desired postoperative refraction
Lens constants
Power calculation results
IOL model name
Seven IOL power levels and the
predicted postoperative refraction
for each lens model
b) Simple mode
6.3 Sample Printouts
47
AL-2000 Biometer &amp; Pachymeter
6.3.3 Sample IOL power calculation printout following biometry (SRK/T)
a) Standard mode
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(19)
(20)
(21)
(22)
(23)
(24)
(25)
(26)
(27)
(28)
(29)
(30)
Time/Date
Patient name
Patient ID number
Physician name
Eye (Right/Left)
Measurement mode
Eye type
Average axial length velocity
Lens velocity
ACD velocity
Gain
Average axial length
Standard deviation of axial
length data
Difference between minimum and maximum axial
length
Average ACD
Average lens thickness
Memory number of displayed waveform
Axial length/ACD/lens thickness of the displayed waveform
Waveform
Selection cursor for retinal
waveform
Selection cursor for retinal
echo
Scale (2 mm/div)
IOL calculation formula
Mean axial length
Keratometry values
Desired postoperative
refraction
Lens constants
Power calculation results
Seven IOL power levels and
the predicted postoperative
refraction for each lens
model
IOL model name
6.3 Sample Printouts
48
AL-2000 Biometer &amp; Pachymeter
b) Simple mode
6.3 Sample Printouts
49
AL-2000 Biometer &amp; Pachymeter
6.3.4 Sample printout using personal/corresponding surgeon factor values
a) Standard mode
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
Time/Date
Patient name
Patient ID number
Physician name
Eye (Right/Left)
Desired postoperative refraction
Implanted IOL power
Axial length
Anterior chamber depth (ACD)
Keratometry values
Lens constant
Results of calculations
a) Simple mode
6.3 Sample Printouts
50
AL-2000 Biometer &amp; Pachymeter
6.3.5 Sample pachymetry printout - map mode
a) Standard mode
(1)
(2)
(3)
(4)
(5)
(6)
Time/Date
Patient name
Patient ID number
Physician name
Eye (Right/Left)
Converted ultrasound velocity
(7) Measurement mode
(8) Data presentation mode
(9) Data acquisition method
(10) Actual corneal thickness at
each location
(11) Bias rate
(12) Biased corneal thickness at
each location
b) Simple mode
6.3 Sample Printouts
51
AL-2000 Biometer &amp; Pachymeter
6.3.6 Sample pachymetry printout - single mode
a) Standard mode
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
Time/Date
Patient name
Patient ID number
Physician name
Eye (Right/Left)
Converted ultrasound velocity
Measurement mode
Data acquisition method
Actual corneal thickness at
each location
Average actual value
Standard deviation of actual
values
Bias rate
Biased corneal thickness at
each location
Average biased value
Standard deviation of biased
values
b) Simple mode
6.3 Sample Printouts
52
AL-2000 Biometer &amp; Pachymeter
7. UTILITIES
7.1 Accessing the Utility Window
7.1.1 Accessing the Utility window from biometry mode
1. Touch the Utility key (1) on the Biometry
measurement window (fig. 1) or on the IOL
calculation window (fig. 2) to display the Utility
window (fig. 3).
2. If you wish to access the Biometry measurement window, touch the Measure key (2).
3. If you wish to access the IOL calculation window, touch the IOL key (3).
4. If you wish to enter Pachymetry mode, touch
the PACHY key (4) and then touch the OK key
(5).
7.1 Accessing the Utility Window
53
AL-2000 Biometer &amp; Pachymeter
7.1.2 Accessing the Utility window from pachymetry mode
1. Touch the Utility key (1) on the Pachymetry
map mode measurement window (fig. 1) or on
the Pachymetry single mode measurement
window (fig. 2) to display the Utility window
(fig. 3).
2. If you wish to return to Pachymetry measurement, touch the Measure key (2).
3. If you wish to enter Biometry mode, touch the
AL key (3) and then touch the OK key (4).
7.1 Accessing the Utility Window
54
AL-2000 Biometer &amp; Pachymeter
7.2 Description of Utility Windows
7.2.1 Utility window for biometry mode
Personal/corresponding value
Calculate personal lens constants.
Date/Time Setup
Enter current date
and time.
IOL data entry
Enter IOL
information.
IOL Formula
Select IOL
formulas.
Physician data entry
Enter physicians’ names.
Patient data
Display or edit stored
patient data.
Feed/Backfeed
Adjust printer paper.
Measure
Switch to biometry
measurement screen.
Data management
Analyze stored data.
RS-232C
Set data communication parameters.
Sound set
Control sound.
Print mode
Select print
mode.
Contact/immersion
Switch between contact
mode and immersion mode.
IOL
Switch to IOL calculation screen.
PACHY
Switch to Pachymetry mode.
7.2 Description of Utility Windows
55
AL-2000 Biometer &amp; Pachymeter
7.2.2 Utility window for pachymetry mode
Data selection
Select the data presentation mode.
Date/Time Setup
Enter current date
and time.
Map construction
Select the pachymetry
map locations.
RS-232C
Set data communication parameters.
Physician data entry
Enter physicians’ names.
Feed/Backfeed
Adjust printer paper.
Measure
Switch to pachymetry
measurement screen.
Patient data
Display stored patient
data and cross-sectional
view of cornea.
Sound set
Control sound.
AL
Switch to Biometry/IOL
calculation mode.
7.2 Description of Utility Windows
56
Print mode
Select print
mode.
AL-2000 Biometer &amp; Pachymeter
7.3 Utility Setup for Biometry and IOL Calculation
7.3.1 IOL data entry
Up to 10 lens models with associated constant values may be entered in the IOL
data list. These lens models may be selected and their pre-set values used for IOL
power calculation.
The appropriate lens constant for each IOL calculation formula is listed below:
• SRK II formula:
A constant
• SRK/T formula:
A constant
• Holladay formula:
Surgeon’s factor (SF)
• Hoffer-Q formula:
ACD constant
• Haigis standard formula: A constant
• Haigis optimized formula: a0, a1, a2
The procedure for entering IOLs is as follows:
1. Touch the IOL Data Entry key (1) on the biometry Utility screen (fig. 1) to access the IOL data
entry window (fig. 2).
2. Select the memory number to be entered using
the up and down arrow keys (2) and the item to
be entered using the right and left arrow keys
(3). The location of the flashing cursor indicates
the category for the next data entry. If you do
not want to enter data in this category, move to
the desired category using the right and left
arrow keys. Continue pressing the arrow keys to
enter a0, a1 and a2.
3. Enter the IOL data using the alphabetic character and number keys (4). Switch between the
alphabetic character keys and the number keys
by touching the Switchover key (5).
4. The following information may be entered:
• Company: Up to 10 letters or numbers
• Model No.: Up to 10 letters or numbers
• A-const.:
Acceptable range 100.00 - 130.00
• SF:
Acceptable range -5.00 - +10.00
• ACDconst:: Acceptable range 0.00 - +10.00
• a0:
Acceptable range: -9.99 - +9.99
• a1, a2:
Acceptable range: -0.99 - +0.99
The constants a0, a1 and a2 are used under
the following conditions:
2 &lt; a0 + a1 x 3.37 + a2 x 23.39 &lt; 7
2 &lt; a0 + a1 x 2.53 + a2 x 20.00 &lt; 7
2 &lt; a0 + a1 x 3.50 + a2 x 27.00 &lt; 7
In the event of an erroneous entry, press the
Delete key (6).
5. Set entered data by touching the Return key (7).
6. When data entry is complete, touch the IOL
Data Entry key (1) to return to the biometry
Utility screen.
7.3 Utility Setup for Biometry &amp; IOL Calculation
57
AL-2000 Biometer &amp; Pachymeter
7.3.2 IOL formula setup
Six pre-set IOL calculation formulae are available. To select the formulae that you plan to
use, do the following:
1. Touch the IOL Formula key (1) on the
Biometry Utility screen (fig. 1) to display
the formula selection screen (fig. 2).
2. The six available formulas are: SRK II,
SRK/T, Holladay, Hoffer Q, Haigis standard
and Haigis optimized.
