oti OCT User manual

OCT/SLO
Dual Channel
Imaging System
Service Manual
Model-B
•Version: V 4
•September 2005
•Ophthalmic Technologies Inc.
37 Kodiak Crescent, Unit 16 Phone: [phone]
Toronto, Ontario M3J 3E5 CANADA Fax: [phone]
www.oti-canada.com [email protected]

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Table of Contents
•Introduction 3-4
•Description 5
•Specifications 6-7
•Set Up & Maintenance 8-9
•Clinical Set Up 10-14
•Image Capture and I/O Boards (PC) 15
•Initialization Process 16
•Parts – Replacement 17-21
•Procedures and Warning 22
•Service Protocol Scenners Replacement 23
•Service Protocol MFN Stages Replacement 24
•Service Protocol Mini LCD Replacement 25
•Service Protocol
•Alignment Obeservation CCD Camera 26
•Service Protocol SLD Pilot 4 Controller Replacement 27
•Safety 28
•Trableshooting 29
•Warning 30
•Alignment Jigs 31
•Wiring Diagrams 32-34

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OCT/SLO System
Introduction and Theory of Operation
The OCT/SLO is an Optical imaging system designed to image the vitreo-retinal
structure, the retinal layers as well as provide a confocal fundus image. It is based on a
dual channel system, built around an interferometer and a confocal receiver. The OCT
channel resolves retinal structures by measuring the time delay of light that is back-
scattered from different micro-structural layers in the retina. It produces cross-sectional
images (B-Scan) or coronal (C-Scan) images of the retina. The confocal receiver operates
similar to a scanning laser ophthalmoscope (SLO) and produces fundus images of the
retina and the optic nerve.
The OCT/SLO operates in two scanning modes:
•B-Scan OCT - producing cross sectional images
and
•C-Scan OCT – producing coronal images
In both modes of operation, two images are simultaneously produced and displayed, one
OCT and the other Confocal image of the fundus. The OCT/SLO uses light generated
from an infrared broadband Super Luminescent Diode (SLD) source with a wavelength
between 790 nm to 950 nm. The interferometer combines the reflected light from the
retina with the reflected light from a reference mirror. A photo-detector unit detects and
measure the interference and sends the signal to a computer that generates the OCT
image. Part of the light backscattered from the retina is also diverted to a photo-receiver
via a small pinhole, the photo detector detected the signal which is then amplified and
sent to the same computer which generates a Confocal Ophthalmoscope image of the
fundus simultaneously with the OCT image. As both the confocal fundus (retinal surface)
image and the OCT images are generated through the same optics at the same time, they
are displayed simultaneously on the computer screen and are pixel to pixel
correspondent.
In the B-Scan Mode the OCT/SLO projects light onto to the retina through Galvano-
Scanning mirror system which moves the beam in a horizontal line (vertical line or
diagonal or circular line). The OCT image is analogous to ultrasound B-Scan and
represents a longitudinal cross sectional image of the retina, its sub-layers and internal
structures.
In the C-Scan (Coronal) Mode the OCT/SLO projects the light into the retina through a
pair of X,Y Galvano-Scanners which move the beam in a raster fashion across the surface
of the retina. . The C-Scan Coronal OCT images are plane generated at different (preset
and pre-selected) Z depths. Each C-Scan OCT represents a X,Y Plane at a given Z depth.

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Another choice allows the user to produce successive intra-sections of the OCT and the
Confocal Ophthalmic image. In the C-scan regime, the OCT/SLO system can also be
switched into a fast regime of operation which allows collection of a sequential stack of
images at different depths to provide a Topographic Map. The topographic map has the
same resolution irrespective of the pixel within the transverse area of the raster image,
due to the en-face scanning used in the OCT/SLO.
The user may select:
(i) the scanning depth range from 0.5 to 6.0 mm in user pre-selected steps;
(ii) the scanning field/angle (width of the scan, or lateral size in the B-scan regime
and width and height of the raster image in the C-scan regime) from 15° to
25°;
(iii) the scanning rate, either 1Hz or 2Hz (frames per second) in the B-scan regime
or 2, 4, 8, 16, 32 Hz (frames per second) in the C-scan regime
In the C-Scan, when selecting the scanning depth range, the number of C-Scan
slices is altered, with a maximum of 240 slices or cuts per stack.

