Spirometer and spirometer mouthpiece / breathing tube

摘要

A turbine spirometer 1 comprises a breathing tube 13 into which a subject is to breath and a vane 9 to be driven by the subject's breath. The breathing tube 13 has a first axis A-A at its opening 21 in the direction of air flow and the vane 9 rotates about a second axis B-B, 11. The first A-A and second B-B axes are inclined to one another at angle of around 100 degrees such that in use the axis of rotation B-B is substantially vertical. A separate independent claim claims the spirometer mouthpiece / breathing tube having a first opening adapted for a subject to blow through and a second opening adapted for connection to a spirometer, wherein the direction of airflow at the first opening is inclined relative to the direction of airflow at the second opening.