3. To select a formula, touch the adjacent
number key so that it is reverse-highlighted (black).
You may select up to five of the six formlas. Those chosen will be available for
selection from the IOL power calculation
window (see section 4.3).
4. After making your selections, touch the
IOL Formula key (3) to return to the
Biometry Utility screen (fig. 1).
To set a1 and a2 for the Haigis standard formula:
1. Press the Parametr key (4) on the formula
selection screen to activate the parameter
setting screen (fig. 3).
2. Touch the item keys (5) to select a1 and
a2 and enter the desired value for each
using the number keys (6).
In the event of an erroneous entry, press
the Delete key (7).
3. After the values have been entered, touch
the Return key (8) to register the entries.
4. After both a1 and a2 have been set, touch
the Parameter Set key (9) to return to the
formula selection screen (fig. 2) and touch
the IOL Formula key (3) to return to the
biometry Utility screen (fig. 1).
Please contact your Tomey representative to
inquire about loading additional IOL formulae.
7.3 Utility Setup for Biometry &amp; IOL Calculation
58
AL-2000 Biometer &amp; Pachymeter
7.3.3 Personal lens constant calculation (personal/corresponding value)
After the IOL has been implanted and the
post-operative refraction has been determined, the optimal lens constants (personal Aconstant, personal SF, corresponding SF and
personal ACD) can be calculated as follows:
1. Touch the Personal/Corresponding Value
key (1) on the biometry Utility screen to display the calculation screen (fig. 2).
2. Touch the Eye key (2) to select the eye
(right or left) for which you wish to calculate
constants.
3. Touch the databox (3) for each item and
enter the value using the number keys (4).
The selected databox will be reverse highlighted (black).
In the event of an erroneous entry, press the
Delete key (5).
4. Touch either the Return key (6) or touch the
databox (3) again to register the value.
5. Repeat steps 3, 4 and 5 for each item: postoperative refraction, implanted IOL power,
axial length, anterior chamber depth, keratometry values* and A constant.
*Either the flat K or the steep K may be
entered first. Values may be entered in
either diopters or millimeters.
6. After all values have been entered, the
instrument will automatically display the calculation results.
7. Touch the Eye key (2) if you wish to calculate constants for the other eye and repeat
steps 3-7.
8. Touch the Print key (7) to obain a printout
of the calculation results.
9. When you are finished, touch the
Personal/Corresponding Value key (1) to
return to the biometry Utility screen (fig. 1).
Based on the outcome of multiple surgeries,
the optimal personal lens constant values for a
particular surgeon may be determined using
the Data Management utility (see section
7.3.5).
7.3 Utility Setup for Biometry &amp; IOL Calculation
59
AL-2000 Biometer &amp; Pachymeter
7.3.4 Display and compilation of patient data
• The memory card must be inserted securely, as instructed in section
3.2.2f, in order to display and compile stored patient data.
• The memory card must be formatted before using, as described in
section 8.4.
a) Displaying axial length data
To display stored axial length data:
1. Touch the Patient data key (1) on the biometry Utility screen to display the Patient
Data list (fig. 2).
2. Touch the arrow keys (2) to select the
patient whose axial length data you want
to display. If necessary, change the page
using the Forward key (3) or Back key (4).
If you wish to return to the biometry Utility
screen at any time, touch the Exit key (5).
4. Touch the Echo key (6) to display the
selected patient’s axial length data (fig. 3).
5. To obtain a printout of the data, touch the
Print key (7).
6. To display the axial length data for the
patient’s other eye, touch the Eye key (8).
7. If you wish to display the patient’s IOL
data, touch the IOL key (9) and follow the
instructions in section 7.3.4b.
8. If you wish to view personal lens constants,
touch the P/C cal key (10). (If you wish to
calculate personal lens constants, see section 7.3.3.)
9. To return to the Patient Data list (fig. 2),
touch the Exit key (11).
7.3 Utility Setup for Biometry &amp; IOL Calculation
60
AL-2000 Biometer &amp; Pachymeter
b) Compiling IOL data
To compile a patient’s IOL data:
1. Touch the Patient data key (1) on the biometry Utility screen to display the Patient
Data list (fig. 2).
2. Touch the arrow keys (2) to select the
patient whose data you want to display. If
necessary, change the page using the
Forward key (3) or Back key (4).
If you wish to return to the biometry
Utility screen at any time, touch the Exit
key (5).
3. Touch the IOL key (6) to display the
screen for compilation of the selected
patient’s IOL data.
4. To prepare to enter the the IOL model
and manufacturer, touch the Implanted
IOL Model key (7). The lens Model and
Company names (8) will be reverse highlighted.
5. Touch the model/manufacturer of the
selected IOL to enter it in the Implanted
IOL Model databox.
6. To enter the implanted IOL power and
post-operative refraction, touch the
Implanted IOL Power and Post Op. Ref.
keys (9) and enter the value for each
using the number keys (10). The acceptable ranges are:
Implanted IOL Power: 0.01 - 50.00 D
Post Op Refraction: -10.00 - +10.00 D
In the event of an erroneous entry, press
the Delete key (11).
7. To store the implanted IOL model and
power and the postoperative refraction,
touch the Memory key (12).
8. To obtain a printout, touch the Print key
(13).
9. If you wish to view personal lens constants, touch the P/C cal key (14). (If you
wish to calculate personal lens constants,
see section 7.3.3.)
10. To display IOL data for the patient’s
other eye, touch the Eye key (15).
11. To return to the Patient Data list (fig. 2),
touch the Exit key (16).
7.3 Utility Setup for Biometry &amp; IOL Calculation
61
AL-2000 Biometer &amp; Pachymeter
c) Displaying personal lens constants
To display personal lens constant data:
1. Touch the P/C cal key (1) on the axial
length data screen (fig. 1) or the P/C cal
key (2) on the IOL data screen (fig. 2) to
display the personal lens constant screen
(fig. 3).
2. If all of the required values have been
entered, the results of the personal lens
constant calculations will be displayed.
Note: Values cannot be entered on this
screen. To enter values, see sections 4.3.4,
4.3.5 and 7.3.3.
3. To obtain a printout, touch the Print key (3).
4. To display personal lens constant data for
the patient’s other eye, touch the Eye key
(4).
5. To return to the Patient Data list, touch the
Exit key (5).
d) Deleting patient data
To delete patient data from the memory card:
1. Touch the Patient Data key on the biometry
Utility screen to display the Patient Data list.
2. Touch the arrow keys (1) to select the
patient whose data you want to delete. If
necessary, change the page using the
Forward key (2) or Back key (3).
3. To delete the selected patient’s data, touch
the Delete key (4) for approximately one
second until you hear a beep. Data for both
eyes will be deleted.
4. To delete all patient data, touch the All
Clear key (5) for approximately one second
until you hear a beep.
7.3 Utility Setup for Biometry &amp; IOL Calculation
62
AL-2000 Biometer &amp; Pachymeter
7.3.5 Biometry/IOL Data Management
• Ascertain that the memory card is securely inserted as instructed in
section 3.2.2f.
• The memory card must be formatted before using, as described in
section 8.4.
IOL data stored on the memory card (as
described in section 7.3.4b) may be analyzed to
display four types of graphs, illustrated in figs. 25. The patient data are compiled according to
IOL Model name. If two or more IOLs bear the
same name, they will be treated as the same lens
even if they have different lens constants.
1. Insert the memory card as instructed in section
3.2.2f.
2. Touch the Data Management key (1) on the
biometry Utility screen (fig. 1) to display the
Graph screen (figs. 2-5).
3. The following four graphs may be displayed by
touching the corresponding Graph key (2):
Graph 1: Relationship between axial length
and personal lens constant (fig. 2).
Graph 2: Relationship between anterior chamber depth and personal lens constant
(fig. 3).
Graph 3: Relationship between IOL power and
personal lens constant (fig. 4, next
page).
Graph 4: Histogram showing personal lens
constant values (fig. 5, next page).
The following values for the lens constant associated with the selected formula and lens
model are displayed at the left of the screen:
mean value, maximum value, minimum value
and standard deviation. The number of data
points is also displayed.