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Characteristics
Description
The OCT/SLO system is an imaging system intended to be used for ophthalmic
applications. It combines a digital fundus imaging system that includes a Confocal
Scanning Ophthalmoscope CSO and Optical Coherence Tomography OCT. Both the
Confocal fundus SLO image and the OCT image are produced simultaneously from
the same SLD light source through the same optics and therefore they are pixel to
pixel correspondent.
The OCT/SLO software runs on Windows XP, and uses the features of the Windows
interface to direct the operation of the system and maintain patient records, permitting
a user-friendly environment for clinical applications.
System components
The OCT/SLO system consists of:
The Scanner unit or Optical Head, which contains the optical emitter/receiver. An
attached computer for system control, image capture, patient data storage, Image
recall and display and image analysis.
Application
To acquire SLO and OCT images, the operator first selects the “SLO/OCT” tab
which displays the acquisition screen, and follows the instructions for its various
controls (displayed on the upper left corner of the screen). The patient placed their
head on the chinrest and is instructed to fixate on the internal or external fixation
target. The scan parameters are preset, the examiner selects the scan mode of
his/her choice, select “LIVE” and the system starts scanning the eye.

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Specifications
TOMOGRAPHIC IMAGING
Purpose: Cross sectional imaging of fundus
Signal Type: Optical scattering from tissue
Signal Source: Super Luminescent Diode (SLD) 820 nm
Optical Power: <1000 Microwatts at cornea. SLD current will shut off if
safety circuit is activated (upon scanner-motion failure)
Spot Size at Retina: 20 mm.
Longitudinal/Axial Resolution: <10mm. in tissue
Transverse Resolution: 20mm. in tissue
Scanners: Galvanometric with X,Y mirrors
OCT Scan Patterns: Longitudinal XZ (B-Scan), Fast (stack) Topography with
3D OCT, Coronal En-Face XY (C-Scan), Freedom Examination: user
footswitch (or mouse) controlled combination of B-Scan and C-Scan,
Optional in Advance User mode: Detailed Stack (C-Scan) and Radial Scan
and RNFL program.
Scan Pixels: Adjustable – 1024x1024, 512x512, 256x256 and128x128 Scan
Speed: Variable – 1, 2, 4, 8, 16, 32 frames/second.
Scan Acquisition Time: Longitudinal – 1, 2 frames/second.
Coronal (C-Scan) – 2, 4, 8, 16, 32 frames/second
Longitudinal and Coronal (Depth) Scan Range: Variable 0.1 – 6.0mm.
FUNDUS IMAGING
Purpose: Confocal Fundus image for alignment, orientation and registration of
the OCT image and the topographic maps and for diagnostic purposes
Signal Type: CCD image and Confocal Ophthalmoscope.
Field of View: up to 25°
Viewing Method: 19” LCD Color Display Monitor
Internal Fixation: 0.8” LCD display, User/computer controlled with variable
pattern and Size.
External Fixation: Slit lamp type adjustable LED

