| 摘要 |
The present invention provides a method of measuring respiratory flow rate. The method comprises a user exhaling through a flow dependent sound producing device 1 which comprises a mouthpiece 2 and a vortex chamber 3. The vortex chamber 3 has an axis and an outlet such that exhaled air flows through the mouthpiece 2 into the vortex chamber 3 causing the exhaled air to form a vortex around the axis and then pass out of the chamber 3 via the outlet in an axial direction, thereby producing a sound 10. The method further comprises detecting the sound 10 using a mobile electronic device 9 and analysing said sound 10 to determine a frequency of said sound 10 and using said frequency to determine the respiratory flow rate. |