4. Touch the Formula key (3) to change the calculation formula for which data are displayed.
5. Touch the Model key (4) to change the IOL
model for which data are displayed.
6. Touch the Exit key (5) to return to the biometry
Utility screen.
7.3 Utility Setup for Biometry &amp; IOL Calculation
63
AL-2000 Biometer &amp; Pachymeter
7.3.6 Contact/Immersion
To select the biometry probe mode:
1. Touch the Contact/Immersion key (1) on the
biometry Utility screen (fig. 1) to display the
Contact/Immersion screen (fig. 2).
2. Touch the Contact key (2) or the Immersion
key (3). The selected option is reverse highlighted.
3. Touch the Contact/Immersion key (4) to return
to the biometry Utility screen.
7.3 Utility Setup for Biometry &amp; IOL Calculation
64
AL-2000 Biometer &amp; Pachymeter
7.4 Utility Setup for Pachymetry
7.4.1 Map construction
For the map measurement mode, the measuring locations and the order in which the
measurements are taken should be pre-set.
Two maps, MAP 1 and MAP 2, may be constructed.
To construct MAP 1 and MAP 2:
1. Touch the Map Construction key (1) on the
pachymetry Utility screen (fig. 1) to display
the map construction screen (fig. 2).
2. Touch the MAP 1 key (2) to select MAP 1.
The key for the selected map is reverse
highlighted.
3. To delete the pre-set map, touch the AClear key (3). In the event that you have
accidently deleted or wish to stop deleting, touch the Cancel key (4) to restore the
previous map.
4. Consecutively touch as many elements (5)
as you want to measure in the order that
you want to measure them. The selected
elements will be reverse highlighted. The
numbers in the boxes indicate the measuring order. Non-selected elements are
blank.
5. If you wish to remove an element, touch it
again. In the event of an erroneous
removal, touch the Cancel key (4) to
restore the previous selection.
6. After the elements have been selected,
touch the OK key (6) to register the map.
7. Touch the MAP 2 key (2) and repeat steps
3-6 to construct Map 2.
8. When map construction is complete,
touch the Map Construction key (7) to
return to the pachymetry Utility screen
(fig. 1).
7.4 Utility Setup for Pachymetry
65
AL-2000 Biometer &amp; Pachymeter
7.4.2 Data display selection
The following data display options are available:
Latest:
Most recently acquired measurement.
Minimum: Minimum measurement value.
Average: Mean of all measurement values.
The data display option can be changed after
the measurements have been taken.
To select the desired data display option:
1. Touch the Data Selection key (1) on the
pachymetry Utility window (fig. 1) to activate the Data Selection window (fig. 2).
2. Select the desired data display option by
touching the appropriate key (2). The
screen will return to the pachymetry Utility
window (fig. 1).
When measurement results are displayed (fig.
3), the selected data display option will be
indicated to the upper right of the map.
7.4 Utility Setup for Pachymetry
66
AL-2000 Biometer &amp; Pachymeter
7.4.3 Patient data and corneal cross-section display
• In order to display patient data, the memory card must be inserted
securely, as instructed in section 3.2.2f.
• The memory card must be formatted before using as described in
section 8.4.
a) Displaying stored pachymetry data
To display stored pachymetry data:
1. Touch the Patient data key (1) on the
pachymetry Utility screen to display the
Patient Data list (fig. 2).
2. Touch the arrow keys (2) to select the
patient whose pachymetry data you want
to display. If necessary, change the page
using the Forward key (3) or Back key (4).
If you wish to return to the pachymetry
Utility screen at any time, touch the Exit
key (5).
3. After selecting the patient, touch the Data
key (6) to display the selected patient’s
pachymetry data (fig. 3).
4. If you wish to change from actual value display to biased value display, touch the data
display key (7).
5. To obtain a printout of the data, touch the
Print key (8).
6. To display the pachymetry data for the
patient’s other eye, touch the Eye key (9).
7. To return to the Patient Data list (fig. 2),
touch the Exit key (10).
7.4 Utility Setup for Pachymetry
67
AL-2000 Biometer &amp; Pachymeter
b) Displaying cross-sectional view of cornea
• At least the central corneal thickness and the 8 data points surrounding (adjacent to) the center are necessary in order to display
a cross-sectional view of the cornea.
• The cross-sectional view is not scaled. The average K value is used
[(K1 + K2)/2], not the individual K1 and K2 values.
To display a cross-sectional corneal view for
stored pachymetry data:
1. Touch the Patient data key (1) on the
pachymetry Utility screen to display the
Patient Data list (fig. 2).
2. Touch the arrow keys (2) to select the
patient whose pachymetry data you want
to display. If necessary, change the page
using the Forward key (3) or Back key (4).
If you wish to return to the pachymetry
Utility screen at any time, touch the Exit
key (5).
3. Touch the Section key (6) to display the
cross-section selection screen for the
selected cornea (fig. 3).
4. Select the K1 key (7) and enter the K1
value using the number keys (8). Then
select the K2 key (7) and enter the K2 values. (Either the flat K or the steep K may
be entered first. K values may be entered
in either diopters or millimeters. )
In the event of an erroneous entry, press
the Delete key (9).
5. Register the entered values by touching
the Return key (10).
6. Touch the Memory key (11) to store the
K1 and K2 values on the memory card.
7. Touch the arrow keys (12) to determine
the location of the cross-sectional view.
8. Touch the Rotation key (12, center) to
rotate the meridian (13) of the cross-section viewed by 45 degrees counterclockwise.
9. Touch the View key (14) to display the
cross-sectional diagram of the cornea.
10. To return to the cross-section selection
screen (fig. 3), touch the Exit key (15).
11. To return to the Patient Data list (fig. 2),
touch the Exit key (16) on the cross-section selection window (fig. 3).
7.4 Utility Setup for Pachymetry
68
AL-2000 Biometer &amp; Pachymeter
7.5 Utility Setup for General Items
7.5.1 Physicians data entry
Up to seven names can be entered in the
Physician List.
1. Touch the Physicians Data Entry key (1) on the
biometry Utility screen (fig. 1) or the pachymetry Utility screen (fig. 2) to display the Physician
List (fig. 3).
2. Touch a number (2) to activate that slot in the
list. The selected number will be reverse highlighted.
3. Enter the physician’s name using the letter
keys (3). To switch from letters and numbers,
touch the 0-9 key (4). To switch back to letters,
touch the A-Z key.
In the event of an erroneous entry, touch the
Delete key (5).
4. If you wish to enter another physician to the
list, touch the next number key (2) to select
the next slot.
5. Touch the Return key (6) to set the entered
data.
6. Touch the Physicians Data Entry key (7) to
return to the biometry or pachymetry Utility
screen (fig. 1 or fig. 2).
7.5 General Utility Setup
69
AL-2000 Biometer &amp; Pachymeter
7.5.2 Date/time setup
To set the data and time:
1. Touch the Date/Time Setup key (1) on the biometry Utility screen (fig. 1) or the pachymetry
Utility screen (fig. 2) to display the Date/Time
Setup screen (fig. 3).
2. Touch each item key (2) to prepare to enter
information for that item. The selected item
will be reverse highlighted.
3. Enter the information using the number keys
(3).
In the event of an erroneous entry, touch the
Delete key (4).
4. Touch the Return key (5) to register each
value.
5. When settings are completed, touch the
Date/Time Setup key (6) to return to the biometry or pachymetry Utility window (fig. 1 or 2).
7.5 General Utility Setup
70
AL-2000 Biometer &amp; Pachymeter
7.5.3 Data Communication Port (RS-232C)
Measured data may be transferred to a computer via a data communication port (RS-232C).
Follow these steps to attach an RS-232C communication cable:
1. Insert the connector adapter (1) to the RS232C connection terminal (2) on the back of
the instrument and secure the connection by
tightening the screws.
2. Connect the RS-232C communication cable (3)
to the adapter and secure the connection by
tightening the screws.
