Nidek Medical NT-2000 User manual

NON-CONTACT TONOMETER
Model NT-2000 (M)
OPERATOR’S MANUAL

NIDEK CO., LTD. : 34-14, Maehama, Hiroishi-cho, Gamagori, Aichi 443-0038, Japan
(Manufacturer) Telephone: [phone]
Facsimile: (81-533) 67-6610
NIDEK CO., LTD : 3F Sumitomo Fudosan Hongo Bldg., 3-22-5, Hongo,
(Tokyo Office) Bunkyo-Ku, Tokyo 113-0033, Japan
Telephone: [phone]
Facsimile: (81-3) 5844-2642
NIDEK INCORPORATED : 47651 Westinghouse Drive, Fremont, California 94539, U. S. A.
(United States Agent) Telephone: [phone]
Facsimile: [phone]
NIDEK SOCIETE ANONYME : Europarc 13, rue Auguste Perret, 94042 CRETEIL, France
(EU Authorized Representative) Telephone: [phone]
Facsimile: (01) 49 80 32 08
January 2008
18535-P932A
Printed in JAPAN

BEFORE USE OR MAINTENANCE, READ THIS MANUAL.
THIS MANUAL CONTAINS ONLY INFORMATION TO UNDERSTAND
THE OPERATING PROCEDURES AND MAINTENANCE. TECHNICAL
INFORMATION ABOUT THE INTRAOCULAR PRESSURE
MEASUREMENT IS NOT INCLUDED.
This Operator’s Manual contains the cautions for safety and operating procedures for
the NIDEK NON-CONTACT TONOMETER Model NT-2000.
This manual complies with IEC 60601.
The cautions for safety and operating procedures must be thoroughly understood before
using the instrument by reading this operator’s manual. Keep this manual near the
instrument for reference whenever necessary.
Use of the instrument is limited to the measurement of intraocular pressure by qualified
physicians following the instructions in the operator’s manual. The physicians are
responsible for other applications of this instrument.
There are no user-serviceable parts inside the device except printer paper and fuses.
If you encounter any problems or have questions about the instrument, please contact
NIDEK or your authorized distributor.
[NOTE]
Words specific to this instrument are used in this operator ’s manual. These words are explained in the
“Glossary” section near the end of this manual. See the table of contents for the glossary pages.
The “**” mark in this manual indicates that the word on the left is in the glossary. The “**” mark is
attached to a word at every first appearance of it on a page.
CAUTION
•UnitedStatesFederallawrestrictsthisdevicetosalebyorontheorderofaphysician.
MEDICAL ELECTRICAL EQUIPMENT
34VK
UL60601-1
CAN/CSA C22.2 NO. 601.1
WITH RESPECT TO ELECTRIC SHOCK, FIRE AND
MECHANICAL HAZARDS ONLY IN ACCORDANCE WITH
UL6060l-1 AND CAN/CSA C22.2 NO. 601.1
(This applies only to the equipments whose power source is 100/120VAC.)

I
Page
Table of Contents
§
1INTRODUCTION ........................................................................................................ 1-1
1.1 Outline ....................................................................................................................... 1-1
1.2 Principle ..................................................................................................................... 1-2
1.3 Indications for Use ..................................................................................................... 1-2
1.4 Classifications ............................................................................................................. 1-3
1.5 Symbol Information .................................................................................................... 1-4
§
2SAFETY PRECAUTIONS ............................................................................................ 2-1
2.1 In Storage, Transport, and Installation ......................................................................... 2-1
2.2 In Wiring and Connection ........................................................................................... 2-4
2.3 In Use ........................................................................................................................ 2-5
2.4 After Use and During Maintenance and Checks ........................................................... 2-6
2.5 Disposal ..................................................................................................................... 2-7
2.6 Safety Functions ......................................................................................................... 2-7
2.7 Labels ........................................................................................................................ 2-8
§
3SYSTEM DESCRIPTIONS ......................................................................................... 3-1
§
4OPERATING PROCEDURES ..................................................................................... 4-1
4.1 Operation flow ........................................................................................................... 4-1
4.2 Measurement procedure ............................................................................................. 4-2
4.2.1 Basic measurement ............................................................................................ 4-2
4.3 Errors during Measurement ......................................................................................... 4-9
4.4 Setting and Operation of the Sub-switches ................................................................ 4-12
4.4.1 Eyelid detection mode ..................................................................................... 4-12
4.4.2 Test mode ....................................................................................................... 4-13
4.4.3 Parameter setting mode ................................................................................... 4-14
4.5 Cleaning of theAir Nozzle ........................................................................................ 4-19
4.5.1 Cleaning the air nozzle ..................................................................................... 4-19
§
5TROUBLESHOOTING GUIDE .................................................................................. 5-1
5.1 Primary Troubles and the Countermeasures ................................................................. 5-1
5.2 Error Messages and the Countermeasures ................................................................... 5-2
§
6MAINTENANCE.......................................................................................................... 6-1
6.1 Replacing the Printer Paper ......................................................................................... 6-1

