The Body Plethysmography is done sitting in an enclosed clear chamber. The test is conducted inside a tightly sealed box where changes in air pressure and volume as you inhale and exhale can be measured. If you are claustrophobic, you may be uncomfortable doing this test. Let the respiratory therapist know if you are having problems.
The purpose of the test is to measure the volume of air in the lungs, diagnose lung disease or assess its severity, and to determine whether the airways are obstructed or restricted and to what extent.