Accessory equipment connected to the RS-232C
interface must be certified according to the
appropriate IEC 60601-1 standard for medical
equipment. Furthermore, all configurations must
comply with the IEC 60601-1 system standard.
Anyone who connects additional equipment to
the signal input port or signal output port is configuring a medical system and is, therefore,
responsible for assuring that the system complies with the requirements of the IEC 60601-1
system standard. If in doubt, contact the Tomey
technical service department or your local Tomey
representative.
a. Pin positions of the RS-232C connection terminals
RxD:
TxD:
DTR:
SG:
DSR:
RTS:
CTS:
Receive data
Transmit data
Data terminal ready
Signal ground
Data set ready
Request to send
Clear to send
7.5 General Utility Setup
71
AL-2000 Biometer &amp; Pachymeter
b. Setting the communication conditions
To set the communication conditions:
1. Touch the COM (RS-232C) key (1) on the
biometry Utility screen (fig. 1) or the
pachymetry Utility screen (fig. 2) to display
the biometry or pachymetry RS-232C Data
Communication screen (fig. 3 and fig. 4,
respectively).
2. Touch the Setup key (2) to display the RS232C Setup screen (fig. 5).
3. Select the parameter to be set using the
up/down arrow keys (3). The options for the
selected parameter are shown at the bottom of the screen.
4. Select the desired option for each parameter using the left/right arrow keys (4).
5. Touch the Return key (5) to register each
selection.
6. Touch the Exit key (6) to return to the RS232C Data Communication screen for biometry (fig. 3) or pachymetry (fig. 4).
7. To return to the biometry or pachymetry
Utility screen, touch the COM (RS-232C) key
(7) on the RS-232C screen (fig. 3 or fig. 4).
7.5 General Utility Setup
72
AL-2000 Biometer &amp; Pachymeter
c. Transmitting data
After biometry or pachymetry measurements
have been acquired from one or both eyes, the
biometry and IOL data or pachymetry data can
be transmitted to another AL-2000 or to a computer (PC) as follows:
1. Touch the COM (RS-232C) key on the biometry Utility screen or the pachymetry Utility
screen (see section 7.3.5b, figs. 1 &amp; 2 ) to display the appropriate RS-232C Data
Communication screen.
2. After the communication conditions have
been set (as described in section 7.3.5b),
touch the Send key (1) on the biometry RS232C screen (fig. 1) or the pachymetry RS232C screen (fig. 2) to display the data (fig. 3
and fig. 4, respectively).
3. Touch the OK key (2) to initiate data transmission.
To abort the transmission, touch the Cancel
key (3).
4. After the data transmission is complete (indicated by “Sent!” at the upper right of the
screen), you may obtain a printout of the
transferred data by touching the Print key (4).
(Shown for biometry in fig. 5.)
5. To return to the Utility screen, touch the COM
(RS-232C) key (5).
7.5 General Utility Setup
73
AL-2000 Biometer &amp; Pachymeter
d. Receiving data
Biometry data may be received from another
AL-2000 or from a computer (PC). (Pachymetry
data cannot be received.)
To receive data:
1. Touch the COM (RS-232C) key on the biometry Utility screen to display the RS-232C
Data Communication screen (fig. 1).
2. After the communication conditions have
been set (as described in section 7.5.3b),
touch the Receive key (1) on the biometry
Data Communication screen (fig. 1). The
instrument is ready for receiving data (fig. 2).
3. Click the OK key (2) to initiate data reception.
To abort the reception, touch the Cancel key
(3).
4. After the data reception is complete (indicated by “Received!” at the upper right of
the screen), you may obtain a printout of the
received data by touching the Print key (4).
5. To return to the Utility screen, touch the
COM (RS-232C) key (5).
7.5 General Utility Setup
74
AL-2000 Biometer &amp; Pachymeter
7.5.4 Sound Setup
To adjust the sound:
1. Touch the Sound Set key (1) on the biometry
Utility screen (fig. 1) or the pachymetry Utility
screen (fig. 2) to display the Sound Adjustment
window (fig. 3).
2. Touch the Volume keys (2) to adjust the sound
level. The options are:
• L:
Low
• M:
Medium
• H:
High
3. To turn the sound on or off, touch the On or Off
key (3).
4. Touch the Sound Set key (4) to return to the biometry or pachymetry Utility screen (fig. 1 or fig.
2).
7.5 General Utility Setup
75
AL-2000 Biometer &amp; Pachymeter
7.5.5 Print Mode Setup
The printout options are:
• Standard: Includes date, patient name and
ID number, physician name and
all data.
• Simple: Includes no identifying information and, for some printouts,
provides an abbreviated version
of the data.
1. Touch the Print Mode key (1) on the biometry
Utility screen (fig. 1) or the pachymetry Utility
screen (fig. 2) to display the Print Mode window (fig. 3).
2. Touch the Standard or Simple key to select
the desired printout mode.
3. Touch the Print Mode key (3) to the biometry
or pachymetry Utility screen (fig. 1 or fig. 2).
7.5 General Utility Setup
76
AL-2000 Biometer &amp; Pachymeter
8. MEMORY CARD
• Biometry measurements, IOL data and pachymetry measurements can be stored
on the memory card. If a memory card other than the one provided is used, there
is no guarantee that the data will be properly stored.
• The PC memory card used with the AL-2000 is an SRAM type card. Therefore,
an SRAM type card reader, not a Flash Memory reader, must be used. If a Flash
Memory reader is used, data stored on the memory card may be corrupted.
• If data on the memory card are edited using a computer, the card no longer can
be used with the AL-2000. It will be necessary to reformat the card before it can
be used with the AL-2000.
8.1 Memory Card Specifications
The memory card is 68 pin SRAM card that complies with the PC Card Standard.
• Configuration:
Type 1
• Bytes of memory:
512 Kb
• Power voltage:
5 &plusmn; 0.5 V
• Access time:
200 ns
Cards with 1 Mb and 2 Mb are also available.
8.2 Memory Card Capacity and Maximum Number of Entries
Either biometry measurements and IOL data or pachymetry measurements can be stored
for both eyes of the specified number of patients. In other words, there are 237 “bins” on
the 512 Kb memory card. Either biometry/IOL data or pachymetry data for one or both
eyes can be stored in each bin.
8.3 Memory Card Battery
8.3.1 Replacing the battery
If the message “Memory card is low battery!” is displayed, replace the battery by
following the directions in the memory card Instruction Manual.
IMPORTANT: If the battery is not replaced within 10 minutes of receiving the “low
battery” message, data stored on the memory card might be lost.
8.3.2 Battery life
The life of the battery varies as a function of the memory capacity, as indicated
below.
8 Memory Card
77
AL-2000 Biometer &amp; Pachymeter
8.4 Formatting the Memory Card
The memory card must be formatted before its initial use.
See instructions in Section 3.2.2f) for inserting the
memory card.
Before using the memory card for the first time, format it as follows:
1. Touch the Patient Data key (1) on the biometry
Utility screen (fig. 1) or the pachymetry Utility
screen (fig. 2) to display the Patient Data screen.
2. If the memory card has not been formatted, the
message “Memory card is is not formatted!” will
be displayed (fig. 3).
3. Touch the Format key (2) for approximately one
second until you hear a beep. The memory card
will be formatted (fig. 4) and ready for data storage.
4. Touch the Exit key (3) to return to the biometry or
pachymetry Utility screen (fig. 1 or fig. 2).
8.4 Formatting the Memory Card
78
AL-2000 Biometer &amp; Pachymeter
8.5 Reading the Memory Card on a Windows Computer
8.5.1 Rewriting the Windows PC system configuration file
1. Open the CONFIG.SYS file in the root directory of the C drive using Notepad.
2. Add the following information to the last line of the Config.sys file:
The directory shown in the box may differ for different computers. Specify the
directory that contains the Windows system file.
3. Save the CONFIG.SYS file, overwriting the previous version.
4. Re-start Windows.
8.5.2 PC data: location, filename and format
1. Insert the Memory Card into the PC card slot. You will hear a beep when Windows
identifies the Memory Card.
2. Open Windows Explorer and view the contents of the Memory Card removable
drive. You will find two directories:
• Axialdt:
Stores biometry and IOL data.
