EE 4BD4 Lecture 12

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EE 4BD4 Lecture 12

• Electro-ocularogram EOG

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Other Theories

• Dipole is generated by a distribution of positive
  and negative charges in the retina only
• Signal results from eyelid moving over the
  eyeball (similar to blink artifact in EEG)
• Not a result of EMG of extra-ocular muscles

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Extra-Ocular Muscles
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Utility of EOG

• Help in diagnosis of eye pathologies
• Important data
• Saccadic movement parameters
• Arden Ratio
• Identification of REM sleep
• Computer interface for the disabled

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Design Considerations

• Electrodes (Ag-AgCl - drift free)
• Bandwidth (filtering)
• What about instrumentation or Op amp voltage
  offsets?
• AD 620 max voltage offset RTI 125 µV
• Additional analog circuitry?

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Offset Adjust Circuit