6.2 Replacing the Fuses .................................................................................................... 6-3
6.3 Attaching the Chinrest Paper ....................................................................................... 6-4
6.4 Cleaning the Exterior .................................................................................................. 6-4
6.5 Consumables and Maintenance Parts List .................................................................... 6-4
§
7SPECIFICATIONS AND CONFIGURATION ........................................................... 7-1
7.1 Specifications ............................................................................................................. 7-1
7.2 Standard Configuration ............................................................................................... 7-2
7.3 Options ...................................................................................................................... 7-2
GLOSSARY ................................................................................................................. Glossary-1
II
Page

1.1Outline
The NT-2000 is a non-contact tonometer to measure intraocular pressure by applanating** the
cornea of the patient’s eye using air pressure for early detection of glaucoma, post-operative care,
and such in ophthalmology.
This instrument is comprised of the main unit, the measuring unit, and the base unit. The former
two units are on top of the base unit. On the base unit, the chinrest and the printer are provided.
On the main unit, the screen, the control panel and the joystick are provided. On the measuring
unit, the air-nozzle and the photo-sensor are provided.
The NT-2000 has the following features:
1. Auto-alignment mode
When the measuring unit approaches the center of the pupil in this mode, the instrument
automatically performs alignment** in the up, down, left, and right directions. Then an optimal
distance between the patient’s eye and the instrument for focusing is obtained by moving the
instrument forward and backward using the joystick. After that, the measurement starts
automatically. Therefore, operators who use the instrument for the first time can use it easily
and obtain stable measurement data without differences in alignment among operators.
2. APC (Automatic Puff Control) function**
The intraocular pressure measurement can be performed using minimal air pressure.
When the measurement range** is set to “APC 40” or “APC 60”, in the first measurement, the
automatic shut-off function**, which is to stop puffing air as soon as the light reflected from the
cornea is detected, activates in order to eliminate excessive puffing. In subsequent measurements,
the APC function activates to perform the measurement with the minimum air pressure based
on the former measurement data. As the patient’s eye is protected from excessive air pressure,
patient discomfort can be decreased and continuous measurement can be performed smoothly.
The NT-2000 is equipped with the above two features for obtaining stable measurement data and
achieving smooth measurement.
(First measurement) (Subsequent measurement)
Time
Air pressure
(Automatic shut-off function) (APC function)
The air pressure is decreased
by this amount.
Suitable air pressure range
(depends on the patient)
Air pressure
Suitable air pressure range
(depends on the patient)
Time
§1
INTRODUCTION

1 - 2
1.2 Principle
According to Imbert-Fick’s law, when a sphere which has internal pressure (Pt) is applanated**
by a strength (W), the formula, “W = Pt ×A” holds as the relation between the flattened surface
(A), W, and Pt. The intraocular pressure (Pt) can be obtained by measuring the strength (W)
under the condition that the degree of flatness (A) is stable. Generally, applanation tonometers
like the Goldmann type use this principle.
The NT-2000 increases the air pressure puffed out** onto the cornea in proportion to time. The
shape of the cornea changes gradually in the order of convex surface →applanated surface →
concave surface. This change is optically detected and the instrument calculates the time (t) required
to make the pressed area (A) flat after puffing out air. The intraocular pressure is calculated from
the relationship between the time (t) and the pressure at the time of applanation.
The flatness of the cornea is detected by monitoring the amount of the reflection of the light
transmitted from the phototransmitter to the cornea. From an undisturbed cornea, little or no light
is captured by the photodetector. When the cornea is applanated, the light reflected from the
cornea travels in the same direction and the photodetector receives the maximum amount of the
light. By this method, the applanated state of the cornea is detected.
Therefore, if the eye is not opened wide enough during measurement, the applanation of the cornea
may become imperfect because the puffed air is prone to be interrupted by the eyelid and eyelashes.
Also the applanated state of the cornea may not be detected properly because the light is blocked.
As reliable measurement data may not be obtained under such a condition, pay special attention
to how wide the eye is opened.
1.3 Indications for Use
The Nidek Model NT-2000 is a non- contact tonometer that is indicated for use in the measurement
of intraocular pressure of the human eye.
(Undisturbed cornea)
Phototransmitter
(Applanated cornea)
Photodetector Phototransmitter Photodetector