• Pachydt: Stores pachymetry data.
3. Each of the data files may be opened using Notepad.
The files are identified by patient ID.
Axial length and corneal thickness data are stored in text mode.
Axial length waveform data are stored in binary mode.
8.5.3 Removing the Memory Card from the computer
1. Click on the Windows Start button.
2. Select Settings.
3. Select Control Panel.
4. Double-click on the PC Card [PCMCIA] icon.
5. On the Socket Status window, select the socket that contains the Memory Card.
6. Click the Stop button
7. When the message “You may safely remove this device” is displayed, click OK
and remove the Memory Card by pressing the button (see section 3.2.2f).
8.5.4 Handling the Memory Card files
Files from the AL-2000 Memory Card are read-only files. If you wish to modify the
contents of the file, you must make a copy of it and release the read-only attributes
of the copy.
8.5 Reading the Memory Card on a Windows Computer
79
AL-2000 Biometer &amp; Pachymeter
8 Memory Card
80
AL-2000 Biometer &amp; Pachymeter
9. TECHNICAL INFORMATION
9.1 IOL Calculation Formulae
9.1.1 SRK/II
a. Emmetropic IOL power (D)
b. Ametropic IOL power (D)
c. Desired postoperative refraction
Where:
if
L &lt; 20.0 mm, then A1 = A + 3
if 20.0 &lt; L &lt; 21.0 mm, then A1 = A + 2
if 21.0 &lt; L &lt; 22.0 mm, then A1 = A + 1
if 22.0 &lt; L &lt; 24.5 mm, then A1 = A
if
L &gt; 24.5 mm, then A1 = A - 0.5
if Pemme &lt; 14, then CR = 1.00
if Pemme &gt; 14, then CR = 1.25
A:
K:
L:
P:
REF:
A-constant
Corneal refraction (D) [(K1 + K2)/2]
Axial length (mm)
Power of IOL implant (D)
Postoperative refractive power
9.1 IOL Calculation Formulae
81
AL-2000 Biometer &amp; Pachymeter
9.1.2 SRK/T
a. Emmetropic IOL power (D)
b. Ametropic IOL power (D)
c. Desired postoperative refraction
Where:
r:
LC:
W:
H:
Ofst:
C1:
V:
na:
nc:
L1:
L:
A:
K:
REF:
P:
Average corneal radius of curvature (mm) = 337.5/K
Modified axial length (mm)
if L &gt; 24.2, then LC = L
if L &lt; 24.2, then LC = -3.446 + 1.716L - 0.0237L*L
Corneal thickness by calculation (mm) = -5.41 + 0.58412LC + 0.098K
Height of the corneal dome (mm) = r - SQRT(r*r - W*W/4)
Calculated distance between the iris surface and IOL optical surface
(including the corneal thickness) (mm)
= ACD const = -3.336
= (0.62467A - 68.747) - 3.336
Estimated postoperative anterior chamber depth (mm)
= H + Ofst
Vertex distance (mm) = 12
Refractive index of aqueous and vitreous = 1.336
Refractive index of cornea = 1.333
Optical axial length (mm) = L + (0.65696 - 0.02029L)
Measured axial length (mm)
A-constant
Average corneal refractive power: (K1 + K2)/2 (D)
Desired postoperative refraction (D)
Power of IOL implant (D)
9.1 IOL Calculation Formulae
82
AL-2000 Biometer &amp; Pachymeter
d. Personal A-constant
Where:
P:
S:
C:
AREF:
Power of IOL implant (D)
Spherical index (D)
Cylindrical index (D)
Postoperative refraction &lt;equivalent to the spherical index (D)&gt;
= S + C/2
RF:
Refractive factor
if P &gt; 16, then RF = 1.25
if P &lt; 16, then RF = 1
L:
Axial length
K:
Average corneal refraction (K1 + K2)/2 (D)
COR: Correcting value
if
L &lt; 20.0, then COR = 3
if 20.0 &lt; L &lt; 21.0, then COR = 2
if 21.0 &lt; L &lt; 22.0, then COR = 1
if 22.0 &lt; L &lt; 24.5, then COR = 0
if
L &gt; 24.5, then COR = -0.5
9.1 IOL Calculation Formulae
83
AL-2000 Biometer &amp; Pachymeter
9.1.3 Holladay
a. IOL power (D)
b. Desired postoperative refraction (D)
Where:
na:
nc:
L:
r:
K:
SF:
REF:
V:
P:
L2:
C2:
Refractive index of aqueous and vitreous = 1.336
Refractive index of cornea = 4.0/3.0
Measured axial length (mm)
Average corneal radius of curvature (mm) = 337.5/K
Average corneal refractive power = (K1 + K2)/2 (D)
Surgeon factor
(Distance between iris surface and optical center of IOL) (mm)
Desired postoperative refraction
Vertex distance (mm) = 12
Power of IOL implant (D)
Modified axial length (mm) = L + 0.2
Anatomical anterior chamber depth (mm) (distance between corneal
apex and iris surface) (mm)
if r &lt; 7 mm, then Rag = 7 mm
if r &gt; 7 mm, then Rag = r
AG = 12.5L/23.45 (if AG &gt; 13.5 mm, then AG = 13.5 mm)
9.1 IOL Calculation Formulae
84
AL-2000 Biometer &amp; Pachymeter
c. Personal SF
Where:
na:
nc:
L:
r:
K:
V:
P:
L2:
S:
C:
AREF:
C2:
Refractive index of aqueous and vitreous = 1.336
Refractive index of cornea = 4.0/3.0
Measured axial length (mm)
Average corneal radius of curvature (mm) = 337.5/K
Average corneal refractive power = (K1 + K2)/2 (D)
Vertex distance (mm) = 12
Power of IOL implant (D)
Modified axial length (mm) = L + 0.2 (mm)
Spherical index (D)
Cylindrical index (D)
Postoperative refraction &lt;equivalent to the spherical index (D)&gt;
= S + C/2
Anatomical anterior chamber depth (mm) (distance between corneal
apex and iris surface) (mm)
if r &lt; 7 mm, then Rag = 7 mm
if r &gt; 7 mm, then Rag = r
AG = 12.5L/23.45 (if AG &gt; 13.5 mm, then AG = 13.5 mm)
d. Corresponding SF
Where:
A:
A-constant
9.1 IOL Calculation Formulae
85
AL-2000 Biometer &amp; Pachymeter
9.1.4 Hoffer Q
a. Emmetropic IOL power (D)
Where:
b. Desired postoperative refraction by spectacle (D)
Where:
C=X+Y
X = C1 + 0.3(L - 23.5) + (tan K)2
Y = 0.1M(23.5 - L) 2 tan {0.1(G - L)2} - 0.99166
if L &lt; 23.0, then M = +1, G = 28.0
if L &gt; 23.0, then M = -1, G = 23.5
if L &gt; 31.0, then L = 31.0
if L &lt; 18.5, then L = 18.5
P:
L:
C1:
K:
Rx:
Power of IOL implant (D)
Measured axial length (mm)
Personalized anterior chamber depth (mm)
Average refractive power = (K1 + K2)/2 (D)
Desired postoperative refraction by spectacle (D)
9.1 IOL Calculation Formulae
86
AL-2000 Biometer &amp; Pachymeter
c. Personal ACD
Where:
d. Predicted postoperative anterior chamber depth (ACD)
Where:
X = C1 = 0.3(L - 23.5) + (tan K)2
Y = 0.1 M(23.5 - L)2 tan{0.1(G - L)2} - 0.99166
if L &lt; 23.0, then M = +1, G = 28.0
if L &gt; 23.0, then M = -1, G = 23.5
if L &gt; 31.0, then L = 31.0
if L &lt; 18.5, then L = 18.5
P:
L:
C1:
K:
ARx:
Power of IOL implant (D)
Measured axial length (mm)
Personalized anterior chamber depth (mm)
Average refractive power = (K1 +K2)/2 (D)
postoperative refraction by spectacle (D)
9.1 IOL Calculation Formulae
87
AL-2000 Biometer &amp; Pachymeter
9.1.5 Haigis standard
a. IOL power (D)
Where:
b. Predicted postoperative refractive power (D)
Where:
na:
nc:
r:
K:
L:
ACD:
REF:
V:
P:
a1:
a2:
VKpr:
ELpr:
Refractive index of aqueous and vitreous = 1.336
Refractive index of cornea = 1.3315
Average corneal radius of curvature (mm)
Average corneal refractive power (D)
Axial length (mm)
Anterior chamber depth (mm)
Desired postoperative refractive power (D)
Vertex distance (mm) = 12
Power of IOL implant (D)
0.4 (default value)
0.1 (default value)
3.37
23.39
