Spirometers

• Spirometers


  • Measure breathing
  • Measure vital capacity
  • Measure tidal volume
  • Measure breathing rate
  • Measure oxygen uptake
• How spirometers work


  1. Subject breathes in and out through spirometer

  2. Carbon dioxide absorbed from exhaled air by soda lime

  3. Trace drawn on rotating drum or digital graph created

  4. Change in volume used to measure oxygen uptake
• Residual volume is a small amount of air always retained in the lungs
• During exercise


  Maximum amount of air taken in and breathed out increases
• Spirometer results can be used to calculate vital capacity, tidal volume and breathing rate
• vital capacity


  maximum volume of air that can be breathed in or out in one breath
• tidal volume


  the volume o air that is breathed in or out during normal breathing.
• breathing rate


  the number of breaths taken in in one minute