Vocal Cord Stroboscope

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Vocal Cord Stroboscope
Team MembersEric MillerStacey Hoebel
ClientsDoug MontequinDiane BlessDivision of
OtolarynologyUW Medical School
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Overview

• Background
• Problem Statement
• Current Design
• Design Specifications
• Design Alternatives
• Final Design
• Future Work
• Questions

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Background

• Stroboscopes Endoscopes
• - Used to diagnose diseases and disorders in the
  vocal cords and larynx
• - Allows physicians to closely observe behavior
  and damage to the vocal cords

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• How does the device work
• Vocal cords vibrate 450 times per second
• Strobe light makes the rapidly vibrating vocal
  cords appear to slow down by periodically
  illuminating the area at a frequency close to
  that of the vibrations
• Principles of Talbots Law/ Sampling Frequency

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Problem Statement
Design a strobe light to be used in conjunction
with an endoscope to observe damaged vocal cords.
The device must have a feature with which the
frequency of the strobe light can be manually
adjusted to as fine as 1/80 cycle. The design
must also be relatively quiet small enough to
carry and independent from a computer.
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Current Design

• KAY machine model RLS 9100 Fiber optic cable
  runs from the light source a large xenon strobe
  light in a metal box to the endoscope. The
  device is attached to an computer printer and
  VCR.

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Current Design

• Problems with Current Design - Excess noise
  interferes with simultaneous audio and
  video observation of vocal cords - Large and
  immobile - Dependent on a computer which
  quickly becomes outdated - Manual frequency
  control dial inconveniently placed

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Design Specifications

• Small (10 x 6 x 10)
• Quiet (lt10 dB)
• 50-600 Hz frequency
• Manually adjustable frequency (fine tuning 1/80
  cycle)
• Independent from a computer

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Design Alternatives

• Basic Box
• Same strobe light used in KAY model RLS 9100
• Smaller better insulated resonant box
• New circuit boards placed inside of box
• Manual frequency control device attached to
  endoscope
• Independent of a computer

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Design Alternatives

• Satellite Design
• A reflective satellite shaped object is placed
  across from the light source to concentrate light
  at the fiber optic cable which is adjacent to
  the bulb
• Manual frequency control device is attached to
  endoscope
• Independent of a computer

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Final Design

• LED Design
• LED light source
• Foot pedal attached to light source provides
  manual frequency adjustment and fine tuning
• Carrying case for easy mobility

• Advantages of LED - Low Power - No IR - Long
  Life - Small

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Final Design
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Future Work

• Research specific LED components - Power
  consumption - Brightness (lumens) - Slew
  rates - Strobe capabilities
• Build a circuit for adjustable frequency
• Work on a digital display for frequency -
  Circuitry - Placement

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Questions