9.1 IOL Calculation Formulae
88
AL-2000 Biometer &amp; Pachymeter
c. Personal A-constant
Where:
na:
K:
L:
ACD:
AREF:
V:
P:
a1:
a2:
Refractive index of aqueous and vitreous = 1.336
Average corneal refractive power (D)
Axial length (mm)
Anterior chamber depth (mm)
Postoperative refractive power (D)
Vertex distance (mm) = 12
Power of IOL implant (D)
0.4
0.1
9.1 IOL Calculation Formulae
89
AL-2000 Biometer &amp; Pachymeter
9.1.6 Haigis optimized
a. IOL power (D)
Where:
b. Predicted postoperative refractive power (D)
Where:
na:
nc:
RC:
DC:
L:
ACD:
REF:
V:
P:
Refractive index of aqueous and vitreous = 1.336
Refractive index of cornea = 1.3315
Average corneal radius of curvature (mm)
Average corneal refractive power (D)
Axial length (mm)
Anterior chamber depth (mm)
Desired postoperative refractive power (D)
Vertex distance (mm) = 12
Power of IOL implant (D)
-10 &lt; a0 &lt; +10
-1 &lt; a1 &lt; +1
-1 &lt; a2 &lt; +1
2 &lt; a0 + a1 x 3.37 + a2 x 23.39 &lt; 7
2 &lt; a0 + a1 x 2.53 + a2 x 20.00 &lt; 7
2 &lt; a0 + a1 x 3.50 + a2 x 27.00 &lt; 7
9.1 IOL Calculation Formulae
90
AL-2000 Biometer &amp; Pachymeter
9.2 Ultrasound Velocity used in Axial Length Measurement
9.2.1 Normal
• Average ultrasound velocity:
1,550 m/s
• Average ultrasound velocity in the lens:
1,641 m/s
• Average ultrasound velocity in the anterior chamber: 1,532 m/s
Axial length is calculated using the following formula:
Where:
L:
V:
t:
Axial length
Average ultrasound velocity
Time
9.2.2 Dense Cataract
• Average ultrasound velocity:
1,548 m/s
• Average ultrasound velocity in the lens:
1,629 m/s
• Average ultrasound velocity in the anterior chamber: 1,532 m/s
Axial length is calculated using the same formula as for the normal lens.
9.2.3 Aphakic
• Average ultrasound velocity:
1,532 m/s
Axial length is calculated using the same formula as for the normal lens.
9.2.4 Pseudophakic
• Ultrasound velocity in IOL*:
Pseudophakic 1 - PMMA
Pseudophakic 2 - Silicon
Pseudophakic 3 - Acrylic
2,718 m/s
1,049 m/s
2,200 m/s
*Ultrasound velocity may vary between materials and manufacturers
and depending on temperature.
• Biometric ultrasound velocity:
1,532 m/s
• Average ultrasound velocity in the anterior chamber: 1,532 m/s
Axial length is calculated using the following formula:
Where:
Lp:
Axial length
L:
Axial length calculated with the biometric ultrasound velocity
Th:
Central thickness of IOL (must be entered)
VBIO: Biometric ultrasound velocity
VIOL: Ultrasound velocity in the IOL (must be entered)
9.2 Ultrasound velocity used in axial length measurement
91
AL-2000 Biometer &amp; Pachymeter
9.3 Axial Length Calculation in Eyes with Silicone Oil
9.3.1 Normal eyes in which vitreous is replaced by silicone oil
After performing axial length measurement with the eye type set for Normal
(default setting), use the following formula to calculate axial length:
Where:
AL(S)
AL
LENS
ACD
V(a)
V(lens)
V(ac)
V(sil)
=
=
=
=
=
=
=
=
Axial length for eye with silicone oil
Axial length (measured)
Lens thickness (measured)
Anterior chamber depth (measured)
Average ultrasound velocity (default = 1,550 m/s)
Velocity in lens (default = 1,641 m/s)
Velocity in anterior chamber (default = 1,532 m/s)
Velocity in silicone oil (provided by silicone oil manufacturer)
9.3.2 Pseudophakic eyes in which vitreous is replaced by silicone oil
After performing axial length measurement with the eye type set for the appropriate Pseudophakic setting, use the following formula to calculate axial length:
Where:
AL(S)
AL(P)
ACD(P)
Th
V(bio)
V(ac)
V(sil)
=
=
=
=
=
=
=
Axial length for eye with silicone oil
Axial length (measured in pseudophakic eye)
Anterior chamber depth (measured in pseudophakic eye)
IOL thickness (provided by IOL manufacturer)
Average ultrasound velocity (default = 1,532 m/s)
Velocity in anterior chamber (default = 1,532 m/s)
Velocity in silicone oil (provided by silicone oil manufacturer)
9.3 Axial length calculation in eyes with silicone oil
92
AL-2000 Biometer &amp; Pachymeter
10. MAINTENANCE
10.1 Replacing fuses
Unplug the power cord when replacing fuses.
If the AL-2000 does not operate when the power switch
is turned ON (and you have ascertained that the power
outlet is functioning properly), it is possible that a fuse
is defective.
To replace the fuses:
1. Turn the AL-2000 off and unplug the power cord
from the power outlet.
2. Rotate the fuse holders counter clockwise approximately 90 degrees using a coin or a screwdriver, and
the holder will pop out.
3. Check both fuses and replace them if necesssary.
A good fuse will have a thin strip of metal from one
end to the other without any noticeable breaks. A
blown fuse will have all or a portion of the metal
melted away inside.
4. Reinsert the fuse holders and turn clockwise to lock
them in place.
10.2 Routine maintenance
10.2.1 Maintenance of the probes
When disconnecting the probes, be sure to hold the plug, not
the cable.
• Do not use an autoclave to sterilize the probes since this may
severely damage them.
• Do not pull on the probe cords when cleaning the probes.
a. Disinfecting the probes
Disinfect the biometry probe and the pachymetry probe by immersing the tip
in a 0.5% solution (1 to 10 dilution) of sodium hypochlorite for 10 to 20 minutes. Then rinse with distilled water and allow to dry before use.
10.1 Replacing fuses
93
AL-2000 Biometer &amp; Pachymeter
b. Cleaning the probe handle and cord
The procedure for cleaning the probe handle and cord is as follows:
1. Wipe the probe handle with a soapy or alcohol-soaked cloth and then rinse
it with water.
2. Clean the cord using a wet cloth.
3. After cleaning, remove excess water from the probe and the cord.
10.2.2 Maintenance of the main unit
• Do not use organic solvents for cleaning the AL-2000 as they
may cause damage to the surface.
• When removing the power cord, grasp the plug, not the cord
and do not apply undue force.
Wipe off dirt gently with a wet cloth and then remove excess water with a dry
cloth. If dirt is difficult to remove, use a diluted, mild detergent.
Clean the surface of the monitor with a dry cloth. If dirt is difficult to remove,
use diluted, mild detergent on a soft cloth. Then rinse and remove excess moisture with a dry cloth.
10.3 Replacing Printer Paper
Replace the paper when red lines appear on both sides of the paper.
1. Display either the biometry Utility screen or the
pachymetry Utility screen (see section 7.1).
2. With the power on, remove the printer cover (1)
by sliding it in the direction of the arrow.
3. Remove the used roll of paper. If necessary, touch
the Feed key (3) or the Backfeed key (4) on the
Utility screen (shown for biometry Utility screen).