1 - 3
1.3 Classifications
[Protection method against electric shock] Class I
The NT-2000 is classified as a Class I instrument.
A Class I instrument is an instrument in which protection against electric shock does not rely on
basic insulation only, but which includes an additional safety precaution in such a way that
means are provided for the connection of accessible conductive parts to the protective (earth)
conductor in the fixed wiring of the installation in such a way that accessible conductive parts
cannot become live in the event of a failure of the basic insulation.
[Degree of protection against electric shock] Type B applied part
The NT-2000 is classified as a system with a Type B applied part.
A system with a Type B applied part provides an adequate degree of protection against electric
shock particularly regarding;
- allowable leakage currents
- reliability of the protective earth connection (if present).
[Degree of protection against ingress of liquids] IP20
The NT-2000 is an ordinary instrument (enclosed instrument without protection against an
ingress of liquids). Be careful not to expose water to the instrument.
[Degree of safety in the presence of flammable anesthetics and/of flammable cleaning
agents]
The NT-2000 should be used in environments where no flammable anesthetics and/or flammable
cleaning agents are present.
[Method(s) of sterilization or disinfection recommended by the manufacturer]
The NT-2000 does not have any parts to be sterilized or disinfected.
[Mode of operation]
The NT-2000 is a continuous operating instrument.
[Classification by transportability]
The NT-2000 is classified as a transportable instrument.

1 - 4
1.4 Symbol Information
This symbol indicates that reference to the operator’s manual is necessary prior to operation
and maintenance.
This symbol indicates that the degree of protection against electric shock is for a Type B
applied part.
The symbol indicates the state of the power switch. When the switch is pressed to the side of
this mark, the power is ON.
The symbol indicates the state of the power switch. When the switch is pressed to the side of
this mark, the power is OFF.
This symbol indicates the fuse rating.
This symbol indicates that the system shall be operated only with an alternating current.
Indicates the date of manufacture.
Indicates the manufacturer.

§2
SAFETY PRECAUTIONS
In this manual, Signal Words are used to designate a degree or level of safety
alerting. The definitions are as follows.
WARNING: Indicates a potentially hazardous situation which, if not avoided,
could result in death or serious injury.
CAUTION: Indicates a potentially hazardous situation which, if not avoided,
may result in minor or moderate injury or a property damage
accident.
Some items described in WARNING and CAUTION may cause a serious
accident depending on the circumstances. Follow all the instructions mentioned below
since they are very important.
2.1 In Storage, Transport, and Installation
CAUTION
•Theplaceforstoringandinstallingandtheenvironmentduringtransportoftheinstrumentneed
to satisfy the following conditions:
-Theinstrumentisnotexposedtodirectsunlightorultravioletrays.
-Theinstrumentisnotexposedtorainorwater.
-Neitherchemicalagentsnororganicsolventsarestored.
-Thereisnosalt,sulfurcontent,toxicgasorlargeamountsofdustintheair.
-Theplaceshouldbevibrationandshock-free,levelandstable.
-Aplacewherethefollowingenvironmentalconditionsforstorage,transport(=packed
condition) and installation (=unpacked condition) are satisfied:
<Storage and transport> ... Temperature: -20 to 60ºC (-4 to 140 ºF)
Humidity: 10 to 95% (non-condensing)
<Installation> .................... Temperature: 10 to 40ºC (50 to 104 ºF)
Humidity: 30 to 85% (non-condensing)
•Beforetransport,movethemeasuringunittothelowerlimitandlockthemainunittothebase.
Failure to do so may cause the measuring unit to move during transport and the instrument to
malfunction.
•Nevertrailthepowercordwhileitisconnectedtotheinstrumentduringtransport.
The instrument may fall and that may cause injury and malfunction if the cable is stepped on or
pulled.

2 - 2
CAUTION
•Holdthebaseoftheinstrument,nottheforeheadrestorthechinrest,fromthesidesfortransport.
Otherwise, the forehead rest and chinrest may be deformed or damaged.
•Avoidinstallingtheinstrumentwheretheinstrumentisexposedtodirectair-conditioningflow.
Changes in temperature may cause condensation in the instrument and affect sensitivity of the
sensor and the measurement results.
•Installtheinstrumentwheredirectsunlightorscatteredlightdonotcomefromtheairnozzle
side.
The measurement may be affected because of failure of pupil detection, etc..
•Ininstallationandoperationofthedevice,observethefollowinginstructionsaboutEMC
(electromagneticcompatibility):
-Donotusethedevicesimultaneouslywithotherelectronicequipmenttoavoidelectromagnetic
interference with the operation of the device.
-Donotusethedevicenear,on,orunderotherelectronicequipmenttoavoidelectromagnetic
interference with the operation of the device.
-Donotusethedeviceinthesameroomwithotherequipmentsuchaslife-supportequipment,
other equipment that has major affects on the life of the patient and results of treatment, or
other measurement or treatment equipment that involves small electric current.
- Do not use the device simultaneously with portable and mobile radio frequency
communication systems because it may have an adverse effect on operation of the device.
-Donotusecablesandaccessoriesthatarenotspecifiedforthedevicebecausethatmay
increase the emission of electromagnetic waves from the device or the system and decrease
the immunity of the device to electromagnetic disturbance.

