1. EOG-controlled Visual Prosthesis
Bree Christie, Ashley Godin, Umakanthan Kavin, Parth Sheth

2. Background Enucleation: Removal of entire eye
Reasons for surgery: trauma, glaucoma, tumors, pain
Replace with orbital implant and ocular prosthetic
Common complication: loss of function in extraocular muscles
Leads to less control over prosthetic device movement
Prosthetic is more noticeable

3. Representation

4. Electrooculography (EOG)
The eye acts as a dipole where the front is positive and back is negative
Attributed to higher metabolic rate in the retina
Position of the eye creates a voltage potential

5. Objective
Goal: Use EOG signals from the natural eye to dictate movement of artificial eye model
This would allow for natural movement of the artificial eye and lessen the visibility of the prosthetic

6. Approach

7. Pre-Breadboard
Electrodes detect magnitude of potential and polarity of potential
Polarity of potential will indicate direction
Amplitude will be ~0.3 mV

8. Signal Conditioning Amplifier (gain ~ 300)
Band-Pass Filter ( Hz)
Noise
Decay

9. Block Diagram

10. LabVIEW Data Acquisition and Analysis
50 samples read at a rate of 1 kHz
Results in a “refresh rate” of 50 ms for quasi-real-time output
In-program band-pass filter of Hz
Signals were compared against selected thresholds and generated an output accordingly

11. Arduino and Servo Motor Control
Arduino Uno microcontroller board (ATmega328)
USB connection
MATLAB control
Servo motor: rotary motor allowing control of specific positions

12. Results & Validation

13. Signal Conditioning Results
DC filtering will result in signal decays (bottom)
Yellow is horizontal movement
Blue is vertical movement (blinks) 1a 1b 2 3

14. Validation
Achieved horizontal movement and blinks in animated computer model based on synchoronous natural eye EOG signals
Demo

15. Questions