4. Insert the leading end of the new roll of paper
into the paper insertion slot (5). The paper will be
detected and automatically fed into the printer.
(See figure on next page.)
Care should be taken to place the paper with the
correct side up, as indicated in the diagram.
5. When the leading end of the paper emerges from
the outlet slot (6), touch the Feed key (3) or the
Backfeed key (4) to adjust it. (See figures on next
page.)
6. Place the printer cover in position and cut off the
excess paper.
10.2 Routine Maintenance
94
AL-2000 Biometer &amp; Pachymeter
10.4 Storage
When storing the AL-2000, the protective cap should be placed on the clean biometry
probe tip and both probes should be placed in the cases provided.
If the instrument is not to be used for a prolonged period, disconnect the power cord
and place the dust cover over the instrument.
• Do not store this instrument in a location where it might be exposed to
water.
• Avoid excessive atmospheric pressure, high temperature, excessive
humidity, poor ventilation, direct sunlight, dust, salt or sulfur in the air.
• Do not store this instrument near chemical substances or in a location
where gas may be generated.
• Ascertain that factors such as excessive slope, vibration and impact will
not endanger the instrument (including during transportation).
10.5 Packing materials
• Keep the carton and packing materials for future use.
• If you discard the packing materials, be sure to comply with local ordi nances and regulations for disposal.
10.6 Tomey One-Year Limited Warranty
The Seller warrants this product to be free from defects in material and workmanship
under the normal use of this product for one year from the date of invoice issued by the
Seller to the original purchaser.
This warranty shall apply only to the original purchaser and shall NOT, in any way, be
transferable or assignable to any other party than the original purchaser.
This warranty also shall NOT apply if the product has not been installed, operated or
maintained in accordance with the OPERATOR MANUAL of Tomey Corporation (hereinafter called &quot;Tomey&quot;). Neither the Seller nor Tomey shall be liable for any damages
caused by the purchaser's failure to follow instructions for proper installation, use and
maintenance of the product.
10.4 Storage
95
AL-2000 Biometer &amp; Pachymeter
This warranty is only applicable to the new product and does NOT cover any damage
resulting from or caused by accident or negligence, abuse, misuse, mishandling, improper
installation, improper repair or improper modification of this product, by persons other
than personnel duly authorized by Tomey, nor to a product whose serial number or batch
number is removed, altered or effaced.
THIS WARRANTY IS EXPRESSLY IN LIEU OF ANY AND ALL OTHER WARRANTIES,
EXPRESS OR IMPLIED (INCLUDING SPECIFICALLY, WITHOUT LIMITING THE GENERALITY OF THE FOREGOING, ALL WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE), AND ALL OTHER OBLIGATION AND LIABILITY ON THE
PART OF THE SELLER AND TOMEY. NEITHER THE SELLER NOR TOMEY SHALL BE
LIABLE FOR INCIDENTAL, CONSEQUENTIAL OR SPECIAL DAMAGES UNDER ANY CIRCUMSTANCES OR FOR MORE THAN REPAIR, REPLACEMENT OR REFUND OF THE
PURCHASE PRICE OF DEFECTIVE GOODS.
10.6 Warranty
96
AL-2000 Biometer &amp; Pachymeter
11. TROUBLESHOOTING
DO NOT REMOVE THE OUTER COVER OF THIS INSTRUMENT. If you do,
you may be exposed to the danger of direct high voltage.
Do not attempt to use this instrument for any purposes other than those
specified in the manual
Before presuming that the instrument is malfunctioning, check the following troubleshooting
suggestions. If you are still unable to correct the problem, contact your local Tomey representative.
11.1 General problems
&gt; No power when the instrument is turned on. (Power indicator light not lit.)
• Is the power plug securely connected to the power receptacle?
• Is the power properly supplied?
• Is the power cord securely inserted into the power source receptacle on the back
of the AL-2000? (See section 3.2.2d)
• Are the fuses intact? (See section 10.1)
&gt; The monitor screen is too dark.
• Is the power on (see above)?
• Is the contrast adjusted properly? (See section 4.1.1)
• Is the auto power-off function activated? (See section 4.1.1)
&gt; Cannot obtain printout.
• Is the printer paper loaded properly? (See section 10.3)
• Is there any paper left?
• Is Is the correct type of printer paper used?
11.2 Biometry function
&gt; Biometry probe check is negative.
• Is the biometry probe securely connected to the terminal labeled BIO? (See section 3.2.2b)
&gt; Biometry measurement cannot be obtained.
• Is the biometry probe securely connected to the terminal labeled BIO? (See section 3.2.2b)
• Have the biometry settings been entered? (See sections 4.1.3 and 7.3)
11.1 Troubleshooting - General Problems
97
AL-2000 Biometer &amp; Pachymeter
&gt; Automatic measurement cannot be performed.
• Is the instrument set for manual measurement. (See section 4.1.3e)
• Is there any contamination due to the proximity of electromagnetic radiation (e.g.,
from a motor or high voltage power line)?
• Is the patient fixating properly?
• Is the tip of the biometry probe damaged?
&gt; Manual measurement cannot be performed.
• Is the footswitch properly connected? (See section 3.2.2e)
• Is the instrument set for automatic measurement? (See section 4.1.3e)
&gt; The measurement data are not accurate.
•
•
•
•
•
•
•
•
•
•
Is the biometry probe securely connected? (See section 3.2.2b)
Is the pachymetry probe connected to the terminal labeled BIO?
Is the probe cord pulling on the chin rest slider? (See section 3.2.3a)
Is the tip of the biometry probe damaged?
Is the converted velocity set properly? (See section 4.1.3c)
Is an excessive amount of corneal protective agent being used?
Is too much pressure being applied to the cornea?
Is the biometry probe applied to the cornea at a right angle?
Does the waveshape appear to be correct? (See section 4.2.7)
Is there any waveshape between the actual retinal wave and the retinal wave cursor? (See section 4.2.7)
&gt; The beep sounds when measurements are not being taken.
• Is the biometry probe immersed in water?
&gt; A beep does not occur when a measurement is taken.
• Is the Utility Sound setting set to OFF? (See section 7.5.4)
&gt; The waveshape is contaminated with noise.
• Is the biometry probe securely connected? (See section 3.2.2b)
• Is the power receptacle properly grounded?
• Is a source of electromagnetic radiation (such as a motor or high voltage power
line) located close to the instrument?
11.3 Pachymetry function
&gt; Pachymetry probe check is negative.
• Is the pachymetry probe securely connected to the terminal labeled PACHY? (See
section 3.2.2c)
&gt; Pachymetry measurement cannot be obtained.
• Is the pachymetry probe securely connected to the terminal labeled PACHY? (See
section 3.2.2c)
11.2 Troubleshooting - Biometry
98
AL-2000 Biometer &amp; Pachymeter
• Have the pachymetry settings been entered? (See sections 5.1.3 and 7.4)
• Is “Out of range” indicated? (See section 5.1.3f)
&gt; Automatic measurement cannot be performed.
•
•
•
•
•
Is
Is
Is
Is
Is
the instrument set for manual measurement. (See section 5.1.3d)
“Out of range” indicated? (See section 5.1.3f)
the tip of the pachymetry probe damaged?
the probe applied to the cornea at a right angle?
the corneal surface too dry?
&gt; Manual measurement cannot be performed.
•
•
•
•
•
•
Is
Is
Is
Is
Is
Is
the footswitch properly connected? (See section 3.2.2e)
the instrument set for automatic measurement? (See section 5.1.3d)
“Out of range” indicated? (See section 5.1.3f)
the tip of the pachymetry probe damaged?
the probe applied to the cornea at a right angle?
the corneal surface too dry?
&gt; The measurement data are not accurate.
•
•
•
•
•
•
Is
Is
Is
Is
Is
Is
the pachymetry probe securely connected? (See section 3.2.2c)
the biometry probe connected to the terminal labeled PACHY?
the tip of the pachymetry probe damaged?
the converted velocity set properly? (See section 5.1.3c)
too much pressure being applied to the cornea?
the probe applied to the cornea at a right angle?