2 - 3
CAUTION
•Thepatientenvironmentisthevolumeofspaceinwhichcontactcanoccurbetweenthepatient
and any part of the device (including connected devices) or between the patient and any other
person(s) touching the device (including connected devices).
Use devices that comply with IEC60601-1 in the patient environment. If any device that does
not comply with IEC 60601-1 is to be used, use an isolating transformer or common protective
grounding.
Radius of 1.5 m
1.5 m 1.5 m
2.5 m

2 - 4
2.2 In Wiring and Connection
CAUTION
•Connectthepowercordtoagroundedwalloutletwhichmeetsthepowerrequirementsspecified
on the label on the instrument.
Otherwise, the system may not perform sufficiently or may be damaged.
•Besuretousea(HOSPITALGRADE)walloutletequippedwithagroundingterminalinorder
to avoid electric shock or fire in the event of power leakage.
•Avoidastarburstconnection.
The system may not perform sufficiently and a fire may occur.
•Alwayspulltheplug,notthecord,whenpluggingandunpluggingthepowercord.
If the core wire of the cord breaks, it may cause a fire or electric shock from a short-circuit.
•Donottoletthepowercordgetpressedunderheavyobjectssuchastheinstrumentorget
pinched.
The cable sheath may break, and a short-circuit or electric shock may result.
•Ifthecorewireofthepowercordisexposed,donotcontinueusingthepowercord.Unplug
the power plug and contact NIDEK or your authorized distributor.
Continued use of a broken power cord may cause an electric shock or fire.
•Becarefulnottoletdustaccumulateontheplugofthepowercord.
If dust accumulates, it absorbs moisture and may cause a short-circuit and a fire.
•Installtheinstrumentinaplacewherethereisnodevicesuchasalasersystemwhichgenerates
strong electromagnetic waves.
There may be a case where correct measured values cannot be obtained due to the influence
of the strong electromagnetic waves. Where the instrument is installed in a place with such
devices, stop their operation, and then start measurement.
•Donotuseanypowercordotherthantheonesupplied.
Also do not connect the supplied power cord to any other device.
Failure or fire may result.

2 - 5
2.3 In Use
WARN I NG
•Beforestartingthemeasurement,besuretosetthesafetystopperforeachpatienttoprevent
the air nozzle from touching the patient’s eye.
If the air nozzle touches the eye, the cornea may be damaged.
CAUTION
•Usethisinstrumentonlyformeasuringintraocularpressure.
NIDEK assumes not responsibility for accidents caused by using the instrument for other
than the measurement of intraocular pressure.
• In the event of trouble, unplug the power plug and contact NIDEK or your authorized
distributor without touching the inside of the instrument.
•Donotmodifyortouchtheinsideoftheinstrument.
An electric shock or malfunction may occur.
•Inmeasurementusingtheautoalignment,themeasuringunitautomaticallymovesintheup,
down, right, and left directions. Do not place fingers between the measuring unit and the
mainunit.
Fingers may be pinched and get injured.
•Inadvanceofmeasurementofeachpatient,wipetheforeheadrestandchinrestthatcontact
the patient with clean absorbent cotton or gauze dampened with rubbing alcohol.
If the chinrest paper is used, remove one piece for each patient.
•Donotletdirtsuchasfingerprints,dust,etc.getontheobservationwindowaroundtheair
nozzle.
The accuracy of the alignment decreases and, as a result, the measurement value is
affected.
•Thisdeviceusesaheat-sensitiveprinterpaper.Tokeeptheprinteddataforalongperiodof
time, make copies of the printouts.
The paper degrades over time and the printed data may become illegible.
NOTE
•Apixelmayberarelymissingonthescreenorared,blue,orgreenpixelpointmayalwaysbe
displayed.
It depends on the structure of the LCD, and is not a failure.

