Procedure

1. Walk into the closed chamber

2. Panting (breath rapidly)

3. Measure P_box_1 (before breath), P_box_2 (after breath), known V1 (patient body) → ultimately calculate FRC

   

Interpretation

• Given FRC, measured IC from Spirometry → calculate TLC

• Given TLC, measured VC from Spirometry → calculate RV

  

Key Terms

• Gas Trapping
  • Increase in RV
• Hyperinflation
  • increase in TLC