29-10-2010, 08:34 AM
EYE TELE ANALYSER
Gisha S Asok
S7 AEI
College Of Engineering, Trivandrum
2007-11 batch
EYE TELE ANALYSER.pptx (Size: 1.58 MB / Downloads: 92)
You can thank the author of this presentation at pentarc[at]gmail.com
OVERVIEW
Introduction
Technical details
Hardware
Software
Communication system
Advantages
Conclusion
INTRODUCTION
Telediagnosis system
Two subsystems
Server
Client
Connected by internet
Two control modes:
Server control mode
Client control mode
HARDWARE
Indispensable tool for eye examination.
High intensity light source attached to a stereomicroscope.
Magnifies all anterior eye structures.
Eye images from different angles.
Slit lamp microscope arrangement
MECHANICAL MOVEMENT MODIFICATION
Stepper motor arrangement
VIDEO CAMERA
CCD camera of
resolution 750×582 pixels
Convert analog image signal to digital
One image is captured at a time
DIGITAL CAMERA
Capture patient’s
full face
Nikon D70 is
used
SOFTWARE ARCHITECTURE
GUI Unit
Provides user friendly interaction.
Links and call the other unit.
Interacts with Database Unit.
Communication Unit
Helps sending commands, receiving data, system status.
Control Unit
Captures the eye image & patient’s photo.
Communicates with electronic devices.
Control the movement of the motors.
Movement characteristics functions
Manual Control
Local Area Auto Focus Control
Repositioning AutoFocus Control
Image Evaluation Unit (IEU)
Calculates and returns the focus image
Z position
Manual Control
Adjusts the position by the user.
Repositioning AutoFocus Control
Selected area is repositioned at the center.
Controls X,Y,& R axes motors.
Local Area Auto Focus Control
Adjusts the blurry area.
Controls Z axes motor position.
Auto Focus Algorithm
Finds the best focus value.
Z-axis motor moves to initial position.
Moves for the whole length of the axis.
Accumulates the eye images and their position data.
Data are orderly stored.
Data are sent to the IEU.
IEU calculates the best focus value and its position value
Position value is sent back to CU
CU commands the Z axis motor to move to that position
Focus value
COMMUNICATION SYSTEM
Transfer commands, images, text messages, system status.
3 defined ports :-
Port 1 – transfer commands and
system status
Port 2 – transfer eye image and photo
Port 3 – provide chat channel
ADVANTAGES
Comprehensive examination in cost effective manner.
Beneficial to patients from rural areas.
Accessibility to global eye care experts.
Minimize expenditure.
CONCLUSION
Screening tool for blinding eye diseases.
Beneficial to ophthalmologists, hospitals,
patients.
Performs well in both manual and automatic modes.
REFERENCES
[1] J.K. Ledford, “The Slit Lamp Primer,” Slack Incorporated, Thorofare,N.J., 2006.
[2] Soumela, J., “Telepresence-aided teleoperation of semi-autonomous work vehicles,” Automation Technology Laboratory, Department of Automation and Systems Technology, Helsinkin University of Technology.
[3] Anderson, R. J., and Spong, M. W., “Bilateral Control of Teleportation with Time Delay,” IEEE Transactions on Automatic Control, AC-34, No. 5, 1989.
[4] Niemeyer, G., and Slotine, J. E., “Stable Adaptive Teleportation,” IEEE Journal of Oceanic Engineering, Vol. 16, No. 1, 1991.
[5] Groen F.C.A., Young I.T., and Ligthart G.,“A Comparison of Different Focus Functions for Use in Autofocus Algorithms,” Cytometry, vol. 6, pp. 81-91, 1985.
[6] Subbarao M., Choi T., and Nikzad A., “Focusing Techniques,” J. Opt. Eng., vol. 32, pp. 2824-2836, 1993.