2 - 6
2.4 After Use and during Maintenance and Checks
CAUTION
• After using the instrument, turn OFF the power and put the dust cover on the instrument.
Accumulated dust may make the eye to be measured unsanitary and such a condition
may affect the accuracy of the measurement.
•Whentheinstrumentwillnotbeusedforalongtime,unplugthepowerplugfromthewall-
outlet.
If dust is accumulated on the power plug, it absorbs moisture and may cause a short
circuit or a fire.
•Takecarenottodamageorsoiltheobservationwindowaroundtheairnozzlewithscratches,
finger prints, dust, etc..
The accuracy of the alignment decreases and measurement results will be affected.
• Do not use organic solvents (thinner, etc.) or cleaners containing abrasives.
The surface and paint of the housings may be damaged.
• Use the specified fuses.(See “6.5 Consumables and Maintenance Parts List” p.6-4.)
Otherwise, the instrument may malfunction and a fire may occur.
• Use the printer paper specified by NIDEK. Replace it following the procedure described
in “6.1 Replacing the Printer Paper” (p. 6-1).
Otherwise, jamming of the paper or failure of printing may occur.
•WhentheinstrumentissentbacktoNIDEKforrepairormaintenance,wipethesurface
(especially, the area wherethepatient’sskincontacts)ofthe instrument with a cleanclothimmersed
in ethyl alcohol for disinfection.

2 - 7
2.5 Disposal
CAUTION
•Followlocalgoverningordinancesandrecyclingplansregardingdisposaloftheinstrument.
The circuit board includes lithium batteries. The disposal method varies according to the
local government. Check the specified disposal method for a specific waste in advance.
• When disposing of packing materials, sort them by material and follow local governing
ordinances and recycling plans.
2.6 Safety Functions
[Safety stopper]
For safety, this stopper provides a safety space** so that the air nozzle does not touch a
patient’s eye during measurement.
The amount of space needed for safety depends on the patient. Change the position of the
stopper for each patient to ensure the proper amount of space for safety.

2 - 8
2.7 Labels
In order to catch the user’s attention, the appropriate warning labels are attached to the specified
locations on the instrument.
MADE IN JAPAN
18515-M535-D

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󲩅󲩙󲩦󲩭󲩞󲩙󲩛󲩬󲩭󲩪󲩝󲩜󲨘󲩞󲩧󲩪󲨘󲩆󲩁󲨼󲨽󲩃󲨘󲩁󲩦󲩛󲨦
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[Operator’s side]
Safety stopper
Control panel
Power switch Printer
Screen
Start button
Joystick
Cover for sub-switches
Locking knob
§3
SYSTEM DESCRIPTIONS
Air nozzle
Eye level marker
Forehead rest
LEDs for the cornea
illumination
Chinrest
Chinrest elevation knob
[Patient’s Side]
LEDs for detecting
the eyelid
Measuring unit

3 - 2
[Operator’s Side]
Safety stopper
Used to provide a safety space** so that the
air nozzle does not touch the patient’s eye.
Change the position of the stopper for each
patient to keep the proper amount of space
for safety.
*Whenthesafetystopperislocked,aclickis
heard and the stopper returns to the up po-
sition. After that the measuring unit returns
to the original position in the right, left, front
and back directions automatically.
Start button
When this button is pressed during the mea-
surement, air is puffed out** and the measure-
ment starts regardless of the alignment** and
focusing** conditions. When this button is
pressed in the TEST mode**, air is puffed out.
Joystick
Used for alignment and focusing**.
Alignment in the right and left directions can
be performed by moving the joystick to the
right and left. Rotating the joystick is for align-
ment in the up and down directions. For fo-
cusing, move the joystick back and forth.
Cover for sub-switches
Under this cover, there are switches for se-
lecting the modes, etc..
Press the right side of the cover lightly to open
the cover.
Locking knob
Used to fix the main unit to the base unit.
To fix the main unit at the center of the base
unit, turn the knob in the LOCK direction while
pressing it.
To fix the main unit to a desired position tem-
porarily, turn the knob in the BRAKE direc-
tion.
[Patient’s side]
Air nozzle
Puffs out air.
* The “air nozzle” described in this manual
includes the observation window around the
nozzle.
Eye level marker
The outward ends of the patient’s eyes are
aligned using this marker.
NOTE
• Materials composed of parts that
contact the patient during measurement
are as follows:
Forehead rest: Polyvinyl chloride
resin
Chinrest: ABS resin

3 - 3
[Control Panel]
[Sub-switches]
Memory lamp
switch
switch
switch
switch
Not used
Eyelid detection mode setting switch
Mode setting switch
Contrast adjusting control
Brightness adjusting control
Interface cable receptacle
Fuse holders
[Bottom View]
Inlet