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ELECTRICAL
Imaging System only:
Single phase:
100V ~ systems: (±10%), 3.5A
115V ~ systems: (±10%), 2.6A
230V ~ systems: (±10%), 1.3A
Total Power requirements and Power consumption for:
Imaging system, PC computer, LCD monitor and Motorized Table:
100V ~ : (±10%), 12.0A 1KVA
115V ~ : (±10%), 10.6A 1KVA
230V ~ : (±10%), 5.3A 1KVA
Main fuses: for 100V ~ & 115V 2 each 8.0A. for 230V ~ 5.3A
CONTROL UNIT (Specifications current at time of writing)
CPU: 2.6GHz Pentium 4, 1GB DDR RAM
Monitor: 19” Color LCD Monitor
Control Input Devices: Keyboard, Mouse, Joystick
Storage: 160GB Hard Disk
ENVIRONMENTAL CONDITIONS
Transport and Storage
Temperature: –10 to +60 deg. C
Relative Humidity: 30% to 70%, excluding condensation
Atmospheric Pressure: 500 hPa to 1060 hPa
Operation
Temperature: +17 to +27 deg. C
Relative Humidity: 30% to 70%, excluding condensation
Atmospheric Pressure: 700 hPa to 1060 hPa
DIMENSIONS:
Scanner:
59x67x55cm
41kg
Power Supply:
22x48x20cm
16kg
Note: System specification may change from time to time by the
manufactuere to to improvamnet in components performance or
other technical reasons.

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Set-up and Maintenance
The system will be installed and put into operation by only OTI staff or its official
representatives.
Warranty Note: The OCT/SLO system requires that all replacement parts be replaced by
OTI certified parts. Any attempt to repair and/or replace any of the system parts by the
user without written approval by OTI will void the system warranty. All repairs and
replacement of parts should be preformed by OTI service staff or OTI official
representatives.
OTI Software upgrades and Software updates: OTI will provide users with User-
installed software updates. These updates should be installed whenever the user receives
them from OTI. Users are required to confirm with OTI in writing that the have updated
the software to the current version.
Error Messages: When the OCT/SLO system displays an Error Message, please provide
the service department with the error message and the serial number of your system for
quicker and better service assistance.
System Cleaning: The only parts of the system that require cleaning are the forehead and
the chin rest (these are the parts that come with patient’s contact regularly). These parts
should be cleaned between each examination with an alcohol prep swab. The user can
also use a 2% glutaraldehyde solution for disinfection, however these two solutions may
cause skin irritations, so it is important to make sure to wipe these parts with a clean soft
wet cloth after the application of these disinfection solutions.
System Front Lens Cleaning: It is important to make sure that the system front lens
does not contact the patient eye or face. If the lens contacts the eyelashes or any other
part of the patient’s face, it is important to clean the dust and oily smudges occasionally.
Any oily smudges or major dust on the ocular lens will reduce the quality of the OCT and
SLO images. To clean the lens you may user a Kodak (or other) “lens cleaning paper”
with a “lens Cleaning solution”. Always use lens cleaning paper to avoid scratching the
front lens. To clean the lens dip or spray the lens cleaning paper in the cleaning solution
and wipe the lens in circular motions from the centre of the lens outwards. Make sure that
the lens is dry and without any residue (left after the cleaning), before you proceed with
the next exam.

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Set-up and Maintenance
Power Fuse Replacement: There are number of power fuses installed in different parts
of the system key components. Only OTI service personal or its official representatives
are authorized to replace any of the system’s power fuses. Any attempt to replace any of
the system power fuses by non authorized personal will void the system warranty and
may cause major damage to some of the system key components.
Moving the OCT/SLO system: If the unit has to be moved to a new location, the user
should contact OTI or its official representative to arrange the packing and re-installation
of the system.
OTI or its representatives will not be responsible over any of the system functions or
performance unless the system was Packed, unpacked installed and tested by OTI staff or
its official representative.

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Clinical Setup:
System Description – Full View
The Keyboard Tray and the Computer shelf can be installed on either side of the
motorized table.
Chinrest height
adjustment
Chinrest
Joystick
For Optical
Head height &
position control
Flexmount-
external
fixation light
Computer
Motorized Table
Height adjustment
control
Chinrest Power
Supply
Keyboard and
tray

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Only OTI Service representative or OTI trained Service personal should assemble
and install the OCT/SLO System. Any installation by other than OTI personal or
OTI trained personal will void the system Warranty. The system should be setup in a
room with air conditioning or at least a stable ambient temperature. The system will be
delivered in several parts; the optical head and chinrest (pre-assembled), the PC, the
up/down table and the power supplies. As well as this there is a box containing external
cables and other components such as the keyboard and mouse.
System Description – Computer Wiring Connections
Keyboard
Power Cord
Serial Cable
from chin rest
from
Parallel Cable
Mouse
External
Monitor
Internal Monitor
Cable
P6023 Cable
P6110 Cable

