Nervous System

        
   
 

 

  

Applanation Tonometer

Vagus Nerve Stimulator

EEG Unit

Phacoemulsifier

  

Purpose: Detect eye diseases such as glaucoma and iritis.

Usage: A small section of the cornea is flattened and the pressure is then measured

Portable: Usually Yes

Parts of Machine:

  • Force Transducer - Generater a force to flatten the cornea
  • Flat Ring - Connected to the force transducer and placed on the eye to measure the pressure
 
   
   

The Applanation tonometer consists of a flat ring with concentric disc. The flat ring is connected to a force transducer. After the eye has been anaesthetized, the ring is placed onto the eye. The force transducer then generates a force to the flat ring. The force flattens a section of the cornea and the force needed for the inner disc of the ring to keep the cornea flat is noted. The pressure is then calculated by dividing the force over the surface area of the inner ring. An abnormal reading would indicate a likely eye disease.

  • Most modern applanation tonometers are portable
  • Is more accurate in determining the pressure of eye than other tonometers such as the non-contact tonometer

  • Can only be used to detect abnormalities, but not able to tell accurately what type of eye disease patient is suffering from
  • Requires anesthetizing of the eye, hence is more troublesome than other similar devices.

   
 © 2003 Raffles Junior College Back to top