BODY BOX

A whole body plethysmograph may be used to estimate the residual volume of the lungs and make measurements of other variables of interest in the study of lung function. The main element in a whole body plethysmograph is the body box, which is a sealed chamber, rather like a telephone box, in which the patient sits and breathes through a tube passing out of the box. Since the volume of the patient will change during the breathing cycle, so the air pressure inside the box will vary in sympathy. The residual volume within the lungs can be found by measuring the pressure in the airway when the patient tries to inhale from a closed tube. The residual volume can then be calculated from the increased volume of the lungs and the reduced pressure during attempted inspiration. The body box will be found in a lung function laboratory.

Content and Design Copyright 2000 Dr. Malcolm C Brown.  See Title Page for more details