A novel gas flow sensor based on sound generated by turbulence [and spirometry application]

A novel gas flow sensor has been developed based on the sound produced by turbulence that is created by a small obstruction placed in the path of the flow. A microphone placed behind the obstruction gives an electrical output which is conditioned and calibrated for flow rate. The sensor has no moving parts making it robust. A computerised system with appropriate data correction is being developed for spirometry using this sensor.