Which of the following problems may be identified by using an isothermal lung analog to perform quality control on a body plethysmograph?
1. Improperly calibrated mouth pressure transducer
2. Obstructed or perforated pneumotachometer
3. Increase in mechanical resistance
4. Malfunctioning box pressure transducer

The following test results are available for a 35-year-old subject who is applying for disability:
These findings are consistent with

A pulmonary function technologist is reviewing an asthma action plan. The patient takes a low-dose inhaled corticosteroid and a long-acting beta2-agonist twice daily. The patient's personal best peak flow is 600 L/min.
Which of the following instructions should be given to the patient when the peak flow drops to 500 L/min?

The following data are obtained after an exercise (stress) test for exercise-induced asthma:

Based on these data, the post-exercise FEVi represents a decrease of approximately

An isothermal lung analog has the following specifications:
5-L glass bottle 2000 g of steel wool Density of steel wool 5 g/cm3
Volume of connectors and bulb 100 mi-Repeated FRC measurements in the plethysmograph result in a volume of 5.5 L.
Which of the following should a pulmonary function technologist do?