A 3D printable deisgn for a Pneumotachometer
 

Designed for unsupported FDM 3D Printing. 

A device for measuring the flow rate of air by comparing the pressure differential across a flow restrictor.

Ports on top accept MPXV7002 pressure sensor. https://www.nxp.com/docs/en/data-sheet/MPXV7002.pdf 
https://www.amazon.com/Breakout-MPXV7002DP-Transducer-Differential-Pressure/dp/B01MCVOZJO 

Used in ventilator setup the measure flow, check pressure, and ensure PEEP.