Spirometry provides information about the dynamic volumes of the lungs—air that moves in and out during breathing. However, in some cases, basic spirometry is not sufficient. It may be necessary to assess static lung volumes—such as total lung capacity, residual volume, functional residual capacity, airway conductance, and airway resistance. These are measured using body plethysmography, a specialized test performed with a device called a plethysmograph.
Spirometry provides information about the dynamic volumes of the lungs—air that moves in and out during breathing. However, in some cases, basic spirometry is not sufficient. It may be necessary to assess static lung volumes—such as total lung capacity, residual volume, functional residual capacity, airway conductance, and airway resistance. These are measured using body plethysmography, a specialized test performed with a device called a plethysmograph.
During the test, the child sits in a transparent, airtight chamber and breathes through a special mouthpiece. Initially, breathing is recorded at rest, followed by deeper inhalations and exhalations similar to those in spirometry.
Plethysmography is completely painless and provides critical diagnostic information about various lung conditions.