&gt; The beep sounds when measurements are not being taken.
• Is the pachymetry probe immersed in water?
&gt; A beep does not occur when a measurement is taken.
• Is the Utility Sound setting set to OFF? (See section 7.5.4)
11.4 Memory card
&gt; Data cannot be stored on the memory card.
•
•
•
•
Is
Is
Is
Is
an ID number entered for the patient? (See sections 4.1.3a and 5.1.3a)
the memory card properly inserted? (See section 3.2.2f)
the memory card write protected? (See back of card)
the memory card full? (Message “Memory card is full” will appear.)
&gt; Data stored on the memory card is lost.
• Is the memory card battery dead? (See Sectin 8.3)
• Is the battery properly installed? (See Memory Card Instruction Manual)
11.3 - Troubleshooting - Pachymetry
99
AL-2000 Biometer &amp; Pachymeter
&gt; Data stored on the memory card cannot be read on a computer.
•
•
•
•
Was the memory card properly inserted? (See Section 3.2.2f)
Is the memory card write protected? (See back of card)
Was the Config.sys file rewritten? (See Section 8.5.1)
Does the computer have the capacity to use a memory card?
11.4 Troubleshooting - Memory Card
AL-2000 Biometer &amp; Pachymeter
12. SPARE PARTS AND OPTIONAL PARTS
To order spare parts and/or optional parts, contact your local Tomey representative or distributor. When ordering, be sure to specify that your order is for the AL-2000.
12.1 Spare parts
Printer paper
Memory card
(512 Kb, 1 Mb or 2 Mb)
12.2 Optional part
Chin rest
(AL-1100)
12 Spare and Optional Parts
101
AL-2000 Biometer &amp; Pachymeter
AL-2000 Biometer &amp; Pachymeter
13. SPECIFICATIONS AND MISCELLANEOUS INFORMATION
13.1 Specifications
13.1.1 Biometry/IOL power calculation
&gt; Measurement range
• Axial length:
• Anterior chamber depth:
• Lens thickness:
15.00 - 40.00 mm
2.00 - 7.00 mm
2.00 - 6.00 mm
&gt; Measurement accuracy and resolution
+0.1 mm
0.01 mm
• Accuracy:
• Resolution:
&gt; Converted velocity - factory setting and setting range
• Mean velocity of axial length
Normal:
1,550 m/s
1,500 - 1,600 m/s
Dense cataract:
1,548 m/s
1,500 - 1,600 m/s
Aphakic:
1,532 m/s
1,430 - 1,630 m/s
• Lens velocity
Normal:
1,641 m/s
1,540 - 1,740 m/s
Dense cataract:
1,629 m/s
1,540 - 1,740 m/s
• Anterior chamber velocity
Normal:
1,532 m/s
1,430 - 1,630 m/s
Dense cataract:
1,532 m/s
1,430 - 1,630 m/s
Aphakic:
1,532 m/s
1,430 - 1,630 m/s
• Velocity of vitreous body and anterior chamber
Pseudophakic:
1,532 m/s
1,000 - 2,000 m/s
• IOL velocity
Pseudophakic 1:
2,718 m/s
800 - 3,000 m/s
Pseudophakic 2:
1,049 m/s
800 - 3,000 m/s
Pseudophakic 3:
2,200 m/s
800 - 3,000 m/s
• IOL thickness
Pseudophakic:
1.00 mm
0.10 - 4.00 mm
&gt; IOL formulae
•
•
•
•
•
•
SRK II
SRK/T
Holladay
Hoffer-Q
Haigis standard
Haigis optimized
&gt; Biometry probe
•
•
•
•
•
Type:
Fixation light:
Transducer frequency:
Tip radius:
Dimensions/weight:
solid state
built-in red LED
10 MHz &plusmn;10%
5.0 mm (concave)
8 mm x 100 mm/30 g
13.1 Specifications
103
AL-2000 Biometer &amp; Pachymeter
13.1.2 Pachymetry
&gt; Measurement range:
150 - 1,500 &micro;m
&gt; Measurement accuracy and resolution
&gt;
• Accuracy:
• Resolution:
Bias setting range
• Percent bias:
• Plus/minus bias:
+5 &micro;m
1.00 &micro;m
60 - 130 %
-600 - +450 &micro;m
&gt; Converted velocity - factory setting and setting range
• Factory setting:
• Range:
1,640 m/s
1,400 - 2,000 m/s
&gt; Pachymetry probe
•
•
•
•
Type:
Transducer frequency:
Tip radius:
Dimensions/weight:
solid state
20 MHz +10%
1.5 mm with an angle of 45&deg; (flat)
8.8 mm x 90 mm/40 g
13.1.3 Main Unit
&gt; Display:
9.4” monochrome LCD; 640 x 480
&gt; Dimensions:
300 (w) x 209 (d) x 235 (h) mm
11.8 (w) x 8.2 (d) x 9.3 (h) in
&gt; Weight:
5.4 Kg/11.9 lb
13.1.4 Power Requirements
&gt; Voltage:
AC100V/230V
&gt; Frequency:
50/60 Hz
&gt; Power consumption:
Less than 50VA +15%
*All specifications are subject to change without notice.
13.1 Specifications
AL-2000 Biometer &amp; Pachymeter
13.2 Ultrasound energy
13.2.1 Acoustic Output Reporting Table
Symbols used in the table are described below:
ISPTA.3 Derated spatial-peak temporal-average intensity (milliwatts per square centimeter)
ISPPA.3 Derated spatial-peak pulse-average intensity (watts per square centimeter)
MI
Mechanical index
pr.3
Derated peak rarefactional pressure (megapascals) associated with the
transmit pattern giving rise to the value reported under MI
Wo
Ultrasonic power (milliwatts)
fc
Center frequency (MHz)
13.2 Ultrasound Energy
105
AL-2000 Biometer &amp; Pachymeter
zsp
Axial distance at which the reported parameter is measured (centimeters)
x-6,y-6 In plane (azimuthal) and out of plane -6 dB dimensions, respectively, in the
x-y plane where zsp is found (centimeters)
PD
Pulse duration (microseconds) associated with the transmit pattern giving
rise to the reported value of the respective parameter
PRF
Pulse repetition frequency (Hz) associated with the transmit pattern giving
rise to the reported value of the respective parameter
EBD
Entrance beam dimensions for the azimuthal and elevational planes (centimeters).
13.2.2 Acoustic Output Evaluation - Biometer
a) Test: One-sided T test
Formula: L &gt; X + Ks
Where:
L: Limit
X: Mean of measured values
s: Standard deviation of measured values
K: Factor described in Table A. 12d, p. 315, Statistical Intervals,
Hahn et al.,
Where:
γ: Confidence level = 1 - α
p: Proportion of distribution &lt; X = Ks
n: Sample size
b) Measured data
c) Statistical calculation
13.2 Ultrasound Energy
106
AL-2000 Biometer &amp; Pachymeter
d) Conclusion:
No values exceed the upper limit of the 99% confidence level. From this we
conclude that the ultrasound output is safe for human patients.
13.2.3 Acoustic Output Evaluation - Pachymeter
a) Test: One-sided T test
Formula: L &gt; X + Ks
Where:
L: Limit
X: Mean of measured values
s: Standard deviation of measured values
K: Factor described in Table A. 12d, p. 315, Statistical Intervals,
Hahn et al.,
Where:
γ: Confidence level = 1 - α
p: Proportion of distribution &lt; X = Ks
n: Sample size
b) Measured data
c) Statistical calculation
d) Conclusion
No values exceed the upper limit of the 99% confidence level. From this we
conclude that the ultrasound output is safe for human patients.
13.3 Ultrasound Energy
107
AL-2000 Biometer &amp; Pachymeter
13.3 Sounds generated by the AL-2000
The instrument emits monitoring sounds on the following occasions:
•
•
•
•
•
When
When
When
When
When
the power is turned on.
giving self-diagnosis.
initiating printing.
various keys are operated.
measurements are acquired.
13.3 Sounds Generated by AL-2000
108
AL-2000 Biometer &amp; Pachymeter
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www.tomey.com
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