BREATHING, PLETHYSMOGRAPHY. BREATHING, PLETHYSMOGRAPHY Photo essay at La Louvière clinic, France. Pneumology department. Pulmonary function test. Study and measurement of the pulmonary volume of the patients. Installed in a cabin, the patient must blow in a duct that permits to measure his respiratory output (spirometry). Different phases go with this examination : open cabin to measure the diffusion of carbon monoxide allowing to control the pulmonary membrane or closed cabin in order to