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Cables:
Monster Cable
Connections from the Chin Rest to the rear of the PC are:
•Monster cable: Two 68 pin Cables connected to boards Marked P 6110 and
P6023.
•Serial Cable
•Parallel Cable
•Internal Monitor Cable
Other Connections to the PC are:
•External LCD Monitor VGA Cable
•Mouse
•Keyboard
•External Power Cord
P 20 connects to
Optical Head /
Chin Rest
P 6110, P 6023
and Internal
Monitor
connect to
(back) PC
Internal LCD
Monitor
connector
(back) PC

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Other Connections from or to the Chin Rest are:
•OCT/SLO Power Supply connector
•Monster Cable Connector P20 connects to the Optical Head/Chin rest
•Chin Rest Power connecting to Chin Rest power supply (allows chin rest Up &
Down motion through the Joystick
•External Fixation wire connects to the Chin Rest Power Supply
Optical Head Power Supply
Note: Please make sure not to connect the Power connector in a
Backward/reverse way. Such reverse connection will cause major
damage to internal components of the optical head
Optical Head
Power Supply
Connector

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Connections bottom of the Optical Head /Chin Rest
P 20 connector
Optical Head
Power Supply
connector

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Image Capture and I/O Boards (PC)
NI Image Capture Board
NI I/O Board
Connecting Cable - I/O Board to Capture Board

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Initialization Process:
After assembly is completed, the system should be powered up and ran to check
initialization.
Please follow the steps below :
1. Power “ON” machine, check all cables are attached and boot up the computer
(Initialization program should run automatically after login). If Initialization fails
again, please contact the manufacturer.
2. Initialization should take less than 10 minutes. If there are any problems during
initialization it may be helpful to enter the service mode. Otherwise go to the
SLOOCT tab and click live to begin acquisition. (see User Manual)
Service mode:
1. Go to the utilities tab.
2. Click on “Service” and enter the password ‘room13’
3. Go to Diagnostics and you should see the ongoing communication between the
PC and the system during initialization.
4. If the system fails to initialize check the power supply and cabling to the optical
head.
5. Otherwise contact the manufacturer product service personnel.
Important Information:
C-Scan Settings
Transverse and Longitudinal Panes: Sets image size and calibration parameters.
Stage INIT: Lists COM port number (if connected direct to PC should be port 1, if via
USB to serial converter should be port 3).
AutoAlignment:JIG: Trigger Voltage shows the lower limit for re-adjustment and upper
voltage the upper limit for re-adjustment.
Reconstruction: used for image sizing and adjustment.

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Parts Replacement:
Replacement of any of these parts must be performed by the manufacturer trained
personnel. OTI will not be responsible for any work or replacement of parts
performed by any person other than OTI personnel.
The Replaceable parts in the system are:
•X,Y Galvoscanner Model 6210
•X,Y Scanners Controller Board
•Axis 3 & 4 MFN- type Fiber Alignment stages.
•Observation CCD Camera assembly
•Fixation Mini-LCD & assembly
•MCB Stages Controller
•SLD Pilot4 Controller
•OCT Electronics Detector Box
•SLO Detector
•NI Image Capture Board
•NI I/O Board
Optical Head Top View
X,Y Scanners
Fixation
Mini LCD
Observation
CCD Camera
& Lens
SLO
Detector

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Observation CCD
Camera & assembly
X,Y Scanners
Controller Board
X,Y Scanners

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Fixation
Mini LCD
Assembly
Optical
Head
Interface
Board &
Safety
Board
SLO Detector

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MCB
Stages
Controller
Board
X,Y Scanners
Controller Board
SLD Pilot 4 Controller
OCT
Detector &
Electronics
SLO Detector
Main Ref. Stage