As a pulmonary function technician, your primary responsibilities involve performing respiratory tests, gathering data to help evaluate patients’ lungs, and assisting physicians with procedures. You may test lung capacity, blood and oxygen levels, and diffusion capacity, as well as run other diagnostic tests to check for qualifications of pulmonary disorders and help a physician determine the best treatment. When the doctor performs a bronchoscopy, you help with setup and provide assistance. Your duties may also include maintaining and operating the equipment, educating patients on lung conditions, and explaining test procedures to patients.